# Feasibility and Form Factor Validation of Reflective Shoulder-Mounted Pulse Oximeter in Patients with Suspected Sleep Apnea

## TL;DR

A new shoulder-mounted pulse oximeter is more comfortable and less disruptive to sleep than traditional finger-based devices, with fewer issues related to noise and device removal.

## Contribution

The study validates the feasibility and comfort of a shoulder-mounted pulse oximeter for respiratory monitoring in sleep apnea patients.

## Key findings

- Shoulder-based pulse oximetry produces less noisy data than finger-based devices.
- Participants found the shoulder-mounted device more comfortable, leading to fewer removals and less sleep disruption.
- The shoulder-mounted device showed acceptable agreement with standard finger-based pulse oximeters in measuring oxygen saturation.

## Abstract

What are the main findings?
Shoulder-based pulse oximetry results in decreased noisy data compared with traditional finger-based pulse oximetry.Shoulder-based pulse oximetry is more comfortable than traditional finger-based pulse oximetry, resulting in fewer device removals and decreased self-reported sleep disruption.

Shoulder-based pulse oximetry results in decreased noisy data compared with traditional finger-based pulse oximetry.

Shoulder-based pulse oximetry is more comfortable than traditional finger-based pulse oximetry, resulting in fewer device removals and decreased self-reported sleep disruption.

What is the implication of the main finding?
New medical devices targeting the shoulder for respiratory monitoring in sleep-disordered breathing patients will be well received by patients.It is feasible to get a high accuracy from shoulder-mounted devices.

New medical devices targeting the shoulder for respiratory monitoring in sleep-disordered breathing patients will be well received by patients.

It is feasible to get a high accuracy from shoulder-mounted devices.

The shoulder may be an effective central site for continuous oxygen saturation (SpO2) monitoring but studies of shoulder-mounted pulse oximetry technology are limited. We hypothesized that an alternative location would be similar in function and user acceptance to a standard FDA-cleared finger-based pulse oximeter. We conducted a quantitative and descriptive pilot study of two prototype biosensor designs in patients with clinical suspicion of hypoxic episodes at an outpatient sleep center. Participants wore two prototype biosensors—the primary a shoulder-mounted adhesive and the secondary a combination ring–bracelet—in addition to a control FDA-approved finger-based pulse oximeter. We assessed the comfort of the devices based on a survey. We monitored 27 patients during an overnight polysomnography study. Participants rated the shoulder-mounted device more highly than the control device on a Likert scale survey of comfort (4.6 out of 5 versus 3.1 out of 5). Open-ended questionnaires showed that the two major criticisms of the control and ring devices were devices falling off and disruption to sleep, while only one participant commented on the shoulder device specifically. We also investigated SpO2 agreement between the primary shoulder-mounted prototype and the control finger-based pulse oximeter. This study confirms that alternative configurations for SpO2 monitoring offer potential as well-tolerated devices with preliminary findings of acceptable agreement. Problems with traditional pulse oximetry, such as false readings of hypoxia due to device removal or noisy data, were encountered less frequently in shoulder-mounted pulse oximetry than in the commercial finger-based device. Future directions include studies of additional populations that are at risk of respiratory collapse and surveys to elicit specific feedback on the configurations, whether positive or negative.