INTEGRATOR

Typical Number in Hospital:

Cost Bands:

References: 9

This is basically an electronic circuit for calculating the product of input voltage and time. A steady input voltage will produce a slowly rising ramp of output, whereas a short pulse will cause a small rise with no further change until there is new input. Integrators are employed in electromyography (EMG) equipment to produce a voltage which will represent the electromyographic activity. The EMG signal is first rectified and then fed to the integrator. The integrator will of course reach a saturation voltage after a time and the usual way of dealing with this is to reset the integrator to zero and present a pulse on a separate recording channel or to a counter which will indicate the total activity which has occurred during the test procedure.

Integrating circuits are often used with a leak resistor to discharge the capacitor at a known rate. This is no longer a true integrator but an exponential averager as used in some cardiotachometers and other pulse rate meters.