Cybersecurity Meets Patient Safety: Building an ECG STRIDE Threat Model

* *The purpose of this light version threat model is to demonstrate how STRIDE can be applied to an ECG device. It is intended for readers learning system decomposition and threat modelling techniques. The example includes a simplified set of components, threats, and mitigations for educational purposes and is not intended to represent a comprehensive medical device cybersecurity assessment or any regulatory submission. **Assumption: This example models a typical ECG device, which may include network connectivity in a clinical environment. Trust Boundaries: Trust boundaries exist between the ECG device, hospital network, and external clinical systems. System Definition: ECG is the abbreviation for an Electrocardiogram. It is used to detect electrical activity of the heartbeat in the form of P wave, QRS complex and T wave to identify and diagnose irregularities in heartbeat. Electrodes are placed on patient’s limbs and chest to measure the electrical potentials. It translates tiny electrical signals into digital wave patterns. These waveforms are used by the doctors to evaluate the heart rhythm and check for cardiac damage. Components • Electrodes • Lead wires • Amplifier and filters • Analogue-to-Digital Converter (ADC) • Main processing unit • Display/printer • Local storage • Network interface (Ethernet/Wi-Fi/Bluetooth), if supported. Data Flow Diagram: Electrodes → Lead wires → Amplifier and filters → Analogue-to-Digital Converter (ADC) → Main processing unit → Display / Printer / Local storage / Network interface (if supported) |TRUST BOUNDARY|→ Electronic Health Record (EHR) / Clinical Information System 2. STRIDE Threats: Threats Description Spoofing in general ** - Spoofing is the act of impersonating a legitimate user, device, or system to gain unauthorized access to resources or services. Violates authentication. * Spoofing in ECG * - An attacker may impersonate an authorized clinician, connected medical device, or trusted clinical system to gain unauthoriz