2005 Annual Scientific Meeting - CLICK FOR PROGRAMME

Evaluating TCI systems for the NHS

Craig Davey, Teresa Dunn, Matthew Lipson

Bath Institute of Medical Engineering

Introduction

The NHS Purchasing and Supply Agency’s Centre for Evidence-based Purchasing (CEP) is undertaking an evaluation of the systems available for delivery of anaesthetic drugs by target controlled infusion (TCI). Three pumps using the Diprifusor module and one ‘Open TCI’ pump have been evaluated according to newly established protocols. Evaluation is underway on another open TCI system, and a third will be evaluated soon after it is released in 2006.

Methods

Evaluation of a pump or system entails:

·   technical performance testing to assess the accuracy of TCI delivery for a range of clinical cases

·   testing of the alarm systems

·   usability testing to assess ease of interaction with the pump to achieve clinically realistic goals [1]

·   surveying of a broad range of UK based anaesthetists to assess user satisfaction.

Results

The evaluated pumps have all performed TCI deliveries with a high degree of accuracy and have alarm characteristics that would be expected for a modern critical care syringe pump. They differ in the nature of the usability problems uncovered, though the spread of minor and major usability problems has been broadly the same for each pump. The open TCI pump evaluated showed a greater number of usability problems than the Diprifusor pumps. Surveys of users show an overall high degree of satisfaction with the pumps generally, with specific complaints and suggestions both for individual devices and for TCI generally.

Discussion

BIME testing has so far revealed that accurate reliable performance is likely from all TCI devices, but that usability varies from device to device. Device selection should be based on ensuring:

·         sufficient functionality to meet the requirements of the users

·         adequate usability to enable the available features to be used safely, with the anaesthetist in full control of the infusion.

The higher number of usability problems highlighted for the open TCI pump relate at least in part to the greater functionality of the device.

Acknowledgements

BIME is grateful to the NHS PASA Centre for Evidence-based Purchasing for funding our independent evaluation work.

References

1.       Zhang J, Johnson TR, Patel VL, Paige DL, Kubose T. Using usability heuristics to evaluate patient safety of medical devices. J.Biomed.Inform. 2003; 36: 23-30.