Pulse detection using patient physiological signals

摘要

The presence of a cardiac pulse in a patient is determined by evaluating physiological signals in the patient. In one embodiment, a medical device evaluates optical characteristics of light transmitted into a patient to ascertain physiological signals, such as pulsatile changes in general blood volume proximate a light detector module. Using these features, the medical device determines whether a cardiac pulse is present in the patient. The medical device may also be configured to report whether the patient is in a VF, VT, asystole, or PEA condition, in addition to being in a pulseless condition, and prompt different therapies, such as chest compressions, rescue breathing, defibrillation, and PEA-specific electrotherapy, depending on the analysis of the physiological signals. Auto-capture of a cardiac pulse using pacing stimuli is further provided.

主权项

1. A method comprising:
transmitting light into a patient from a light source positioned external to the patient; receiving the transmitted light at a sensor positioned external to the patient; generating a light detection signal in response to the received light, the light detection signal having a first amplitude and a first shape at a first time; monitoring, over a period of monitored time, the light detection signal for changes in at least one of the first amplitude and the first shape; detecting, at a second time, at least one of a second amplitude and a second shape of the light detection signal; comparing the at least one of the second amplitude and the second shape with a corresponding at least one of the first amplitude and the first shape; analyzing, with a processor, the compared at least one of the second amplitude and the second shape to detect a trend that the patient's pulse is detected and is becoming weaker over the period of monitored time; determining that the patient's pulse is weakening over the period of monitored time based on the detected trend; and providing at least one of treatment and information concerning treatment based on the determined-weakening patient pulse.