HW/SW Framework for Improving the Safety of Implantable and Wearable Medical Devices

TL;DR

This paper proposes a hardware/software framework that monitors both physiological and device internal states of implantable and wearable medical devices to detect unsafe operations, enhancing safety amidst security threats, malfunctions, and user errors.

Contribution

The work introduces a novel HW/SW safety framework with rule checking for IWMDs, demonstrated through a prototype for an artificial pancreas with wireless connectivity.

Findings

Effective safety monitoring with modest overheads

Detection of unsafe operations triggered by errors or attacks

Prototype validation shows improved safety measures

Abstract

Implantable and wearable medical devices (IWMDs) are widely used for the monitoring and therapy of an increasing range of medical conditions. Improvements in medical devices, enabled by advances in low-power processors, more complex firmware, and wireless connectivity, have greatly improved therapeutic outcomes and patients' quality-of-life. However, security attacks, malfunctions and sometimes user errors have raised great concerns regarding the safety of IWMDs. In this work, we present a HW/SW (Hardware/Software) framework for improving the safety of IWMDs, wherein a set of safety rules and a rule check mechanism are used to monitor both the extrinsic state (the patient's physiological parameters sensed by the IWMD) and the internal state of the IWMD (I/O activities of the microcontroller) to infer unsafe operations that may be triggered by user errors, software bugs, or security attacks. We discuss how this approach can be realized in the context of a artificial pancreas with wireless connectivity and implement a prototype to demonstrate its effectiveness in improving safety at modest overheads.