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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.


Related in: MedlinePlus

(a) Anterior FSR placement during full stance phase; (b) posterior FSR placement during full stance phase; and (c) the individual performing full stance phase (heel strike, flat foot, and toe off) while wearing the FSR instrumented socket.
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fig4: (a) Anterior FSR placement during full stance phase; (b) posterior FSR placement during full stance phase; and (c) the individual performing full stance phase (heel strike, flat foot, and toe off) while wearing the FSR instrumented socket.

Mentions: A 29-year-old male, 75 kg, of height 182 cm transfemoral amputee who had been using an above knee prosthesis for the past 10 years, was recruited for this study. An informed written consent was attained from the subject as approved by the ethics committee of University Malaya Medical Centre. Two separate experiments with the same procedure were performed for each sensor, that is, FSR and piezoelectric sensors. In the first experiment, FSR sensors were attached at the regions of the quadrilateral double socket based on the subject's anatomical muscle position. The quadrilateral double socket was selected as it was the type of socket he had been using thus ensuring no compensatory gait deviations of using a new socket type. The sensors' wires were carefully secured and lengthened to ensure that the participant's movement was not affected. The amputee was fitted with the instrumented socket and knee prosthesis and was requested to perform five repetitions each of complete gait cycle, stair ascent, and sit to stand movements. The subject performed the stance phase of the gait cycle, that is, heel strike, flat foot, and toe off, as shown in Figure 4 for 5 repetitions. The subject was then requested to go for stair ascent by positioning his leg in a flexed position upon an elevated step of 250 mm height (Figure 5), afterwards applying a downward force upon instruction. Finally, the amputee performed sit to stand action. The subject initially sat on a chair and stood up upon instruction (Figure 6).


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)

(a) Anterior FSR placement during full stance phase; (b) posterior FSR placement during full stance phase; and (c) the individual performing full stance phase (heel strike, flat foot, and toe off) while wearing the FSR instrumented socket.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig4: (a) Anterior FSR placement during full stance phase; (b) posterior FSR placement during full stance phase; and (c) the individual performing full stance phase (heel strike, flat foot, and toe off) while wearing the FSR instrumented socket.
Mentions: A 29-year-old male, 75 kg, of height 182 cm transfemoral amputee who had been using an above knee prosthesis for the past 10 years, was recruited for this study. An informed written consent was attained from the subject as approved by the ethics committee of University Malaya Medical Centre. Two separate experiments with the same procedure were performed for each sensor, that is, FSR and piezoelectric sensors. In the first experiment, FSR sensors were attached at the regions of the quadrilateral double socket based on the subject's anatomical muscle position. The quadrilateral double socket was selected as it was the type of socket he had been using thus ensuring no compensatory gait deviations of using a new socket type. The sensors' wires were carefully secured and lengthened to ensure that the participant's movement was not affected. The amputee was fitted with the instrumented socket and knee prosthesis and was requested to perform five repetitions each of complete gait cycle, stair ascent, and sit to stand movements. The subject performed the stance phase of the gait cycle, that is, heel strike, flat foot, and toe off, as shown in Figure 4 for 5 repetitions. The subject was then requested to go for stair ascent by positioning his leg in a flexed position upon an elevated step of 250 mm height (Figure 5), afterwards applying a downward force upon instruction. Finally, the amputee performed sit to stand action. The subject initially sat on a chair and stood up upon instruction (Figure 6).

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.


Related in: MedlinePlus