MEDICAL SENSORS / WHITE PAPER
Sensors for Medical Pump Applications
PAGE 6
Other Sensors in Infusion Pumps
The designs for infusion pumps are becoming more sophisticated and additional features and diagnostics are
being added. This will require the use of additional sensors as well as sensors with improved performance.
Two other areas in medical pumps where sensors have been utilized include position sensors for motor
feedback and diagnostics and temperature sensors for the monitoring and control of infusion liquids.
Anisotropic Magnetoresistive (AMR) position sensors are precise and contact-less devices that measure
the changes in the angle of a magnetic field as seen by the sensor. TE's magnetic sensors offer robust non-
contact position measurements in harsh environments. For example, the unique features of the AMR effect
allow the measurement of sub-micrometer displacements in precision linear encoders. The AMR technology
is also successfully used for presence detection, such as the endpoint detection in pneumatic cylinders. This
AMR technology provides a low-cost, robust technology for monitoring either linear or rotary motion and
allows precise position feedback for a range of motors that drive most infusion pumps. These durable products
are designed to provide enhanced output accuracy for smooth motor control and their small size often
reduces replacement costs and allows for design into many compact, automated, lower-cost assemblies.
On the temperature sensor side, it has been shown that intraoperative
intravenous fluid administration and blood product transfusion have considerable
effects on body temperature. Thus, it is important to monitor and control
the temperature of fluids. A range of medical fluid warmers are often utilized
when fluids are infused intravenously, and temperature sensors are integrated
as part of these systems to monitor and control the temperature of the fluid.
While many of the warming units are separate and external to the infusion
pump, there is a push to integrate this option into new infusion pump designs.
TE Connectivity designs and manufactures a wide range of temperature
components and assemblies that have been used in a broad range of invasive
and non-invasive medical applications to monitor everything from core body
temperature to the temperature of cryogenic gases used for angioplasty balloons.
Summary
TE designs and manufactures a broad range of sensors utilizing many different technologies that
are critical for the monitoring and control of electronic systems for a range of applications in
the medical field. One of the major areas within patient treatment is medical pumps and, more
specifically, infusion pumps. TE sensors are applied in the following areas of infusion pumps:
• Force sensors to detect occlusions to confirm there is no blockage
in the tube that delivers medication to the patient.
• Air bubble detectors are capable of positively identifying the presence of a break in flow of any type of liquid.
• Anisotropic magnetoresistive (AMR) position sensors monitor the
angular or linear position of medical pump motors.
• Temperature sensors are used to monitor and control the temperature of
infused liquids that are being delivered into a patient's body.
MEDICAL TEMPERATURE
SENSOR ASSEMBLIES
