The biggest challenge is balancing performance with extremely low energy use. A device must capture and process biosensor data accurately without quickly draining its tiny battery. Designers have to choose specialized low-power components and optimize every software task to save power. Often there are trade-offs to conserve energy while still providing reliable, real-time health insights—such as reducing data acquisition and transmission frequencies, simplifying algorithms, and knowing when it’s worth accepting higher amplifier current drain in favor of lower noise.