Biorhythms derived from consumer wearables predict postoperative complications in children

Figures

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  Fig. 1.. Biorhythms and example wearables data. (A) Biorhythms [suprachiasmatic nucleus (SCN) is the central pacemaker of the circadian timing system, and pineal gland (PG) generates melatonin, regulating most biorhythms in the body]. (B) Biorhythm changes after appendectomy shown with per-minute data of heart rate and step counts collected by consumer wearables. Patient #67 is a female, 12 years old when had surgery; patient #53 is a female, 13 years old when had surgery. bpm, beats per minute.

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  Fig. 2.. Data overview. (A) Availability ratio of wearable data per postoperative day (POD). (B) Number of episodes in duration of missing data. Distributions of (C) age, (D) sex, (E) race/ethnicity, and (F) length of stay (LOS) in the hospital.

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  Fig. 3.. Example recovery scenarios. (A) Number of patients per recovery scenario. Patients who demonstrated (B) normative recovery, (C) abnormal symptoms not leading to complications, and (D) postoperative complications (with or without additional abnormal symptoms) during the 21-day postoperative monitoring period.

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  Fig. 4.. Example heart rate biorhythms. Biorhythms extracted from heart rate of (A) patient #67 with normative recovery and (B) patient #53 with a diagnosed complication on POD6. Raw data of these two patients are in Fig. 1B.

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  Fig. 5.. Early prediction of postoperative complications. (A) Strategy of labeling each day of recovery. (B) Class distribution. (C) Results of early prediction of postoperative complications by BRF machine learning model. (D) Area under the curve of the “receiver operating characteristic” (AUC-ROC) curve. (E) Area under the curve of the precision and recall (AUC-PR) curve. (F) Prediction results for each patient who had complications on each day.

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  Fig. 6.. Comparison of the 21-day monitoring period. Selected biorhythm metrics shown here were considered most important for a prediction model to distinguish PODs with complications versus those without. (A) Step counts, PSD24h/threshold of significance. (B) Step counts, Cosinor amplitude. (C) Step counts, number of episodes. (D) Step counts, average episode duration. (E) Heart rate, PSD24h/threshold of significance. (F) Heart rate, cosinor relative amplitude.