Optimal replacement policy in the medical equipment

Czech Republic
Czech Technical University in Prague
Faculty of Biomedical Engineering
Ilya V. Ivlev
Decisive factor:
 the state of equipment used in hospitals
Problematic issues:
 the standard service life of the majority of
medical equipment has already expired
Caution:
 use of this equipment can become hazardous
to both - patients and medical personnel
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3
annual
maintenance
costs
investment
in the
hospital
↑
↓
physical
life
↓
↑
annual costs
of the
acquisition;
4
Create a mathematical model
contains the main components:
that
1.
the cost of procurement of medical
equipment and annual costs of repair;
2.
the annual operating costs (mainly
including the costs of consumables and
power consumption, etc.)
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Possible solution requires certain rules:
First rule:
medical device down time (tdow) for repair
and maintenance should not exceed half
time of operation (top);
Efficiency coefficient is:
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A. M. Aronov, Biomedical Engineering, 2007
Working days per year = 254 (working year)
device down time
(tdow)
time of operation
(top)
efficiency
coefficient (Ceff)
1
…
253
…
0,99
…
15
…
30
…
239
…
224
…
0,87
…
0,73
…
72
182
0,21
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Second rule:
efficiency coefficient Ceff during medical device
normal service life varies:
Fig. Ceff variation during medical device service life.
Ceff
Time of use, years
I - varies of Ceff during normal service life of medical device;
II - varies of Ceff after double normal service life (if the medical device is still used);
III - Ceff after making 300% of the resource.
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Third rule:
 Practical value of Ceff over than value
determined by the first rule is criterion of final
medical device impracticability THE MEDICAL DEVICE SHOULD BE REPLACED.
Ceff
Time of use, years
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The expectancy economic life of medical
equipment:
P0 - initial price of medical equipment;
W - increase in operating costs each year.
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Chen Kang, Chinese J. of Medical Instrumentation, 2009
CT scanner: General Electric (HiSpeed CT/e Plus):
• initial price (P0) ≈ $190K;
• increase in operating costs each year (W) ≈ $15K
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1.
2.
there are different approaches to determining the
optimal duration of life (physical, economic) of
medical equipment;
application of mathematical models helps more
carefully and dispassionately manage
of
equipment;
3.
no models that take into account most of the
influencing factors and the specifics of medical
equipment;
4.
do not resolved the question of what is
amortization.
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