Physical Computing – Midterm Project (TMG)

TMG (Telemyograph)

The underlying concept for the TMG is fairly simple; elaborating on previous investigations with EMG (electromyography), myself, Stepan Boltalin, and Johnny Lu decided to take the concept a step further… taking the reading function of the EMG and applying it to a write function. The medium being controlled: human muscle tissue.

Expanding the EMG circuit worked on previously by Ezer Longinus and myself we rewrote code making the EMG read more reliable and stable. This signal was used to drive an optoisolator (an LED coupled with a photo sensor) which in turn regulated the output from our muscle stimulator. This signal pathway proved on a somewhat crude level that muscle activity read from one location (person A) and could be transmitted to a second location (person B) and in effect “written” into a similar action by corresponding placement of electrodes.

Seen here is some energetic footage of our initial TMG test.

One concept that interested us though yet to be explored is the idea of gestural recording or sampling; so that a muscle action could be stored and then actuated or played back at a later time on the same or different individual… or machine analog. While these concepts seem beyond the level resolution capable with our current hardware they could prove to be theoretically illustrative within the emerging notion of machines in the service of humans and humans in the service of machines in the service of humans… or how machines may never be capable of human emulation without a little machine emulation on our side. See this project underway at Microsoft.

While we are still developing our own muscle stimulator we couldn’t get it functional in time for our presentation and sadly had to turn to a pre-made Trans-cuntaneous-electrical-nerve-stimulator… also known as a “TENS Unit”… which does work but is far less satisfying.

Our muscle stimulation circuit was met with complication and has proved to be inadequate so far:

Some results but not enough power

Don’t worry… the only thing attached to this while running off the bench-top was the oscilloscope.

Some serious bread boarding

Our second circuit and the second time bread boarding it.

We will eventually perfect our stimulator and EMG boards and be able to produce a small number for multiple electrode mapping. Below are some pictures of our prototyping and PCB’s in process: