# Using Open-Source Technology to Measure Energy Expenditure and Sleep Among Children 3 to 8 Years Old

> **NIH HL R01** · UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA · 2026 · $707,223

## Abstract

Assessing children’s 24-hour movement behaviors (i.e., time spent active, sedentary, and asleep) can reveal
the complex and interdependent ways energy expenditure and sleep are related to health outcomes. However,
assessing energy expenditure and sleep among children in free-living conditions is inherently difficult, and no
single method is without limitation. A combination of heart rate and accelerometry data provides a more precise
estimate of energy expenditure and sleep than either heart rate or accelerometry alone, when compared to a
criterion measure of indirect calorimetry or polysomnography, respectively. Yet, devices that measure both heart
rate and acceleration (such as ActiHeart or Fitbit) were not designed for children and may be distracting or
uncomfortable. Moreover, nearly all devices use proprietary algorithms and do not allow access to raw signal
data, and thus, are fundamentally unverifiable.
Our study team has developed the PATCH, a small, open-source wearable device which integrates multiple
sensors to measure heart rate and acceleration among children. The proposed project leverages the initial
PATCH calibration progress and extends this work to conduct a series of studies to establish the validity of the
PATCH to measure children’s energy expenditure and sleep in both laboratory and free-living conditions. The
objectives of the proposed project are (1) develop estimates of energy expenditure for children aged 3-8 years,
(2) measure sleep, compared to criterion polysomnography and (3) validate PATCH estimates of energy
expenditure and sleep in 24-hour free-living contexts. Our long-term goal is to advance the measurement field
for epidemiologic- and intervention-based studies that measure energy expenditure and sleep in the context of
free-living 24-hour movement behavior.
This project is innovative because it leverages off-the-shelf hardware and open-source processing. This means
that results from this project will enable other researchers to b

## Key facts

- **NIH application ID:** 11229791
- **Project number:** 5R01HL171295-03
- **Recipient organization:** UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
- **Principal Investigator:** Bridget R. Armstrong
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** HL
- **Fiscal year:** 2026
- **Award amount:** $707,223
- **Award type:** 5
- **Project period:** 2023-12-01T00:00:00 → 2028-11-30T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11229791

## Citation

> US National Institutes of Health, RePORTER application 11229791, Using Open-Source Technology to Measure Energy Expenditure and Sleep Among Children 3 to 8 Years Old (5R01HL171295-03). Retrieved via AI Analytics 2026-07-11 from https://api.ai-analytics.org/grant/nih/11229791. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*