MEMS-based bubble pressure sensor for prosthetic socket interface pressure measurement

The concept of measuring pressure at the interface between the stump and the prosthetic socket could provide valuable information in the process of prosthetic socket fabrication, modification, and fit. Two systems, the Rincoe Socket Fitting System (SFS) and Tekscan's FSocket Pressure Measurement System, have been commercially designed for in situ interface pressure measurement over the past decade. Their use is not common in prosthetic practice, perhaps due to questions of cost effectiveness and the difficulties of interpreting the data. Another concern is the use of sensors for pressure measurements in areas of high contour and complex geometries such as the stump. Before these systems can be used in a clinical setting, it is necessary to determine the reliability and accuracy of each system. In order to assess the clinical validity of the Rincoe SFS and FSocket systems, a series of trials was conducted to evaluate different aspects of sensor performance, namely; accuracy, hysteresis, drift and the effect of curvature. The sensors were subjected to tests in flatbed and customdesigned pressure vessels. Overall results indicated an accuracy error for the Rincoe SFS system of 25% (flatbed) and 33% (mould), with a corresponding 15% (flatbed) and 23% (mould) error in hysteresis, and 7% (flatbed) and 11% (mould) drift errors. The FSocket system demonstrated an 8% (flatbed) and 11% (mould) accuracy errors, 42% (flatbed) and 24% (mould) hysteresis errors, and 12% (flatbed) and 33% (mould) drift errors. These findings indicate favourable results for the FSocket Pressure Measurement System compared to the Rincoe Socket Fitting System with respect to its accuracy errors only. Nevertheless, it is the authors’ belief that these systems are adequate in indicating areas of high pressure at the stump socket interface for clinical purposes, but both systems should be used with caution.

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Laboratory and clinical tests of a prototype pressure sensor for clinical assessment of prosthetic socket fit

Prosthetics and Orthotics International ◽

10.1080/03093640208726618 ◽

2002 ◽

Vol 26 (1) ◽

pp. 23-34 ◽

Cited By ~ 19

Author(s):

A. A. Polliack ◽

D. D. Craig ◽

R. C. Sieh ◽

S. Landsberger ◽

D. R. McNeal

Keyword(s):

Pressure Sensor ◽

Bench Test ◽

Test Results ◽

Capacitance Sensor ◽

Prosthetic Socket ◽

Technological Advances ◽

Post Test ◽

Capacitance Pressure ◽

Biomechanical Factors ◽

Socket Interface

Lower limb prosthetic socket fabrication is a highly refined process relying on the prosthetist's skill and experience. Despite their best efforts, patients often return with complications. Additionally, clinical application of technological advances for the quantification of biomechanical factors at the socket interface has not changed in practice. Measuring pressure levels at the stump/socket interface could provide valuable information in the process of prosthetic socket fabrication, fit and modification.This paper presents findings on the performance of a prototype capacitance pressure sensor designed for prosthetic socket use. Bench tests using compressed air were performed to measure accuracy, hysteresis and drift responses in both a flatbed chamber and a custom-modified pressure vessel. For the contoured testing, the sensors were placed on nine sites on a positive trans-tibial stump mould and enveloped with a silicone liner. Additionally, a preliminary clinical evaluation was performed with two trans-tibial amputee subjects at the nine sites during normal ambulation.Bench test results showed that the prototype capacitance sensor performed well in all categories, exhibiting a 2.42% (flatbed) and 9.96% (contoured) accuracy error, a 12.93% (flatbed) and 12.95% (contoured) hysteresis error, and a 4.40% (flatbed) and 6.20% (contoured) drift error. The clinical study showed that after three hours of continual use, no noticeable sensor drift occurred between pre and post-test calibration values.The results from this study were encouraging and the authors hope to conduct further laboratory and clinical trials to assess the influence of shear force and dynamic loading on sensor response.

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Review on the Interface Pressure Measurement for Below Knee Prosthetic Socket

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1094/1/012036 ◽

2021 ◽

Vol 1094 (1) ◽

pp. 012036

Author(s):

Esraa A Abbod ◽

Kadhim K Resan

Keyword(s):

Pressure Measurement ◽

Interface Pressure ◽

Prosthetic Socket

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Review of the Socket Design and Interface Pressure Measurement for Transtibial Prosthesis

The Scientific World JOURNAL ◽

10.1155/2014/849073 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 17

Author(s):

Gh. Pirouzi ◽

N. A. Abu Osman ◽

A. Eshraghi ◽

S. Ali ◽

H. Gholizadeh ◽

...

Keyword(s):

Pressure Measurement ◽

Clinical Settings ◽

Residual Limb ◽

Interface Pressure ◽

Prosthetic Limb ◽

Transtibial Prosthesis ◽

And Function ◽

Socket Interface ◽

Quantitative Evaluations

Socket is an important part of every prosthetic limb as an interface between the residual limb and prosthetic components. Biomechanics of socket-residual limb interface, especially the pressure and force distribution, have effect on patient satisfaction and function. This paper aimed to review and evaluate studies conducted in the last decades on the design of socket, in-socket interface pressure measurement, and socket biomechanics. Literature was searched to find related keywords with transtibial amputation, socket-residual limb interface, socket measurement, socket design, modeling, computational modeling, and suspension system. In accordance with the selection criteria, 19 articles were selected for further analysis. It was revealed that pressure and stress have been studied in the last decaeds, but quantitative evaluations remain inapplicable in clinical settings. This study also illustrates prevailing systems, which may facilitate improvements in socket design for improved quality of life for individuals ambulating with transtibial prosthesis. It is hoped that the review will better facilitate the understanding and determine the clinical relevance of quantitative evaluations.

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Interface Pressure System to Compare the Functional Performance of Prosthetic Sockets during the Gait in People with Trans-Tibial Amputation

Sensors ◽

10.3390/s20247043 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7043

Author(s):

Salvador Ibarra Aguila ◽

Gisel J. Sánchez ◽

Eric E. Sauvain ◽

B. Alemon ◽

Rita Q. Fuentes-Aguilar ◽

...

Keyword(s):

Gait Cycle ◽

Peak Pressure ◽

Functional Performance ◽

Physical Therapists ◽

Residual Limb ◽

Interface Pressure ◽

Pressure System ◽

Prosthetic Socket ◽

Critical Regions ◽

Socket Interface

The interface pressure between the residual limb and prosthetic socket has a significant effect on the amputee’s mobility and level of comfort with their prosthesis. This paper presents a socket interface pressure (SIFP) system to compare the interface pressure differences during gait between two different types of prosthetic sockets for a transtibial amputee. The system evaluates the interface pressure in six critical regions of interest (CROI) of the lower limb amputee and identifies the peak pressures during certain moments of the gait cycle. The six sensors were attached to the residual limb in the CROIs before the participant with transtibial amputation donned a prosthetic socket. The interface pressure was monitored and recorded while the participant walked on a treadmill for 10 min at 1.4 m/s. The results show peak pressure differences of almost 0.22 kgf/cm2 between the sockets. It was observed that the peak pressure occurred at 50% of the stance phase of the gait cycle. This SIFP system may be used by prosthetists, physical therapists, amputation care centers, and researchers, as well as government and private regulators requiring comparison and evaluation of prosthetic components, components under development, and testing.

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Relationship between socket pressure and EMG of two muscles in trans-femoral stumps during gait

Prosthetics and Orthotics International ◽

10.1080/03093640500116764 ◽

2005 ◽

Vol 29 (1) ◽

pp. 59-72 ◽

Cited By ~ 15

Author(s):

Jung Hwa Hong ◽

Mu Seong Mun

Keyword(s):

Muscle Activity ◽

Three Dimensional ◽

Rectus Femoris ◽

Biceps Femoris ◽

Interface Pressure ◽

Prosthetic Socket ◽

In Trans ◽

Pressure Changes ◽

Interface Pressures ◽

Socket Interface

The biomechanical interaction between the leg stump and the prosthetic socket is critical in achieving close-to-normal ambulation. Although many investigations have been performed to understand the biomechanics of trans-tibial sockets, few studies have measured the socket interface pressure for trans-femoral amputees. Furthermore, no report has examined how the residual muscle activities in the trans-femoral stump affect the socket interface pressure characteristics during gait. In this study, an experimental method was developed to measure the trans-femoral socket interface pressures and EMG of muscles in the stumps of two trans-femoral amputees. Also, the measurement of three-dimensional prosthetic locomotion was synchronized to understand detailed socket biomechanics. Based on the experimental results, a significant correlation ( P 50.05) was found between the measured temporal EMG amplitude and the interface pressure at the knee flexor (biceps femoris) and extensor (rectus femoris). Therefore, the residual muscle activity of a trans-femoral amputee's stump could be an important factor affecting socket-interface pressure changes during ambulation.

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An Interface Pressure Sensor for Routine Clinical Use

Engineering in Medicine ◽

10.1243/emed_jour_1980_009_038_02 ◽

1980 ◽

Vol 9 (3) ◽

pp. 151-156 ◽

Cited By ~ 8

Author(s):

J C Robertson ◽

J Shah ◽

H Amos ◽

J E Druett ◽

J Gisby

Keyword(s):

Blood Pressure ◽

Great Britain ◽

Pressure Sensor ◽

Pressure Measurement ◽

Pressure Sores ◽

Clinical Use ◽

Interface Pressure ◽

Tissue Viability ◽

Pneumatic Pressure ◽

Standard Instrument

The art of fitting the environment to the patient is sadly lacking. There are at least 24 000 patients in Great Britain suffering from pressure sores. The art will not improve until relevant parameters of tissue viability are measured routinely wherever patients are cared for. Disorders of temperature and blood pressure were not understood until standard measurements were widely taken. What are the relevant parameters for disorders of tissue viability? The authors single out pressure and movement, and note that pressure recorded with time will also monitor movement. They offer their flanged 28 mm electro-pneumatic pressure sensor as a possible standard instrument for most clinical purposes whether research or routine. The discussion covers the theoretical objections to interface pressure measurement, analyses the sources of error in their electro-pneumatic technique and compares its accuracy to that of other transducers.

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