Wearable Device Solutions

Wearable battery optimization involves ultra-low-power microcontrollers, efficient power management ICs, duty-cycled sensing, BLE optimization, and power-aware firmware design. Our wearable designs typically achieve 5-14 days battery life depending on feature set and display type.

Yes, we develop FDA-compliant medical wearables following IEC 62304 for software lifecycle, IEC 60601-1 for electrical safety, and ISO 13485 quality management. Our process includes risk management per ISO 14971 and support for 510(k) submission documentation.

Flexible PCB design for wearables uses polyimide substrates that bend to conform to body contours, requiring careful attention to bend radius constraints, trace routing perpendicular to fold lines, and stiffener placement under component pads. We design flex and rigid-flex stackups that balance mechanical durability with electrical performance, using hatched ground planes to improve flexibility.

Most commercial wearables target IP67 or IP68, with fitness watches often rated to 5ATM (50 meters) for swim tracking. Achieving these ratings requires ultrasonic welding or adhesive bonding of enclosure seams, laser-welded sensor windows, silicone gaskets on button mechanisms, and hydrophobic nano-coatings on exposed connectors and microphone ports.

Bluetooth Low Energy (BLE 5.x) is the dominant protocol for wearables due to its ubiquitous smartphone compatibility, low power consumption, and sufficient throughput for health data streaming. For specific use cases, ANT+ serves multi-device sport sensor networks, Thread enables smart home integration, and ultra-wideband (UWB) provides centimeter-level spatial awareness for proximity-based features.

Wearable UI/UX design must account for extremely limited screen real estate (often under 1.5 inches), glanceable interaction patterns requiring information delivery in under 5 seconds, and input modalities restricted to small touch targets, rotary crowns, or gesture recognition. We design with high-contrast color palettes for outdoor visibility and leverage haptic and audio feedback to reduce visual dependency.

Continuous health monitoring algorithms use PPG signals processed through bandpass filters and peak detection to extract heart rate, heart rate variability, and SpO2 readings, with motion artifact removal via accelerometer-correlated adaptive filtering. Advanced implementations run lightweight ML models on-device to detect arrhythmias or classify sleep stages in real time while maintaining multi-day battery life.

Wearable health devices must comply with HIPAA in the US if they process protected health information, GDPR in Europe for all personal biometric data, and FDA 21 CFR Part 11 for devices classified as medical devices. We implement on-device data encryption (AES-256), anonymized data processing pipelines, explicit user consent flows, and data minimization principles to ensure compliance.

Wearable miniaturization employs chip-on-board and system-in-package integration to consolidate multiple ICs into a single module, combined with 01005-size passive components and multi-layer HDI PCBs with microvias. We also use 3D stacking of die and flexible interconnects to utilize the full interior volume of curved enclosures rather than being constrained to a single planar board.

Haptic feedback in wearables uses linear resonant actuators or piezoelectric actuators driven by specialized haptic driver ICs, which synthesize vibration patterns from a library of waveforms or custom-designed sequences. We tune haptic responses to match notification types while keeping actuator power draw under 100mW average, and design mounting structures that efficiently couple vibration to the skin contact surface.

Wireless charging via Qi or proprietary magnetic puck alignment is the dominant approach for sealed wearables, using inductive coils at 100-200kHz to deliver 1-5W through waterproof enclosures without exposed contacts. We also design pogo-pin cradle chargers for higher power transfer efficiency, and for extended-wear medical devices, implement energy harvesting from thermoelectric generators or small photovoltaic cells.