Cardiological simulator

A method of generating a simulated continuous heartbeat with an arrhythmia, comprising the steps:

• (a) loading indexing information corresponding to a selected primary rhythm into a memory means adapted to be an index means to a rhythm look-up table containing a plurality of sets of individual digitized samples, each set comprising in sequential order all of the samples necessary to produce one and only one of a plurality of unique rhythms,
• (b) using the indexing means to retrieve in sequential order and generally at uniform time intervals a set of individual digitized samples from the rhythm look-up table, the set uniquely corresponding to the indexing information,
• (c) converting each individual digitized sample to an analog signal by means of a digital to analog converter,
• (d) processing the analog signal to remove unwanted high frequency components by means of a signal filter,
• (e) after the last sample has been converted, causing the processed analog signal to become steady state,
• (f) measuring time from the conversion of the first digitized sample,
• (g) comparing the measured time with an impulse period derived from a selected heartbeat rate by means of a period look-up table until a match occurs,
• (h) determining if the next rhythm produced should be a selected secondary rhythm,
• (i) if not, then loading the indexing information corresponding to the selected primary rhythm into the indexing means, but if so, then loading indexing information corresponding to the selected secondary rhythm into the indexing means, and
• (j) repeating steps (b) through (i).

A device for generating a simulated continuous heartbeat comprising:

• (a) a means for operator inputing information identifying one of a plurality of unique heartbeat rhythms,
• (b) a means for operator inputing information identifying a desired hearbeat rate,
• (c) a first means for storing the rhythm identifying information,
• (d) a second means for storing the rate identifying information,
• (e) a means for converting the heartbeat rate identifying information into a period of the heartbeat rate,
• (f) a means for measuring elapsed time,
• (g) a means for comparing the heartbeat period with the elapsed time and for resetting the time measuring means when a match occurs,
• (h) a means for setting a first flag signifying that a time equal to the heartbeat period has elapsed when said match occurs,
• (i) a third means for storing a plurality of sets of digitized samples of rhythm patterns, each set comprising in sequential order all the samples required to produce one and only one of the plurality of selectable rhythms,
• (j) a means for retrieving sequentially from the third storing means all of the samples associated with the rhythm identified in the first memory means,
• (k) a means for sequentially receiving the digitized samples from the third storing means and converting them to corresponding analog signals,
• (l) a means for synchronously starting the elapsed time measuring means and the sample retrieving means, and for timing the retrieving of samples from the third storing means and the transferring of said samples to the conversion means such that all necessary samples of the selected rhythm get uniformly transferred to the conversion means within a time less than or equal to the heartbeat period,
• (m) a means for setting a second flag when all necessary samples of a set have been transferred to the conversion means,
• (n) a means for recognizing the second flag and in response thereto suspending the conversion means until the first flag is set suspension of the conversion means causing the conversion means to produce a constant reference signal, and for then clearing both flag means, and further for resetting and restarting the synchronous starting and timing means whenever the flags are cleared, and
• (o) a means for filtering the signals from the conversion means to produce a generally continuous processed heartbeat having the desired heartbeat rate.