Healthcare / Neonatal Care
Neonatal vitals wearable: 20 mm wireless SpO₂ and heart-rate monitor for NICU care
For an Indian medical-device client we designed a 20 mm wireless wearable that streams a newborn's SpO₂ and heart rate over BLE, using a MAXM86161 optical module. Completed by early 2025; evaluated in a NICU setting under the client's ethics approval (client-reported).
What we did: We designed the 20 mm-diameter wearable's electronics and low-power RTOS firmware: a MAXM86161 integrated optical module (LEDs, photodiode and analog front-end) for SpO₂ and heart rate (PPG), Bluetooth Low Energy streaming to a hospital dashboard, and power management for extended use, in a soft, non-adhesive enclosure made of biocompatible materials.
Medical-device client, India8 monthsTeam of 6
Status: Completed; evaluated in a NICU setting under the client's ethics approval (client-reported; case study first published February 2025)
Published Last reviewed:
Illustrative imageThe challenge
Newborns in neonatal intensive care units (NICUs) need continuous monitoring of vital signs such as heart rate and blood-oxygen saturation (SpO₂). Wired sensors can cause discomfort and skin irritation, restrict movement and get in the way when parents hold their baby. The client wanted a wireless wearable only 20 mm across that monitors vitals in real time while staying comfortable and safe on fragile newborn skin.
Wires on a newborn
Wired leads restrict movement, can irritate the skin and get in the way of skin-to-skin contact with parents.
20 mm diameter
The optical sensor, radio, battery and power electronics all had to fit in a device 20 mm across.
Fragile skin
Adhesives and hard materials can damage newborn skin, so attachment and materials had to be gentle.
Continuous data
Clinicians need a continuous, real-time stream at the nursing station, not occasional spot checks.
Impact figures describe the situation before the project, as the client reported it to us; we did not measure them.
Our solution
We designed a 20 mm wearable built around the MAXM86161, an integrated optical module (LED drivers, LEDs, photodiode and analog front-end in one package) that measures SpO₂ and heart rate by photoplethysmography (PPG): shining light into the skin and measuring how much returns with each heartbeat. A low-power embedded system streams the data over Bluetooth Low Energy to a hospital dashboard, and optimised power management extends each session. The enclosure uses soft, biocompatible materials and a non-adhesive attachment to reduce the risk of skin irritation.
System architecture
Optical sensing, low-power processing and BLE in a 20 mm package.
Sensing
- MAXM86161 integrated optical module (LEDs, photodiode and AFE)
- SpO₂ and heart-rate measurement
- Continuous vitals monitoring
Embedded system
- Low-power embedded system with RTOS firmware
- Optimised power management for extended use
- Battery-powered, all in a 20 mm package
Connectivity and enclosure
- Bluetooth Low Energy streaming
- Real-time hospital dashboard
- Soft, biocompatible, non-adhesive enclosure
Key design points
- Size
- 20 mm diameter
- Optical module
- MAXM86161 (LEDs, photodiode and AFE)
- Measurements
- SpO₂, heart rate (PPG)
- Wireless
- Bluetooth Low Energy
- Firmware
- RTOS, low-power
- Attachment
- Non-adhesive, biocompatible materials
- Safety framing
- Designed with neonatal medical-device safety requirements in mind
- SpO₂ accuracy
- Not validated against ISO 80601-2-61; no accuracy claim
What we delivered
- 20 mm wearable electronics design
- MAXM86161 integration for SpO₂ and heart rate
- Low-power RTOS firmware and power management
- BLE streaming to a hospital dashboard
- Soft, non-adhesive enclosure using biocompatible materials
Outcome
We developed the 20 mm wearable and it streamed continuous SpO₂ and heart-rate data over BLE. The client reports that it was evaluated in a NICU setting under the client's ethics approval. SpO₂ accuracy was not validated against ISO 80601-2-61 (the pulse-oximeter standard), and the device is not a cleared pulse oximeter. The wireless, non-adhesive design is meant to reduce skin-irritation risk, allow remote monitoring from the nursing station and keep wires out of the way of parent contact; these are design goals, and no clinical-outcome figures are published here.
How to read the labels: Client-reported baseline = the client's own figure for the situation before the project; we did not measure it. Figures without a label are specifications or project scope.
NICU evaluation
Ethics-approved
Evaluated in a NICU setting under the client's ethics approval, as reported by the client (not a performance figure)
Continuous monitoring
SpO₂ + heart rate
Real-time data over BLE to a hospital dashboard
Form factor
20 mm
Diameter of the complete wearable
Design duration
8 months
Team of 6
Technologies used
- MAXM86161
- PPG
- SpO₂
- Bluetooth Low Energy
- RTOS
- Low-power design
- Biocompatible materials
- Hospital dashboard
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