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Chapter 13
Fiber Optic Pressure
Overview
The Fiber Optic Pressure option for the Model 1030 provides the capability to
continuously monitor physiological pressure using ultra-miniature, fiber optic pressure
sensors. The ultra-miniature sensors are intended for use in small infusion needles,
catheters and guide wires enabling minimally invasive physiology pressure
measurements.
The pressure sensors can be used to measure pressure in a number of locations like
the aorta, left ventricle of the heart, ventricles of the brain and in the spinal canal.
However, for many users, the most exciting application is to provide minimally invasive,
continuous monitoring of blood pressure and heart rate by simply inserting the sensor
tip into an artery
The ultra-miniature pressure sensor consists of a tiny silicon cavity attached to a
relatively long fiber optic cable. White light is sent via the fiber to and from the cavity.
Polarization interferometer processing electronics precisely computes the Fabry-Perot
cavity length and determines the corresponding pressure reading.
An internal
manometer automatically corrects the reading for changes in atmospheric pressure.
Fiber optic pressure sensors are not affected by the strong RF and magnetic fields of
the MR scanner. They can not contribute to RF heating and they do not produce an
artifact in MR images.
The Fiber Optic Pressure Module is located next to the magnet bore. A fiber optic
pressure sensor extends into the bore and attaches to the animal. The module receives
and sends data along with other optional modules from and to the ERT Control/Gating
Module using fiber optic communication cables. It receives power from a dedicated
supply or a daisy chain power cable if other options are present.
Sensor and extension connections
The pressure sensor connects to the module using an optical extension cable. A 1 m
extension is standard but other lengths are available. Special cleaning procedures for
sensors and extension cables, detailed later in this chapter, provide for reliable long
term operation. We recommend leaving the extension cable connected to the module
when disconnecting the pressure sensor.
The optical sensor extension cable (FOP-OEX-1M) has a male SC connector on one
end and a female SC adapter on the other end. The male SC connector connects to
the Fiber Optic Pressure Module at the port labeled "sensor". Align the keyway and
insert the male connector to make the connection. Use the thumb and forefinger to
grasp the male connector housing on either side of the keyway and pull to disconnect.
Two fiber optic pressure sensors are available with tip OD of 0.3 mm and 0.4 mm. They
have a male SC connector that connects to the extension cable's female SC adapter.
Revision C, August 2013
13-1
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