A philips product support engineer and philips clinical specialist reviewed the logs, strips and information provided from the devices involved, including the mx40 telemetry device and the mx450 patient monitor device.One of the strips provided indicated the rhythm has beat labels of n which means the algorithm would not issue a vtach alarm.Output file data received was only from one of the beds (the patient had been transferred).The data was for only 40 seconds and show a learning phase was occurring while the patient was in a ventricular rhythm.This is most likely the reason the beats are labeled as n instead of v.The star application note and the product instructions for use (ifu) guides indicate how many runs are required to identify and alarm for v-tach.The definition for vtach is a run of consecutive beats labeled as v with run length greater than or equal to the v-tach run limit and ventricular hr greater than the v-tach hr limit.The factory setting for the v-tach run is 5 and the v-tach hr is 100.The star algorithm had classified the beat as n instead of v.Because of this, the criteria for vtach was not met, hence there was no alarm for vtach generated.Once the algorithm detects and measures the qrs, the beat is labeled as n (normal), s (supraventricular), v (ventricular ectopic), or p (paced).To aid the algorithm in labeling a new beat, previously detected beats that have similar shapes are grouped into template families.Each patient can have up to 16 different active template families for each individual lead.To keep the template family information current, they are dynamically created and replaced as the patient¿s beat morphology change.If a patient begins to display a new beat morphology, a new template family is created.Older template families from beats no longer experiencing are automatically deleted.The following warning is found in the ifu: warning: if arrhythmia learning takes place during ventricular rhythm, the ectopics may be incorrectly learned as the normal qrs complex.This may result in missed detection of subsequent events of v-tach and v-fib.For this reason you should: take care to initiate arrhythmia relearning only during periods of predominantly normal rhythm and when the ecg signal is relatively noise-free.Be aware that arrhythmia relearning can happen automatically.Respond to any inop messages (for example, if you are prompted to reconnect electrodes) as the effectiveness of the arrhythmia monitoring for the patient is compromised.Be aware that a disconnected easi electrode triggers an arrhythmia relearn on all leads.Always ensure that the arrhythmia algorithm is labeling beats correctly.The cause of the reported problem was not confirmed.The patient information center ix (pic ix) device was alarming appropriately throughout and functioning to specification.Related cases are reported under mfr report numbers 1218950-2024-00233, 9610816-2024-00179 and 9610816-2024-00179.
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