Loop System

The Spry Health Loop System is a wrist-worn device for adult home use that employs reflectance photoplethysmography and accelerometry to intermittently measure arterial oxygen saturation, heart rate, and respiration rate during rest. This data is uploaded to a server for remote clinician review, with its accuracy validated through clinical studies against standard benchmarks.

The Loop System by Spry Health, Inc. is a prescription-only, wrist-worn medical device designed for adult patients in a home environment. Its purpose is to passively and intermittently collect physiological data—specifically arterial oxygen saturation (SpO2), heart rate (HR), and respiration rate (RR)—when the patient is at rest. The system utilizes reflectance-based photoplethysmography (PPG) signals generated by LEDs of varying wavelengths and photodiodes embedded in the Loop Band. An integrated accelerometer monitors patient activity, ensuring data is recorded only during periods of no motion. Collected raw data is stored on the Loop Band, which patients wear for up to 24 hours before needing to charge it using the provided Loop Charging Station. During charging, the data is uploaded via a cellular connection to the Spry Server for processing and subsequent remote review by a clinician via a web interface as a time-stamped CSV file. The device itself can display resting HR and SpO2, but respiration rate determination requires server-side analysis. The Loop System does not provide physiological alarms. Supporting data for the Loop System includes bench testing and two clinical studies. Bench tests confirmed heart rate monitoring accuracy in compliance with ISO 80601-2-61 and FDA guidelines. Electrical safety and electromagnetic compatibility were verified against IEC standards (60601-1, 60601-1-2, 60601-1-11, 60601-1-6), and biocompatibility met ISO 10993-1 requirements. One clinical study with 12 healthy adults demonstrated respiration rate monitoring accuracy equivalent to a gold standard. Another clinical study, also with 12 healthy adults, assessed pulse oximetry (SpO2) accuracy against arterial blood gas analysis, showing compliance with ISO 80601-2-61 and FDA guidelines for pulse oximeters. These studies confirmed the device's accuracy for SpO2 (3% ARMS, no motion) and HR (3 BPM ARMS, no motion), with a respiration rate accuracy of 3 RPM ARMS.

AI Regulatory Concerns

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Jev reads the full FDA letter and returns calibrated concern probabilities per regulatory category. These are AI estimates, not regulatory advice.

• Q1. How does the device's filtering technology for removal of noise, including ambient light, perform across diverse home environments and varying patient skin pigmentations?; What is the specific data on the accuracy (e.g., ARMS values cited as 3% for SpO2 and 3 BPM for HR) during actual home use conditions, considering the device only records when no motion is detected by the accelerometer?; Since respiration rate is determined by the Spry Server after data upload, what is the typical latency between data collection on the Loop Band and the availability of RR for clinician review, and how might this impact clinical decision-making?; The device collects data for up to 24 hours. What is the internal data storage capacity of the Loop Band, and what mechanisms are in place if the band cannot upload data (e.g., due to lack of cellular connection at the charging station)?; The clinical study for respiration rate involved 12 healthy adults. How does the device's RR accuracy perform in patient populations with common respiratory conditions (e.g., COPD, asthma) or irregular breathing patterns?