MEDTEQ IBP Simulator (IEC 60601-2-34)

As of January 2017, please refer to the new MEDTEQ website www.medteq.net for latest version. As of July 2017, a new version IBPS 2.0 has been released. The information below is retained for reference and may be out of date. 

IEC 60601-2-34:2005 requires the following performance tests for the invasive blood pressure (IBP) function of a patient monitor:

- Accuracy of pressure measurement (static, real pressure sources)
- Accuracy of systolic (dynamic, real or simulated pressure sources)
- Frequency response (dynamic, real pressure sources)
- Alarm response time (dynamic, real or simulated pressure sources)

Although some of the tests refer to real pressure sources, in many cases manufacturers of the monitor and sensor are different. In this case, it can be appropriate to test the patient monitor using simulated signals only, using the industry wide 5µV/V/mmHg specification for IBP sensors. Also for the frequency response test, an alternate method is to test the patient monitor and sensor separately, with the patient monitor tested by simulated signals, and the sensor tested by step response (see here for more details).

On this basis, MEDTEQ system has developed a system which can provide simulated signals for all of the test in IEC 60601-2-34 as well as streaming real biological signals. The system provides the following features and functions:

- Active (electrical) simulation of pressures using a precision divider, with voltages output at 5µV/Vs/mmHg, where Vs is the measured or set sensor supply voltage. Active simulation includes the following types of output:

o Static pressures (constant output voltage)
o Dynamic pressures, sine waves up to 40Hz
o BioSim Mode, a real biological waveform with adjustable SYS/DIA & heart rate
o Biological waveforms, with embedded samples from the Pysionet website

- Internal measurement of sensor supply voltage (allows the system to
  automatically adjust for the sensor supply)

- Terminals (4mm) to monitor the actual output voltage directly, e.g by high accuracy 6.5 digit multimeter 

- graphical on-screen display of output waveforms

- Passive simulation of static pressures using an isolated network of precision
  resistors, for cases where there are concerns with excessive noise from the active simulation

Refer to the Test Equipment Overview page for links on pricing, operation manual (which includes specifications) and software.

Below is a screen show to show functionality. All MEDTEQ software can be downloaded for free and trialed in a simulation mode.

 Specifications

Active simulation

 

Parameter

Design Specification

Notes

Output voltage range

-1.25mV  ~ +8.25mV

Equivalent to
-50mmHg  ~ +330mmHg

DAC resolution

 

2.2µV

1 LSB

Overall Accuracy

±5µV

DAC compensation applied for increased accuracy.

Output Drift

<2µV / 30 min

 

After 5 min warm up time

Output Noise

<2µV

 

 

Frequency range

Sine: 0 – 40Hz

 

 Actual output is 5kHz sample rate, with 720Hz filter

Frequency accuracy

±0.1%

 

50ppm crystal

Sample rate (waveform streaming)

5kHz

 Filtering at 720Hz applied

Sensor load resistance

1.33kΩ

Resistance between sensor supply voltage leads

Sensor voltage measurement accuracy

±0.1%

 

Voltage monitor output

Direct connection to the differential output 

Allows monitoring of the real simulated voltage, e.g. by high accuracy 6.5 digit multimeter

 

Passive simulation

 

Parameter

Design Specification

Notes

Sensor load resistance

1.33kΩ

Resistance between sensor supply voltage leads

Network accuracy

±0.1% (full scale)

0.05% resistors used

 

Network values

300, 240, 150, 60, 30, 0, -30, -45mmHg

Matches the values in IEC 60601-2-34 for 300mmHg full scale.

 

Other

 

Parameter

Design Specification

Notes

Power supply

USB (+5Vdc, 0.3A)

 

USB high powered mode

Environment

+15°C ~ +35°C

35-80% RH

By design only, not tested

Warm up time

5 min

<2µV drift after warm up