Hypno: building a low cost sleep tracker for babies

Prototyping, Design engineering, Wearables, Bbaby monitor, Healthcare, Concept testing


Sleep-related problems is one of the leading cause for infant deaths globally, yet there are concerns around the market of existing products in regard to their features.  Other โ€œsmartโ€ product precedents are approaching with more complex solutions, causing false positives with data not to mention the hefty price tags .
In other words,  existing products are expensive, complex, and having multiple concerns in understanding data.

We aim to provide peace of mind to worried parents by prototyping a simple, low cost sleep tracker for babies in a form of wearable belt that could read the babyโ€™s sleeping position and track the breathing movements in abdomen area.

Project for

Master in Design Engineering Collaborative Design Engineering Studio I


Togo Kida, Zongheng Sun, Muhammad Hanif Wicaksono

Problem statement and ideation sketches


In US, about 3500 babies are lost due to sleep-related deaths each year. Given that infants sleep over 12+ hours a day, intercepting sleep-related accidents are in strong need. In order to combat this situation, there are solutions in the market which utilizes oximeter to measure the oxygen level in the infants. However, the prices for these products are expensive, and there are researches pointing out concerns regarding the efficacy of this product.


We tried several approaches and iterations during the fast-paced project. The goal was to fail as fast possible so we could came up with a viable solution. We started by ideating on improving the breathibility for the mattress and made some mock ups with a number of foam materials. However, we found out that we could use simple sensors to identify babyโ€™s breaths by detecting the change in the abdomen area, plus a gyroscope to determine where the baby is facing.

We introduced a simple and inexpensive wearable device solution which enables to track the state of the infant during sleep. Hypno is a wearable device which is consisted of a flex sensor and an accelerometer that tracks the posture of the infant and their breathing. Based on the tracked information, if the infant is in a critical state, parents will be notified instantaneously.

In addition to the functional prototype, Hypno is also designed as smart clothes which track the entire movement of the infant. This enables to obtain richer data regarding the infant and therefore provides a better understanding of the biometric state of the infant.

Several approaches to develop the idea. Left to right: Pneumatics, foams, wearables.

Electronics diagram

Process diagram


We tried pneumatics, computational foam molds, and finally settled on wearable belt for detection. In the final presentation on this subject, we propose a product that detects chest breathing and posture by bonding an inexpensive sensor to baby's clothing. In the prototype, we prepared two functions, "functional prototype" which explains the function and "formal prototype" which is the ideal prototype of the final design.

We made a functional prototype which demonstrated the basic mechanism. The prototype is a belt consists of a flex sensor, an accelerometer and an Arduino control module. Though BlueTooth connection, the belt can detect if the baby ihas been facing down for a while and send alert to parentsโ€™ mobile phones. We also design the UI of the application in the demo.
Furthermore, we studied new materials such as Stretchy Variable Resistance Sensor Fabric, Conductive Hook & Loop Tape, and Knit Conductive Fabric.

With these materials, the prototype can be deployed to a broader application, named Hypno. The concept opens up the possibility of gathering a wide range of data related to child movement, and biometric, which has a strong impact on further child development. We developed the suit by sketching and patterning with fabric and completed a sensor calibration to detect motion and collect data systematically.