Hand exerciser
AssigneeDanninger Medical Technology, Inc.
InventorsJan B. Yates, Lawrence M. Lubbers
Life of this patent
Estimating the term…
Abstract
A device for exercising an articulated limb such as a finger includes an elastomeric element for biasing the finger to a flexed position and a motorcontrolled cable is provided to oppose the flexion bias. The elastomeric element, motor, and cable are carried on the arm by a splint. A feed mechanism is provided for regulating the length of cable, which in turn regulates the degree of flexion and extension. The feed mechanism includes a motor having an automatic mode which continuously reverses motor operation when programmed flexion and extension limits are reached. An overtravel is provided to maintain a constant tension on the cable should a sudden extension of the finger prevent proper cable feed or take-up.
Claims11
A device for passively exercising a digit of a human limb comprising:
- an elastic element biasing the digit towards a first position and drive means for selectively moving the digit between the first position and a second position by applying a force to the digit substantially opposing the bias of the elastic element;
- the drive means comprising a cable operatively connected to the digit to a drum driven by a reversible motor;
- and
- overtravel means for maintaining a relatively constant tension on the cable independently of the rate of the motor, the overtravel means comprising a drive wheel rotatable with respect to the drum and operably coupled to the motor and the drum, the drive wheel permitting the drum to rotate in a first direction as the elastic element applies a tension to the cable when the motor rotates the drive wheel in said first direction and the drum is inhibited from rotating in the first direction other than when the motor rotates the drive wheel in the first direction, and the drive wheel rotating the drum in a second opposite direction when the motor rotates the drive wheel in a second opposite direction;
- and said overtravel means further comprising a means for biasing said drum in said second opposite direction against the bias of the elastic element so as to maintain a constant tension on the cable should a sudden movement of the digit occur in said first or second direction.
A portable cable feed mechanism for use with a continuous passive motion device to cause continuous passive motion of a digit on a human limb comprising:
- a flexible cable attached at a first end to the digit;
- a housing including a rotatable drum mounted within said housing, the cable being operatively connected to the drum at a second end such that rotation of the drum in a first direction unwinds the cable to extend cable, and rotation of the drum in a second direction winds the cable about the drum to retract cable, said drum having means for biasing the drum to rotate in the second direction;
- a drive wheel operably associated with drive wheel motor means and mounted in said housing in coaxial relationship with the drum to form two rotational members, the drive wheel being operatively connected to the drum to drive the drum and having overtravel means which allows independent operation of the drum and the drive wheel motor means;
- said overtravel means operably associated with the drum for maintaining a relatively constant tension on said cable independently of the rate of travel of the drive wheel, the overtravel means comprising a slot on one of the two rotational members, the slot providing two detent edges, the other rotational member including a pin which engages the slot and further engaging one of the detent edges when the rotational members rotate coincidentally, and the pin sliding along the slot as a result of said drum biasing means when one rotational member rotates at a rate of rotation which varies from the rate of the other rotational member so that the cable is subjected to at least a minimum tension.
Dependencies are inferred from the claim text.