Sensing system and method for motion-controlled foot unit

A system for sensing a rotational movement of a device associated with a limb, the system comprising:

• a foot unit;
• an attachment member having an upper end and a lower end;
• a pivot assembly rotatably coupling the lower end of the attachment member to the foot unit to allow for rotation of the foot unit about an axis extending through the pivot assembly, wherein the pivot assembly is configured to substantially mimic a natural ankle joint;
• an actuator operatively coupled to the foot unit and to the attachment member, wherein the actuator is configured to actively adjust an angle between the foot unit and the attachment member;
• and
• a sensor assembly coupled to the pivot assembly and configured to detect the rotation of the foot unit about the axis and to substantially neglect axial and radial movement of the foot unit with respect to the axis, wherein the sensor assembly further comprises,
• a potentiometer, and
• an elongated bellow portion coupled to the potentiometer, wherein the elongated bellow portion substantially extends along the axis.

A system for sensing a rotational movement of a device associated with a lower limb, the system comprising:

• a foot means for contacting a ground surface;
• a means for attaching the foot means to a patient;
• a means for pivotably coupling the foot means to a lower end of the means for attaching to allow for rotation of the foot means about an axis extending through the means for pivotably coupling, wherein the means for pivotably coupling substantially mimics an ankle joint;
• means for actively adjusting, about the means for pivotably coupling, an angle between the foot means and the means for attaching;
• and
• a means for sensing coupled to the means for pivotably coupling, the means for sensing further configured to detect the rotation of the foot means about the axis and to substantially neglect axial and radial movement of the foot means with respect to the axis, wherein the means for sensing further comprises,
• a potentiometer, and
• an elongated bellow portion coupled to the potentiometer, wherein the elongated bellow portion is configured to restrict movement of the foot means to rotation about the axis.