J. Vander Sloten, P. Verdonck, M. Nyssen, J. Haueisen (Eds.): ECIFMBE 2008, IFMBE Proceedings 22, pp. 1581–1584, 2008
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Health Technology Management: Medical Equipment Classification
N.F. Oshiyama
1
, A.C. Silveira
1
and J.W.M. Bassani
1,2
1
Universidade Estadual de Campinas (UNICAMP)/Departamento de Engenharia Biomédica,
Faculdade de Engenharia Elétrica e Computação, Campinas, Brazil
2
Universidade Estadual de Campinas (UNICAMP)/Centro de Engenharia Biomédica, Campinas, Brazil
Abstract — This paper presents two methods for medical
equipment classification according to three maintenance indi-
cators (NC
C
= annual number of corrective maintenances
divided by the median of the number of corrective mainte-
nances for the specific maintenance group; TM
C
= time spent
on corrective maintenance per year divided by the median of
the time for the specific maintenance group, $M
C
= annual cost
of corrective maintenance divided by 6% of the depreciated
acquisition cost of the equipment). The main tool was a simple
database for each type of equipment. As shown in a previous
paper, one of the methods is based on the fact that the indica-
tor values increase as the equipment gets older. The other
method is based on the ABC analysis, in which three limits
were established based on Pareto’s law. Data of syringe infu-
sion pumps from years 2004 - 2006 (database of the Center for
Biomedical Engineering, University of Campinas) were used.
One-way analysis of variance revealed that NCc, TMc and
$Mc values increase significantly with age. Out of 50 syringe
infusion pumps, 42% were classified as C, although 80% of the
equipments were not in the 10-14 year category. The results of
the ABC and age analyses were 96% coincident. Maintenance
indicators seem to keep a relation with the equipment age and,
if used in nationwide scale, they might be a robust tool for
equipment classification. Unexpected behaviors may be rele-
vant warnings to the Clinical Engineering staff, regulatory
agencies and manufacturers interested in data mining.
Keywords — Clinical Engineering, equipment maintenance,
medical equipment, maintenance indicators, ranking
I. INTRODUCTION
Current technological development increases the variety
of medical equipment available to the market. Since these
new technologies usually create a disproportion between the
costs and the resources available, Clinical Engineering (CE)
work becomes more important and requires more efficient
management methods [1][2]. One of the main problems in
this effort, however, is to find the appropriate way to obtain
quantitative information on equipment performance along
its lifetime. This type of information may be useful to help
regulatory agencies to identify aberrant behavior in medical
devices and investigate its causes before patients are harmed
or deficient results are delivered to particular health pro-
vider. In practical terms, it is quite valuable for the CE
group to know whether a specific device performs well
according to some criteria that take into account a larger
population of similar devices under care of different CE
groups.
This work proposes two methods for medical equipment
classification based on three maintenance indicators, which
could be used at any hospital, independently of the number
of beds or pieces of equipment. One of the methods is based
on the hypothesis that the maintenance indicators increase
as equipment ages (Aging Method, AM). The second
method is based on the ABC (“Always Better Control”)
analysis and is presented as a simpler, more limited, but yet
useful method (in short, ABCM).
II. MATERIALS AND METHODS
In order to calculate the three indicators in the AM, data
were collected from the Center for Biomedical Engineering
(CEB) of the University of Campinas (UNICAMP), Campi-
nas, Brazil, database from 2004 to 2006. A Microsoft®
Excel™ spreadsheet was prepared with medical equipment
attributes, such as identification, manufacturer, model, serial
number, location, acquisition price and date, as well as the
number of corrective maintenances (NC), total maintenance
cost ($M) and time (TM).
The three annual indicators are then calculated as fol-
lows:
Year
NC median
NC
NC
L
C
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
) (
(1),
where NC
L
is the number of corrective maintenances from
the local maintenance group.
Year
TM median
TM
TM
L
C
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
) (
(2),
where TM
L
is the total corrective maintenance time from
the local maintenance group.
Year
A
M
M
D
C
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
⋅
=
$ 06 , 0
$
$
(3),
where $A
D
is the depreciated acquisition cost.