Consideration of the Human Factor in the Design and Development of a New Medical Device: Example of a Device to Assist Manual Ventilation

摘要

The human factor is often critical in the performance and safety of a large number of medical devices. To minimize risks to users and patients, health authorities have reinforced their requirements including human factors and usability testing during the development of new technologies. Human factors engineering (HFE) is an interdisciplinary approach to evaluating and improving use safety, efficiency, and robustness of work systems. The new device should be tested to show its safety and effectiveness for the intended users, uses and use environments. In order to fulfill these regulatory requirements, international standards suggest implementing the User Centered Design process during the technology design and development lifecycle. We would like to present here a case study of a HFE plan about an ongoing medical device development in order to illustrate how to practically process; then we will present some more general considerations on HFE development for medical devices. Manual ventilation is an essential step in the resuscitation of respiratory distressed patients. It must be carried out adequately so as not to worsen patient's condition. This technique has its advantages but also risks such as excessive insufflated pressures resulting in pulmonary barotrauma and gastric insufflation. In fact, many studies have shown that manual ventilation practices are far above recommended guidelines. Several solutions have been proposed by some manufacturers to achieve better control over manual ventilation parameters, but none has really convinced the medical community to date. Thus we propose to develop a new technology guided by a well adapted HFE. We first carried out a study with the existing material to observe the practices of 140 professionals in several clinical situations on an artificial lung, allowing to reproduce situations of respiratory deficiency and to record the parameters. The preliminary results showed a fairly low rate of manual ventilation performance with high ventilation rates, confirming the fragmented data of the literature on the subject. Thus, with the help of a local company, Polycaptil, we developed a new medical device, with an algorithm for real-time analysis on the basis of the 54,000 ventilatory cycles recorded during our study. After the prototype reached the technical objectives and demonstrated good reliability, we organized a usability validation test with 40 end-users. After the ventilation tests, participants were asked to complete a survey on the ease of use of the prototype, including the ergonomics of the entire system, the human-machine interface and its main functions. Both usability surveys provided important guidance for the development of the final device. Finally, the human factors validation testing should be realized during a prospective clinical trial of the first use in humans of a device for monitoring manual ventilation. The human factor is one of the most differentiating characteristics of the development of a medical device compared to the development plan of a drug. Specific methodologies are being developed and adapted tools have been set up. Based on our example, methods and purposes of HFE evaluation will be described at every stage of the device development lifecycle in order to sensitizing designers of new technologies.