Accuracy of Measurement of Respiration Rate
Conditions
Keywords
Respiration rate
Brief summary
A trial conducted within the company with a new non-contact respiration rate (RR) sensor. The device was compared for accuracy in RR measurement with a cleared device, the SOMNOScreen Easy, which uses chest effort bands. The RR was measured over a short duration on subjects sitting upright in a chair, with the non-contact sensor at various distances from the subject. A total of 20 subjects were tested, from both genders, selected to represent a wide range of age and body mass index
Detailed description
The Reassure uses Radio Frequency (RF) waves to detect the small movements of the human body due to respiration. The reference device, the SOMNOScreen, uses chest effort bands. The Reassure is non-contact and so more comfortable and convenient for quick RR measurement, in a similar way that an Infra-Red thermometer is compared to a traditional under-the-tongue mercury thermometer. The aim is to explore the variations in the human body that could have an effect on the radio reflection from the human torso, and thus affect the potential detection and accuracy of breathing rate. Factors that could affect non-contact RF performance are: * High Body Mass Index (BMI) could potentially reduce the chest wall movement during breathing, or alter the nature of the breathing. * Elderly, thin skin (ie pensioner with low BMI) may have less RF reflection. * Female breast tissue may have an effect on detection or accuracy. This was tested at a number of distances from the non-contact sensor and also with the subject having a thick comforter (duvet) laid across them. The test conditions were * Distances of 0.5 m, 1.0m and 1.5m between the subject and the RF sensor. * Additional test condition of comforter (duvet) on the subject when the distance from subject to sensor is 1.0 m. * Each test condition carried out twice. The use of the comforter in one test condition is to confirm that the RR measurement by the Reassure is unaffected by the thickness of clothing or blankets being worn.
Interventions
None listed
Sponsors
ResMed
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* Greater or equal to 18 years old and less than or equal to 75 years old * BMI within the range of greater or equal to 18 and less than or equal to 45
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Respiration Rate Accuracy | Recording duration of 2 minutes; measurement made after 45 seconds settling time, for at least 60 seconds | The respiration rate measured contemporaneously by the Reassure and the reference device, SomnoScreen, are compared on a second-by-second basis, over the recording duration. The difference between the two respiration rate measurements (the delta) for all 20 subjects' recordings, in all positions, are plotted on a normal distribution chart, giving 8,800 data points. The distribution chart reveals the mean difference between the two devices' measurements and the Standard Deviation (SD). The measure of success is if the 95% (ie 2SD) of the difference in the respiration rate indicated by the two devices (the delta) is less than 5 breaths per minute. This measure is derived from the peer review paper by Lim et al, cited in the References section |
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Respiration Rate Sensor All 20 subjects. Selected to have a range of ages (18 to less than 75) and BMI from 18.5 to 45 | 20 |
| Total | 20 |
Baseline characteristics
| Characteristic | Respiration Rate Sensor |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 20 Participants |
| Region of Enrollment Ireland | 20 participants |
| Sex: Female, Male Female | 10 Participants |
| Sex: Female, Male Male | 10 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 20 |
| other Total, other adverse events | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 |
Outcome results
Primary
Respiration Rate Accuracy
The respiration rate measured contemporaneously by the Reassure and the reference device, SomnoScreen, are compared on a second-by-second basis, over the recording duration. The difference between the two respiration rate measurements (the delta) for all 20 subjects' recordings, in all positions, are plotted on a normal distribution chart, giving 8,800 data points. The distribution chart reveals the mean difference between the two devices' measurements and the Standard Deviation (SD). The measure of success is if the 95% (ie 2SD) of the difference in the respiration rate indicated by the two devices (the delta) is less than 5 breaths per minute. This measure is derived from the peer review paper by Lim et al, cited in the References section
Time frame: Recording duration of 2 minutes; measurement made after 45 seconds settling time, for at least 60 seconds
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Respiration Rate Sensor | Respiration Rate Accuracy | 0.4 breaths per minute | Standard Deviation 1.75 |