This project describes an analog laboratory EKG pre-amplifier for a chart recorder. This pre-amp can also be used to visualize EKGs on an oscilloscope.

This project was based off of a laboratory amplifier for an electrophysiology course. For background information on basic cardio-electrophysiology, check out Course 6.022J on MIT OpenCourseWare.

The EKG pre-amplifier unit consists of one differential amplifier (Gain = 1000) and three single-ended amplifiers with adjustable offset (Gain = 10). It is battery powered with an on/off switch and power supply indicator LEDs. The input connectors are binding posts: the intent is that electrode leads for the measurement are connected to the inputs (V+, V-, V_REF) and DC_1, DC_2, DC_3. The output connectors are BNCs. The offset voltages for the three DC/single-ended amplifiers are independently adjustable (rail-to-rail) via three potentiometers.

If you're looking to explore basic EKG and issues of signal offset, this is a good circuit to start with.

Where Do I Start?¶

For a description of how the circuit works, go over to the Wiki tab.

To download all of the Design Files, and Engineering Files go over to the Documents tab.

If you'd like to see the list of things that still need work on this project, look at the Issues tab.

If you want to audit the activity on this project (put on your project management hat, because this action item is open) - go to the Activity tab.

Enjoy!

--w0z