Warnings

The ECG device is intended only as a design research project; it is NOT a medical device and it is not intended to be used to diagnose or treat any conditions.

Use ONLY battery (max voltage supply: 9V).

The author cannot be responsible for any harm caused by using any of the circuits or procedures here described The author does not claim any of the circuits or procedures are safe. Use at your own risk. It is imperative that anyone who wants to build this device has a good understanding of using electricity in a safe and controlled manner.

The ECG device is electrically connected to a person and only low voltage batteries must be used for safety precautions and to prevent damage to the device.

DO NOT use any AC power supply, any transformer or any other voltage supply to avoid serious injury and electrical shock to yourself or others. DO NOT connect any AC-line powered instrumentation or device to the ECG device here proposed.

Placement of the electrodes on the body, provides an excellent path for current flow. When the body is connected to any electronic device, you must be very careful since it can cause a serious and even fatal electric shock.

In the new EcgSmartApp version, the hardware includes the AD8232 module that uses a Right Leg Driver (RLD) to reduce common-mode interference. As specified in the AD8232 component datasheet, “Note that when using this amplifier to drive an electrode, there should be a resistor in series with the output to limit the current to be always less than 10uA even in fault conditions”. Off the shelf AD8232 modules usually uses a 360 kOhm resistor in series with the RLD output since its supply is 3.3V. To power the Arduino Nano board at least a 6V battery is needed (7V is the value recommended by Arduino), so to keep the RLD current limit lower than 10 uA, a higher resistor is needed. See assembly manual for more details.