Development and evaluation of a portable automatic test system for clinical use

The intensifying development of biomedical instrumentation is having a major impact on the delivery of health care. All of the diagnostic, monitoring and theraputic equipment within a hospital must be inspected.on a regular bases to insure proper operation and patient safety. In this project an automatic test system was configured to accomplish automatic performance testing of selected medical equipment. Much work by others has been done to automate the scheduling of inspections, the generation of inspection forms and the storing of test results. The emphasis here is to automate the actual test process. The test system eliminates the necessity for the reading of test procedures, logging of test results, manual calculations and the checking of test values obtained against published tolerances. The system was required to be portable, economical, easy to operate and reconfigerable for testing a variety of clinical equipment.

The developed system consisted of a Hewlett-Packard Model 41C programmable calculator with printer and mass storage device on a digital interface loop. A general purpose multimeter and special interface device were also connected to the loop. Dedicated test interface devices and complete software programs were developed for testing a Travenol Model BW-5 blood warmer and a IMED Model 960 infusion pump. In addition, general formats and routines were developed which would facilitate producing test programs for other devices.

Four biomedical equipment technicians and the author performed eighteen final test trials using the system. Several major conclusions were drawn from the system development. First, the $3,000 hardware cost is negligible compared to engineering time required for program development. Secondly, the increase in reliability and thoroughness in performance inspections is offset by a corresponding increase in test time. Thirdly, portability and modularity in the system was achieved but at the expense of operational ease. Finally, the major advantage associated with the use of the automatic system is the required rigorous application of specifications and procedures while testing clinical equipment.