305 Prosthetic socket design system using ultrasound image : Modeling of a residual lower limb

Background: Prosthetic socket fit is an important element associated with successful ambulation and use of a prosthesis. Prosthetists and rehabilitation clinicians would benefit from an assessment tool that discriminates between and quantifies the multiple determinants that influence the lower limb amputee’s performance and satisfaction of a prosthetic socket. Objectives: To determine the internal consistency of the comprehensive lower limb amputee socket survey, a new self-report measure of prosthetic socket satisfaction that quantifies suspension, stability, comfort, and appearance. Study design: Cross-sectional sample of active amputees. Methods: Interviews were conducted with prosthetists, physical therapists, and lower limb amputees to identify clinical concerns and common activities influencing socket fit. An expert panel of five clinicians reviewed the items and constructed the original version of the comprehensive lower limb amputee socket survey which was then administered to a convenience sample of 47 active lower limb amputees. Item analysis and Cronbach’s alpha were used to determine the final version of the comprehensive lower limb amputee socket survey. Results: Following item raw score-to-total score correlation with Cronbach’s alpha for comprehensive lower limb amputee socket survey determinants, internal consistency improved when nine questions were eliminated. Conclusion: The comprehensive lower limb amputee socket survey is a self-report measure of prosthetic socket satisfaction with very good internal consistency. Clinical relevance When socket problems occur, the ability to determine the specific cause can reduce modification time, enhance socket fit, and promote patient satisfaction. A standardized multi-dimensional assessment measure of socket satisfaction enables prosthetists to quantify the multiple determinants of socket satisfaction, improve patient communication, and demonstrate the value of socket interventions.

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Evaluating the Effect of an Amputee’s Physical Parameters of Pressure on a Lower-Limb Prosthetic Socket Using a Fuzzy-Logic-Based Model

Applied Mechatronics and Mechanics ◽

10.1201/9781003019060-11 ◽

2020 ◽

pp. 167-189

Author(s):

Vimal Kumar Pathak ◽

Chitresh Nayak ◽

Deepak Rajendra Unune

Keyword(s):

Fuzzy Logic ◽

Lower Limb ◽

Physical Parameters ◽

Prosthetic Socket

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Developing a control framework for self-adjusting prosthetic sockets incorporating tissue injury risk estimation and Generalized Predictive Control

10.31224/osf.io/cd6pg ◽

2021 ◽

Author(s):

Florence M Mbithi ◽

Joshua Steer ◽

Andrew J Chipperfield ◽

Alexander Dickinson

Keyword(s):

Predictive Control ◽

Lower Limb ◽

Injury Risk ◽

Tissue Injury ◽

Risk Estimation ◽

Soft Tissue Injury ◽

Estimation Method ◽

Generalized Predictive Control ◽

Prosthetic Socket ◽

Interfacial Pressure

Purpose: To perform activities of daily living (ADL), people with lower limb amputation depend on the prosthetic socket for stability and proprioceptive feedback. Poorly fitting sockets can cause discomfort, pain, limb tissue injuries, limited device usage, and potential rejection. Semi-passively controlled adjustable socket technologies exist, but these depend upon the user’s perception to determine safe interfacial pressure levels. This paper presents a framework for automatic control of an adjustable transtibial prosthetic socket that enables active adaptation of residuum-socket interfacial loading through localized actuators, based on soft tissue injury risk estimation. Method: Using finite element analysis, local interfacial pressure vs. compressive tissue strain relationships were estimated for three anatomical actuator locations, for tissue injury risk assessment within a control structure. Generalized Predictive Control of multiple actuators was implemented to maintain interfacial pressure within estimated safe and functional limits. Results: Controller simulation predicted satisfactory dynamic performance in several scenarios, based on previous related studies. Actuation rates of 0.06 – 1.51kPa/s with 0.67% maximum overshoot, and 0.75 – 1.58kPa/s were estimated for continuous walking, and for a demonstrative loading sequence of ADL, respectively. Conclusion: The developed platform could be useful for extending recent efforts in adjustable lower limb prosthetic socket design, particularly for individuals with residuum sensory impairment.

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Design and Additive Manufacturing of Lower Limb Prosthetic Socket

Volume 11: Systems, Design, and Complexity ◽

10.1115/imece2017-71494 ◽

2017 ◽

Cited By ~ 2

Author(s):

Andrea Vitali ◽

Daniele Regazzoni ◽

Caterina Rizzi ◽

Giorgio Colombo

Keyword(s):

Additive Manufacturing ◽

Lower Limb ◽

New Paradigm ◽

Prosthetic Socket ◽

Lower Limb Prosthesis ◽

Virtual Modeling ◽

High Level ◽

Inhomogeneous Properties ◽

Design And Manufacture ◽

Important Design

Additive Manufacturing (AM) is not only an innovative approach of fabrication but it fosters a new paradigm to design products. The possibility to confer inhomogeneous properties to the product provides an important design key. This paper concerns the design and manufacture of medical devices that require a high level of customization. We focus the attention on lower limb prosthesis and in particular on the prosthetic socket. The proposed method is centered on the virtual modeling of patient’s residual limb and the virtual process is highly integrated and the data flow is as fluid as possible. Three main phases can be identified: design, validation and manufacture of the socket. Firstly, the technician uses the Socket Modeling Assistant (SMA) tool to design the socket shape. Then, a numerical simulation is run to check pressure distribution and validate the socket shape. Finally, a multi-material 3D printer is used to build the socket. Preliminary results are presented and conclusions are drawn concerning the challenge of multi-material 3D printing of the socket.

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ESTABLISHMENT AND APPLICATION OF LOWER LIMB FINITE ELEMENT MODEL BASED ON MUSCLE GROUPS

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519418400249 ◽

2018 ◽

Vol 18 (08) ◽

pp. 1840024

Author(s):

MONAN WANG ◽

RONGPENG LI ◽

JUNTONG JING

Keyword(s):

Experimental Study ◽

Finite Element ◽

Finite Element Model ◽

Lower Limb ◽

Element Model ◽

Upper And Lower Bounds ◽

Three Point Bending ◽

Living Body ◽

Prosthetic Socket ◽

Simulation Results

Living body or corpse could be replaced with the virtual human tissue model for biomechanical experimental study, which effectively avoids the non-reusability, great social controversy, huge costs and difficulty in extracting parameters, and finally, the accurate analysis results are obtained. Unlike the previous lower limb models, the finite element models of hip and thigh were established based on the concept of muscle group in this paper. The cortical bones of hip bone and femur were set as *MAT_PIECEWISE_LINEAR_ PLASTICITY. The material of cancellous bone was set as *MAT_ELASTIC_PLASTIC_ WITH_DAMAGE_FAILURE. The material of articular cartilage was set as *MAT_ISOTROPIC_ELASTIC. The materials of muscle and fat were set as *MAT_VISCOELASTIC. The accuracy of the finite element model was verified by dynamic three-point bending experiment of the thighs. Mechanical simulation was carried out to the stump-prosthetic socket and the comfort of socks by the established model. The simulation results were all between the upper and lower bounds of the experimental results in the dynamic three-point bending experiment of the thighs where the loads were separately applied to one-third of the distal end of thighs and the middle part of thighs. The simulation results of the stump-prosthetic socket example show that the optimal elastic modulus of silicone pad is 2.5[Formula: see text]MPa. Simulation results of socks comfort show that the distribution of stress and deformation of the anterior and posterior thighs is different when the human lower limbs are in stockings. The established simulation model meets the accuracy requirement and can replace the living body or corpse to carry out biomechanical experimental study. The finite element simulation results converge, and the time to complete a finite element calculation is less than or equal to 10[Formula: see text]min.

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Accuracy Verification of Magnetic Resonance Imaging (MRI) Technology for Lower-Limb Prosthetic Research: Utilising Animal Soft Tissue Specimen and Common Socket Casting Materials

The Scientific World JOURNAL ◽

10.1100/2012/156186 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Mohammad Reza Safari ◽

Philip Rowe ◽

Arjan Buis

Keyword(s):

Surface Area ◽

Cross Sections ◽

Lower Limb ◽

Residual Limb ◽

Cross Sectional ◽

Prosthetic Socket ◽

Semiautomatic Segmentation ◽

Segmented Images ◽

Cad Cam ◽

Volume Measurements

Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements.

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Issues Faced by Prosthetists and Physiotherapists During Lower-Limb Prosthetic Rehabilitation: A Thematic Analysis

Frontiers in Rehabilitation Sciences ◽

10.3389/fresc.2021.795021 ◽

2022 ◽

Vol 2 ◽

Author(s):

Shruti Turner ◽

Athina Belsi ◽

Alison H. McGregor

Keyword(s):

Thematic Analysis ◽

Lower Limb ◽

Limb Amputation ◽

Service Users ◽

Prosthetic Rehabilitation ◽

Structured Interviews ◽

User Perspective ◽

Prosthetic Socket ◽

Clinician Perspectives ◽

Insight Into

Successful prosthetic rehabilitation is essential to improve the physical and mental outcomes of people with lower-limb amputation. Evaluation of prosthetic services from a prosthesis user perspective have been published and commissioned by the national bodies, however, the perspectives of clinicians working with service users during rehabilitation have not to date been sought. We sought to determine factors impacting lower-limb prosthetic rehabilitation from a clinician's perspective to inform studies focusing on prosthetic and socket design and fitting. Six clinician (2 prosthetists, 4 physiotherapists) interviewees were self-selected from a survey exploring issues and frustrations during lower-limb prosthetic rehabilitation. Semi-structured interviews explored the impactors on and frustrations with rehabilitation and the prosthetic socket. A thematic analysis was subsequently conducted to identify themes in the responses. Five themes were identified: Service Disparity, Body Impactors, Consequences of Ill-Fit, Prosthesis Irritants, and Limitations of Practice. Each theme, though distinct, relates to the others either as a cause or consequence and should be viewed as such. Addressing the themes will have benefits beyond the issues addressed but also expand into the other themes. This study provides an insight into the clinician perspectives on lower-limb prosthetic rehabilitation, which has not been formally documented to date.

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