Sproutling vital signs monitor

Engineering peace of mind for parents

Sproutling engaged Synapse to design the hardware component of a wearable intended exclusively for infants infants. The ankle bracelet provides valuable data, including heart rate and temperature, to parents while their baby is sleeping. It also delivers helpful insight on the child’s sleep patterns and alerts parents as to when the child is asleep, awake, or rolls over. With real-time measurement of a baby’s vitals and position while sleeping, parents can have greater peace of mind.

Finding the right material

The wearable had to be appropriate for babies, meaning it had to be chew-proof, not a choking hazard, and biocompatible with strict infant standards. Liquid silicone rubber (LSR) was identified as the material for the device’s exterior, so engineers had to find the right plastic for the electronics enclosure that was transparent, to allow for optical heart rate measurement, and would withstand heat and pressure from LSR overmolding. Internal prototype testing (utilizing maple syrup and hot oil) proved the enclosure material — and the battery and electronics inside — would survive overmolding.

Pushing the limits of design

Sproutling is one of the first examples of an electronics enclosure with a battery entirely overmolded with LSR. Synapse engineers made the design work with the material, delivering a fully functional form-factor prototype complete with firmware for signal processing to conduct optical heart rate measurement and on-baby detection. Engineers developed a basic data-collection platform — overcoming challenges related to use cases, skin variance, and safety concerns — that enabled Sproutling’s data-analysis team to continue their algorithm development in parallel.