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Detection of Prosthetic Knee Movement Phases via In-Socket Sensors: A Feasibility Study.

El-Sayed AM, Hamzaid NA, Tan KY, Abu Osman NA - ScientificWorldJournal (2015)

Bottom Line: In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand.FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states.In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Mechatronics Section, Mechanical Engineering Department, Faculty of Engineering, Assiut University, Assiut 71516, Egypt.

ABSTRACT
This paper presents an approach of identifying prosthetic knee movements through pattern recognition of mechanical responses at the internal socket's wall. A quadrilateral double socket was custom made and instrumented with two force sensing resistors (FSR) attached to specific anterior and posterior sites of the socket's wall. A second setup was established by attaching three piezoelectric sensors at the anterior distal, anterior proximal, and posterior sites. Gait cycle and locomotion movements such as stair ascent and sit to stand were adopted to characterize the validity of the technique. FSR and piezoelectric outputs were measured with reference to the knee angle during each phase. Piezoelectric sensors could identify the movement of midswing and terminal swing, pre-full standing, pull-up at gait, sit to stand, and stair ascent. In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand. FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states. The study highlighted the capacity of using in-socket sensors for knee movement identification. In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.

No MeSH data available.


FSR and piezoelectric sensors output during sit to stand movement: (a) FSR anterior, piezo anterior distal, and piezo anterior proximal sites, (b) FSR and piezoelectric sensors at posterior sites, (c) knee angle during stride, and (d) piezoelectric sensors with the knee angle at a region from 5% to 60%.
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Related In: Results  -  Collection


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fig8: FSR and piezoelectric sensors output during sit to stand movement: (a) FSR anterior, piezo anterior distal, and piezo anterior proximal sites, (b) FSR and piezoelectric sensors at posterior sites, (c) knee angle during stride, and (d) piezoelectric sensors with the knee angle at a region from 5% to 60%.

Mentions: Similarly, FSR and piezoelectric sensors were used to measure the dynamic variation inside the socket during sit to stand movement. Figure 8 illustrated the FSR output versus the complete stride during sit to stand. The knee angle shown as a reference (Figure 8(c)) at the start of the sitting position was about 90 degrees opposite to amplitude of 3 to 3.1 V from both anterior and posterior FSR. The knee angle increased to 130 degrees at 5% of the movement. However the output of FSRs decreased below the 3 V, due to the pressure decrease at both anterior/posterior sites compared to the sitting position. The knee angle increased gradually to 180 degrees and consequently the anterior/posterior FSR sensors decreased linearly to the minimum value of about 0 V. Linear decrease of the FSR can be interpreted due to the sudden change of the movement by the subject which started from the sitting position to about 60% of the full stride before the full standing. This is one of the limitations of the FSR during that movement that should be considered in the future applications.


Detection of Prosthetic Knee Movement Phases via In-Socket Sensors: A Feasibility Study.

El-Sayed AM, Hamzaid NA, Tan KY, Abu Osman NA - ScientificWorldJournal (2015)

FSR and piezoelectric sensors output during sit to stand movement: (a) FSR anterior, piezo anterior distal, and piezo anterior proximal sites, (b) FSR and piezoelectric sensors at posterior sites, (c) knee angle during stride, and (d) piezoelectric sensors with the knee angle at a region from 5% to 60%.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4402191&req=5

fig8: FSR and piezoelectric sensors output during sit to stand movement: (a) FSR anterior, piezo anterior distal, and piezo anterior proximal sites, (b) FSR and piezoelectric sensors at posterior sites, (c) knee angle during stride, and (d) piezoelectric sensors with the knee angle at a region from 5% to 60%.
Mentions: Similarly, FSR and piezoelectric sensors were used to measure the dynamic variation inside the socket during sit to stand movement. Figure 8 illustrated the FSR output versus the complete stride during sit to stand. The knee angle shown as a reference (Figure 8(c)) at the start of the sitting position was about 90 degrees opposite to amplitude of 3 to 3.1 V from both anterior and posterior FSR. The knee angle increased to 130 degrees at 5% of the movement. However the output of FSRs decreased below the 3 V, due to the pressure decrease at both anterior/posterior sites compared to the sitting position. The knee angle increased gradually to 180 degrees and consequently the anterior/posterior FSR sensors decreased linearly to the minimum value of about 0 V. Linear decrease of the FSR can be interpreted due to the sudden change of the movement by the subject which started from the sitting position to about 60% of the full stride before the full standing. This is one of the limitations of the FSR during that movement that should be considered in the future applications.

Bottom Line: In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand.FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states.In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Mechatronics Section, Mechanical Engineering Department, Faculty of Engineering, Assiut University, Assiut 71516, Egypt.

ABSTRACT
This paper presents an approach of identifying prosthetic knee movements through pattern recognition of mechanical responses at the internal socket's wall. A quadrilateral double socket was custom made and instrumented with two force sensing resistors (FSR) attached to specific anterior and posterior sites of the socket's wall. A second setup was established by attaching three piezoelectric sensors at the anterior distal, anterior proximal, and posterior sites. Gait cycle and locomotion movements such as stair ascent and sit to stand were adopted to characterize the validity of the technique. FSR and piezoelectric outputs were measured with reference to the knee angle during each phase. Piezoelectric sensors could identify the movement of midswing and terminal swing, pre-full standing, pull-up at gait, sit to stand, and stair ascent. In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand. FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states. The study highlighted the capacity of using in-socket sensors for knee movement identification. In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.

No MeSH data available.