Connect the sensor following the steps in the Getting Started section of the user manual.
When performing blood pressure measurements, it is best to work with a partner. Follow these general procedures when using Go Direct Blood Pressure:
- Attach the rubber hose from the cuff to the connector on the sensor.
- Wrap the cuff firmly around the subject's arm, approximately 2 cm above the elbow as shown below. The two rubber hoses from the cuff should be positioned over the bicep muscle (near the brachial artery) and not under the arm. Important: The arm should rest at the level of the heart, and remain relaxed throughout data collection. A desk or table can be used to support the arm. The subject must remain still during data collection—no movement of the arm or hand should occur during measurements.
- Find the sensor indicator light. It is located in the top right corner of the sensor label next to the check mark.
- Begin data collection. Quickly and repeatedly squeeze the bulb to inflate the cuff. Continue inflating the cuff to a pressure between 150 and 170 mmHg. The sensor indicator light will flash red as the cuff is inflated. When the light flashes green, an appropriate pressure has been reached. Note: A meter in the data-collection software will also display the live pressure readings from the sensor.
- When the light flashes green, set the bulb pump down on the table. The built-in pressure release valve will slowly deflate the cuff. The sensor indicator light will flash green as the pressure decreases.
- When the pressure drops to 50 mmHg, you may press down on the pressure release valve to release any air remaining in the cuff.
- When the sensor indicator light turns solid green, blood pressure parameters have been reported. Stop data collection. Results will be displayed in the meters at the bottom of the graph. Results can also be found in the data table and will be reported on the meter screen.
Note: If the sensor indicator light turns solid red, blood pressure parameters were not reported by the sensor. Repeat data collection.
Note: If the cuff pressure does not reach 50 mmHg after 90 seconds, adjust the exhaust rate of the pressure release valve according to the directions listed under “Adjusting the Pressure Release Valve.”
Go Direct Blood Pressure has seven measurement channels:
- Cuff Pressure
- Mean Arterial Pressure
- Systolic Pressure
- Diastolic Pressure
- Pulse Rate
This channel measures the pressure applied to the cuff. This channel is active by default when the sensor is connected.
Mean Arterial Pressure
This channel reports the estimated mean arterial blood pressure using the oscillometric method. The value is reported at the end of the run after the pressure has fallen below 50 mmHg. This channel is active by default when the sensor is connected.
This channel reports the estimated systolic blood pressure using the oscillometric method. The value is reported at the end of the run after the pressure has fallen below 50 mmHg. This channel is active by default when the sensor is connected.
This channel reports the estimated diastolic blood pressure using the oscillometric method. The value is reported at the end of the run after the pressure has fallen below 50 mmHg. This channel is active by default when the sensor is connected.
This channel reports the pulse rate of the subject in beats per minute (bpm). The sample window for the calculation is the last 30 seconds of data collection. The value is reported at the end of the run after the pressure has fallen below 50 mmHg. This channel is active by default when the sensor is connected.
This channel displays the pulses found during cuff deflation. This channel is not active by default when connected to the sensor.
This channel graphs the peak-to-peak amplitudes of all pulses detected during cuff deflation. The resulting graph is the "envelope" used to calculate blood pressure parameters using the oscillometric method. This channel is not active by default when connected to the sensor.
Adjusting the Pressure Release Valve
The pressure release valve is set to release at a rate of 3.0 mmHg/s on an arm that is 32 cm in circumference. For arms much larger or much smaller it may be necessary to adjust the valve so that the exhaust rate stays in the range of 2.0 to 4.0 mmHg/s. With the bulb in hand and the hose leading away from you, place a screwdriver into the metal slot on the top of the release valve. To increase the rate of exhaust, turn the screwdriver clockwise. To decrease the rate of exhaust, turn the screwdriver counter-clockwise. The larger a subject’s arm the slower the release valve will exhaust.
Using Go Direct Blood Pressure at High Altitudes (above 6,000 ft)
To record proper measurements at altitudes above 6,000 ft (0.8 atm or 609 mmHg) the pressure release valve will need to be readjusted. The pressure release valve is set to release at a rate of 3.0 mmHg/s at sea level, where atmospheric pressure is 1 atm or 760 mmHg. At higher altitudes, the pressure release valve will exhaust at a slower rate. To use Go Direct Blood Pressure at altitudes above 6,000 ft, open the pressure exhaust valve by turning it a half turn clockwise. See the instructions above. Verify that the exhaust rate is now in the range of 2.0–4.0 mmHg/s after making the adjustment.