Electronics Design for Life-Critical Medical Devices
Medical device electronics carry a unique burden: they must function correctly every time, because patient safety depends on it. The regulatory pathway for medical electronics is rigorous and unforgiving, requiring documented design controls, risk analysis at every stage, and traceability from requirements through verification and validation. Cutting corners is not an option, and retrofitting compliance after the design is complete is prohibitively expensive.
At Specto Silicon, we integrate regulatory awareness into every phase of the electronics design process. From initial architecture through schematic capture, PCB layout, and design verification, we work within the frameworks of IEC 62304 (software lifecycle), IEC 60601-1 (electrical safety), and ISO 14971 (risk management) to produce designs that are not only technically excellent but also ready for regulatory submission.
IEC 62304 Compliant Designs
IEC 62304 defines the lifecycle processes for medical device software, and since modern medical electronics are inseparable from their firmware, compliance with this standard shapes our entire design approach. We classify software safety classes (A, B, or C) early in the project based on the device's risk profile, and we scale our development processes accordingly. For Class C software items that could contribute to a hazardous situation, we implement full unit architecture documentation, detailed design specifications, code reviews, and comprehensive verification testing. Our hardware designs support software safety by providing hardware watchdog timers, redundant sensor inputs for plausibility checking, and memory protection units that isolate critical software tasks from non-critical functions.
Patient Monitoring Systems
We design electronics for bedside monitors, central station displays, and ambulatory monitoring devices that capture vital signs including ECG (single and multi-lead), SpO2, NIBP, temperature, respiration rate, and capnography. Our analog front-end designs achieve the signal quality required for clinical-grade measurements: ECG circuits with CMRR exceeding 100 dB, input impedance above 10 megaohms, and noise floors below 10 microvolts RMS. We design the signal conditioning chains — instrumentation amplifiers, driven-right-leg circuits, analog filters, and high-resolution ADCs — as well as the digital processing backends that extract parameters, detect arrhythmias, and generate alarms. Patient isolation is implemented using medical-grade isolation barriers (2 x MOPP per IEC 60601-1) with reinforced insulation between patient-applied parts and earth-referenced circuits.
Diagnostic Equipment Electronics
Diagnostic devices span a wide range of complexity, from handheld point-of-care analysers to benchtop laboratory instruments. We design the electronic subsystems these devices require: precision analog measurement circuits for optical sensors (photodiodes, photomultiplier tubes), electrochemical sensor interfaces (potentiostats, amperometric circuits), motor control for fluidic handling (syringe pumps, peristaltic pumps, centrifuges), thermal control for incubation chambers, and high-resolution display driver electronics. For point-of-care devices, we optimise designs for battery operation, fast measurement cycles, and compact form factors while maintaining the measurement accuracy and repeatability that clinical use demands. Our designs include self-test and calibration verification circuits that support the quality control workflows required in clinical environments.
Wearable Health Devices
The wearable medical device market demands electronics that combine clinical-grade measurement performance with consumer-grade size, weight, and battery life expectations. We design ultra-low-power sensor acquisition circuits that operate from coin cells or small lithium-polymer batteries for days or weeks at a time. Our wearable electronics designs incorporate low-power microcontrollers with integrated BLE 5.x radios, MEMS accelerometers and gyroscopes for motion tracking, optical heart rate sensors (PPG), bioimpedance measurement circuits, and skin temperature sensors. We pay careful attention to skin-contact electrode design, motion artefact rejection, and power management strategies including duty-cycling sensor subsystems and implementing efficient charge circuits for rechargeable batteries. For devices that require continuous data streaming, we design with BLE throughput optimisation and local data buffering to handle intermittent connectivity.
Class II & Class III Medical Device Electronics
Higher-risk medical devices classified as Class II (510(k) pathway) or Class III (PMA pathway) by the FDA — or equivalently classified under the EU MDR — require electronics designed with formal design controls and thorough risk management. We follow ISO 14971 risk management processes throughout the design, maintaining a risk analysis file that traces identified hazards to design mitigations and verification activities. Our design documentation packages include design input/output specifications, design reviews, verification protocols and reports, and traceability matrices that map every requirement to its verification evidence. For Class III devices, we implement additional hardware safety mechanisms such as redundant microprocessors with cross-checking, independent safety monitoring circuits, and fault-tolerant power supply architectures that ensure the device enters a safe state under any single-fault condition.
Biocompatible Sensor Interfaces
When electronics interface directly with the human body, biocompatibility of the sensor-tissue interface becomes a design consideration that extends beyond the electrical domain. We design electrode interfaces using materials and geometries that minimise skin irritation for long-wear applications, and we work with biocompatible substrate materials (medical-grade flex PCBs, polyimide, and LCP) that meet ISO 10993 requirements. Our analog front-end designs for body-contact sensors include DC offset removal circuits to handle electrode half-cell potentials, high-impedance inputs to accommodate varying skin-electrode impedance, and defibrillation protection circuits that safely handle high-voltage transients without damage to the measurement electronics.
Why Medical Electronics Require Specialist Design Expertise
Medical electronics are not simply industrial electronics with more documentation. The safety and regulatory requirements fundamentally shape design decisions at every level. Creepage and clearance distances on PCBs must meet the means of patient protection (MOPP/MOOP) requirements of IEC 60601-1, which are significantly more conservative than commercial standards. Leakage current limits — both normal condition and single-fault condition — constrain power supply topologies and grounding strategies. EMC requirements under IEC 60601-1-2 include not only emissions limits but also stringent immunity requirements, because a medical device must continue to function correctly in the presence of electromagnetic disturbances from other equipment. And cybersecurity requirements under FDA guidance and IEC 81001-5-1 mean that connected medical devices must incorporate secure boot, encrypted communications, and software update mechanisms.
Specto Silicon understands these interlocking requirements and designs electronics that satisfy them holistically. We help medical device companies avoid costly redesigns by building compliance into the design from the start, accelerating time to regulatory clearance and market.