Accuracy and repeatability are required for any reliable test method. This is particularly important for testing of medical devices in which an error in testing can result in failing to administer the desired dosage of a therapeutic agent. One such device is a wearable medication pump.
A wearable medication pump, such as an insulin pump, is a small device about the size of a small cell phone that is worn externally. The wearable medication pump delivers precise doses of a therapeutic agent to a patient by injection, and can be adjusted manually and/or through feedback sensors to closely match the patient's needs. The therapeutic agent is typically held within a reservoir installed in a reservoir compartment in the wearable medication pump. A pump motor slide advances a piston in the reservoir to deliver the therapeutic agent to the patient.
Because the dose of therapeutic agent delivered is a function of pump motor slide position, testing of the wearable medication pump must assure that the pump motor slide does not move unnecessarily and only moves the distance requested to deliver the desired dose. One method of measuring pump motor slide position is to insert a ruler into the reservoir compartment until the ruler contacts the pump motor slide, then note the distance from a point on the wearable medication pump casing to the point where the ruler contacts the pump motor slide. Another method of measuring pump motor slide position is to position a caliper against the pump casing, advance the caliper depth probe into the reservoir compartment until the depth probe contacts the pump motor slide, then read the distance on the caliper.
Unfortunately, such distance measurement methods are neither accurate nor repeatable. The person performing the test can place the ruler or caliper depth probe into the reservoir compartment at different angles. When reading the distance on the ruler, the person performing the tests can use different landmarks points on the wearable medication pump casing. The test results can vary in a single test and can vary even more over a number of tests when different persons are likely to be performing the test. This, in turn, prevents achievement of highest product quality, product reliability, and patient safety.
It would be desirable to have a medication pump test devices and methods of use that would overcome the above disadvantages.