Healthcare / Neonatal Care

Neonatal Vitals Wearable: 20 mm Wireless SpO₂ and Heart-Rate Monitor for NICU Care

For a Hyderabad medical-device client we designed a 20 mm wireless wearable that streams a newborn's SpO₂ and heart rate over BLE, using a MAX86161 optical sensor. Completed by early 2025 and evaluated in a controlled NICU setting (client-reported).

What we did: We designed the 20 mm-diameter wearable's electronics and low-power RTOS firmware: a MAX86161 optical 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, Hyderabad, India8 monthsTeam of 6

Published February 2025Last reviewed: September 2026

20 mm

Device diameter

MAX86161

SpO₂ and heart-rate sensor

BLE

Real-time streaming to a dashboard

NICU

Controlled-setting evaluation (client-reported)

Illustrative image

The 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.

Impact: Wireless design needed

20 mm diameter

The optical sensor, radio, battery and power electronics all had to fit in a device 20 mm across.

Impact: Ultra-compact electronics

Fragile skin

Adhesives and hard materials can damage newborn skin, so attachment and materials had to be gentle.

Impact: Non-adhesive, biocompatible

Continuous data

Clinicians need a continuous, real-time stream at the nursing station, not occasional spot checks.

Impact: Real-time BLE streaming

Our Solution

We designed a 20 mm wearable built around the MAX86161 optical sensor, which 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

MAX86161 optical (PPG) front-end
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 front-end	MAX86161
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

What We Delivered

20 mm wearable electronics design
MAX86161 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 controlled NICU setting. 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.

NICU evaluation

Controlled setting

Evaluated in a controlled NICU environment, 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

MAX86161PPGSpO₂Bluetooth Low EnergyRTOSLow-power designBiocompatible materialsHospital dashboard

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