Medical City · Device Lab 56 of 69
Infusion Pump
A number on a screen is a command, not a measurement of what reached the patient. Every other lesson in this device depends on you accepting that sentence, because this pump has no instrument anywhere in it that measures delivered volume.
- 10 parts
- 4 configurations in the Device Lab
- Also called: Syringe Pump, Volumetric Pump
The parts
Part by part.
Display
A number on a screen is a command, not a measurement of what reached the patient. Every other lesson in this device depends on you accepting that sentence, because this pump has no instrument anywhere in it that measures delivered volume.
Door
The door is not a cover. It is a working part of the pumping mechanism, and a learner who files it under enclosure will never understand why this pump stops.
Latch
Three different things are happening at this door and they are routinely collapsed into one. The door can look closed.
Fingers
Watch one finger move and you learn almost nothing. This mechanism works by the order in which the fingers move, not by the fact that they move.
Motor
Three questions hide inside one report that the pump is not delivering. Was motion requested at all.
Upstream
Upstream means toward the bag, before the pumping segment. This sensing role exists because the pump can starve: the mechanism is perfectly capable of trying to draw fluid from a source that cannot supply it, and the fingers will keep working while it does.
Downstream
Do not let the word occlusion turn into a location. This sensing role reports that resistance on the outlet side has risen past a threshold.
Air
This detector watches a few centimetres of tubing and nothing else. Everything upstream of that window and everything downstream of it is invisible to it, which means air can enter the line in places this device will never see and can pass through places it cannot report.
Clamp
Here is the failure that kills people with this device, and it has nothing to do with the motor. Fluid can flow through an open set under gravity alone, with the pump stopped, the screen dark and everything apparently safe.
Board
Calling this the brain stops the investigation before it starts. The useful description is narrower: this assembly receives inputs, applies rules to them, and issues commands.
Simulations
Where it appears in the simulations.
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