Date of download: 6/1/2016 Copyright © ASME. All rights reserved. From: An Experimental Powered Lower Limb Prosthesis Using Proportional Myoelectric Control J. Med. Devices. 2014;8(2): doi: / The powered prosthesis in three different ankle positions. Two artificial muscles acted as dorsiflexors, and two artificial muscles acted as plantar flexors. The range of motion of the ankle with uninflated actuators was 25 deg of dorsiflexion and 35 deg of plantar flexion. The prosthetic socket was interchangeable so that the amputee's prescribed socket could be used. Standard stainless steel prosthetic components above the ankle and below the socket interface allowed for proper alignment. The ankle was a modified Rampro Swim Ankle (Rampro, Oceanside, CA). The foot was a modified Seattle LiteFoot (Trulife, Dublin, Ireland). Figure Legend:

Date of download: 6/1/2016 Copyright © ASME. All rights reserved. From: An Experimental Powered Lower Limb Prosthesis Using Proportional Myoelectric Control J. Med. Devices. 2014;8(2): doi: / Tension and length data from a pair of muscles during isometric benchtop testing at 20, 22, 24, 26.5, and 27.5 cm lengths and 25%, 50%, 75%, and 100% of maximum pressure (approximately 1.6, 3.1, 4.7, and 6.2 bar). The functional length of the artificial plantar flexor muscles during walking was 23.5–27.5 cm, which is approximately 85–100% of nominal length. We calculated he functional length as the range of muscle length measured during walking using three-dimensional kinematics. Figure Legend:

Date of download: 6/1/2016 Copyright © ASME. All rights reserved. From: An Experimental Powered Lower Limb Prosthesis Using Proportional Myoelectric Control J. Med. Devices. 2014;8(2): doi: / Force bandwidth and phase lag of a pair of pneumatic artificial muscles in an isometric benchtop configuration at nominal muscle length (27.5 cm). The input was a sinusoid signal with peak-to-peak amplitude of 10 V. Point characters on the plots show the frequencies that data were recorded. The bandwidth of the artificial muscles was 2.0 Hz. At 2.0 Hz, the output lags the input by 39 deg. Figure Legend:

Date of download: 6/1/2016 Copyright © ASME. All rights reserved. From: An Experimental Powered Lower Limb Prosthesis Using Proportional Myoelectric Control J. Med. Devices. 2014;8(2): doi: / Electromechanical response times of a pair of pneumatic artificial muscles in an isometric benchtop configuration at nominal muscle length (27.5 cm). The input signal was a 5 ms square pulse whose amplitude produced a control signal with a 10 V peak. Vertical lines indicate time points used to calculate electromechanical delay, time to peak tension, and half relaxation time. EMD was the time from the start of the square pulse to the onset of artificial muscle force development (three standard deviations above baseline force). TPT was the time from the onset of force development to when peak force was achieved. HRT was the time from peak force to when the force dropped 50% from peak force. Figure Legend:

Date of download: 6/1/2016 Copyright © ASME. All rights reserved. From: An Experimental Powered Lower Limb Prosthesis Using Proportional Myoelectric Control J. Med. Devices. 2014;8(2): doi: / Residual gastrocnemius EMG control signal during walking. Each plot shows ten consecutive strides at 1 min, 5 min, and 30 min of walking. Black lines show mean of ten strides. Shaded regions show ± two standard deviations. Horizontal lines show the 1.2 V offset to achieve the ankle set-point stiffness. Vertical lines show the average toe-off timing of ten strides. Figure Legend:

Date of download: 6/1/2016 Copyright © ASME. All rights reserved. From: An Experimental Powered Lower Limb Prosthesis Using Proportional Myoelectric Control J. Med. Devices. 2014;8(2): doi: / Comparison of ankle angle, ankle moment, and ankle power for prescribed and powered prosthesis. Ankle angles, moments, and powers were calculated from ten consecutive cycles. For the powered prosthesis, ten consecutive cycles starting at the 30 min time point were used. The proportional EMG control signal for these ten cycles is shown in Fig. 6. Outlined regions (intact side) and shaded regions (prosthetic side) show ± two standard deviations about the mean. Vertical lines show the average toe-off timing for intact and prosthetic sides. Figure Legend: