I think Alaris recommends the use of a dial-gauge for P-series syringe-pumps: to determine the rate of travel of the actuator is within specified tolerances. This range of pumps is pretty consistent at passing this test but on the odd occasion there are problems - I think they are due to damage and wear: not a design flaw.

I have found that, generally, dial-gauges can be used for spotting drive-mechanism non-linearity (where the rate of travel is not constant along the leadscrew). This is not possible with a syringe loaded in my opinion.

Actually there is an algorithm to detect drive-mechanism linearity problems on the PX000's. This can be accessed within the test-mode (No 176). My main concerns are at particularly lower infusion rates - I would not want excessive backlash, spurious errors due to non-linearity, sticking mechanism due to bent leadscrews - leading to occlusion problems or travel potentiometers failing due to poor mechanical contact through mis-alignment of the mechanism or worn travel potentiomenter.

Personally, I only 'go to town' on pumps that 'cough-up' any errors associated with mechanisms or where there are rate-inaccuracy problems reported. I will agree with you that most of the time a syringe would do as a quick confidence-check. However; I would be concerned that this test might not be seen to be thorough enough to a third-party questioning the competence of someone carrying out servicing or repairs on the equipment.

A (technical) department that has responsibility for maintaining the device might be required under certain circumstances (adverse-incident, perhaps, irrepsective of whether the problem is rate-related or not) to justify this sort of test on a device; particularly if it is not recommended by the manufacturer.

And especially after it has had repairs to any of it's mechanism or internal components replaced.

So, for ppm functionality checks, use a combination of dial guages and service codes and if any 'work' has been done..use an IDA??

Is there such a thing as a quick and acceptable check on these things.

Allowing for a 'good' syringe driver, how long should these checks take?

cheers

A quick function check can be done using 2 Syringes, a 50 ml and a 20 ml joined by a 3 way stopcock. If you set the rate at 60ml per hr it should infuse a ml a minute into the 20 ml attached syringe, by checking with a stopwatch ie 10 minutes = 10ml.

Clever boy Tony.. you were always good at the sums..

You've forgotten to allow for the dead space in the tubing and the three way tap as well as taking the elasticity coeficient of the tubing linked to the stiction of the smaller syringe causing back pressure in the system into account.

You see it all looks very simple, but isn't really if you look hard enough ! :p

Looks like the dial-guages win - simple to use and understand plus they're cheap..ish.

cheers

I think you're taking me too seriously ! I was being frivolous - again. In fact I suppose I was saying that any task can appear impossible if you take it to extremes.

How accurate do you actually need to be ?
Do small errors introduced by an IDA (for example) matter if they are consistant ?
If you expect it to read 2% high all the time then the readings are still useful for checking error trends and it's still well within the MDA guidlines for critical infusions so is it valid to take it as a definitive test ?

Answers on a postcard please, enclosing a £5 note in case you are the winning entry to cover postage and packing !

I agree, we can bog ourselves down with too many technicalities, if, buts, the way the winds blowing etc..
IDA or/and dial-guage..who cares, as long as they do the job.
For some reason our dept tends to use IDA's(because its always been that way..)even though Alaris service manuals refer to dial-guages.
I'm trying to set-up an infusion device testing bench in our equipment library so, in a round about way, I was trying to pick some brains.

cheers

Our department is ISO registered and so we work to manufacturers recommendations where possible. I personally prefer the dry test option as it is alot easier when working in different areas within the hospital. Also as mentioned in previous posts the d.t.i.'s have shown drive problems that I would not have picked up on the IDA. We have a test kit carried in a dedicated case and have recently created a laminated test sheet (manufacturers engineering codes, rates to test at and pump specifications) so that all technicians test the pumps in the same way. I'll be making another dry test kit soon for the Graseby 3xxx series.