2
Description
The Blood Pressure sensor is used to measure arterial blood pressure in humans (non-
invasively). It measures the pressure signal caused by the interaction between the cuff and
the blood flow through the brachial artery.
The pressure sensor uses the SenSym SDX05D4 pressure transducer. This element has a
membrane that flexes as pressure changes. It is arranged to measure differential pressure.
The sensor produces an output voltage that varies in a linear way with pressure. Special
circuitry minimizes the errors that might be caused by changes in temperature. The sensor
is delivered with standard adult size adjustable cuff (27 cm to 39 cm) and bulb pump (with
release valve).
The Blood Pressure sensor
is equipped with a BT plug and can be connected to the
following CMA interfaces: €Lab
,
CoachLab II/II
+
and
U
LAB. Furthermore the
sensor can be used with Texas Instruments CBL
, CBL2
and Vernier LabPro
.
Important:
The Blood Pressure sensor is not appropriate for medical applications.
This sensor is to be used only for educational purposes. Read this manual before you start
measurements with the sensor. Notice that over inflation of the cuff may cause pain and/or
injury
.
Sensor specifications
The Blood Pressure sensor
has a memory chip (EEPROM) with information about the
sensor. Through a simple protocol (I
2
C) the sensor transfers its data: name, quantity,
unit and calibration to the interface
1
.
Suggested experiments
The following experiments can be performed with the Blood pressure sensor:
Measure blood pressure before and after exercise and while sitting or standing;
Compare blood pressure after voluntary isometric contractions (weight lifting) and a
rhythmic activity such as running or biking;
Study the effect of caffeine on blood pressure.
Calibration
The output of the Blood Pressure sensor is linear with respect to pressure. To collect data
you can:
1.
Use the calibration supplied by the sensor EEPROM memory.
2.
Use the calibration supplied in the standard sensor library of the Coach program. The
name of the Blood pressure sensor in the sensor library of Coach is
Blood pressure sensor (0377i) (CMA) (0..250 mm Hg).
1
This is valid for the following interfaces: CMA €Lab
,
BT inputs of CoachLab II/II
+
and
U
LAB,
TI CBL
and CBL2
, and Vernier LabPro.
