Respiration From Pleth Validation

Respiratory rate is a key clinical vital sign and an early indicator of patient deterioration, but traditional manual counting is often inaccurate and inconsistently performed. Prior research has demonstrated that respiratory rate can be derived from the plethysmography waveform used for SpO₂ monitoring. Philips has developed enhancements to its FAST Pulse Oximetry technology to derive respiratory rate from plethysmography (Respiration from Pleth, RfP). This clinical investigation is designed to validate the accuracy and performance of the RfP algorithm by comparing pleth-derived respiratory rate with respiratory rate obtained from clinician-annotated capnography waveforms.

This is a multi-center, prospective, non-randomized, non-blinded observational study enrolling adult and pediatric inpatients who are spontaneously breathing room air and undergoing routine spot-check vital signs. Each participant completes one study visit. Age- and weight-appropriate Philips SpO₂ sensors (finger, nasal alar, ear) are placed according to the sensor Instructions for Use, and capnography is collected using the LoFlo Sidestream etCO₂ sensor with adult or pediatric oral/nasal cannulas. For each applicable sensor type, a 20-minute plethysmography and capnography recording is collected. A spot-check analysis window covering the first 5 minutes of the finger-sensor recording is also evaluated. Manual respiratory rate is recorded once during this period.

Waveform data are annotated by clinicians blinded to other signals to identify normal breathing, exclude artifacts, and determine reference respiratory rate values. Respiratory rate accuracy is evaluated using Accuracy Root Mean Square (ARMS), mean bias, and precision. Predefined performance criteria specify ARMS ≤ 3 breaths per minute and mean bias between -1 and +1 BPM for each population. The investigation also evaluates time to first valid pleth-derived respiratory-rate value, as well as adult participant acceptability of the CO₂ cannula. Data collected during the study do not influence patient care, and the investigational respiratory-rate algorithm is not displayed on the monitoring equipment during data acquisition.

Inclusion criteria

• Adult Participants (defined as aged 18 years or older): Willing and able to understand and provide written informed consent
• UK Pediatric subjects:

• Aged 16 years and older willing and able to understand and provide written informed consent
• Aged 4-15 years and their legal guardians willing and able to understand and provide written informed consent/assent
• US Pediatric Participants: aged 4 to 17 years and their parent/legal guardian are willing and able to understand and provide written informed assent/consent
• Participant weight is within intended use of at least one SpO2 sensor under test as time of enrollment.

• M1191T, adult participants > 50 kg
• M1192A, pediatric participants 15-50 kg
• Nasal Alar Sensor, adult and pediatric participants ≥ 15 kg
• M1194A, adult and pediatric participants > 40 kg
• Willing and able to wear study devices for the entirety of study procedures
• Undergoing regular spot-check measurements as per the site's standard of care

Exclusion criteria

• Palliative patients
• Patients with tremors, cardiac pacemakers, or known atrial fibrillation
• Patients receiving oxygen supplementation at the time of study participation
• Critically ill patients with severe physiological instability
• Pregnant and/or lactating patients (self-reported)
• Injury, wounds, and/or physical malformation of any sensor application site (e.g., fingers, nose, ear)
• Self-reported severe contact allergies to standard adhesives, latex, and/or other materials found in pulse oximetry sensors
• Unwillingness or inability to remove colored nail polish or artificial nails from the application site
• Unwillingness or inability to remove foreign objects, such as nose and/or ear jewelry from sensor application sites
• Nail fungus on application site
• Severe dermatitis or hyperkeratosis (e.g. ichthyosis) at sensor application site