Separating Technological and Clinical Safety Assurance for Medical Devices

TL;DR

This paper proposes a novel approach to medical device safety assurance by separating the safety validation of the device itself from its clinical use, simplifying complex assurance processes.

Contribution

It introduces the concept of separate, linked assurance cases for device safety and clinical effectiveness, enhancing clarity and manageability in safety assurance.

Findings

Separated assurance cases improve clarity in safety validation

Linked assurance cases address device safety and clinical effectiveness independently

Method applicable to high-risk medical systems like ultrasound and radiation therapy

Abstract

The safety and clinical effectiveness of medical devices are closely associated with their specific use in clinical treatments. Assuring safety and the desired clinical effectiveness is challenging. Different people may react differently to the same treatment due to variability in their physiology and genetics. Thus, we need to consider the outputs and behaviour of the device itself as well as the effect of using the device to treat a wide variety of patients. High-intensity focused ultrasound systems and radiation therapy machines are examples of systems in which this is a primary concern. Conventional monolithic assurance cases are complex, and this complexity affects our ability to address these concerns adequately. Based on the principle of separation of concerns, we propose separating the assurance of the use of these types of systems in clinical treatments into two linked assurance cases. The first assurance case demonstrates the safety of the manufacturer's device independent of the clinical treatment. The second demonstrates the safety and clinical effectiveness of the device when it is used in a specific clinical treatment. We introduce the idea of these separate assurance cases, and describe briefly how they are separated and linked.