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Westhoff, Oneida Dugarte.
Development of an instrumented mannequin for training of caregivers in safe patient handling and movement
h [electronic resource] /
by Oneida Dugarte Westhoff.
[Tampa, Fla.] :
University of South Florida,
Thesis (M.S.E.)--University of South Florida, 2004.
Includes bibliographical references.
Text (Electronic thesis) in PDF format.
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ABSTRACT: A common problem associated with patient handling is the risk of bodily injury due to acute or cumulative trauma. The objective of this research was to develop an integrated solution, using commercially available components, to help health care providers handle patients in a safe manner. The objective was achieved by retrofitting a mannequin with flex sensors, electrogoniometers, pressure sensors, and photocells. The sensors were capable of quantifying angular displacement, skin pressure distribution and undignified exposure. All of these variables were monitored by a computer-based data acquisition system. The design of this integrated system was implemented using National Instruments LabView software, which possessed the capability to provide both spasm simulation process control and a history of the acquired sensor data. A virtual instrument, (VI), was developed using LabView as the interface between the user or instructor and the instrumented mannequin. The VI had the capability of displaying the history of the acquired data. With access to the data's history the trainer is able to analyze the sensor information and verify the procedural accuracy of the actions performed on the simulated patient by the student. The system technologies employed can help the instructor improve the training of health care workers. Additionally, providing the trainer with useful information about the student's skill building during interaction with a patient enhances evaluation of the student's performance. Once the data is collected, the instrumented mannequin is capable of identifying problems such as excessive force or pressure when health care providers are interacting with patients. This provides the healthcare community with useful information to improve and provide a safer and more comfortable environment for the patient. The instrumented mannequin will be a valuable tool in evaluating and assessing the merits of clinical procedures. It may also be used in biomechanical studies involving patient handling by caregivers.
Adviser: Moreno, Wilfrido
x Engineering Science
t USF Electronic Theses and Dissertations.
Development of an Instrumented Ma nnequin for Training of Caregivers in Safe Patient Handling and Movement by Oneida Dugarte Westhoff A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Engineering Department of Electrical Engineering College of Engineering University of South Florida Major Professor: W ilfrido, Moreno, Ph.D. James, Leffew, Ph.D. John Lloyd, Ph.D. Date of Approval: March 16, 2004 Keywords: biomedical engineering, ergonomic s, biomechanics, patient safety, nursing, goniometer, flex sensor, presure sensor, labview Copyright 2004 Oneida Dugarte Westhoff
DEDICATION To my daughter, with all my love and life, for bein g patient with me when I didnt have enough time to share with her. Nathaly, I lov e you. To my family, although they are far from me, they w ill always be with me in my prayers. I love you so much. To my husband Wayne, who is my inspiration, for sup porting me all the way. Thank you, TAM.
ACKNOWLEDGMENTS Support for this project was provided by Patient Sa fety Research Center, James A. Haley Veterans' Hospital, Tampa, Florida. A special Thank you to John Lloyd, Wilfrido More no, James Leffew, Andrea Baptiste, Shawn Applegarth, Eduardo Zurek, and Luis Navarrete for all their advise and support on this project.
i TABLE OF CONTENTS LIST OF TABLES iv LIST OF FIGURES v ABSTRACT x CHAPTER 1 INTRODUCTION 1 1.1 Introduction 1 1.2 Quality Patient Care 1 1.3 Dignity and Care of the Patient 4 1.4 High Risk Patient Handling Task 6 CHAPTER 2 BACKGROUND THEORY 11 2.1 Measurement of Joint Motion 11 2.1.1 Basic Definitions 12 22.214.171.124 Planes and Axes 12 126.96.36.199 Goniometry 14 188.8.131.52 Biomechanics 15 184.108.40.206 Range of Motion 16 220.127.116.11 Active Range of Motion 16 18.104.22.168 Passive Range of Motion 17 22.214.171.124 Validity and Reliability 17 2.2 Biomechanics of the Knee 18 2.2.1 Anatomy of the Knee 18 2.2.2 Range of Motion of the Knee 19 2.2.3 Evaluation of Range of Motion of the Knee 2 0 126.96.36.199 Flexion and Extension of the Knee 20 2.3 Biomechanics of the Hip 21 2.3.1 Anatomy of the Hip Joint 21 2.3.2 Range of Motion of the Hip 22 2.3.3 Evaluation of the Range of Motion of the Hi p 24 188.8.131.52 Flexion of the Hip 24
ii 184.108.40.206 Extension of the Hip 26 220.127.116.11 Abduction of the Hip 27 18.104.22.168 Adduction of the Hip 28 2.4 Biomechanics of the Elbow 29 2.4.1 Anatomy of the Elbow 29 2.4.2 Range of Motion of the Elbow 31 2.4.3 Evaluation of Range of Motion of the Elbow 31 22.214.171.124 Flexion and Extension of the Elbow 32 CHAPTER 3 DESCRIPTION OF HARDWARE AND SENSORS 34 3.1 Hardware 34 3.1.1 Multifunction DAQ NI PCI-6052E 34 3.1.2 NI SCXI-1000 Chassis 37 3.1.3 NI SCXI-1300 Terminal Block 38 3.2 Sensors 40 3.2.1 Flex Sensor 40 126.96.36.199 Description 40 188.8.131.52 Basic Circuit of the Flex Sensor 40 3.2.2 Electrogoniometer 42 184.108.40.206 Description 42 220.127.116.11 Basic Circuit for the Electrogoniometer 44 3.2.3 Photocell 46 18.104.22.168 Description 46 22.214.171.124 Basic Circuit for the Photocell 47 3.2.4 Brake Pad Sensor 48 126.96.36.199 Description 48 188.8.131.52 Basic Circuit for the Brake Pad Sensor 4 9 CHAPTER 4 SYSTEM DESCRIPTION 51 4.1 Overview 51 4.2 Joint Angle Measurements 52 4.2.1 Knee Angle Measurement 52 4.2.2 Hip Angle Measurement 54 4.2.3 Elbow Angle Measurement 58 4.3 Undignified Exposure Measurement 60 4.4 Skin Pressure Measurement 62 4.5 Interface Human-Computer 66 4.5.1 Main VI LabView Screen 66 4.5.2 Description of the Developed VIs Using Lab ViewTM 68 184.108.40.206 Data Acquisition VI 68
iii 220.127.116.11 Interpolation of Values 69 18.104.22.168 Plot of Data and Conditions 71 22.214.171.124 Export and Save Data 72 CHAPTER 5 RESULTS 74 5.1 Results 74 5.2 Results: Phase II 80 CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS 85 6.1 Conclusions 85 6.2 Recommendations 86 REFERENCES 88 APPENDICES 90 Appendix A: Examples of Resident Lifting and Repos itioning Tasks 91
iv LIST OF TABLES Table 1: Recollection of Consent Obtained Before Ex amination of Anaesthetized Patients 5 Table 2: Knee Flexion Range of Movement Required in Various Activities 19 Table 3: Range of Movement at the Hip During Variou s Activities 23 Table 4: Elbow Flexion Range of Movement Required in Various Activities 31 Table 5: Angle-Voltage Data for Knee Joint 53 Table 6: Angle-Voltage Data for Hip Joint Flexion/E xtension 56 Table 7: Angle-Voltage Data for Hip Joint Abduction /Adduction 57 Table 8: Angle-Voltage Data for Elbow Joint 59 Table 9: Photocell Characteristics Right Chest 61 Table 10: Photocell Characteristics Left Chest 61 Table 11: Photocell Characteristics Genital Area 61 Table 12: Photocell Characteristics Buttocks Area 6 2 Table 13: Angle-Voltage Data for Force Sensing Resi stor Installed on the Mannequins Arm 64 Table 14: Angle-Voltage Data for Force Sensing Resi stor Installed on the Mannequins Thigh 65 Table 15: Data Report Exported to Excel 75
v LIST OF FIGURES Figure 1: Resident Lifting 2 Figure 2: Safe Patient Handling 3 Figure 3: Clinical Examination 6 Figure 4: Lateral Transfer of a Patient from Bed to Stretcher 6 Figure 5: Typical Patient Handling Tasks 7 Figure 6: Synovial Joint 12 Figure 7: Sagital Plane 13 Figure 8: Frontal Plane 13 Figure 9: Transverse Plane 14 Figure 10: Examples of Mechanical Goniometers 15 Figure 11: Example of How to Place a Goniometer 15 Figure 12: Flexion/Extension to/from Zero 16 Figure 13: The Knee Joint 18 Figure 14: Range of Motion of the Knee Joint 19 Figure 15: Goniometer Alignment for Measurement of Knee Flexion 20 Figure 16: Goniometer Alignment for Measurement of Knee Extension 21 Figure 17: Hip Joint 22 Figure 18: Movements of the Hip Joint 23 Figure 19: Hip Flexion 25
vi Figure 20: Alignment of the Goniometer for the Hip Joint Measurement 25 Figure 21: Hip Extension 26 Figure 22: Hip Abduction 27 Figure 23: Alignment of the Goniometer for Hip Abdu ction Angle Measurement 28 Figure 24: Hip Adduction 29 Figure 25: Anterior View of the Right Limb Showing the Three Articulations of the Elbow Joint 30 Figure 26: Elbow Flexion 32 Figure 27: Elbow Extension 32 Figure 28: Alignment of the Goniometer for Elbow Jo int Angle Measurement 33 Figure 29: National Instruments PCI-6052E Board 34 Figure 30: PCI-6052E Block Diagram 35 Figure 31: I/O Connector Pin Assignment 36 Figure 32: NI SCXI-1000 Chassis 38 Figure 33: SCXI-1300 Terminal Block 39 Figure 34: Interconnection between the Chassis, Ter minal Block and the Computer 39 Figure 35: Flex Sensor 41 Figure 36: Basic Circuit for the Flex Sensor 41 Figure 37: Illustration of the Electrogoniometer 42 Figure 38: Electrogoniometrers 43 Figure 39: Parts of the Electrogoniometer 44 Figure 40: Basic Circuit for the Electrogoniometer 45
vii Figure 41: Wheatstone Bridge 45 Figure 42: Photocell Concept Diagram 47 Figure 43: Basic Circuit Photocell 47 Figure 44: Brake Pad Sensor 49 Figure 45: Basic Circuit for the Brake Pad Sensor 4 9 Figure 46: Typical Sensor Response 50 Figure 47: Integrated Mannequin System 51 Figure 48: Installation of the Flex Sensor on the K nee Joint 52 Figure 49: Angle Measurement Knee Joint 53 Figure 50: Angle-Voltage Data for Knee Joint 54 Figure 51: Installation of the Electrogoniometer Ac ross the Hip Joint 55 Figure 52: Flexion of the Hip Joint 55 Figure 53: Hip Joint Modification 56 Figure 54: Angle-Voltage Data for the Hip Joint Fle xion/Extension 57 Figure 55: Angle-Voltage Data for the Hip Joint Abd uction/Adduction 58 Figure 56: Installation of the Flex Sensor of the E lbow Joint 59 Figure 57: Angle Measurement Elbow Joint 59 Figure 58: Angle-Voltage Data for Elbow Joint 60 Figure 59: Installation of Photocell on the Chest 6 1 Figure 60: Subject Turning the Mannequin Over 62 Figure 61: Force Sensing Resistor Covered to Standa rdize Measurement Area 63
viii Figure 62: A) Chatillon DG-1000N, B) Calibration of the Force Sensing Resistor 63 Figure 63: Force-Voltage Calibration for Force Sens ing Resistor Located on Mannequins Arm 64 Figure 64: Force-Voltage Calibration for Force Sens ing Resistor Located on Mannequins Thigh 65 Figure 65: WorkStation of the Instrumented Mannequi n 66 Figure 66: Main VI Interface Screen 67 Figure 67: Data Acquisition Interface Design 68 Figure 68: Mean Value Example Design 69 Figure 69: Mean Value Example Design for Photocell on the Left Chest 69 Figure 70: Angle and Voltage Arrays for Elbow and H ip Joints 70 Figure 71: Example of Interpolation Design for the Elbow Joint 71 Figure 72: Plot of Data and Conditions for Elbow Jo int 72 Figure 73: Design to Export and Save the Data 73 Figure 74: Pop Up Window to Save the Data 73 Figure 75: Elbow and Knee Activity 76 Figure 76: Patient Left Chest Exposure 77 Figure 77: Patient Right Chest Exposure 77 Figure 78: Hip Flexion/Extension and Abduction/Addu ction Activity 78 Figure 79: Force Application for the Arm and Thigh 79 Figure 80: Unfiltered Data for Elbow Angular Displa cement 80 Figure 81: Unfiltered Elbow Angular Velocity 81 Figure 82: FFT of the Elbow Angular Displacement Da ta 82
ix Figure 83: Butterworth Digital Filter Design 83 Figure 84: LabviewTM Front Panel Design with Velocity Display 84
x DEVELOPMENT OF AN INSTRUMENTED MANNEQUIN FOR TRAINI NG OF CAREGIVERS IN SAFE PATIENT HANDLING AND MOVEMENT Oneida Dugarte Westhoff ABSTRACT A common problem associated with patient handling i s the risk of bodily injury due to acute or cumulative trauma. The objective o f this research was to develop an integrated solution, using commercially availabl e components, to help health care providers handle patients in a safe manner. T he objective was achieved by retrofitting a mannequin with flex sensors, electro goniometers, pressure sensors, and photocells. The sensors were capable of quanti fying angular displacement, skin pressure distribution and undignified exposure All of these variables were monitored by a computer-based data acquisition syst em. The design of this integrated system was implemented using National In struments LabView software, which possessed the capability to provide both spasm simulation process control and a history of the acquired senso r data. A virtual instrument, (VI), was developed using Lab View as the interface between the user or instructor and the instrumented mannequ in. The VI had the capability of displaying the history of the acquired data. Wi th access to the datas history the trainer is able to analyze the sensor informati on and verify the procedural
xi accuracy of the actions performed on the simulated patient by the student. The system technologies employed can help the instructo r improve the training of health care workers. Additionally, providing the t rainer with useful information about the students skill building during interacti on with a patient enhances evaluation of the students performance. Once the data is collected, the instrumented manneq uin is capable of identifying problems such as excessive force or pressure when h ealth care providers are interacting with patients. This provides the healt hcare community with useful information to improve and provide a safer and more comfortable environment for the patient. The instrumented mannequin will be a valuable tool in evaluating and assessing the merits of clinical procedures. It may also be used in biomechanical studies involving patient handling by caregivers.
1 CHAPTER 1 INTRODUCTION 1.1 Introduction A common problem associated with patient handling i s risk of bodily injury due to acute or cumulative trauma. The objective of this research was to develop an integrated solution using commercially available components to help health care providers handle patients in a safe manner. The ob jective was achieved by retrofitting a mannequin with flex sensors, electro goniometers, pressure sensors and photocells. The sensors were capable of quanti fying angular displacement, skin pressure distribution and undignified exposure All of these variables were monitored by a computer-based data acquisition syst em. 1.2 Quality Patient Care Many health groups support the plan of establishing a safe environment of care for caregivers and patients . Patient handling such as lifting, repositioning and transferring has to be performed by skilled health care workers. The performance of these tasks exposes caregivers and p atients to increased risk of physical injury . In addition, there might be c ircumstances when patients are agitated, aggressive, unreceptive or can offer limi ted levels of assistance, which
2 increase the risk for injury. With the development of patient handling equipment, such as lift and transfer devices, the risk of inju ry to patients and caregivers can be significantly reduced , see Figure 1. Effect ive use of equipment and devices for patient handling creates a safe healthc are environment by reducing the physical demands on the caregiver and heighteni ng/improving the safety, comfort and dignity of the patient . Technology and specialized equipment currently exis ts in industry to assist with patient handling. Examples of patient handling equ ipment are presented in Appendix A. The level of effectiveness for using p atient handling equipment and devices to prevent patient and caregiver injuries i s a function of availability, maintenance and sufficient space. Equipment and de vices must be available to caregivers in order to encourage their use. This w as one of the goals of The Instrumented Mannequin, a project developed by the University of South Florida and the Patient Safety Research Center at James A. Haley Veterans Hospital in Tampa Florida. Figure 1: Resident Lifting 
3 A study of any patient lifting and moving task invo lves an evaluation of the needs and abilities of the patient. The evaluation allow s health care workers to study the patient characteristics. Additionally, the eva luation determines the safest method for performing a task that provides appropri ate care and service for the patient. The patient evaluation should include exa mination of factors such as : 1. The level of assistance the patient requires 2. The size and weight of the patient 3. The ability and willingness of the patient to un derstand and cooperate 4. Any medical conditions that may influence the ch oice of methods for lifting or repositioning. These factors are important in determining the appr opriate method for lifting and moving a patient. The size and weight of a patient will establish the equipment requirements and the number of caregivers required to provide the assistance ; see Figure 2. Figure 2: Safe Patient Handling
4 1.3 Dignity and Care of the Patient One of the fundamental objectives for health care p rofessionals is respecting the patients dignity. Patients want to be treated as human, not simply as a body with a disease. Respecting the patients dignity r equires that caregivers provide careful, knowledgeable and helpful medical care to the patient according to the training that health workers have received . A patients perception of appropriate dignified han dling may be influenced by religious and ethical values. An examination that was once acceptable may become unacceptable or improper in another period o f time based on cultural/religious setting of the patient. Health care workers face special difficulty in trying to balance their knowledge with varying r eligious and ethical values. For example, patients may feel that doctors have behave d improperly during an intimate examination. Examinations may also be str essful and embarrassing for patients , . Doctors should explain certain factors, to the pati ent, before performing an examination. Some of these factors are : Make clear why an examination is necessary 1. Clarify, in a manner that he/she can understand, which factors the examination will involve 2. Get the patient's permission before the examinat ion 3. Suggest to the patient that he/she can have a re lative or friend present during the examination
5 4. If the patient needs to undress or dress, provid e him/her the required privacy 5. Use long curtains to maintain the patient's dign ity. Table 1 presents data from an exploratory study in a medical school that was performed to study whether students followed the pr ocedures during intimate examinations . Table 1: Recollection of Consent Obtained Before E xamination of Anaesthetized Patients  Written Consent Year of Study Examinations performed For named Student For Any Student Oral Consent Not Known if Consent was given Second 11 0 0 0 11 Third 128 0 0 12 116 Fourth 563 162 6 356 39 Total 702 162 6 368 166 The data presented in Table 1 shows that the studen ts conducted a total of 702 intimate examinations. However, only 24% of the ex aminations had the patients permission. An additional 24% of the examinations were performed without written or oral approval . This data presented in Table 1 clearly shows that s tudents must be responsible in requesting the patients permission prior to perfor ming any examination. Additionally, these results show that some students were uninformed about their ethical and legal responsibility to obtain the patients permission. This study suggests that doctors have to be sure that an appro val was obtained and that students are ready to follow all the standards procedures applicable w hen performing clinical examinations , see Figure 3.
6 Figure 3: Clinical Examination 1.4 High Risk Patient Handling Task High-risk patient handling tasks are always present when caregivers work with any patient. Some tasks, for example, transferring from bed to chair or from chair to bed, might involve high-risk activities if good technical procedures and equipment are not used correctly, see Appendix A. The difficulty of the movement task will vary depending of the dependency level of the patient . Examples of patient handling tasks are presented in Figures 4 and 5. Figure 4: Lateral Transfer of a Patient from Bed t o Stretcher 
7 Figure 5: Typical Patient Handling Tasks 
8 An instructional manual titled Patient Care Ergono mics Resource Guide: Safe Patient Handling and Movement was produced by the Patient Safety Center of the Veterans Hospital to reduce the frequency of wo rk injuries related to patient handling and movement. This document offers guidel ines that concentrate on patient evaluation issues and proposes solutions fo r patient lifting and repositioning problems . Different patient handling techniques must be used accurately to prevent caregivers and patients from getting injured. Some studies related to patient handling techniques suggest that caregivers should plan in advance the activities that will be required to carry out the task. The p lan should be constructed in such a manner that the patient is handled with more subr outines instead of executing the entire technique in one continuous routine. Most importantly, the instructional manual, Patien t Care Ergonomics Resource Guide: Safe Patient Handling and Movement, enumerat es the most demanding tasks in evaluation order : 1. Transferring patient between toilet and chair 2. Transferring patient between chair and bed 3. Transferring patient from bathtub-to-chair 4. Transferring patient from chair lift-to-chair 5. Weighing a patient 6. Lifting a patient up in bed 7. Repositioning a patient in bed side-to-side 8. Repositioning a patient in a chair
9 9. Changing an absorbent pad 10. Making an occupied bed 11. Undressing a patient 12. Tying supports 13. Feeding a bed-ridden patient 14. Making an unoccupied bed The investigators from the Patient Safety Center at the Veterans Hospital documented that the following nursing tasks are als o high risk ; see Figure 5. 1. Bathing a patient in bed 2. Making an occupied bed 3. Dressing a patient in bed 4. Transferring a patient from bed to stretcher 5. Transferring from bed to wheelchair 6. Transferring from bed to dependency chair 7. Repositioning a patient in a chair 8. Repositioning a patient in bed 9. Applying anti-embolism stockings (TED hose) The key to preventing injuries to caregivers and pa tients lies in conducting a proper ergonomic/biomechanical evaluation of the wo rk place. The objective of the evaluation is to analyze job tasks and discover high risk factors that can jeopardize health care workers or patients. The I nstrumented Mannequin was created to train caregivers in safe patient handlin g in order to reduce the potential
10 for injury. This technology provides the healthcar e community with useful information to improve and provide a safer and more comfortable environment for both the patient and caregiver.
11 CHAPTER 2 BACKGROUND THEORY 2.1 Measurement of Joint Motion Health professionals use a technique called goniome try to determine joint angle measurements. The measurement of joint motion is v ery significant in the physical evaluation of the extremities and spine of a patient . Through joint motion examinations doctors can evaluate dysfunctio ns and provide the patient with an appropriate rehabilitation program. This c oncept will be studied in detail in the next section. The joints permit the articulation and movement of the bones. Joints can be grouped into three different classes depending on t heir structure : 1. Fibrous: The least mobile joint 2. Cartilaginous: The medium mobile joint 3. Synovial: The most mobile joint. In both fibrous and cartilaginous joints the articu late surfaces of the two bones are joined by connective tissue. However, in synov ial joints the articulate surfaces are not directly connected . Figure 6 presents an example of the synovial class of joint.
12 Figure 6: Synovial Joint  2.1.1 Basic Definitions The basic definitions involved with the study of th e measurement of the joint are presented in this subsection. 126.96.36.199 Planes and Axes The surface motion of a joint is described in three planes, which are termed the sagittal, frontal and transversal. These planes ar e associated with three axes, which are termed the medial-lateral, anterior-poste rior and vertical , . The sagittal plane possesses the following characterist ics: 1. Advances from the anterior to the posterior port ion of the body 2. Divides the body into right and left halves 3. Flexion and extension motions are described in t he sagittal plane. The axis that is perpendicular to the sagittal plan e is called medial-lateral axis . Figure 7 presents an example of the sagittal plane.
13 Figure 7: Sagital Plane  The frontal plane divides the body into front and b ack halves , . The frontal plane possesses the following characteristi cs: 1. Advances from one side of the body to the other 2. Abduction and adduction motions are described in the frontal plane and occur around the anterior-posterior axis. Figure 8 illustrates the frontal plane. Figure 8: Frontal Plane 
14 The transverse plane is horizontal and divides the body into superior and inferior parts ; see Figure 9. The transverse plane has the following characteristics: 1. Motions that occur in this plane are rotation of the head, shoulder and hip. Also, the motions of pronation and supination of th e forearm occur in this plane. 2. The vertical axis is perpendicular to the transv erse plane. Figure 9: Transverse Plane  188.8.131.52 Goniometry Norkin and White  states that: The term goniometry is derived from two Greek word s, gonia, meaning angle and metron, meaning measure. Therefore, goniometry refers to t he measurement of angles. In particular, the measurem ent of angles created at human joints by the bones of the body. The instrument used to measure angles is called a g oniometer. Figure 10 presents an example of different mechanical goniome ters.
15 Figure 10: Examples of Mechanical Goniometers  To operate a goniometer, position each arm along th e centerline of a segment across a joint. Figure 11 presents an example of h ow to place a goniometer to determine an angle measurement. Figure 11: Example of How to Place a Goniometer 184.108.40.206 Biomechanics Biomechanics is the study of the body in terms of i ts mechanical structure and properties. Stated in another way, biomechanics st udies the forces that act on limbs . Moving Arm Stationary Arm
16 220.127.116.11 Range of Motion Range of motion, (ROM), refers to the extent of mot ion of a joint and can be measured in any plane , . The measure of t he ROM at a joint is influenced by factors such as age, sex and whether the movement is executed actively or passively. Flexion/extension and hyper -flexion/extension are two terms that are used when describing a joints ROM. The term flexion/extension refers to the movement that returns from the full f lexion/extension to the zero initial position. The term hyperflexion/extensio n refers to the movement that is greater that the normal flexion/extension motion [1 1]. Figure 12 presents an example of these concepts. Figure 12: Flexion/Extension to/from Zero  18.104.22.168 Active Range of Motion The active range of motion, (AROM), is the range of movement realized during the voluntary motion by a person. AROM provides th e clinician with information
17 about coordination, muscle strength and the willing ness of the patient to move. The AROM has tends to be less than that realized pa ssively . 22.214.171.124 Passive Range of Motion The passive range of motion, (PROM), is the range o f movement realized by a clinician without any contribution from the patient In this movement each joint permits an extra amount of movement because the pat ient is calm and does not help in producing the motion. Therefore, passive r ange of motion is normally greater than the active range of motion , . 126.96.36.199 Validity and Reliability Information that is collected is valid and reliable if it represents meaningful values of the data , . Norkin and White state tha t : Validity refers to how well the measurement repres ent the true value of the variable of interest. In other words, the validity of an angle measuremen t is the value that represents the actual joint angle that was measured. Furthermore, Norkin and White state that : Reliability is the consistence between successive measurements of the same variable, on the same subject, under the same conditions. Stated in another manner, angle measurements of a j oint are reliable if every time that the measurements are taken their values y ield the same results. To maximize reliability it is recommended that the examiner use standardized
18 test positions, use the same amount of force that i s applied to the body and employ the same measuring devise to minimize variab ility between measurements . 2.2 Biomechanics of the Knee This subsection presents a study of the anatomy and range of motion of the knee joint. Evaluation of the range of motion is also i ncluded. 2.2.1 Anatomy of the Knee The knee joint is the largest and most complex join t of the human body. The knee joint is composed of two distinct articulation s, which are performed by the tibiofemoral and patellofemoral joints ; see Fi gure 13. The tibiofemoral joint links the femur and the tibia. The patellofemoral articulation is between the posterior surface of the patella and the patella su rface of the femur . The location of the knee, between the two longest b ones of the body, makes it more vulnerable to injury. Figure 13: The Knee Joint  Tibiofemoral joint Tibia Femur Patellofemoral joint
19 2.2.2 Range of Motion of the Knee The range of motion at the tibiofemoral joint is de scribed in three planes. The biggest ROM is in the sagittal plane . This jo int has two degrees of freedom. The total motion of the joint from extension to ful l flexion is approximately 140 degrees. Flexion and extension motions are located in the sagittal plane around a medial-lateral axis. The rotation is located in the transverse plane around a vertical axis ; see Figure 14. Table 2 present s an example of the different ROMs of the knee in diverse activities. Figure 14: Range of Motion of the Knee Joint Table 2: Knee Flexion Range of Movement Required In Various Activities  Activity Max Range of Flexion Required (degrees) Walking Slow (stance phase) Free (stance phase) Fast (stance phase) 65 5 15 20 Running (stance phase) 30 Ascending Stairs 105 Descending Stairs 105 Sitting Down 90 Tying shoes laces 105 As described in Table 2, a person walking fast or r unning produces maximum range of flexion for the knee joint in the neighbor hood of 20 to 30 degrees. If the Sagittal Plane Medial-lateral axis
20 person is sitting down the maximum range of flexion is 90 degrees. Further, the maximum range of motion that a person experiences i s 105 degrees, which occurs when tying shoe laces. 2.2.3 Evaluation of Range of Motion of the Knee This sub-subsection explains the correct procedure for measuring the flexion and extension in the knee joint. Additionally, a descr iption of how to align the goniometer is included. 188.8.131.52 Flexion and Extension of the Knee The best way to measure the angle of the knee inclu des three activities , : 1. The participant should be placed in the supine p osition (lying on the back) 2. The knee should be extended and the hip placed i n zero degrees of extension, adduction and abduction motion. 3. The knee can be flexed. The hip also flexes wit h the knee; see Figure 15. Figure 15. Goniometer Alignment for Measurement of Knee Flexion
21 To correctly align the goniometer, it should be pos itioned over the lateral epicondyle of the femur with the proximal arm point ing towards the Greater Trochanter and the distal arm pointing toward the l ateral malleolus ,. Figures 15 and 16 illustrate proper alignment of th e goniometer for measurement of knee flexion and extension respectively. Figure 16: Goniometer Alignment for Measurement of Knee Extension 2.3 Biomechanics of the Hip This subsection studies the anatomy and range of mo tion of the hip joint. Evaluation of the range of motion of the hip joint is also included. 2.3.1 Anatomy of the Hip The hip joint is a synovial ball-and-socket joint l ocated between the head of the femur and the acetabulum of the pelvis ; see Fi gure 17. The hip joint is one of the largest and most stable joints of the body t hat connects the inferior, (lower), extremities with the trunk.
22 Nordin and Frankel document states that : The head of the femur is the convex component of t he ball-and-socket configuration of the hip joint and forms two thirds of a sphere. Figure 17: Hip Joint  During regular activities the hip joint helps to su stain and transmit the weight of the person from the trunk to the lower extremity. Additionally, the hip joint has a large range of mobility . 2.3.2 Range of Motion of the Hip Joint The range of motion of the hip joint is described i n three planes , : 1. Sagittal plane: The movements are flexion and ex tension. The motion is greater with flexion, which is from zero to approximately 140 degrees. Extension ranges from zero to approximate ly fifteen degrees; see Figure 18 A. Anterior Superior Iliac Spine (ASIS) Anterior Inferior Iliac Spine Greater Trocanter Head of Femur Acetabulum Femur
23 2. Frontal plane: The movements in this plane are a bduction-adduction. Abduction ranges from zero to thirty degrees and ad duction ranges from zero to approximately twenty-five degrees; see Figu re 18 B and C. 3. Transversal plane: These motions are the intern al and external rotation. External rotation ranges from zero to ninety degree s and internal rotation ranges from zero to approximately seventy degrees; see Figure 18 D and E. Figure 18: Movements of the Hip Joint  Table 3 illustrates the range of motion of the hip for various activities. Table 3: Range of Movement at the Hip During Various Activities  Activity Plane of Motion Max Range Required () Walking on level surfaces Flexion Extension Abduction Adduction Medial Rotation Lateral Rotation 30 10 5 5 5 5 Ascending Stairs Flexion Extension 65 5 Descending Stairs Flexion Extension 65 5 Sitting Flexion 90 Tying shoes laces Flexion 50
24 Table 3 shows that a person walking on a level surf ace produces a maximum range of flexion for the hip joint of 30 degrees, e xtension of 10 degrees and abduction/abduction of approximately five degrees. A person ascending or descending stairs produces an equal and opposite ra nge of flexion and extension of 65 degrees and 5 degrees respectively. When a person sits down, the maximum range of flexion is 90 degrees. Additional ly, the maximum range of flexion when a person ties their shoes laces is abo ut 50 degrees. 2.3.3 Evaluation of the Range of Motion of the Hip This sub-subsections explains the proper procedures to correctly measure the flexion/extension and abduction/adduction in the hi p joint. A description of how to align the goniometer is included. 184.108.40.206 Flexion of the Hip The testing procedure required to acquire flexion m easurements of the hip consists of three actions , : 1. The participant should be placed in the supine p osition (lying on the back). 2. The hip is placed in zero degrees of adduction/ abduction and rotation motions 3. The hip is flexed. The knee also flexes with th e hip; see Figure 19.
25 Figure 19: Hip Flexion Correct alignment of the goniometer for flexion mea surement requires three steps : 1. Center the fulcrum of the goniometer over the la teral aspect of the hip joint using the Greater Trochanter of the femur for refer ence 2. Align the proximal arm with the lateral midline of the pelvis 3. Align the distal arm with the lateral midline of the femur using the lateral epicondyle for reference; see Figures 20 A and B. A B Figure 20: Alignment of the Goniometer for Hip Joi nt Angle Measurement
26 220.127.116.11 Extension of the Hip The testing procedure to acquire extension measurem ents of the hip joint requires three actions , : 1. The participant should placed in the prone posit ion (lying face downward) 2. The hip is placed in zero degrees of adduction/ abduction and rotation with the knee fully extended 3. The hip is extended; see Figure 21. Figure 21: Hip Extension Correct alignment of the goniometer for extension m easurement requires three steps : 1. The center of the goniometer is placed over the lateral aspect of the hip joint using the Greater Trochanter of the femur for reference. 2. Align the proximal arm with the lateral midline of the pelvis 3. Align the distal arm with the lateral midline of the femur using the lateral epicondyle for reference, see Figure 20 A.
27 18.104.22.168 Abduction of the Hip The testing procedure to acquire abduction measurem ents of the hip joint requires three actions , : 1. The participant is placed in the supine position (lying on the back) 2. The hip is placed in zero degrees of flexion/ext ension and rotation motions with the knee fully extended 3. The hip is abducted; see Figure 22. Figure 22: Hip Abduction Correct alignment of the goniometer for abduction m easurement requires three steps : 1. The center of the goniometer should be positione d over the anterior superior iliac spine, (ASIS), of the extremity bein g measured 2. Align the proximal arm with an imaginary horizon tal line extending from one ASIS to the other ASIS 3. Align the distal arm with the anterior midline o f the femur using the midline of the patella for reference; see Figure 23 A and B
28 A B Figure 23: Alignment of the Goniometer for Hip Abd uction Angle Measurement 22.214.171.124 Adduction of the Hip The correct procedure to measure the adduction of t he hip joint requires three actions , : 1. The participant is placed in the supine position (lying on the back) 2. The hip is placed in zero degrees of flexion/ext ension and rotation with the knee fully extended 3. The hip is adducted; see Figure 24. The alignment of the goniometer for adduction measu rement is the same as for the abduction movement; see Figure 23. ASIS
29 Figure 24: Hip Adduction 2.4 Biomechanics of the Elbow This subsection studies the anatomy and range of mo tion of the elbow joint. Evaluation of the range of motion of the elbow join t is included. 2.4.1 Anatomy of the Elbow The elbow is the middle joint of the superior extre mity that links the humerus with the forearm , . Nordin and Frankel state that : The bony structures of the elbow are the distal en d of the humerus and the proximal ends of the radius and ulna. The dist al end of the humerus is formed by the hyperboloid trochlea medially and the convex capitellum laterally. Figure 25 presents an illustration of the elbow joi nt.
30 Figure 25: Anterior View of the Right Limb Showing the Three Articulations of the Elbow Joint  There are three synovial articulations that integra te the elbow joint; refer to Figure 25. The three articulations occur at : 1. The humeroulnar joint, which is the articulation between the trochlea of the distal humerus and the shaped trochlear fossa of th e ulna 2. The humeroradial joint, which is composed by the articulation between the capitellum of the distal humerus and the head of th e radius 3. The proximal radioulnar joint, which is composed by the head of the radius and the radial notch of the proximal ulna. In the anatomic position of the arm the large axes of the humerus and the forearm form an acute angle at the elbow that is ca lled the "carrying angle". The measurement of the carrying angle is approximately five degrees in men and ten to fifteen degrees in women , . Radioulnar joint Humeroulnar joint Humeroradial joint
31 2.4.2 Range of Motion of the Elbow The range of motion of the elbow joint is limited t o flexion and extension in the sagittal plane around the transverse axis , [13 ]. The elbow joint possesses two degrees of freedom . The humeroulnar and h umeroradial articulations permit flexion and extension motions of the elbow. In addition, the proximal radioulnar articulation permits the forearm the mov ements of pronation and supination. Table 4 presents an example of the dif ferent ROMs of the elbow in diverse activities. Table 4: Elbow Flexion Range of Movement Required in Various Activities  Activity Max Range of Flexion Required () Eating/drinking 130 Opening door 60 Reading 105 Using Telephone 135 Rising from chair 95 Pouring from jug 60 For example, Table 4 illustrates that the maximum r ange of flexion that the elbow executes during eating or drinking is approximately 130 degrees. In the case of reading a book or using the phone, the elbow is fle xed approximately 105 degrees and 135 degrees, respectively. 2.4.3 Evaluation of Range of Motion of the Elbow This sub-subsection explains the procedure required to correctly measure the flexion/extension of the elbow joint. A procedure for alignment of the goniometer is also included.
32 126.96.36.199 Flexion and Extension of the Elbow The correct procedure for measurement of the flexio n and extension of the elbow joint requires four actions , : 1. The participant is placed in the supine position (lying on the back) 2. The shoulder in zero degrees of flexion/extensio n and abduction/adduction 3. The forearm is oriented with the palm facing upw ards 4. Firm the distal end of the humerus and flex or e xtend the elbow as desired; see Figures 26 and 27 for details. Figure 26: Elbow Flexion Figure 27: Elbow Extension
33 Correct alignment of the goniometer for elbow joint angle measurement requires three steps : 1. Place the center of the goniometer over the late ral epicondyle of the humerus 2. Align the proximal arm with the lateral midline of the humerus. Use the center of the acromial process for reference 3. Align the distal arm with the lateral midline of the radius. Use the radial head and radial styloid process for reference; see Figure 28. Figure 28: Alignment of the Goniometer for Elbow J oint Angle Measurement
34 CHAPTER 3 DESCRIPTION OF HARDWARE AND SENSORS 3.1 Hardware This subsection includes the theory and background related to the hardware utilized during this research. A description of th eir characteristics is also included. 3.1.1 Multifunction DAQ NI PCI-6052E The PCI-6052E is a data acquisition, (DAQ), board m ade by National Instruments. The PCI-6052E is a multifunction anal og, digital and timing I/O board for PCI bus computers. The PCI-6052E utilize s E Series technology to bring high-performance and reliable data acquisitio n capabilities in order to meet application requirements ; see Figure 29. Figure 29: National Instruments PCI-6052E Board [1 4]
35 Figure 30 presents a block diagram for the PCI-6052 E. The characteristics of the PCI-6052E board are: 1. Rates up to 333 kS/s 2. Resolution of 16-bits for 16 singled-ended analo g inputs. 3. Analog and digital triggering capability 4. Two 24-bit, 20 MHz counter/timers 5. Eight, (8), digital I/O lines 6. Two 16-bit analog outputs. Figure 30: PCI-6052E Block Diagram 
36 The I/O connector pin assignment for the PCI-6052E is presented in Figure 31. Figure 31: I/O Connector Pin Assignment
37 The PCI-6052E is able to interface with an SCXI sys tem so that it can simultaneously acquire over 3,000 analog signals fr om thermocouples, RTDs, strain gauges, voltage sources and current sources. The PCI-6052E can also acquire or generate digital signals for communicati on and control. The SCXI system was used as the instrumentation front end fo r plug-in DAQ boards . 3.1.2 The NI SCXI-1000 Chassis The NI SCXI-1000 is a 4-slot chassis with a number of standard AC power options. This chassis is ideal for low-channel cou nt applications. The NI SCXI1000 chassis is a low noise chassis that houses, po wer, SCXI control modules and conditioned signals. The NI SCXI-1000 architec ture includes the SCXI-bus, which routes analog and digital signals and operate s as the communication device between modules. The SCXI-bus acts as a con duit for signal routing, transferring data, programming modules and passing timing signals. Chassis control circuitry manages the bus by synchronizing the timing between each module and the DAQ device. The NI SCXI-1000 can sc an input channels from several modules in several chassis at rates up to 3 33 kS/s for every DAQ device ; see Figure 32. The main characteristics of the SCXI-1000 chassis a re: 1. Rugged and compact 4-slot AC-powered chassis hou ses any SCXI module 2. Low-noise signal conditioning environment 3. Three internal analog buses 4. Timing circuitry for high-speed multiplexing
38 5. NI-DAQ driver simplifies configuration and measu rements 6. Shielded enclosures for SCXI modules 7. Rugged, compact chassis 8. Forced air-cooling 9. Optional rack mounting Figure 32: NI SCXI-1000 Chassis  3.1.3 The NI SCXI-1300 Terminal Block The SCXI-1300 connects input signals to the SCXI-11 00 module. The SCXI1300 is a general-purpose terminal block with an on board temperature sensor for cold-junction compensation. SCXI terminal blocks p rovide a convenient method for connecting and disconnecting signals to the sys tem. The SCXI-1300 frontmount terminal block supplies direct connections to transducers at the screw terminals located within a fully shielded enclosure or at front-mounted BNC connectors. Strain-relief clamps hold the signal w ires safely in place ; see Figure 33.
39 Figure 33: SCXI-1300 Terminal Block The characteristics of the SCXI-1300 terminal block are : 1. Quick and easy connections 2. Strain-relief clamps for reliable wiring 3. Connectivity options including BNC and thermocou ple plugs 4. Shielded front-mount terminal blocks 5. Onboard temperature sensor for cold-junction com pensation Terminal blocks are ideal solutions for large-chann el-count temperature or voltage applications. Figure 34 presents the interconnection between the NI SCXI-1000 chassis, the SCXI-1300 terminal block and the computer. Figure 34: Interconnection between the Chassis, Terminal Block, and the Computer 
40 3.2 Sensors This subsection includes the theory and background related to the sensors utilized during this research. A description of th eir characteristics is also included. 3.2.1 Flex Sensor This subsection provides a description of the Flex sensor. Its basic circuit characteristics are also included. 188.8.131.52 Description The flex sensor is a component that changes its res istance when bent. This sensor has a nominal resistance when it is at rest or unbent. As the Flex Sensor is bent the resistance gradually increases. For ex ample, if a sensor produces 10,000 ohms, (10 Kohms), at rest, its resistance wi ll range between 25-40 Kohms when it is bent to 90 degrees . Figure 3 5 illustrates a standard flex sensor. 184.108.40.206 Basic Circuit of the Flex Sensor Flex sensors use the basic circuit presented in Fig ure 36. The circuit uses a general-propose operational amplifier, LM741CN, to amplify the signal from the sensor. The input voltage, Vin, is 5 volts and the resistors R1 and R2 are equal to the resistance of the sensor and 20 Kohms respec tively. Vout is the output voltage that will be received by the data acquisiti on device and sent to the computer .
41 Figure 35: Flex Sensor  Figure 36: Basic Circuit for the Flex Sensor  LM741CN
42 3.2.2 Electrogoniometer This subsection provides a description of the elect rogoniometers. Its basic circuit characteristics are also included. 220.127.116.11 Description Electrogoniometers are devices capable of transform ing angular position into a proportional electrical signal. Electrogoniometers include gauge elements that measure bending strain along or around a particular axis. The bending strain is proportional to the sum total of the angular shift along an axis. The output signal is a function that is proportional to the angular m ovement. Electrogoniometers are designed for the measurement of limb angular mo vement . Figure 37 presents a detailed illustration of an electrogonio meter. Figure 37: Illustration of the Electrogoniometer Where 1. A Max: 150 mm 2. A Min: 130 mm 3. B: 70 mm 4. C: 18 mm 5. D: 54 mm
43 6. E: 20 mm 7. Weight: 19g The characteristics of the sensor can be summarized as follow: 1. Transducer type: Strain gauge 2. Life: 600,000 cycles typical 3. Accuracy: 2 measured over a range of 90 4. Repeatability: 1 measured over a range of 90 5. Operating temperature range: +10C to +40C 6. Temperature zero drift: 0.15 degrees angle / C 7. Number of Channels: 2 The sensor used for this study was the SG150 twin a xis electrogoniometer, which was built by Biometrics. The SG150 twin axis electrogoniometer can simultaneously measure angles in two planes of move ment. For example, flexion/extension and abduction/adduction deviation can be measured simultaneously. The SG150 twin axis electrogoniome ter possesses a separate output connector for each of the movements . F igure 38 presents an example of twin axes electrogoniometers. Figure 38: Electrogoniometers 
44 Electrogoniometers are unobtrusive, lightweight and can be attached to the body surface using double sided surgical tape and can be further secured with single sided tape. Electrogoniometers have a telescopic e nd block that compensates for changes in distance between the two mounting po ints as the limb moves . The various parts of an electrogoniometer are illus trated in Figure 39. Figure 39: Parts of the Electrogoniometer  18.104.22.168 Basic Circuit for the Electrogoniometer The basic circuit associated with an electrogoniome ter is a differential amplifier; see Figure 40. This circuit amplifies the differen ce between its two input terminals.
45 Figure 40: Basic Circuit for the Electrogoniometer The differential amplifier presented in Figure 40 r equires that R1 = R4 and R2 = R3. The output voltage is determined from the equation Vout = (R2/R1) x (Vin2-Vin1). Each channel of the electrogoniometer is a Wheatsto ne bridge arrangement; see Figure 41. Figure 41: Wheatstone Bridge LM741CN
46 The specifications of the Wheatstone bridge are: 1. Power supply to the bridge is from one to five v oltages 2. Sensitivity: 10 milli-volt / degree angle / supp ly voltage. Wiring details for the four colored interconnecting cables of the electrogoniometer are: 1. Red: +ve supply voltage 2. Green: Ground 3. Yellow: +ve output voltage 4. Blue: Output ground Vin1 is the output ground (blue cable); and Vin2 is the +ve output voltage (yellow cable). 3.2.3 Photocell This subsection provides a description of the photo cells that were utilized to measure skin pressure distribution. Its basic circ uit and characteristics are also included. 22.214.171.124 Description A photocell is a type of resistor whose resistance value is proportional to incident light. When not exposed to light the resistance of the photocell is maximum. When the photocell is exposed to light its resistan ce decreases in a manner proportional to the exposure level. Photocells can be used to detect large or small fluctuations in light levels to differentiate between one light bulb or two,
47 direct sunlight or total darkness and anything in b etween. Figure 42 presents an example of the changes in resistance of the photoce ll . Figure 42: Photocell Concept Diagram  126.96.36.199 Basic Circuit for the Photocell The circuit for the photocell is a basic voltage di vider. This circuit is employed because it is necessary to get a voltage to the dev ice. The purpose of the voltage divider is to provide a counterbalance to t he resistance the photocell will provide in the desired light conditions . Figu re 43 presents the details of a voltage divider circuit for a photocell. Figure 43: Basic Circuit Photocell 
48 When light impinges on the photocell its resistance reduces and the voltage at Ain increases towards five Volts. If light does no t impinge on the photocell its resistance increases and the voltage at Ain decreas es towards zero volts. To select the proper resistance, r, in the voltag e divider, the photocell is positioned in the place where it is going to be use d with room light. An ohmmeter is utilized to measure the resistance of the photoc ell. The value measured, or a little higher, is the recommended value for r. 3.2.4 Brake Pad Sensor This subsection provides a description of the Brake Pad Sensor. Its basic circuit and characteristics are also included. 188.8.131.52 Description A Brake Pad Sensor utilizes matrix pressure sensi ng technology . Each pressure measurement system is a thin, ~0.1 mm, fle xible tactile force sensor. Sensors come in both grid-based and single load cel l configurations. These sensors are capable of measuring pressures ranging from 0-15 KN/m2 to 0-175 MN/m2. Sensing locations within the matrix can be as sm all as .0009 square inches, (.140 mm2),. Therefore, a one square centimeter area can co ntain an array of 170 sensors ; see Figure 44. The brake pad sensor can be trimmed as a function of the requirements or special needs of the location where the sensor will be placed.
49 Figure 44: Brake Pad Sensor 184.108.40.206 Basic Circuit for the Brake Pad Sensor The basic circuit utilized with the brake pad senso r is presented in Figure 45. The circuit has an operational amplifier, LM741CN, to amplify the o utput signal. The sensor is powered with -5 volts. The resistanc e value is 33 Kohms or 47 Kohms depending of the place where the sensor is to be utilized. Vout is the output voltage. The typical sensor response betwee n force in pounds and the output voltage is illustrated in Figure 46. -5V Vout +12V -12V3 2 6 4 7 + Sensor R Figure 45. Basic Circuit for the Brake Pad Sensor LM741CN
50 Figure 46: Typical Sensor Response 
51 CHAPTER 4 SYSTEM DESCRIPTION 4.1 Overview The design of instrumented mannequi n was implemented using National Instruments LabView software , wh ich was able to provide both spasm simulation process control and a history of the acquired sensor data. A virtual instrument (VI) was developed using LabViewTM as the interface between the user or instructor and the instrumented mannequin. This VI has the capability to show the history of the acquired data so the trainer is able to analyze the sensors information and verify the procedural accuracy of the tasks performed on the simulated patient by the student. Figur e 47 shows illustrate the integrated system. Figure 47: Integr ated Mannequin System
52 4.2 Joint Angle Measurements This subsection will describe in detail t he method used to install each one of the sensors on the mannequin used to measure t he joint angles. A description of the technique utilized to acquire the data in this study is also provided. 4.2.1 Knee Angle Measurement To install the flex sensor on the knee joint, the mannequin was lying on its back with its right leg straight. The sensor was aligned in the center of the knee joint. A plastic tube was used as a guide or channel for the flex sensor to run back and forth when the knee joint was flexed. The plastic tube was attached on the mannequin with a regular adhesive tape; see Figure 48. The cable coming from the sensor to the circuit was r un inside the body of the mannequin. Figure 48: Installation of the Flex Sensor on the Knee Joint To acquire angle measurements for the kn ee joint, the procedures presented in chapter 2 for performing flexion and extension motions and aligning the goniometer were followed; see figure 49. Measurements were taken three times
53 and then averaged. Table 5 shows the measurements recorded for the knee joint. Angle measures were recorded up to 100 degrees flexion due to restriction of movement for the mannequin knee joint. Figure 49: Angle Measurement Knee Joint Table 5: Angle-Voltage Data for Knee Joint Angle Volt1 Volt2 Volt3 Average 0 1.79 1.8 1.79 1.79 10 1.77 1.78 1.74 1.76 20 1.67 1.67 1.67 1.67 30 1.54 1.59 1.53 1.55 40 1.47 1.5 1.48 1.48 50 1.37 1.38 1.38 1.38 60 1.28 1.27 1.3 1.28 70 1.24 1.25 1.25 1.25 80 1.21 1.22 1.24 1.22 90 1.21 1.21 1.22 1.21 100 1.2 1.2 1.21 1.20 It can be observed from Table 5 that t he three voltage values from the flex sensor are very similar, indicating a high le vel of sensor reliability. These values were graphed in Excel and are presented in Figure 50.
54 Angle-Voltage Data for Knee Joint0 20 40 60 80 100 1201 .7 9 1 76 1 .6 7 1.55 1.48 1 .3 8 1 .2 8 1 .2 5 1.22 1 21 1.20Volt(V)Angle(degrees) Knee Figure 50: Angle-Voltage Data for Knee Joint It can be observed from Figure 50 that relation between angle and voltage is linear. The equation defining voltage av erage relationship was used for the interpolation of the angle in LabViewTM. 4.2.2 Hip Angle Measurement The electrogoniometer was mounted across the hip joint. The fixed endblock was attached to the side of the trunk in the pelvic region as shown in Figures 51A and Figure 51B. With the limb in the posit ion of reference, the electrogoniometer was extended to maximum length. The telescopic endblock was attached to the thigh so that the axis of the thig h and endblock coincide, when viewed in the sagittal plane. Double-sided adhes ive tape was employed between the endblocks and the mannequins skin, and single sided adhesive tape was placed over the top of the endblocks. No tape should come into contact with the spring . The thigh may now be flexed or extended, abducted or adducted, see
55 figure 52. Measurements of flex ion/extension were obtained from the green marked plug; abduction/adduction from the grey plug. The cable coming from the sensor to the circuit was r un inside the body of the mannequin. A B Figure 51: Installation of the El ectrogoniometer Across the Hip Joint Figure 52: Flexion of the Hip Joint It was necessary to modify the mannequin hip joint to permit more freedom of movement of this joint; see Figure 53. Note that marks were made on the mannequin. These marks indicate limits of motion of the elec trogoniometer to prevent damage of the sensor.
56 Figure 53: Hip Joint Modification To acquire angle measurements for the hi p joint, the directions presented in chapter 2 for performing flexion/extens ion and abduction/adduction motions were followed; as well for aligning the elec trogoniometer. The m easurements were taken three times and then averaged. T able 6 shows the measurements taken for the hip joint flexion/extension mo tions. The flexion angle measure was recorded up to 70 degrees and the extension angle measure was only recorded up to 30 degrees due to the restriction of the mannequin hip joint. Table 6: Angle-Voltage Data for Hip Joint Flexion/Extension Angle Volt1 Volt2 Volt3 Average -30 1.91 1.9 1.91 1.91 -20 1.84 1.85 1.83 1.84 -10 1.8 1.81 1.8 1.80 0 1.72 1.71 1.72 1.72 10 1.68 1.67 1.67 1.67 20 1.59 1.56 1.54 1.56 30 1.48 1.49 1.49 1.49 40 1.4 1.4 1.39 1.40 50 1.35 1.36 1.35 1.35 60 1.26 1.29 1.28 1.28 70 1.22 1.21 1.2 1.21 *The negative sign of the angle val ue indicates extension motion. Table 7 presents the measurements tak en for the hip joint abduction/adduction motions. The abduction angle measure was recorded up to 35 degrees and the
57 adduction angle measure was only recor ded up to 7 degrees due to the restriction of the mannequin hip joint. Table 7: Angle-Voltage Data for Hip Joint Abduction/Adduction Angle Volt1 Volt2 Volt3 Average -7* 1.21 1.2 1.22 1.21 0 1.28 1.26 1.28 1.27 5 1.32 1.29 1.31 1.31 10 1.36 1.32 1.34 1.34 15 1.41 1.39 1.4 1.40 20 1.46 1.43 1.44 1.44 25 1.51 1.5 1.5 1.50 30 1.53 1.54 1.55 1.54 35 1.57 1.56 1.58 1.57 *The negative sign of the angle value indicates adduction motion. It can be observed from Tables 6 and 7 that the three voltages values from the sensor are very similar, indicating a high level of sensor reliability and measurement repeatability. These values were graphed in Excel; see Figure 54 and 55. Angle-Voltage Data for Hip Joint Flexion/Extension -40 -20 0 20 40 60 80 1.911.841.801.721.671.561.491.401.351.281.21 Volt(V)Angle (Degrees) Hip Flex/Ext Figure 54: Angle-Voltage Data for the Hip Joint Flexion/Extension
58 Angle-Voltage Data for Hip Joint Abduction/Adduction-10 -5 0 5 10 15 20 25 30 35 40 1.211.271.311.341.401.441.501.541.57Volt(V)Angle(Degrees) Hip AB/AD Figure 55: Angle-Voltage Data for the Hip Joint Abduction/Adduction Figures 54 and 55 illustrate that the relation between an gle and voltage is almost linear. The equation defining voltage average relationship was used for interpolation of the angle values in LabViewTM. 4.2.3 Elbow Angle Measurement A flex sensor it was installed across the el bow joint. A plastic tube was used as a guide or channel for the flex sensor to run back and forth when the elbow joint was flexed. The plastic tube was attached on the mannequin with regular adhesive tape; see Figure 56. The cable co ming from the sensor to the circuit was run inside the bod y of the mannequin. To acquire angle measurements for the el bow joint, the directions presented in chapter 2 for performing flexion and ext ension motions were followed; see Figure 57. The measurements were taken th ree times and then averaged. Table 8
59 presents the measurements taken for t he elbow joint. The angle measure was recorded up to 90 degrees due to restri ction of the mannequin elbow joint. Figure 56: Installation of the Fl ex Sensor of the Elbow Joint Figure 57: Angle Measurement Elbow Joint Table 8: Angle-Voltage Data for the Elbow Joint Angle Volt1 Volt2 Volt3 Average 0 1.41 1.41 1.41 1.41 10 1.37 1.37 1.37 1.37 20 1.31 1.3 1.31 1.31 30 1.24 1.24 1.24 1.24 40 1.19 1.18 1.19 1.19 50 1.14 1.14 1.14 1.14 60 1.08 1.08 1.09 1.08 70 1.04 1.04 1.04 1.04 80 0.99 1.00 1.00 1.00 90 0.97 0.98 0.97 0.97
60 According to Table 8 the three voltages va lues from the elbow flex sensor are very similar, indicating a highly reli able sensor. The average values were graphed in Excel and are pr esented in Figure 58. Angle-Voltage Data for Elbow Joint0 10 20 30 40 50 60 70 80 90 1001 41 1.37 1.31 1 2 4 1 19 1.14 1.08 1. 0 4 1 00 0 97Volt (V)Angle (Degrees) Elbow Figure 58: Angle-Voltage Data for the Elbow Joint Figure 58 illustrates that relation bet ween angle and voltage is linear. The equation defining voltage average was used fo r interpolation of the angle value in LabViewTM. 4.3 Undignified Exposure Measurement To study the dignity of the patient, photoc ells were installed on the mannequins body. The areas of the mannequin select ed were the nipples, the genital area and the buttocks. Two sensors were placed on the chest, one on the right side and another one on the left side. One s ensor was placed on the genital area, and the last sensor on the buttocks area. Figure 59 illustrates the locations of the photocells on the chest.
61 Figure 59: Installation of Photocell on the Chest The characteristics of each of the photocells are summarized as follow: 1. Right side chest: Photocell charac teristics are presented in Table 9. Table 9: Photocell Characteristics Right Chest Conditions Resistance (ohms) Voltage (volts) Light 420 2.56 Dark 772 1.66 2. Left side chest: Photocell characte ristics are presented in Table 10. Table 10: Photocell Characteristics Left Chest Conditions Resistance (ohms) Voltage (volts) Light 230 2.68 Dark 423 1.91 3. Genital Area: Photocell characte ristics are presented in Table 11. Table 11: Photocell Characteristics Genital Area Conditions Resistance (ohms) Voltage (volts) Light 2.3 k 2.3 Dark 3.26 k 1.64
62 4. Buttocks Area: Photocell characte ristics are presented in Table 12. Table 12: Photocell Characteristics Buttocks Area Conditions Resistance (ohms) Voltage (volts) Light 270 1.753 Dark 570 0.0023 The voltage values were used to record undignified exposure, and recorded by LabViewTM VI. This procedure will be descr ibed in detail in subsection 4.5. 4.4 Skin Pressure Measurement Two force sensing resistors, (FSR), were placed on the mannequins body to study the skin pressure distribution w hen a patient is being turned over, see figure 60. One sensor was placed on the mannequins left upper arm and another one on the left thigh. The sensor s were covered with a plastic board to distribute more uniform the fo rce on the FSR, see figure 61. Figure 60: Subject Turn ing the Mannequin Over
63 Figure 61: Force Sensing Resistor Co vered to Standardize Measurement Area The sensors were calibrated using a Chatillon force gauge (DG-1000N), see Figure 62A and Figure 62B. Measurem ents were taken three times and averaged. The values taken for the FSR installed on the mannequins arm were acquired every 50 N until 550 N, and the measurements taken for the FSR installed on the mannequins thigh were ac quired every 20 N until 180 N. Table 13 and Table 14 show the measurements ta ken in each force sensing resistor. A B Figure 62: A) Chatillon DG-1000N, B) Ca libration of the Force Sensing Resistor
64 Table 13: Angle-Voltage Data for Force Sensing Resistor Installed on the Mannequins Arm Force (N) Sensor1ASensor1BSensor1CAverage 0 0 0 0 0 50 0.61 0.58 0.57 0.59 100 1.09 0.95 1.01 1.02 150 1.62 1.5 1.44 1.52 200 2.08 1.96 2.06 2.03 250 2.45 2.23 2.39 2.36 300 2.94 2.35 2.77 2.69 350 3.36 2.85 3.15 3.12 400 3.57 3.22 3.37 3.39 450 3.79 3.49 3.55 3.61 500 4.16 4.06 4.09 4.10 550 4.39 4.22 4.47 4.36 Table 13 presents the anglevoltage average for the s ensor located on the mannequins arm. The three voltages valu es recorded for the sensor is very similar, indicating a high level of sensor reliability and measur ement repeatability. The average value was graphed in Ex cel and presented in Figure 63. Calibration Force Sensing Resistor Located on the Mannequin's Arm0 50 100 150 200 250 300 350 400 450 500 00.591.021.522.032.362.693.123.393.61Volt(V)Force (N) Sensor1_Arm Figure 63: Force-Voltage Calibration for Force Sensing Resistor Located on Mannequins Arm
65 Table 14: Angle-Voltage Data for Force Sensing Resistor Installed on the Mannequins Thigh Force (N) Sensor2A Sensor2BSensor2C Average 0 0 0 0 0.00 20 0.66 0.61 0.72 0.66 40 1.15 1.03 1.14 1.11 60 1.62 1.56 1.59 1.59 80 1.98 1.84 1.96 1.93 100 2.38 2.23 2.24 2.28 120 2.61 2.85 2.55 2.67 140 3.21 3.41 3.32 3.31 160 4.56 4.18 4.38 4.37 180 5.01 4.69 5.22 4.97 Table 14 presents the anglevoltage averages for the sensor located on the mannequins thigh. The three voltages values taken for the sensor are also very similar, indicating a high level of sensor reliability and measur ement repeatability. The average value was graphed in Exce l and can be seen in Figure 64. Measurements for both FSR sensors were used to interpolate the angle value in LabViewTM. Calibration Force Sensing Resistor Located on the Mannequin's Thigh0 20 40 60 80 100 120 140 160 180 200 0.000.661.111.591.932.282.673.314.374.97Volt(V)Force(N) Sensor2_Thigh Figure 64: Force-Voltage Calibration for Force Sensing Resistor Located on Mannequins Thigh
66 4.5 Interface Human-Computer A virtual instrument, (VI), was developed using LabViewTM as the interface between the user or instructor and the instrumented mannequin. The VI had the capability of presenting the hi story of the acquired data to allow the trainer to be able to analyze the sensors information and verify the procedural accuracy of tasks performed on the simulated patient by the student. Figure 65 illustrates the workstation for the Ins trumented Mannequin. The fo llowing subsections will describe in detail the virtual instru ment (VI) created for this system. Figure 65: WorkStation of the Instrumented Mannequin 4.5.1 Main VI LabViewTM Screen The main LabviewTM VI screen was the interface between the instrumented mannequin and the user. The VI scr een is presented in Figure 66.
67 Figure 66: Main VI Interface Screen The characteristics of the Main VI Interface Screen were: 1. Samples are the number of data poi nts per channel that the VI acquires before acquisition completes; 300 data points per channel was the default solution. 2. Samples/s is the number of samp les per second that the VI acquires. This is the sampling rate per channel; 1000 samples/sec is the default solution. 3. The three first graphs show the angle plot for the elbow, knee, and hip joints. The last graph shows the force for the skin pressure distribution on the mannequins arm and thigh. 4. The four LEDs are included to study the dignity of the patient. Each LED is illuminated respective of the area on the patient that is exposed or undressed.
68 5. The button Save Data is used to st ore the data in a .tx t file to generate a report. 6. The Stop button suspended data collection. 4.5.2 Description of the Developed VIs using LabViewTM This subsection describes the LabViewTM program that was created for this system. A description for each of the designs is included. 220.127.116.11 Data Acquisition VI The following design was used to acquire data: Figure 67: Data Acquisition Interface Design
69 Oneida0 thru Oneida9, labeled above, represent the channels used on the data acquisition board. The mean value wa s calculated for each of the variables in study; see Figure 68. Figure 68: Mean Value Example Design The structure presented in Figure 68 was us ed to calculate the mean values for each of the joints and for the force on the arm and the thigh. The structure presented in Figure 69 was used to calc ulate the mean value and to create an array for all photocells. Figure 69: Mean Value Example Design for Photocell on the Left Chest Calibrated means were used to compute the interpolation of the data as described in the following subsection. 18.104.22.168 Interpolation of Values Angle, force, and voltage val ues from section 4.2 were copied to the program to produce an array of the values for subseque nt use in the interpolation design.
70 Figure 70 shows the components of this desi gn for the elbow and hip joints. The negative angle (-0.01) shown on Figure 70A is used to check the hyperextension of the elbow. The negative values on Fi gure 70B indicates adduction motion of the hip joint. For example, if the Main VI Screen shows in the Angle Ab/Ad box the value minus seven, this means that the motion is seven degrees adduction. After the values were compiled in an arra y, they were used to interpolate the angle of the joints. In the case of t he force-sensing resistor, the force and voltage arrays were used to interpolate the force on the mannequins arm and thigh. Figure 70: Angle and Voltage Arrays for Elbow and Hip Joints
71 Figure 71 presents the standard in terpolation for all angle joints. This design was used to compute the interpolation values for the elbow, knee, and hip joints, as well as forces on the arm and thigh. Figure 71: Example of Interpolation Design for the Elbow Joint 22.214.171.124 Plot of Data and Conditions Once the data were interpolated, t hey were graphed using the LabView graph command. In addition, there were some conditions that the system had to take into consideration. The system had to alert the instructor when the student was using too much force in the motion of the elbow, knee or the hip joint. To accomplish this task a structure was designed as shown on Figure 72. For example, in the case of the elbow join t, if a student pushes too hard on the arm of the mannequin during flexion, the graph will change color and a sound will beep to alert the instructor. A similar structure was utilized for the knee and hip joints.
72 Figure 72: Plot of Data and Conditions for Elbow Joint 126.96.36.199 Export and Save Data The VI design shown in Figure 73 was used to export the data and store it for future use. Once the instructor pushes the button Save Data on the Main VI Screen, a window pops up to save the data in a .txt file, see Figure 74. After the data is saved, it can be exported to Exce l for further analysis. The instructor can produce a report for each of his/her students.
73 Figure 73: Design to Export and Save the Data Figure 74: Pop Up Window to Save the Data
74 CHAPTER 5 RESULTS 5.1 Results Once the data was acquired and sav ed it was exported to Microsofts spreadsheet program, Excel, where a report was gener ated. Examples of the report are presented in Table 14. The angle values obtained for the elbow, knee and hip joints were very similar to the ones measured manually using the goniometer. The force measurements for the mannequins arm and leg were also shown to be accurate. The zeroes and ones presented for the photocells, Left Chest, Right Chest, Genital Area, Buttocks Area, indicate that the mannequin was either dressed or not dressed. A value of one indicates that the mannequin was undressed and a value of zero indicates that the mannequin was dressed. The column labeled Buttocks Area recorded only zeroes because the mannequin was lying on its back. A graph was generated for each of the variables studied on the Instrumented Mannequin. The graphs for the variables studied are presented in Figures 75, 76, 77, 78 and 79.
75 Table 15: Data Report Exported to Excel Development of a Instrumented Mannequin for Training Caregivers Measurements Result Elbow Knee Hip Flex/Ext Hip Ab/AdForce ArmForce Leg Left Chest Right Chest Genital Area Buttocks Area 1.19 1.36 3.06 1.08 18 3.84 1 0 1 0 2.25 1.36 3.08 1.07 18 3.84 1 0 1 0 2.29 1.31 14.6 1.27 29.3 34.4 1 0 1 0 2.08 1.35 14.6 1.21 16.9 32.1 1 0 1 0 1.89 6.28 14.7 1.28 35.8 23.3 1 0 1 0 1.67 6.21 6.14 1.21 67 54 1 0 1 0 7.69 6.18 6.18 1.18 63.9 46.6 1 0 1 0 20.3 6.21 6.21 1.21 70.3 40.5 1 0 1 0 19.9 6.22 6.19 1.22 64.3 39.6 1 0 1 0 24.3 6.19 6.15 1.19 60.5 39.7 1 1 1 0 25.8 6.15 6.2 1.15 54.3 39.2 1 1 1 0 25.5 6.2 6.18 1.2 55 39 0 1 1 0 28 6.14 6.16 2.14 59 38.7 0 1 1 0 31.3 6.18 6.18 2.18 85.5 52 0 0 1 0 36.6 6.21 6.14 2.21 108 69.9 0 0 1 0 38 6.19 6.15 2.19 103 63.8 1 0 1 0 40.6 6.15 6.19 2.15 90.7 51.5 1 0 1 0 44.8 6.2 6.14 2.2 86 44.5 1 0 1 0 54.2 6.18 6.15 2.18 82.4 43 1 0 1 0 60.6 6.16 6.26 2.16 81.6 40.9 1 0 1 0 66.2 6.18 9.08 2.18 67.5 36.4 1 0 1 0 69.7 6.14 12.6 2.14 73.5 33.4 1 0 1 0 72 6.15 13.3 3.15 30.8 35.4 1 0 1 0 66 6.19 17.3 3.19 30.9 35.4 1 0 1 0 54.9 6.14 19.1 1.19 30.1 34.4 1 0 1 0 48.4 6.15 24.9 2.25 30 35.6 1 0 1 0 41.7 6.26 28.2 2.29 29.8 36.3 0 0 0 0 39 9.08 30.5 2.08 28.5 33.9 0 0 0 0 38.1 12.6 36.1 1.89 29.8 37.4 1 0 0 0 37.7 13.3 42.5 1.67 30.8 36.4 1 0 0 0 37.6 17.3 49.1 1.36 30.8 35.4 1 0 1 0 36.3 19.1 50.2 1.36 18 3.84 1 0 1 0 36.2 24.9 50.8 1.31 18 3.84 1 0 1 0 47.2 28.2 55.4 1.35 29.3 34.4 1 0 1 0 60.7 30.5 70.3 0.49 16.9 32.1 0 0 1 0 68.4 36.1 81.8 1.61 35.8 23.3 0 0 1 0 77.7 42.5 85.5 12.5 16.9 32.1 0 1 1 0 82.1 49.1 92.2 19.1 35.8 23.3 1 1 1 0
76 Elbow & Knee Angle Report0 10 20 30 40 50 60 70 80 901 4 7 10 13 16 19 22 25 28 31 34 37Time(s)Angle (Degrees) Elbow Knee Figure 75: Elbow and Knee Activity The graph of the values from the Elbow Report illustrate that the elbow was gradually flexed to approximately 70 degrees Afterwards, the arm was extended to approximately 35 degrees and flexed again to approximately 80 degrees. The values for the Knee Report illus trate that the knee was flexed to approximately 5 degrees and was steady in t hat position for few seconds. Then the knee was gradually increased in flex to approximately 50 degrees.
77 Patient Left Chest Exposure0 0.2 0.4 0.6 0.8 1 1.21 5 9 13 17 21 25 29 33 37Time(s)Exposure Left Chest Figure 76: Patient Left Chest Exposure Patient Right Chest Exposure 0 0.2 0.4 0.6 0.8 1 1.21 5 9 13 17 21 25 29 33 37Time(s)Exposure Right FC Figure 77: Patient Right Chest Exposure The graph of the data asso ciated with the Left Expos ure Report, which is presented in Figure 76, indicates t hat the mannequin was undressed for approximately 12 seconds, dressed fo r 3 seconds and undressed again for
78 approximately 10 seconds. Studies of the graphs for the rest of the photocells produce similar results. Flexion/Extension & Abduction/Adduction Hip Report0 10 20 30 40 50 60 70 80 90 1001 4 7 10 13 16 19 22 25 28 31 34 37Time(s)Angle (Degrees) Flex/Ext Ab/Ad Figure 78: Hip Flexion/Extensi on and Abduction/Adduction Activity A graph of the hip data is pr esented in Figure 78. The graph indicates that the hip joint was flexed to approximately 15 degrees for the first 5 seco nds, extended to approximately 5 degrees where it remai ned for approximately 15 seconds and then the hip was gradually flexed to approx imately 90 degrees. The hip joint was also abducted to approximately 2 degrees.
79 Arm & Thigh Force Report0 20 40 60 80 100 1201 4 7 10 13 16 19 22 25 28 31Time(s)Force (N) Arm Thigh Figure 79: Force Application for the Arm and Thigh A graph of the force application data is presented in Figure 79. Pressure was applied to the mannequins arm with a fo rce between 50 and 100 Newton, which corresponds to 12 to 22 pounds. Similarly, pressure was applied to the thigh with a force between 45 and 70 Newton, which corresponds to approximately 10 to 16 pounds. The peaks on the above graph indicate that when the mannequin was turned over the pressure was released on the arm and leg and then the arm and leg were held back again.
80 5.2 Results: Phase II Based on recommendations, arising from a critical design review, velocity measurements associated with joint angle motions were incorporated as an additional monitoring tool for me asure of risk to the patient. An analysis of the data was performed in order to discover if significant noise was associated with the signal data. The noise investigation was performed with the aid of Matlab software. The unfilt ered angular displace ment data for the elbow exhibited some noise; see Figure 80. Figure 80: Unfiltered Data for Elbow Angular Displacement Since velocity is a derivative operati on, any noise associated with the signal, whose velocity is to be calculat ed, will be accentuated. The derivative associated with the unfiltered elbow angular displacement data was calculated. The results, unfiltered el bow angular velocity, are presented in Figure 81.
81 Figure 81: Unfiltered Elbow Angular Velocity The unfiltered angular velocity is essent ially unusable due to the presence of noise in the unfiltered angular displacement data. Therefore, prior to developing a velocity profile for the data, a Fast Fourier Transform, (FFT), analysis was performed. The results of the FFT analysis are presented in Figure 82. The FFT data shows that the frequency components associ ated with elbow angular displacement lie in a frequency b and that does not exceed ten hertz.
82 Figure 82: FFT of the Elbow Angular Displacement Data The velocity analysis indicated a need for filtering the data associated with elbow angular displacement and the FFT analysis unc overed the required filter range. Since a sharp cutoff for the filter was desired a fourth order Butterworth Low-pass digital filter was designed and incorporated into the LabviewTM system in order to minimize the effect of the presence of noise on velocity profile data. The LabviewTM panel used in the filter desi gn is presented in Figure 83. dc component Harmonics of angular motion
83 Figure 83: Butterworth Digital Filter Design The velocity profile associated with the filtered elbow angular displacement data was computed and the LabviewTM front panel was modified to display the results; see Figure 84.
84 Figure 84: LabviewTM Front Panel Design with Velocity Display The first graph, upper left, displays the elbow and knee angle measurement. The second graph, upper right, displays the angular velocity for the elbow and knee joints. The lower graphs were unmodified.
85 CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS 6.1 Conclusions The main motivation for this research was the desir e to find an appropriate solution to a common problem associated with patien t handling. Patient handling can cause bodily injury due to acute or cumulative trauma if tasks are performed incorrectly. The overall objectives of this resear ch were successfully accomplished. The research resulted in the develop ment of an integrated solution using commercially available components to help health care providers handle patients in a safe manner. This was achieve d by retrofitting a mannequin with flex sensors, electrogoniometers, pressure sen sors and photocells. The final design consisted of the integration of the se nsors and the implementation of a LabViewTM software based system. Data was collected, stored and analyzed by a virtual instrument, (VI), which was used as th e interface between the user or instructor and the instrumented mannequin. The VI, which was developed for this research, possessed the capability of displayi ng the history of the acquired data. Availability of data history enables the inst ructor to analyze the sensor information and verify the procedural accuracy of t he tasks performed by the student on the simulated patient.
86 The system developed during this research was also capable of identifying problems such as the application of excessive force or pressure by health care providers when interacting with patients. The syst em was designed to provide the healthcare community with useful information to improve and provide a safer and more comfortable environment for the patient. Providing the trainer with useful information about the students skill buildi ng during interaction with a patient will enhance evaluation of the students pe rformance. The results of this research clearly indicate that the instrumented mannequin will be a valuable tool in evaluating and assessing the merits of clinical procedures. The system developed may also be used in biomechani cal studies involving patient handling by caregivers. 6.2 Recommendations Recommendations for future work with Instrumented M annequins are: 1. Acquire a new mannequin that has more realistic joint movements. In this research, the mannequin did not possess totally rea listic joint characteristics. Therefore, the investigation was performed to only limited degrees of freedom within the existing capability o f the mannequins joints. 2. Design a better mechanical casing that can prote ct and guide the flex sensor during its movement. It was found during th is research that the flex sensor would occasionally stick when it was fl exed. 3. Incorporate mechanical limits in the mannequins hip joint in order to prevent goniometer damage due to excessive rotation of the sensor.
87 4. Design and integrate a wireless technology solut ion. Such a design would eliminate the cables running from the mannequin to the workstation.
88 REFERENCES  Patient Handling to Prevent Work-Related Musculoske letal Disorders, American Nurses Association, 2003. http:// www.osha.gov  Development of a Task Analysis Methodology and Repo rting Procedure for Patient Handling Tasks, University South of Florida, Mary W. Matz, 1999  Ergonomics Guidelines for Nursing Homes, U.S. Department of Labor Occupational Safety & Health Administration http://www.osha.gov  The Yale Journal for Humanities in Medicine, 20 02 http://info.med.yale.edu/intmed/hummed/yjhm/spirit/ dignity/dignityintro.htm  Patient Dignity and Privacy Intimate Examinations , Department of Health 2002. http://www.doh.gov.uk/cmo/letters/patientdign ity.htm  Coldicott Y., Pope, C. and Roberts, C. The Ethics of Intimate Examinationsteaching tomorrow's doctors, [commentaries by B. I. Nesheim and J. MacDougall], BMJ, 326, 97-101, 2003 http://bmj.bmjjournals.com  Patient Care Ergonomics Resource Guide: Safe Patien t Handling and Movement ,Patient Safety Center of Inquiry, Veterans Health Administration and the Department of Defense, 2001 http://www.patientsafetycenter.com  Charney, William and Hudson, Anne. Back Injury Among Healthcare Workers. Causes, Solutions, and Impacts Florida, USA: Lewis Publishers, 2004  Skotte, J., Essendrop, M., Hansen, A. and Schib ye, B., A Dynamic 3D Biomechanical Evaluation of the Load on the Low Bac k During Different Patient Handling Tasks, Journal of Biomechanics 35, 1357-1366, New York: Elsevier Science, 2002  Schibye, B., Hansen, A., Hye-Knudsen, C., Esse ndrop, M. and Bocher, M., Biomechanical Analysis of the Effects of Changing P atient-Handling Techniques , Journal of Biomechanics 34, 115-123, 2003. Butte rworthHeinemann, Oxford
89  Norkin, C. and White, J., Measurement of Joint Motion A Guide to Goniometry , F.A. Davis Company, Philadelphia 1985  Nordin, M. and Frankel V., Basic Biomechanics of the Musculoskeletal System , Philadelphia, London: Lea & Febiger, 1989  Soames, R., Joint Motion Clinical Measurement and Evaluation , United Kingdom: Churchill Livingstone, 2003  National Instruments Analog Input Multifunctio n DAQ http://www.ni.com  National Instruments NI SCXI-1000 Chassis http://www.ni.com  National Instruments SCXI-1300 Terminal Block http://www.ni.com  Flex Sensors http://www.imagesco.com/catalog/flex/FlexSensors.h tml  Flex Sensors http://www.spectrasymbol.com  Photocell Sensor http://www.makingthings.com/projects/cookbook/phot ocell.htm  Brake Pad Sensor http://www.tekscan.com  Biomechanics http://www.wordiq.com/cgi-bin/knowledge/lookup.cgi? title=Biomechanics  Electrogoniometers http://www.biopac.com/AppNotes/app140goniometer/pr ogoniometer.htm  The SG series twin axis goniometers http://www.biometricsltd.com/gonio.htm  National Instruments Programming http://www.ni.com  AGUR, Anne and LEE, Ming. Grants Atlas of Anatomy , 1999 Lippincott Williams & Wilkins, Philadelphia
91 Appendix A Examples of Resident Lifting and Reposi tioning Tasks A.1 Transfer from Sitting to Standing Position A.1.1 Description: Powered sit-tostand or standing assist devices. A.1.2 When to Use: Use this device when transferring residents who are partially dependent, have some weight-bearing capacity, are cooperative, can sit up on the edge of the bed, with or without assistance, and are able to bend their hips, knees and ankles. Additionally, use the device for transfers of patients from bed to wheelchair, Geri or cardiac, chair to bed or for bathing and toileting. These devices can be used for repositioning where space or storage is limited. A.1.3 Points to Remember: Look for a device that has a variety of sling size s, lift-height ranges, battery portability and handhel d control with emergency shutoff and manual override. Ensure that the device is rated for the residents weight. Electric/battery powered lifts are preferred to cra nk or pump type devices since they allow smoother movement for the resident and l ess physical exertion by the caregiver. A.2 Resident Lifting A.2.1 Description: The portable sling type lift device can be a universal/hammock sling or a band/leg sling. A.2.2 When to Use: Use this device for lifting residents who are totally dependent, are partial or non-weight bearing, are very heavy or have other physical limitations. Additionally, use this lift device for transfers from bed to wheel chair, Geri or cardiac, chair or floor to bed, for bathing and toileting or after a resident fall. A-1 A-2
92 Appendix A (Continued) A.2.3 Points to Remember: More than one caregiver may be required. Look for a device with a variety of slings, lift-height rang e, battery portability, hand-held control with emergency shut-off and manual override a boom pressure sensitive switch that can easily move the equipment and has a support base that goes under beds. Having multiple slings allows one of t hem to remain in place while the resident is in a bed or a chair for only short periods. The availability of multiple devices reduces the number of times the ca regiver lifts and positions resident. Portable compact lifts may be useful whe re space or storage is limited. Ensure the device is rated for the residents weigh t. Electric/battery powered lifts are preferred to crank or pump type devices in orde r to allow a smoother movement for the resident, demands less physical ex ertion by the caregiver and enhances resident safety and comfort. A.3 Resident Lifting A.3.1 Description: Ceiling mounted lift device A.3.2 When to Use: Employ this device when lifting residents who are totally dependent, are partial or non-weight bearing, are very heavy or have other physical limitations. Additionally, use for transfers from bed to wheelchair, Geri or cardiac, chair or floor to bed, for bathing and toileting or after a resident falls. A horizontal frame system or litter attached to the ceiling-mounted device can be used when transferring residents, who cannot be transferred safely otherwise, between two horizontal surfaces such as a bed to a stretche r or gurney while lying on their back. A.3.3 Points to Remember: More than one caregiver may be needed. Some residents can use the device without assistance. I t may be quicker to use than portable device. Motors can be fixed or portable and lightweight. Devices can be operated by a hand-held control that is attached to the unit or by infrared remote control. Ensure the device is rated for the resident weight. These devices increase the residents' safety and comfort during transfer. A 3
93 Appendix A (Continued) A.4 Ambulation A.4.1 Description: Ambulation assist device A.4.2 When to Use: For residents who are weight bearing and cooperative and who need extra security and assistance when ambulating. A.4.3 Points to Remember: This device increases resident safety during ambulation and reduces the risk of falls. The device supports residents as they walk and push it along during ambulation. Ensure that the height adjustment is correct for the resident before ambulation. Ensure that the device is in good working order before use and is rated for the weight of the resident to be lifted. Apply brakes before positioning the resident in or releasing the resident from device. A.5 Lateral Transfer; Repositioning A.5.1 Description: A device designed to reduce friction forces when t ransferring a resident. These devices include draw sheets or transfer cots with handles to be used in combination with slippery sheets, low friction mattress covers or slide boards. Other devices in this category include boards or mats with vinyl coverings and rollers, gurneys with transfer devices and air-assist lateral sliding aids or a flexible mattress, which can be inflated by a portable air supply. A.5.2 When to Use: Employ these devices when transferring a partial or non-weight bearing resident, positioned on the back, between two horizontal surfaces such as a bed to a stretcher or gurney or when repositioning the resident in bed. A 4 A 5
94 Appendix A (Continued) A.5.3 Points to Remember: More than one caregiver is required in order to perform this type of transfer or repositioning. Ad ditional assistance may be needed depending upon resident status. For example, additional assistance may be required when moving heavier or non-cooperative residents. Some devices may not be suitable for bariatric residents. When using a draw sheet combination, insure a good handhold by rolling up d raw sheets or use other friction-reducing devices with handles such as slip pery sheets. Narrower slippery sheets with webbing handles positioned on the long edge of the sheet may be easier to use than wider sheets. When using boards or mats with vinyl coverings and rollers use a gentle push and pull motion to mo ve the resident to new surface. Look for a combination of devices that wi ll increase the resident's comfort and minimize risk of skin trauma. Ensure t ransfer surfaces are at the same level and at a height that allows caregivers t o work at waist level to avoid extended reaches and bending of the back. Count do wn and synchronize the transfer motion between caregivers. A.6 Lateral Transfer; Repositioning A.6.1 Description: Convertible Geri or cardiac wheelchairs and beds that convert to chairs. A.6.2 When to Use: Use these devices for lateral transfer of residents who are partial or non-weight bearing. These devices eliminate the need to perform lift transfer in and out of wheelchairs. They can also be used to assist residents who are partially weight bearing from a sit-to-stand position. Beds that convert to chairs can aid in the repositioning of residents who are totally dependent, non-weight bearing, very heavy or those with other physical limitations. A.6.3 Points to Remember: More than one caregiver is required to perform a lateral transfer. Depending on resident status, ad ditional assistance for lateral transfers may be required. For example, additional assistance may be required when moving heavier or non-cooperative residents. Additional friction-reducing devices may also be required to reposition a reside nt. Heavy-duty beds are available for bariatric residents. Device should h ave easy-to-use controls located within easy reach of the caregiver, sufficient foot clearance and wide ranges of adjustment. Motorized height adjustable devices ar e preferred to those adjusted by a crank mechanism to minimize physical exertion. Always ensure that the A 6
95 Appendix A (Continued) device is in good working order before use. Ensure that the wheels associated with the equipment are properly locked. Ensure tha t transfer surfaces are at the same level and at a height that allows caregivers t o work at waist level in order to avoid extended reaches and bending of the back. A.7 Repositioning in a Chair A.7.1 Description: Variable position Geri and Cardiac wheelchairs A.7.2 When to Use: Use these devices when repositioning partial or non-weight-bearing residents who are cooperative. A.7.3 Points to Remember: More than one caregiver is required and use of a friction-reducing device is needed if the resident cannot assist in the reposition activity. Ensure the use of good body mechanics by caregivers. The wheels on chair add versatility. Ensure that the chair is easy to adjust, move and steer. Lock the chairs wheels before repositioning. Remove trays, footrests and seat belts, where appropriate. Ensure that the device is rated for the residents weight. A.8 Lateral Transfer in a Sitting Position A.8.1 Description: Transfer boards; wood or plastic. Some boards are equipped with a movable seat. A.8.2 When to Use: Use these devices when transferring or sliding residents who have good sitting balance and are cooperative. Such transfers are from one level surface to another such as from bed to wheelchair, wheelchair to car seat or toilet. Residents who require limited assistance but need additional safety and support can also use these devices. A.8.3 Points to Remember: Movable seats increase resident comfort and reduce the incidence of tissue damage during transfer. More than one caregiver is needed to per form a lateral transfer. A-7 A-8
96 Appendix A (Continued) Ensure that clothing is present between the residen t's skin and the transfer device. The seat may be cushioned with a small tow el for comfort. Such a transfer may be uncomfortable for larger residents. Depending on residents status, these devices are usually used in conjuncti on with gait belts for safety. Ensure that boards have tapered ends, rounded edges and the appropriate weight capacity. Ensure that the wheels on the bed or chair are locked and that transfer surfaces are at the same level. Remove th e lower bedrails from a bed and remove the arms and footrests from chairs as ap propriate. A.9 Transfer from a Sitting to a Standing Position A.9.1 Description: Devices include lift cushions and lift chairs. A.9.2 When to Use: These devices are used when transferring residents who are weight bearing and cooperative but require assistance when standing and ambulating. Such devices can also be used for independent residents who require an extra boost in order to stand. A.9.3 Points to Remember: Lift cushions employ a lever that activates a spri ng action in order to assist residents in the activity of moving to a standing position. Lift cushions may not be appropriate for heavier re sidents. Lift chairs are operated via a handheld control that tilts the chai r forward slowly while raising the resident. Residents need to have physical and cogn itive capacity to be able to operate a lever or other controls. Always ensure t hat the device is in good working order before use and that it is rated for t he weight of the resident to be lifted. These devices provide the resident with a measure of independence. A.10 Transfer from a Sitting to a Standing Position A.10.1 Description: Stand-assist devices can be fixed to a bed or chair or be freestanding. A.10.2 When to Use: Use these devices when transferring residents who are weight-bearing, cooperative and who can pull themselves up from a sitting to a standing position. These devices can be used for independent residents who require extra support in order to stand. A-9 A-10
97 Appendix A (Continued) A.10.3 Points to Remember: Check that the device is stable before use and is rated for the weight of the resident to be supporte d. Ensure that the frame is firmly attached to bed. If the device must rely on mattress support ensure that the mattress is heavy enough to hold the frame. Th ese devices can provide the resident with a measure of independence. A.11 Weighing A.11.1 Description: Scales with ramps to accommodate wheelchairs, portable powered lift devices with built-in scales and beds with built-in scales. A.11.2 When to Use: Use these devices to reduce the number of transfers of partial or non-weight-bearing residents or totally dependent residents to weighing device. A.11.3 Points to Remember: Some wheelchair scales can accommodate larger wheelchairs. Built-in bed scales may increase the weight of the bed and prevent it from lowering to appropriate work heights. A.12 Transfer from a Sitting to a Standing Position ; Ambulation A.12.1 Description: Gait belts/transfer belts with handles. A.12.2 When to Use: Use these devices when transferring residents who are partially dependent, have some weight-bearing capacity and are cooperative. Employ these devices for transfers such as bed to chair, chair to chair, chair to car, repositioning residents in chairs, supporting residents during ambulation, and in some cases when guiding and controlling falls or assisting a resident after a fall. A.12.3 Points to Remember: More than one caregiver may be required. Belts with padded handles are easier to grip and A 11 A-12
98 Appendix A (Continued) increase security and control. Always perform the transfer to the resident's strongest side. Use good body mechanics along with a rocking and pulling motion rather than lifting directly when using a be lt. Belts may not be suitable for ambulation of heavy residents. Belts should not be used for lifting residents with recent abdominal or back surgery or those with an a bdominal aneurysm. Ensure that the belt is securely fastened and canno t be easily undone by the resident during transfer. Ensure that a layer of c lothing is between the residents skin and the belt in order to avoid abrasion. Keep the resident as close as possible to the caregiver during transfer. Be sure to lower bedrails, remove arms and footrests from chairs and any other items that could obstruct the transfer. If a belt is to be used after a fall always assess the resident for injury prior to movement. If the resident can regain a standing po sition with minimal assistance, use gait or transfer belts with handles to aid the resident. Keep the back straight, bend legs and stay as close to the r esident as possible. If the resident cannot stand with minimal assistance, use a powered portable or ceilingmounted lift device to move the resident. A.13 Repositioning A.13.1 Description: Electric powered height adjustable beds. A.13.2 When to Use: Use these devices for all activities involving resident care, transfer or repositioning in the bed. These devices reduce caregiver bending when interacting with the resident. A.13.3 Points to Remember: The device should have easy-to-use controls, which are located within easy reach of the caregiver to promote use of the electric adjustment, sufficient foot clearance and wide ranges of adjustment. Adju stments must be completed in 20 seconds or less to ensure staff use. Beds th at lower closer to the floor may be required for residents that may be at risk of fa lling from bed. Heavy-duty beds are available for bariatric residents. Beds raised and lowered with an electric motor are preferred over crank-adjust beds in order to allow a smoother movement for the resident and less physical exertio n for the caregiver. A-13
99 Appendix A (Continued) A.14 Repositioning A.14.1 Description: Trapeze bar; hand blocks and push up bars attached to the bed frame. A.14.2 When to Use: Use these devices to reposition residents that have the ability to assist the caregiver during the activity. These devices are particularly appropriate for residents with upper body strength, maintain the use of extremities, are cooperative and can follow instructions. A.14.3 Points to Remember: Residents use the trapeze bar by grasping the bar while it is suspended from an overhead frame in order to raise them up and reposition them in a bed. Heavy-duty trapeze frames are available for bariatric resident s. If a caregiver is Assisting, ensure that the bed wheels are locked, b edrails are lowered and the bed is adjusted to the caregiver's waist height. B locks also enable residents to raise themselves up and reposition themselves in be d. Bars attached to the bed frame serve the same purpose. These devices may no t be suitable for heavier residents. Such devices can provide the resident w ith a measure of independence. A.15 Repositioning A.15.1 Description: Pelvic lift devices (hip lifters). A.15.2 When to Use: Use these devices to assist residents who also are cooperative and can sit up to a position on a special bed pan. A.15.3 Points to Remember: Use of the device may reduce the need for resident lifting during toileting. The device is positioned under the pelvis. The part of the device located under the pelvis gets inflated so the pelvis is raised and a special bedpan is put underneath. The head of the bed is raised slightly during this procedure. Use correct body mechanics, lower bedrails and adjust the bed to the caregivers waist height in o rder to reduce bending. A-14 A-15
100 Appendix A (Continued) A.16 Bathtub, Shower, and Toileting Activities A.16.1 Description: Height adjustable and easy-entry bathtubs. A.16.2 When to Use: Use these devices when bathing residents who can sit directly in the bathtub or to assist ambulatory residents to enter into a low tub, or easy-access tub more easily. Bathing residents in portable-powered or ceiling mounted lift device requires the use of and appropriate bathing sling. A.16.3 Points to Remember: These devices reduce awkward postures for caregivers and those who clean the tub. The tub can be raised to eliminate bending and reaching for the caregiver. Use correct body mechanics and adjust the tub to the caregiver's waist height when performing hygiene activities. Use of these d evices increases resident safety and comfort. A.17 Bathtub, Shower, and Toileting Activities A.17.1 Description: Height adjustable shower gurney or lift bath cart with waterproof top. A.17.2 When to Use: Use these devices for bathing non-weight bearing residents who are unable to sit up. Transfer the resident to a cart that is equipped with lift or lateral transfer boards or other friction-reducing devices. A.17.3 Points to Remember: The cart can be raised to eliminate bending and reaching for the caregiver. Foot and head supports are available for resident comfort. These devices may not be suitable for bariatric residents. Look for carts that are power-driven in order to re duce the force required to move and position the device. A-16 A-17
101 Appendix A (Continued) A.18 Bathtub, Shower, and Toileting Activities A.18.1 Description: Built-in or fixed bath lifts. A.18.2 When to Use: Use these devices when bathing residents who are partially weight bearing, have good sitting balance, can use their upper extremities, are cooperative, and can follow instructions. These devices are useful in small bathrooms where space is limited. A.18.3 Points to Remember: Ensure that the seat rises sufficiently for the resident's feet to clear the tub, rotates easily and lowers properly in order to place the resident into the water. Such devices may not be suitable for heavy residents. Always ensure that the lifting device is in good working order before use and is rated for the residents weight. Choose a device with a lift mechanism that does not require excessive effort by the caregiver when raising and lowering device when it is occupied by a reside nt. A.19 Bathtub, Shower, and Toileting Activities A.19.1 Description: Shower and toileting chairs. A.19.2 When to Use: Use these devices when showering and toileting residents who are partially dependent, have some weight bearing capacity, can sit up unaided and who are able to bend their hips, knees, and ankles. A.19.3 Points to Remember: Ensure that the chair wheels move easily and smoothly and that the chair is high enough to fit over the toile t. Additionally, ensure that the chair has removable arms, adjustable footrests, saf ety belts, is heavy enough to be stable, the seat is comfortable, accommodates la rger residents and has a removable commode bucket for toileting. Ensure tha t brakes lock, hold effectively and that the weight capacity is adequat e. A-18 A-19
102 Appendix A (Continued) A.20 Bathtub, Shower, and Toileting Activities A.20.1 Description: Bath boards and transfer benches. A.20.2 When to Use: Use these devices when bathing residents who are partially weight bearing, have good sitting balance, can use their upper extremities, are cooperative and can follow instructions. Independent residents can also use these devices. A.20.3 Points to Remember: To reduce friction and possible skin tears insert clothing or material between the resident's skin and the board. These devices can be used with a gait or transfer belt and/or grab bars to aid transfer. Back support and vinyl-padded seats add to the residents bathing co mfort. Look for devices that provide for water drainage and have height-adjustab le legs. These devices may not be suitable for heavy residents. If a wheelcha ir is used ensure that the wheels are locked, the transfer surfaces are at the same level and the device is securely in place and rated for the weight to be tr ansferred. Remove arms and footrests from chairs as appropriate and ensure tha t the floor is dry. A.21 Bathtub, Shower, and Toileting Activities A.21.1 Description: Toilet seat risers. A.21.2 When to Use: Use these devices for toileting partially weight-bearing residents who can sit up unaided, use their upper extremities, are able to bend their hips, knees, and ankles and are cooperative. Independent residents can also use these devices. A.21.3 Points to Remember: Risers decrease the distance and amount of effort required to lower and raise residents. Grab bars and height-adjustable legs add safety and versatility to the device. Ensure that the device is stable and can accommodate the resident's weight and size. A-20 A-21
103 Appendix A (Continued) A.22 Bathtub, Shower, and Toileting Activities A.22.1 Description: Grab bars and stand assists; fixed or mobile, long -handled or extended showerheads and brushes used for person al hygiene. A.22.2 When to Use: Use devices such as bars and assists to help when toileting, bathing, and/ or showering residents who need extra support and security. Residents must be partially weight bearing, able to use their upper extremities and be cooperative. Long-handled devices reduce the amount of bending, reaching and twisting required by the caregiver when washing the feet, legs and trunk of a resident. Independent residents who have difficulty reaching lower extremities can also use these devices. A.22.3 Points to Remember: Movable grab bars on toilets minimize workplace congestion. Ensure that bars are securely fastened to the wall before use. A-22