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Itamar Medical Ltd.
NOTE:
It is recommended to leave the finger probe connected to the WPONE-M at all
times in order to avoid leaving the connector exposed.
2.2
Finger Probe Description
The WatchPAT Finger Probe is an electro-opto-pneumatic finger-mounted probe. Its role is to
continuously measure the relative state of the vasomotor activity in the distal part of the finger
based on a plethysmographic method. The Finger Probe is designed to cover the distal part
of the finger with a uniform predetermined pressure field extending to the tip of the finger, at
all fingers' sizes. This design prevents venous blood pooling, engorgement and stasis, which
inhibits retrograde venous shock wave propagation, and allows partial unloading of arterial
wall tension that significantly improves the dynamic range of the measured signal. The optic
component of the probe measures the optical density related changes of the arterial blood
volume in the digital arteries, associated with each heartbeat. Peripheral arterial constrictions,
when present, are shown by attenuation in the PAT signal amplitude, a marker of sympathetic
activation.
The Finger Probe also measures the changes in absorbance of the finger at both red and
infrared light at peak wavelengths of approximately 660nm and 910nm respectively. The
maximum optical output power is 65mW. These measurements are used to calculate the
oximetry signal in an offline program according to the pulse oximetry principles.
The Finger probe is an integral part of the WatchPAT™ device and is to be used only with the
WatchPAT device.
2.3
Chest Sensor Description
This section is applicable for those using a WatchPAT™ONE configuration that has a chest
sensor.
The Chest Sensor consists internally of two sensors: a snore sensor and a chest movement
sensor. The Snore Sensor is an acoustic decibel detector. It uses a highly sensitive microphone
that responds to snoring and other sounds in the audio range and converts them to a signal
that provides a clear, reliable indication of the presence of these sounds.
The Chest Sensor uses a 3-axis accelerometer that provides a signal that reflects the
movement of the chest, which can be translated both to the patient's sleeping posture
(supine, prone, right, left and sit) and to the chest movement signal resulted by the subject's
breathing during the night.
WatchPAT™ONE System
20
Operation Manual
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