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Table 2 - Medical metrology studies at international organizations
Organization
Area of study

JCI

ECRI

WHO

FDA

IPEM

EMRP

OIML

APMP

Accreditation
for hospital
management

Training

Establishment
of calibration
systems

Certification

Method
development

Standardization

Health policy

Asia Pacific Metrology Programme (APMP) scope is to:
◗◗ Support the entire value chain from research and development design to manufacturers and end users, regulatory
and accreditation bodies,
◗◗ Establish national and international equivalence in medical measurements,
◗◗ Establish the traceability of medical devices and diagnostics, and
◗◗ Exchange experiences among NMIs, DIs and TCs to identify gaps and needs in medical fields.
Some international organizations focus on regulations,
while the others focus on standardizations and certifications.
Some of them organize training courses and others establish
the calibration systems, as seen in Table 2. The main objective
of all of the international organizations is to increase the quality of medical measurements and applications.

Measurement Parameters and
Traceability in Medical Devices
The patient simulator, defibrillator/pacer, infusion pump
simulator, electrosurgery analyzer, electrical safety analyzer,
pulseoximeter analyzer and gas flow analyzer are the most
used medical device calibrators. Parameters, measurement
ranges and accuracies for these devices are given in Table 3.
For example, blood pressure measuring devices (that are
individual or engaged to a patient monitor) are calibrated by
using a patient simulator device that is calibrated routinely in
NMSs or DIs to establish metrological traceability. Establishment of similar links to calibrators and to SI/derived SI units
maintains the accuracy in the medical measurements. The calibration of the infusion pump analyzer is realized according to
manufacturer specifications (Fig. 2). Before the calibration process, the device flow channels are cleaned by flowing distilled
and degassed water with soft detergent by connecting the Syringe3 directly into channels to remove any remaining dirt and
chemical residues. This process prevents the formation of unwanted bubbles during calibration. All hose connections are
52

completed and filled with water to avoid bubbles in the water
during calibration, as seen in Fig. 2. The cleaning process is repeated a few times until no bubbles left.
Then, the calibration process is realized by the following:
◗◗ First, some amount of distilled and degassed water is
injected from a reservoir to fill the Syringe3, as indicated
by the red arrows, while valves V1, V2 and V3 are closed
and valve V4 is open.
◗◗ Then V4 is closed and V1 is opened. The water is sent
to calibrated Syringe2 (and Syringe3 for the calibration
of 2 channels at the same time), as indicated by the blue
arrows, until they are full.
◗◗ The infusion device has been set to desired flow rates
and volumes between 75 ml/hr and 830 ml/hr and at
25 ml and 45 ml volumes according to manufacturer
specifications.
◗◗ The process starts automatically for each set of measurements. The water flows through the channels of the
infusion pump analyzer, as indicated by the yellow
arrows, while V1 and V4 are closed and V2 and V3 are
opened.
◗◗ Pressure tests are realized between 5 PSI and 40 PSI.
◗◗ Solenoid valve release tests are conducted and value is
measured.
◗◗ All values are measured and recorded for each measurement at each channel and compared to tolerances and
manufacturer specifications.

Discussion
The current situation, needs and infrastructures have been
outlined in this review paper. The reasons that metrology is not
as powerful in the medical field as in the military and industrial fields can be listed as follows:
◗◗ In metrology institutes, even though there are laboratories for the establishment of SI and derived SI units,
there is no specific calibration laboratory for medical
devices. There is no general consensus between NMI/DI

IEEE Instrumentation & Measurement Magazine

June 2020

Instrumentation & Measurement Magazine 23-4

Table of Contents for the Digital Edition of Instrumentation & Measurement Magazine 23-4