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Original Authors: Park Jong-Dea, System Integration Dept. Ltd. INNOTEMS
Edited by Cyth Systems
The Challenge
To develop a high-precision test of pacemakers post manufacture to ensure their reliability before they are given to patients.
The Solution
Using the NI PXI hardware platform and LabVIEW software we were able to simulate input and outputs signals to automated the validation of pacemakers.
Pacemaker
When the beating of the heart is abnormal (for example too slow) or irregular, a device can keep the heart rate normal through periodic electrical stimulation. Different types of pacemakers include body catering, body embedded, or inductive.
A pacemaker is composed of a heart rate generator and an electrode lead. The heart rate generator may contain the electronic circuit and the battery to control the electrical stimulation at regular intervals. The electrode lead is an electric signal generated in the pacemaker that passes to the heart.
The Configuration of the Pacemaker Simulator System
Through simulating biological input signals to the pacemaker using our control software, one can monitor the output signals the pacemaker gives. This shows the functionality of the pacemaker and if it reacts correctly according to each signal it is given. which outputs a biological signal analog output channel, and measures a feedback signal analog input channel.
Arrhythmia—The rhythm of the heart rate is irregular status.
Bradycardia—The heart rate is beating slower than normal.
Tachycardia—The heart rate is beating faster than normal.
Left: Pacemaker Test Configuration, Right: NI PXI hardware used to perform validation test.
The Configuration of the Pacemaker Test System
Display the electrocardiogram that occurs in the heart. Pacing threshold, refractory period, heart rate, and coordinated pacing can set the escape interval and impedance.
Data logging so that data can be stored on any heartbeat. This feature has been added. And selecting the type of pacemaker like AAI, VVI, and DDD is possible.
AAI: Paces and senses in the atrial.
VVI: Paces and senses in the ventricle. A sensed beat inhibits the pacing stimulus (demand pacing).
DDD: Paces and senses in both chambers. A sensed beat in the ventricle inhibits both the ventricular and atrial pacing stimulus and triggers a ventricular pacing stimulus after a programmed AV interval.
Pacemaker Function Tests
Inspection of the pacemaker. Except for lead and electrode, inspection items are processed by the Pacemaker Performance Evaluation Manual.
Inspection items
Amplitude, pulse, length, rate, interval of pulse
Sensitivity
Input impedance
Detection refractory period, beating refractory period
The software configuration of the pacemaker test system was built with TestStand, and each test sequence was constructed by function.
Detailed unit test software was written with LabVIEW, and inspection items and the inspection method were carried out according to standards such as IEC 62304 and ISO 14971.
Original Authors:
Park Jong-Dea, System Integration Dept. Ltd. INNOTEMS
Edited by Cyth Systems