WatchPAT™200 System
9
Operation Manual
2
OVERVIEW
Obstructive sleep apnea syndrome (OSAS) is considered a major public health
problem. The prevalence of the syndrome is estimated at 2% to 5% in the adult
population. It is characterized by recurrent events of complete or partial obstruction of
the upper airways during sleep, often leading to hypoxemia, and/or arousals associated
with sympathetic nervous system activation. The diagnosis and assessment of the sleep
apnea patient is based on the Respiratory Disturbance Index (RDI), the number of
Apneas, Hypopneas and Respiratory Effort Related Arousals (RERA) per hour of
sleep, along with sleep architecture. The common consequences of this sleep disruption
are daytime sleepiness, poor daytime performance and increased vulnerability to
accidents. Cardiovascular complications such as systemic/pulmonary hypertension,
ischemic heart disease and arrhythmias are the major sequel of OSAS in the adult
population.
The WatchPAT™ device is worn on the wrist and is utilizing a plethysmographic
based finger–mounted probe, to measure the PAT
®
(Peripheral Arterial Tone) signal.
The PAT
®
signal is a measurement of the pulsatile volume changes in the fingertip
arteries which reflects the relative state of the arterial vasomotor activity, and thus
indirectly the level of sympathetic activation. Peripheral arterial vasoconstriction,
which mirrors sympathetic activation, is shown as attenuation in the PAT
®
signal
amplitude. The PAT
®
signal is recorded continuously and stored on an embedded
micro SD card, together with data from a built-in pulse-oximetry sensor (mounted on
an adjacent finger) and an actigraph (embedded in the WatchPAT™200 device).
Following the sleep study, the recordings are automatically downloaded and analyzed
in an offline procedure using the proprietary zzzPAT software.
The zzzPAT algorithms use the four W
atch
PAT™ channels (PAT
®
, Pulse Rate,
Oxygen saturation and actigraphy) for the detection of sleep related breathing disorders
and sleep staging (Rapid Eye Movement (REM), Light Sleep, Deep Sleep and Wake).
The zzzPAT uses WatchPAT™ device snoring and body position channels (SBP) to
generate snoring level and body position discrete states. The use of SBP is optional and
according to physician preference.
The software issues comprehensive reports of the study, with statistics and graphic
presentation of the results. The whole night data can be viewed and the automatically
detected events can be revised manually.
