PC based instrumentation as an economic method for quality assurance-an experience based on development of hydrocephalus shunt test system

A PC based system is an attractive alternative to conventional methods of industrial quality assurance for its high reliability at lower cost. A custom assembled system with user friendly software is ideal for industries, especially when the quantity requirement is small. This concept is illustrated with an example of the development of a PC based test system for the quality assurance of hydrocephalus shunt-a neurosurgical implant. During the technology transfer of the device, a 16 channel PC controlled test system has been developed for classifying the device according to their pressure-flow characteristics. Here, the speed of the multichannel peristaltic pump is controlled for various flow rates ranging from 5 ml/hour to 50 ml/hour and the corresponding pressure drop sensed by the transducer is amplified, digitized and monitored. Depending on the measured values, the software classifies all the accepted devices in appropriate ranges and rejects the rest. The test results are printed out in proper format. All the subsystems and components used are in modular form and are standard products of leading manufacturers, enabling the user industry to operate and maintain the system without the help of the developer.