Why a Wearable Is a Serious Test for a New Circuit Approach

One reason wearable monitoring matters is because a device that stays with someone through ordinary life has more time to capture something a short examination or doctor’s visit might miss. Electronics have a demanding job. They must acquire a useful signal while the wearer moves, within a device small enough to tolerate and efficient enough to keep running. For a new circuit approach, that combination makes a wearable a serious test.

More time to capture the signal

In a study published in The American Journal of Medicine, researchers evaluated 146 patients who wore a conventional 24-hour Holter monitor and an adhesive ECG patch intended for monitoring over as many as 14 days.

Over their respective total wear periods, the patch detected 96 arrhythmia events, compared with 61 for the Holter monitor. The longer observation window is essential context: this was not evidence that the patch produced a cleaner signal.

It illustrates why engineers work to make monitoring practical over extended periods. Size, power consumption and wearability help determine whether a device can remain in use long enough to collect that information.

Smaller electrodes change the measurement

Miniaturization reaches beyond the enclosure. It can affect the interface between the body and the electronics. Writing about wearable ECG design, a Texas Instruments' engineer identifies “signal quality degradation resulting from small, dry electrodes.” The technical article explains that high electrode–skin contact impedance can lead to signal attenuation and increased noise.

The circuitry must accommodate those conditions while meeting the wearable’s size and power requirements. Electrode design, amplification, filtering and interference rejection all contribute to the result. A 2025 review in the IEEE Open Journal of the Solid-State Circuits Society summarizes the challenge:

“The reliable extraction of low-amplitude and low-frequency biosignals is hindered by electrode offset, noise, motion artifacts, and environmental interference.” The review examines circuit techniques and tradeoffs involving noise, input impedance, dynamic range, common-mode rejection and power consumption. Improving one measure is only part of the task. The circuit still has to meet the others.

The budget is measured in millimeters and microamps

Commercial components show how tight those constraints can be. For example, analog devices’ is available in a package measuring just 2 × 1.7 millimeters. Its typical quiescent supply current is 50 microamps.

Those figures describe one component, not a complete wearable. A finished device also needs some combination of sensing, processing, storage, communications and power management. Each function consumes part of the available space and energy budget.

For a new circuit technique, this sets a practical standard. It must deliver a useful benefit while accounting for any additional circuitry, power consumption or timing requirements it introduces.

First, identify the disturbance

Wearable measurements can be disturbed in several ways. Movement can change the electrode–skin interface. External electrical fields can couple into a measurement. The electronics themselves can contribute noise. These mechanisms require different responses.

A 2024 review in Nature Reviews Bioengineering describes how body movement affects the bioelectronic–tissue interface and discusses approaches spanning materials, device design, circuits and algorithms.

That distinction matters when evaluating a technology intended to reduce electromagnetic interference. Reducing an unwanted contribution from digital switching would not, by itself, fix an electrode that shifts against the skin. A meaningful test must identify the source it targets and measure its effect on the acquired signal.

What this means for Slip Signal

Slip Signal Technologies is developing technology to reshape digital transitions and reduce unwanted high-frequency spectral content. The intended wearable prototype (in our University of Maryland collaboration) provides a setting in which to investigate that approach alongside biopotential sensing circuitry. The specific prototype and test conditions will determine what conclusions can be drawn.

The important comparison is between comparable operation with and without our specifically efficient digital logic (SEDL) technology: does transition shaping reduce a measurable interference contribution? Does that change improve the acquired signal? What happens to power consumption and timing?

Evidence of lower emissions would be valuable. Establishing a benefit to sensing would require additional measurement. Claims about longer battery life or clinical performance would require further evidence of their own.

That is what makes a wearable a serious test. A new circuit approach has to demonstrate its value alongside sensitive measurement electronics, within a limited physical and electrical budget. The wearer may never know how that circuit works. The engineering has to show why it belongs there.