Embedded Systems Engineer for Wearable Device

**Project: Short-Term Embedded Engineering Consultancy — Patent Validation for Adaptive Frequency Control in Wearable Wellness Devices** I am seeking an embedded systems / wearable-device engineer for a short-term consultancy project to help validate and strengthen a pending patent application. The patent covers a real-time method for extracting a specific physiological oscillation frequency from wrist-worn PPG-derived data and using that frequency to adaptively control the output of a haptic/vibrotactile actuator. The core algorithm is already specified in the patent draft. The purpose of this project is to implement the method on representative wearable-class hardware and generate technical evidence that can support patent prosecution, technical due diligence and future investor or partner discussions. This is not a full commercial product-build at this stage. The immediate goal is a focused engineering validation package demonstrating feasibility, real-time performance and practical implementation constraints. **Scope of work** The consultant will be asked to: 1. Review the relevant patent claims and algorithm description from an embedded engineering perspective. 2. Implement the core signal-processing algorithm on representative wearable-class hardware, preferably a Nordic nRF52840 or equivalent ARM Cortex-M4F platform. 3. Process PPG-derived inter-beat interval data and validate real-time spectral extraction across the relevant frequency range, including frequencies below the conventional 0.15 Hz HRV boundary. 4. Demonstrate adaptive closed-loop control of a vibrotactile or haptic actuator based on the extracted physiological frequency. 5. Characterise implementation performance, including latency, computational load, RAM/flash usage, sampling requirements, numerical stability and power-consumption implications. 6. Identify any engineering limitations, edge cases or design modifications that would strengthen the patent specification and fallback embodiments. 7. Produce a concise technical report suitable for use by a patent attorney, technical reviewer or potential investor. **Expected deliverables** The expected outputs are: * working prototype firmware or demonstrator code; * documented test setup and hardware configuration; * raw and processed validation data; * performance metrics for latency, memory use, computational load and power implications; * demonstration of closed-loop actuator frequency control; * engineering feasibility report; * recommended patent-strengthening additions, including implementation options, parameter ranges, hardware alternatives and fallback embodiments. **Required skills** * Embedded firmware development in C/C++ on ARM Cortex-M or equivalent platforms. * Real-time signal processing on constrained hardware. * Digital signal processing, including filtering, spectral estimation and peak detection. * Experience with PPG, heart-rate variability, inter-beat interval analysis or comparable physiological signals. * Experience with wearable sensor hardware, haptic actuators, low-power embedded systems or consumer biomedical devices. * Ability to document engineering results clearly for a non-specialist patent/investor audience. **Desirable skills** * Experience with Lomb-Scargle periodograms or other methods for non-uniformly sampled physiological data. * Experience with HRV analysis, respiratory sinus arrhythmia, autonomic physiology or wearable biosignal processing. * Experience with Nordic nRF52, STM32, Zephyr, FreeRTOS or similar embedded platforms. * Experience with actuator control, vibrotactile feedback or haptic driver circuits. * Experience contributing to patents, medical-device development, consumer wearable products or regulated health technology. **Engagement** This is a fixed-term consultancy project, expected to run for approximately 4–8 weeks. Part-time or full-time arrangements can be discussed. Remote work is acceptable, provided the consultant can access suitable development hardware or advise on hardware procurement. An NDA will be required before the detailed patent material is shared. All work product generated during the consultancy, including code, reports, test data, diagrams and design recommendations, must be assigned to the commissioning party. Please respond with: 1. a short summary of relevant experience; 2. examples of similar embedded/wearable/DSP projects; 3. your suggested approach to the validation task; 4. estimated timescale and fixed-price or day-rate proposal; 5. any hardware or data you would require to begin.