Evaluation of a Portable Device Based on Peripheral Arterial Tone for Unattended Home Sleep Studies

doi:10.1378/chest.123.3.695

Chest

Volume 123, Issue 3, March 2003, Pages 695-703

https://doi.org/10.1378/chest.123.3.695 Get rights and content

Background

Diagnosis of obstructive sleep apnea syndrome (OSAS) by ambulatory systems is a growing practice in view of the large number of patients awaiting correct diagnosis. The Watch PAT100 (WP100) [Itamar Medical; Caesarea, Israel] is a portable device based on the peripheral arterial tone (PAT) signal, and is designed for unattended home sleep studies.

Objectives

To evaluate the efficacy, reliability, and reproducibility of the WP100 device for the diagnosis of OSAS as compared to in-laboratory, standard polysomnographic-based manual scoring.

Design and methods

One hundred two subjects (78 men; 69 patients with OSAS and 33 normal volunteers; mean ± SD age, 41.4 ± 15.2 years; body mass index, 26.8 ± 5.5) underwent in-laboratory full polysomnography simultaneously with WP100 recording. Fourteen subjects also underwent two additional unattended home sleep studies with the WP100 alone. The polysomnography recordings were blindly scored for apnea/hypopnea according to the American Academy of Sleep Medicine criteria (1999), and the polysomnography respiratory disturbance index (RDI) [PSG-RDI] was calculated. The WP100 data were analyzed automatically for the PAT RDI (PRDI) by a proprietary algorithm that was previously developed on an independent group of subjects.

Results

Across a wide range of RDI levels, the PRDI was highly correlated with the PSG-RDI (r = 0.88, p < 0.0001), with an area under the receiver operating characteristic curve of 0.82 and 0.87 for thresholds of 10 events per hour and 20 events per hour, respectively. The PRDI scores were also highly reproducible, showing high correlation between home and in-laboratory sleep studies (r = 0.89, p < 0.001).

Conclusion

The WP100 may offer an accurate, robust, and reliable ambulatory method for the detection of OSAS, with minimal patient discomfort.

Section snippets

Study Population

The study group consisted of 69 consecutive subjects referred to the clinical sleep laboratory of the Technion Sleep Medicine Center (Haifa, Israel) with suspected OSAS, and 33 additional healthy adult volunteers, without complaints of snoring or daytime sleepiness. None of the subjects had previously undergone a polysomnographic study. Seventy-eight subjects were men, and 24 were women. The mean ± SD age of the group was 41.4 ± 15.2 years. The men were slightly more obese (body mass index

Results

Of 102 in-laboratory studies, 3 studies were rejected: 2 polysomnography studies had synchronization failure and 1 study was rejected due to PAT valid sleep time < 1.5 h. Three of the 28 at-home PAT studies were originally rejected due to technical failure but were repeated successfully; thus, the at-home rejection rate was 3 of 31 studies. None of the participants requested to withdraw from the study due to discomfort or any other reason, and no adverse or side effects were reported. A wide

Discussion

This study shows that the WP100 is a simple, reliable and accurate device for ambulatory diagnosis of OSAS. The in-laboratory measured PRDI results were well correlated with the in-laboratory PSG-RDI results (r = 0.88, p < 0.0001), with good efficacy for both OSAS diagnosis (RDI > 10)¹⁶ and for CPAP therapy indication (RDI > 20)¹⁷ [AUC of 0.82 and 0.87, respectively]. The in-laboratory PRDI results were highly reproducible in the home sleep studies, with correlation coefficients of 0.89 and

Conclusion

Despite these limitations, we believe that this study shows that the WP100 is a simple, reliable, and accurate device for diagnosing OSAS in the unattended home set-up. Using a device with sensors placed only on the fingers and forearm makes it simple to self-administer and well tolerated. Using the automated scoring algorithm allows for objectivity and is time saving.

References (29)

Y Yamashiro et al.
CPAP titration for sleep apnea using a split-night protocol
Chest
(1995)
MJ Decker et al.
Ambulatory monitoring of arterial oxygen saturation
Chest
(1989)
P Levy et al.
Accuracy of oximetry for detection of respiratory disturbances in sleep apnea syndrome
Chest
(1996)
LJ Epstein et al.
Cost-effectiveness analysis of nocturnal oximetry as a method of screening for sleep apnea-hypopnea syndrome
Chest
(1998)
O Le Bon et al.
Mild to moderate sleep respiratory events: one negative night may not be enough
Chest
(2000)
S Redline et al.
Measurement of sleep-related breathing disturbances in epidemiologic studies: assessment of the validity and reproducibility of a portable monitoring device
Chest
(1991)
F Cirignotta et al.
Unreliability of automatic scoring of MESAM 4 in assessing patients with complicated obstructive sleep apnea syndrome
Chest
(2001)
T Young et al.
Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle aged men and women
Sleep
(1997)
American Academy of Sleep Medicine
Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurements techniques in clinical research; the report of an American Academy of Sleep Medicine Task Force
Sleep
(1999)
F Portier et al.
Evaluation of home versus laboratory polysomnography in the diagnosis of sleep apnea syndrome
Am J Respir Crit Care Med
(2000)

ASDA Standards of Practice Committee

Portable recording in the assessment of obstructive sleep apnea

Sleep

(1994)

LB Grote et al.

Alteration of digital pulse amplitude reflects α adreno-receptor mediated constriction of the digital vascular bed [abstract]

Sleep

(2001)

RP Schnall et al.

Periodic, profound peripheral vasoconstriction: a new marker of obstructive sleep apnea

Sleep

(1999)

G Pillar et al.

Detection of obstructive sleep disordered breathing events utilizing peripheral arterial tonometry and oximetry [abstract]

Sleep

(2000)

Cited by (184)

Portable evaluation of obstructive sleep apnea in adults: A systematic review
2023, Sleep Medicine Reviews
Obstructive sleep apnea (OSA) is a significant healthcare burden affecting approximately one billion people worldwide. The prevalence of OSA is rising with the ongoing obesity epidemic, a key risk factor for its development. While in-laboratory polysomnography (PSG) is the gold standard for diagnosing OSA, it has significant drawbacks that prevent widespread use. Portable devices with different levels of monitoring are available to allow remote assessment for OSA. To better inform clinical practice and research, this comprehensive systematic review evaluated diagnostic performances, study cost and patients’ experience of different levels of portable sleep studies (type 2, 3, and 4), as well as wearable devices and non-contact systems, in adults. Despite varying study designs and devices used, portable diagnostic tests are found to be sufficient for initial screening of patients at risk of OSA. Future studies are needed to evaluate cost effectiveness with the incorporation of portable diagnostic tests into the diagnostic pathway for OSA, as well as their application in patients with chronic respiratory diseases and other comorbidities that may affect test performance.
Impact of undiagnosed obstructive sleep apnea on atrial fibrillation recurrence following catheter ablation (OSA-AF study)
2022, IJC Heart and Vasculature
Sleep-disordered breathing (SDB) may hamper the outcome of catheter ablation of atrial fibrillation (AF). However, SDB is underdiagnosed in clinical practice and the relevancy of undiagnosed SDB on the outcome of catheter ablation is unclear.
To evaluate if undiagnosed SDB has an impact on AF recurrence after catheter ablation.
In this single-center cohort study we enrolled patients who had a catheter ablation of AF 12 to 18 months prior to enrolment. Patients with diagnosed SDB at the time of catheter ablation were excluded. Enrolled patients underwent screening using WatchPAT (WP). SDB was defined as an apnea-hypopnea index (AHI) ≥ 15.
A total of 164 patients were screened for eligibility. After exclusion of patients with previously diagnosed SDB (n = 30), 104 of 134 eligible patients were enrolled and underwent SDB screening. The median AHI was 11.5 (interquartile range 6.8–21.9) and 39 patients (38%) had SDB which was undiagnosed during the first year after ablation. AF recurrence in the first year after catheter ablation occurred in 40 patients (38%). The risk of AF recurrence was higher in the group with undiagnosed SDB in comparison to those without SDB (51% versus 31%, P = 0.04). Interestingly, the prevalence of AF recurrence was similar between patients with previously diagnosed and undiagnosed SDB (51% versus 50%, P = 0.92).
A significant proportion of patients undergoing catheter ablation of AF have undiagnosed SDB which is associated with a twofold higher risk of AF recurrence. SDB screening may improve patient counselling regarding the efficacy of catheter ablation.
Peripheral arterial tonometry–PAT technology
2022, Sleep Medicine Reviews
Citation Excerpt :
When the finger is inserted into the probe, air is shifted from the inner compartment of the probe to its outer compartment, causing the pre-tensioned outer membrane to be pushed off the wall of the inner shell and to thus apply pressure to the air within the probe. The elastic properties of the balloon-like outer membrane are such that over a wide range of volumes it creates a constant pressure, as shown in C [9]. When blood in the venous system begins to pool in the finger, which can happen due to lowering the hand below heart level or by partially blocking venous outflow with a circumferential pressure cuff, the intravenous pressure increases and this can result in substantial changes in the pulse wave signals measured by an optical sensor (PPG) which is not covered by the PAT pressure field.
PAT Technology is a plethysmographic based measurement method which facilitates the accurate recording of the pulsatile volume changes of the arteries of peripheral vascular beds at the distal end of the fingers over sustained periods of time.
It represents a departure from previously available plethysmographic methods, in so far as it applies a uniform pressure field which completely envelopes the measured part of a digit, including its distal-most tip.
Applying near diastolic blood pressure levels of pressure within the PAT probe optimizes the dynamic range of the signal, prevents confounding veno-arteriolar reflex vasoconstriction at the measurement site, reduces respiratory and movement artifacts and thus facilitates accurate long term measurement.
The vascular bed of the distal phalanx of the finger is a major site of sympathetic nervous system mediated vasoconstrictor activity, and the PAT response to sympathetic changes provides a platform for accurate and robust measurement in a number of sleep and sleep related clinical areas, foremost as a patient friendly and extensively validated home sleep testing device.
Sleep Measurement in Children—Are We on the Right Track?
2021, Sleep Medicine Clinics
Getting More from the Sleep Recording
2021, Sleep Medicine Clinics
Sleeping with Hippocampal Damage
2020, Current Biology
The hippocampus plays a critical role in sleep-related memory processes [1, 2, 3], but it is unclear which specific sleep features are dependent upon this brain structure. The examination of sleep physiology in patients with focal bilateral hippocampal damage and amnesia could supply important evidence regarding these links. However, there is a dearth of such studies, despite these patients providing compelling insights into awake cognition [4, 5]. Here, we sought to identify the contribution of the hippocampus to the sleep phenotype by characterizing sleep via comprehensive qualitative and quantitative analyses in memory-impaired patients with selective bilateral hippocampal damage and matched control participants using in-home polysomnography on 4 nights. We found that, compared to control participants, patients had significantly reduced slow-wave sleep—likely due to decreased density of slow waves—as well as slow-wave activity. In contrast, slow and fast spindles were indistinguishable from those of control participants. Moreover, patients expressed slow oscillations (SOs), and SO-fast spindle coupling was observed. However, on closer scrutiny, we noted that the timing of spindles within the SO cycle was delayed in the patients. The shift of patients’ spindles into the later phase of the up-state within the SO cycle may indicate a mismatch in timing across the SO-spindle-ripple events that are associated with memory consolidation [6, 7]. The substantial effect of selective bilateral hippocampal damage on large-scale oscillatory activity in the cortex suggests that, as with awake cognition, the hippocampus plays a significant role in sleep physiology, which may, in turn, be necessary for efficacious episodic memory.

View all citing articles on Scopus

: Drs. Bar, Dvir, Sheffy, and Schnall are employees of Itamar Medical Ltd. Dr. Pillar and Professor Lavie are consultants in that firm.

: Supported in part by a grant from Itamar Medical Ltd., Caesarea, Israel.

View full text

Chest

Clinical InvestigationsSleep and BreathingEvaluation of a Portable Device Based on Peripheral Arterial Tone for Unattended Home Sleep Studiesa

Background

Objectives

Design and methods

Results

Conclusion

Section snippets

Study Population

Results

Discussion

Conclusion

Chest

Chest

Chest

Chest

Chest

Chest

Chest

Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle aged men and women

Sleep

Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurements techniques in clinical research; the report of an American Academy of Sleep Medicine Task Force

Sleep

Evaluation of home versus laboratory polysomnography in the diagnosis of sleep apnea syndrome

Am J Respir Crit Care Med

Portable recording in the assessment of obstructive sleep apnea

Sleep

Alteration of digital pulse amplitude reflects α adreno-receptor mediated constriction of the digital vascular bed [abstract]

Sleep

Periodic, profound peripheral vasoconstriction: a new marker of obstructive sleep apnea

Sleep

Detection of obstructive sleep disordered breathing events utilizing peripheral arterial tonometry and oximetry [abstract]

Sleep

Clinical Investigations
Sleep and Breathing
Evaluation of a Portable Device Based on Peripheral Arterial Tone for Unattended Home Sleep Studies^a