2026-02-26 ワシントン大学
DopFone uses an off-the-shelf smartphone’s existing speaker and microphone to accurately estimate fetal heart rate.
Photo: Garg et al./Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies
＜関連情報＞
- https://www.washington.edu/news/2026/02/26/dopfone-fetal-heart-rate-app/
- https://dl.acm.org/doi/abs/10.1145/3770671
DopFone: 市販スマートフォンを用いたドップラー法による胎児心拍数推定 DopFone: Doppler-Based Fetal Heart Rate Estimation Using Commodity Smartphones
Poojita Garg, Mingzhuo Ma, Hayley Jane MacKinnon, Michael Richley, Vikram Iyer, Shwetak Patel, Alexander T. Adams
Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies Published: 02 December 2025
DOI:https://doi.org/10.1145/3770671
Abstract
Fetal heart rate (FHR) monitoring is critical for prenatal care, yet current methods rely on expensive, specialized equipment and trained personnel, limiting accessibility in low-resource and at-home settings. We present DopFone, a novel approach leveraging the built-in speaker and microphone of commodity smartphones to non-invasively estimate FHR via Doppler-based audio sensing. Our system emits an 18 kHz low-pitched ultrasound from the smartphone speaker and analyzes reflected signals recorded by the microphone to detect abdominal surface vibrations caused by fetal cardiac activity. Combining Doppler sensing with an AdaBoost regression model (validated via Leave-One-Out Cross-Validation on 23 pregnant participants), DopFone achieved a mean absolute error of 2.1±1.3 BPM compared to a reference-standard medical Doppler device. The 95% limits of agreement (±4.90 BPM) fall well within the clinically acceptable threshold of ±8 BPM. The system demonstrated robustness across gestational ages (19-39 weeks), maternal BMI (23-67 kg/m2), and variations in phone positioning. Our results establish that smartphones can deliver clinically reliable FHR estimation without external hardware, gel, or probes, bridging the gap between clinical monitoring and accessible at-home assessment.
