Body surface mapping unit for recording during coronary angioplasty

A low-noise multichannel recording system for simultaneously registering up to 256 ECG (electrocardiogram) signals in digital form is described. The unit's features include: patient isolation and radiolucent electrodes required for use during cardiac catheterization and angioplasty procedures; continuous data collection over several minutes; gain and sampling frequency under software control; and flexible, modular design. The mapping system consists of three physically separate units: the bedside unit, the controller and communications interface, and the computer. The method chosen to ensure adequate patient isolation and still maintain sufficient sensitivity and signal/noise characteristics is to isolate the entire input stage of the recording system and power it with rechargeable batteries.