Lessons we Have Learnt on the Stages of an A-Mode Us Prosthetic Control Interface

The research and development of Ultrasound (US) interfaces for prosthetic hand control has seen an increase in the past few years. Among the reasons for this rise is the capacity of easy detection of the state of deep muscles that are almost invisible to the standard electromyography. The two main modes of Ultrasound operation for this task are Amplitude mode (A-mode) and Brightness mode (B-mode). While B-mode can accurately represent the tissue state (as a 2D image of the forearm section), due to its bulkiness and greater computational costs, the application of A-mode for sonomyography is increasing (which results in vectorized data along the intersecting line of each individual transducers). In contrast to B-mode systems, a multichannel A-mode US system can be built from roughly a half dozen ICs and its size could be as small as a couple of coins, perfect for wearable applications. This paper explores which are these required ICs, what design considerations should be taken when choosing them and what are the test setups one could use to individually test each component.