The purpose of shielding is to provide a low resistance path to ground for any interference, how/what factor am i looking for in order to check integrity of the cable shielding? For example if i wanted to check how well the integrity of the shielding of an ECG cable.

 

how/what factor am i looking for in order to check integrity of the cable shielding?

An Ohm meter set to Ohm's?

 

A comm radio, such as a walkie-talkie, will transmit frequencies that might manifest as noise in an unshielded cable. You may test the integrity of your shielded cable by transmitting an audio signal through it as you set the comm radio to transmit, and see how it's being affected. Or you could use an oscilloscope if you want to get fancy.