Question

The transducer required for recording these movements in apexcardiograph is similar to the electrocardiograph.

(a) True

(b) False

This question was addressed to me during an interview.

My doubt stems from Catheterization Laboratory Instrumentation topic in portion Patient Monitoring System of Biomedical Instrumentation

Answer 1

Correct answer is (b) False

For explanation: False, The transducer required for recording these movements in apexcardiograph is similar to that employed for a phonocardiograph (PCG) but which has a frequency response much below the audio range. It can be an aircoupled microphone or a contact microphone. They are further categorized into crystal type or dynamic type based on their principle of operation. The crystal microphone contains a wafer of piezo-electric material, which generates potentials when subjected to mechanical stresses due to heart sounds. The dynamic type microphone consists of a moving coil having a fixed magnetic core inside it. The coil moves with the heart sounds and produces a voltage because of its interaction with the magnetic flux.