【Prosthetic Hands】09 Second Generation - New Ideas and Attempts

 In the development of the new generation of prosthetic hand, I made some changes. These changes were based on the practical part.

1. Use EMG electrodes instead of ready-made commercial device

The idea was quite simple. The commercial device, MYO armband, has its limits, which further restrained the number of recognizable classes. In this generation, I tried to use two sets of electrodes to acquire muscle EMG signals and use MATLAB to categorize them.

2. Relocate the actuators and choose ones with larger torque so that the length can be reduced and the grasping strength can be increased.

The actuators used only generated less than 2.0 kg-cm torque output, while the new ones, despite their larger size, could reach 15 kg-cm torque output. Also, due to the changes in sizes and the goal to shorten the forearm part, I reduced the number of the actuators to 6. The reduced actuators meant less active DoF, which I compensated through the "double 8-shaped wiring". (I will introduce it in the following articles)

3. Redesign the hand to increase the structural integrity

I adapted larger finger design and fortified joint connection to avoid the hand breaking when lifting heavy objects.

In the next article, I will talk more about the acquisition of the EMG signals through independent electrodes and how I managed to categorize them into usable classes.