IRadimed MRidium 3860, Service Manual

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4-1
SECTION 4
PRINCIPLES OF OPERATION
4.0 PRINCIPLES OF OPERATION
4.1 Introduction
The operational principles upon which the Iradimed 3860+ MR IV pump and
its accessory parts are based is presented in the following sub-sections. The
presentation format compliments the maintenance and troubleshooting
instructions found in their associated sections of this manual. Reference
should be made to the system block diagrams, schematics, mechanical
drawings and parts lists, as one follows the operating principles description
herein. The theory behind the fundamental operating principles is also given,
however it is assumed that users of this information are generally familiar
with the operation and maintenance of linear peristaltic infusion pumps.
Generally, the presentation is broken into mechanical and electronic
subsections. Mechanical operation and componentry are discussed first.
Electronic circuitry and theory of operation are described second. The
electronics discussion can better understood if one reviews the block diagrams
and schematics in parallel with the text. It must be kept in mind that this
equipment is software controlled, and so much of the operation is not obvious
from the drawings alone. In fact the 3860+ MR IV pump has two processors
with much of the safety and control based upon these processors ‘watching’
the operation of the other.
4.2 Mechanical Operation
Though complete direct observation of the mechanical operation which occurs
as the pump runs is not possible with a fully assembled unit, detailed
drawings of the mechanical assembly are included below, which along with the
following text, should provide a thorough understanding of the pumping
operation.
It is assumed that the reader has previously obtained an understanding of the
3860+’s basic user operation and setup. A general familiarity of the operation
of linear peristaltic mechanisms and the operation of the 3860 is a pre-
requisite.
4.2.1 Physical Description
Reviewing the block diagram ( See Figure 4-1 ) and overall chassis
assembly ( See Figure 4-2 ), it can be seen that the 3860 is housed in
a multi-chambered cast aluminum chassis. Two main chambers exist,
one for the RF ‘noisy’ electronics (left side) and the other for the
mechanical pump assembly and sensors or the right side. Electrical
connections pass through a separating center wall via RF feed through
filter plates (PFxx). As the 3860+ has been specifically designed to
operate in close proximity to the high magnetic fields and extremely RF
sensitive environment of Magnetic Resonance Imaging ‘Scanners’,
much of design will reflect the attention given to reducing magnetic
hazards and RF susceptibility in addition to IV fluid delivery.