Malicious behavior monitoring of embedded medical devices

Abstract

This research paper proposes and analyzes a hardware based specification rules approach for detecting malicious behaviors of sensors and actuators embedded in medical devices in which the safety of the patient is critical and of utmost importance. The study includes four types of medical devices, namely the Vital Sign Monitor (VSM), Patient Analgesic Control (PCA), Cardiac Device (CD), and Continuous Glucose Monitor (CGM) devices. The research is based on a methodology that transforms a device's behavior rules into a state machine. We design a Finite State Machine (FSM) model out of transformed behavior rules to build a Behavior Specification Rules Monitoring (BSRM) tool for each device. Mentor Graphics Altera ModelSim and Quartus II software packages are used to check the validity of the transformed states machines. Through our simulation and synthesis, we demonstrate that the BSRM tool can effectively identify the expected normal behavior of the device and detect any deviation from its normal behavior. Furthermore, the model is consistent with the requirements for lower power consumption and higher bandwidth applications. The FPGA module of the BSRM can be embedded in the medical devices so that any deviation from the behavior specification can be detected. Moreover, the reconfigurable nature of the FPGA chip adds an extra advantage to the designed model in which the behavior rule can be easily updated and tailored according to the requirements of the device, patient, treatment algorithm, and/or pervasive healthcare applications.