Abstract: Changes in the volume of residual limbs on which prosthetic sockets are worn can be measured based on bioimpedance measurements along one or more segments of the limb. A current at an appropriate frequency (e.g., in the range from 1 kHz to 1 MHz) is injected at two current electrodes that contact the skin of the residual limb. The voltage at the voltage electrodes disposed between the current electrodes is measured and using an appropriate model, the change in the segmented volume of the limb can be determined during periods of different activity and at different times during the day. This information can be used for assessing the fit of the socket and can also provide a feedback signal for automatically controlling volume management devices, to ensure a more comfortable fit when the volume of the limb is changing.

Abstract: Changes in the volume of residual limbs on which prosthetic sockets are worn can be measured based on bioimpedance measurements along one or more segments of the limb. A current at an appropriate frequency (e.g., in the range from 1 kHz to 1 MHz) is injected at two current electrodes that contact the skin of the residual limb. The voltage at the voltage electrodes disposed between the current electrodes is measured and using an appropriate model, the change in the segmented volume of the limb can be determined during periods of different activity and at different times during the day. This information can be used for assessing the fit of the socket and can also provide a feedback signal for automatically controlling volume management devices, to ensure a more comfortable fit when the volume of the limb is changing.

Abstract: Changes in the volume of residual limbs on which prosthetic sockets are worn can be measured based on bioimpedance measurements along one or more segments of the limb. A current at an appropriate frequency (e.g., in the range from 1 kHz to 1 MHz) is injected at two current electrodes that contact the skin of the residual limb. The voltage at the voltage electrodes disposed between the current electrodes is measured and using an appropriate model, the change in the segmented volume of the limb can be determined during periods of different activity and at different times during the day. This information can be used for assessing the fit of the socket and can also provide a feedback signal for automatically controlling volume management devices, to ensure a more comfortable fit when the volume of the limb is changing.

Abstract: Changes in the volume of residual limbs on which prosthetic sockets are worn can be measured based on bioimpedance measurements along one or more segments of the limb. A current at an appropriate frequency (e.g., in the range from 1 kHz to 1 MHz) is injected at two current electrodes that contact the skin of the residual limb. The voltage at the voltage electrodes disposed between the current electrodes is measured and using an appropriate model, the change in the segmented volume of the limb can be determined during periods of different activity and at different times during the day. This information can be used for assessing the fit of the socket and can also provide a feedback signal for automatically controlling volume management devices, to ensure a more comfortable fit when the volume of the limb is changing.

Abstract: An approach is described for identifying sites of imminent skin breakdown in amputee prosthesis users. Thermal recovery time (TRT) for a limb is optically determined using an infrared camera. TRT is the time interval for the temperature of the skin to achieve 70% of its maximum value during a 10-minute recovery period after a subject has completed a standing/walk-in-place procedure. A limb tolerance map is produced in which 5×5 pixel squares are colored to indicate their TRT and labeled to indicate a temperature vs. time curve (indicative of blood flow characteristics) for the square. TRT data can also be used for prosthetic fitting and socket replacement, by locating tolerant/intolerant regions on a limb and providing a visual “limb tolerance map” for a proposed socket design and applied to other areas, such as the design of shoes for patients with insensate feet, cushions for wheelchair users, and mattresses for bedridden patients.