A comparative experimental study of fetal phono- and movement-sensors from Amsterdam, Cambridge and Edinburgh.

This paper describes the experimental studies and results of a collaborative investigation between three European institutes: Amsterdam, Cambridge and Edinburgh. The object of this investigation and the collaborative exchanges was to evaluate and compare different sensors for recording fetal sounds and movements from each centre. This would be carried out in a series of experimental and clinical tests involving researchers from each of the European institutes, and using three sensors: one from each centre. Experimental measurements have been performed regarding the conversion gain, frequency response, equivalent input noise and dynamic range of the transducers. The measurements were carried out using a vibration-free table testing rig to evaluate these characteristics of each of the sensors. The equivalent input noise ranged from 50 nm to 1600 nm for the transducers studied.