Wireless medical sensor chip with machine learning
Ensilica has created a customisable single-chip medical sensor ASIC platform to speed the development of wearable medical / fitness vital-sign monitoring products.
Called eSi-MediSense, it is a single chip medical sensor with wireless capability, and by being single chip, it brings costs down significantly: for example enabling a health monitoring watch to drop in cost from c.£250 to c.£100.
The ultra-low-power platform is able to work with multiple processor and DSP configurations and has an optional machine learning accelerator such as the Arm Ethos-U55 that enable artificial intelligence to be designed into medical sensors - both reducing the frequency of wireless communication and extending battery life.
The platform supports the accurate and reliable measurement of ECG, heart rate, respiration rate, pulse oximetry and temperature. A flexible interface is also provided for electro chemical-based measurement such as amperometric, voltammetric or impedance measurements.
Applications include recyclable smart plasters; physiotherapy monitors to track orthopaedic recovery, track abnormal heart conditions; or provide non-invasive glucose monitoring. By continuously monitoring expected vs unexpected activity, it is able to flag the need for medical assistance autonomously.
After processing, data is encrypted and transmitted over either the 2.4GHz ISM band radio (WiFi / Bluetooth / proprietary and medical), a sub-1 GHz MBAN standard or an ultra low power standard such as BLE 5.0 or 802.15.4. An NFC-A tag can be integrated to simplify device pairing and enable medical sensor data to be read by a smartphone.
“The platform has been developed to work with a huge range of sensors: from ECG to temperature and from electro-chemical to bioimpedance. Plus, our design team have the expertise to develop and integrate additional custom sensor interfaces with demanding performance requirements," said Ian Lankshear, CEO at EnSilica. "It is an ideal platform to integrate custom sensors or run your smart diagnostic and remote healthcare applications on a single chip.”
The eSi-MediSense is designed to conform to: IEC 60601-1, IEC 60601-2-27 and IEC60601-2-49.
The platform’s specialised medical analogue front end is able to work with single lead and multi-lead ECG with clinical grade accuracy to enable R-R heart rate monitoring; temperature sensor interfaces to ISO 80601-2-56; bioimpedance channel capable of measuring respiration; and multi-channel electrochemical impedance spectroscopy (EIS).
It is able to support voltages between 1.0 and 3.6V and its multiple power states are able to deliver a standby current of <1µA.
Data is encrypted on the chip using crypto accelerators: AES-256, SHA-512 and ECC-384 with a true-random number generator (NIST 800-22). And the platform is able to use a range of real time operating systems, including FreeRTOS, SafeRTOS, ThreadX and eBed OS, and comes with a feature rich DSP software library for easy algorithm programming.
The eSi-MediSense platform comes in Low-pin count QFN or B/LGA packaging options or a bare die for flip-chip bumping directly onto the PCB.