Design and Implementation of Arch Function for Adaptive Multi-Finger Prosthetic Hand

Abstract

Although arch motions of the palm substantially contribute to frequent hand grasping, they are usually neglected in the development of prosthetic hands which focuses on digit movements. We designed the arch function for its implementation on an adaptive multi-finger prosthetic hand. The digits from the developed hand can perform adaptive grasping, and two carpometacarpal joints enable the palm of the prosthetic hand to form an arch with the thumb. Moreover, the arch posture can be passively released, mimicking the human hand switching between sphere and medium wrap grasps according to the situation. Other requirements such as weight, cost, and size limitations for hand prostheses were also considered. As a result, we only used three actuators fully embedded in the palm through a novel tendon-driven transmission. Although the prosthetic hand is almost the same size of an adult hand, it weighs only 146 g and can perform 70% of the 10 most frequent grasps.

Development of Multifunctional Myoelectric Hand Prosthesis System with Easy and Effective Mode Change Control Method Based on the Thumb Position and State

“…In this study, two EMG sensors were installed on the extensor carpi radialis on the lateral side and on the flexor carpi ulnaris on the medial side. (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) shows that upon receiving an EMG CC signal, the hand changed from the grip motion state to the gesture motion state. At this time, because HS1 was higher than HS2, the hand was in the abduction state.…”

“…However, it cannot execute the same range of motions as that executed by human hands because it has less than two degrees of freedom (DOFs), owing to the use of just one actuator. Recently, multiple-degrees-of-freedom (multi-DOF) myoelectric hand prostheses with four or more embedded actuators in the finger phalange or palm have been developed [3][4][5][6][7]. These hands can perform various hand gestures and grip motions in a manner that is similar 2 of 13 to the human hand owing to their additional DOFs.…”

“…Figure 9(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) shows that upon receiving an EMG CC signal, the hand changed from the grip motion state to the gesture motion state. At this time, because HS1 was higher than HS2, the hand was in the abduction state.…”

Highly Anthropomorphic Finger Design With a Novel Friction Clutch for Achieving Human-Like Reach-and-Grasp Movements

“…Kamper et al pointed out that finger motions remained highly consistent across reaching trials with varying objects in a natural manner, both within a given subject and among different subjects, regardless of how the initial finger posture changed [30]. Remarkably, thanks to this consistency, our brain can reduce the control complexity [31], [32] and avoid uncertainty in multi-joint motion during reaching, which improves grasping stability as well as success rate in advance [28], [33], [34]. Moreover, the consistency can help users operate prosthetics more naturally in practical use.…”

“…In the design of prosthetic hands, achieving natural finger movement to enable grasp functionality is quite importance and has been extensively studied [19], [25]- [28], as it directly relates to the activities of daily living (ADLs) [29]. Essentially, the natural reach-and-grasp task involves two distinct stages: reaching and grasping.…”