Project Hodgkin

Full stack showing both boards in their relative positions. Long light pipes will be used to get the light from the bottom board's LEDs to the surface, and short light pipes from the top board will keep a uniform external appearance.

The shortest distance between any component on the lower (isolated) board to any component on the upper (unisolated) board is around 8.5mm, a bit beyond the 8mm creepage distance required by IEC 60601.
3D render of the Project Hodgkin PCBs. Click for detailed view and description.

Since 2015, The Shoulders of Giants has offered its flagship summer program, the Summer Biomedical Engineering Experience (SBEE) to high school students interested in exploring careers in biomedical engineering and related medical sciences. The original contents of the program were 60 hours of rigorous curriculum covering biomedical electronics, mechanical CAD and 3D printing, and microcontroller programming. Through this program, nearly 400 students have designed and built their own electromyograph (EMG) controlled prosthetic hands.

In SBEE 2020, we will be rolling out an all-new curriculum focused on the signals of the human cardiovascular system, including the photoplethysmograph (PPG) and electrocardiograph (ECG). The ECG is a particular safety concern, as it must involve an electrical pathway across the patient’s heart in order to function. This can safely be performed via a low-voltage battery powered circuit, but connecting the circuit to a computer via a microcontroller for acquisition, visualization, or signal processing exposes the user to a major safety concern in the event of a PC power supply failure or power surge. Although such an event is unlikely, it is not a risk we can take, particularly with students’ safety on the line. That is why our microcontroller development board will be built to satisfy the electrical safety requirements of 4000 VAC isolation and 8mm of creepage distance between the isolated / unisolated portions of the circuit, as laid out in the IEC 60601 electrical safety standard for medical devices.

GitHub Repository:

https://github.com/floating-point-laboratories/hodgkin

Other Helpful Links:

Initial /r/opensource post.

Follow-up /r/opensource post.