Features for a prosthetic wrist and associated methods are described. The wrist couples with a prosthetic socket and a prosthetic hand. The wrist may rotate the hand. The wrist includes features to prevent or mitigate undesirable separation of the wrist from the socket. The wrist may have an expanding coupling, such as an expanding ring, to better secure the wrist with the socket. An actuator may cause the coupling to expand outward to prevent or mitigate undesirable separation of the wrist from the socket. Alternatively or in addition, the wrist may include torque control features to prevent undesirable or premature separation of the hand from the wrist, for example when using a “quick wrist disconnect” (QWD) apparatus. A torque control method may tailor or limit multiple torques to be applied by the wrist to the hand based on operational requirements and phases, such as anticipated torque loads and operational timing.

A system and method for a compliant four-bar linkage mechanism for a robotic finger that includes: a monolithic bone structure comprised of a compliant joint region and an input link segment and a coupler link segment, wherein the input link segment and the coupler link segment are connected through the compliant joint; an output link; a ground structure; wherein the monolithic bone structure, output link, and ground structure are connected through a set of joints in a configuration of a compliant four-bar linkage mechanism which comprises: the output link on a first end and the coupler link segment connected through an output joint, the output link on a second end connected to a ground joint on the ground structure, and the monolithic bone structure connected to an input joint connected to the ground structure; and an actuation input coupled to the input joint.

Prosthetic hand (1) with a wrist (13) and provided with a hand palm (2) and fingers (4) attached to the hand palm (2), wherein the hand palm (2) and fingers (4) comprise bars (5) and joints (6) connecting the bars (5) forming a construction (7) supported by the wrist (13), wherein said bars (5) occupy a position with reference to each other de-pending on an external load applied to the construction (7), wherein a reaction force for said load applied to the construction (7) is provided by or through the wrist (13), and wherein the construction (7) has an unloaded position wherein the fingers (4) are stretched and a plurality of loaded positions corresponding to loads applied to an inner side of the hand (1) wherein the construction (7) is deflected from the unloaded position wherein the fingers (4) are stretched into a series of loaded positions in which the fingers (4) are flexed into increasingly bonded positions so as to eventually close the hand (1), and that said construction (7) is provided with a locking mechanism (9) to lock the construction (7) in one of the plurality of loaded positions.

This disclosure provides systems, apparatuses, and devices for a powered prosthetic digit. The disclosed devices restore prehension in a person with missing fingers or thumb by providing motor-driven extension and flexion, and opposition to forces in the extension direction via a pawl and locking rack ratchet mechanism, thereby allowing an individual to manipulate or stabilize objects. In one embodiment, a digit comprises a base configured to be removably couplable to an anchor, a first segment pivotably coupled to the base, and a second segment removably coupled to the first segment. The first segment comprises a rack with a plurality of rack teeth and a pawl with a nose configured to engage with the rack to prevent pivoting of the first segment in a rotational direction corresponding to extension of the prosthetic digit. The second segment comprises a drive gear operable to pivot the first segment with respect to the base.

An under-driven prosthetic hand with a self-adaptive grasping function is provided, which belongs to the field of medical equipment. The prosthetic hand simultaneously controls four fingers to implement bending and stretching movements by a first motor through structural designs of a prosthetic hand body, a finger transmission module, an inter-finger transmission module, and a thumb driving module, and limits the transmission torque between the motor and screws using a damping shaft and in cooperation with the telescopic characteristic of a telescopic component. On the one hand, mechanical damage to the prosthetic hand structure due to excessive torque outputted by the motor can be prevented. On the other hand, the self-adaptive grasping function of the prosthetic hand can be implemented. The disclosure can also effectively solve issues such as excessive volume or mass of the prosthetic hand, complicated control system, and low operation precision.

The invention discloses a bionic wrist joint based on an asymmetric 3-RRR parallel mechanism, including: an asymmetric 3-RRR parallel mechanism and a drive unit. The asymmetric 3-RRR parallel mechanism includes: a moving platform, a first static platform, and three asymmetrically distributed parallel branch chains, wherein each branch chain includes a passive rod and an active rod. An end of the active rod is connected to the first static platform via the revolute pair, and another end thereof is connected to the passive rod via the revolute pair. The axes of the revolute pairs at two ends of the active rod form an axis included angle. Three axis included angles are different, the passive rod and the moving platform are connected by the revolute pair, and three axis included angles corresponding to the passive rods are different. The drive unit is configured to drive the asymmetric 3-RRR parallel mechanism to move.

Technology is described to provide a powered prosthetic wrist flexion device or elbow device. This device helps individuals with upper-limb loss to orient and position grasped objects.

Powered limb prostheses with multi-stage transmissions are provided.

Features for a powered prosthetic thumb are described. The thumb provides for rotation of a digit that mimics the natural movement possible with a sound thumb. The thumb may attach to a full or partial prosthetic hand or socket on a residual limb. The thumb may include an upper assembly, including a prosthetic thumb digit, rotatably attached to a mount about a pinch axis and a lateral axis. The digit may rotate about only the pinch axis, only the lateral axis, or both the pinch and lateral axes simultaneously. A first actuator may actuate to cause rotation of the digit about the pinch axis. A second actuator may actuate to cause rotation of the digit about the lateral axis. The first and second actuators may be actuated together at appropriate speeds to cause rotation about both the pinch and lateral axes simultaneously. A swaying chassis may be rotatably connected with the upper assembly and a lower assembly about various offset axes to provide for rotation about the lateral axis.

A system for powering a prosthetic arm is disclosed. The system includes at least one internal battery located in the prosthetic arm, at least one external battery connected to the prosthetic arm, and a master controller configured to connect either the at least one internal battery or the at least one external battery to a power bus to power the prosthetic arm.