Heart rate change sensor

In combination for detecting changes in the heart beat of a patient,

• first means for prerecording and recirculating a heart beat of a patient,
• second means for detecting each heart beat of the patient and producing signals representing such heart beat,
• third means responsive to the signals from the first and second means for producing signals having characteristics representing any differences between the rates of the heart beats from the first and second means,
• fourth means responsive to the signals from the third means for producing signals having a variable frequency in accordance with variations in the difference signals from the third means,
• fifth means responsive to the signals from the fourth means for producing an output indication upon abrupt changes in the frequency of the signals from the fourth means, and
• sixth means responsive to the signals from the fourth means for varying the rate of recirculation of the prerecorded heart beat in accordance with the characteristics of the signal from the fourth means.

In combination for detecting changes in heart beat of a patient,

• first means for prerecording a heart beat of the patient as a reference
• and for recirculating the prerecorded heart beat at an adjustable frequency to reproduce the prerecorded heart beat on a periodic basis,
• second means for detecting the heart beat of the patient and for producing signals representing the detected heart beat,
• third means responsive to the signals from the first and second means for adjusting the rate of the recirculated heart beat to correspond to the rate of the detected heart beat,
• fourth means for detecting changes in the rate of the recirculated heart beat above a particular value, and
• fifth means responsive to the detected heart beat and the recirculated heart beat for detecting a lack of correspondence between the characteristics of such heart beats.

In combination for detecting changes in the heart beat of a patient,

• means for providing signals representing a reference heart beat of the patient on a recurrent basis,
• means for providing signals representing the actual heart beat of the patient,
• means for comparing the rates of occurrence of the signals representing the reference heart beat and the actual heart beat to provide an error signal representing any differences in rate,
• means responsive to the error signal for adjusting the recurrent rate of the signals representing the reference heart beat in a direction to minimize such error signal, and
• means responsive to the reference heart beat and the actual heart beat for comparing the characteristics representing the reference heart beat and the actual heart beat to provide an output signal when the characteristics of the signals representing the actual heart beat do not correspond to the characteristics of the signals representing the reference heart beat.

In combination for detecting changes in the heart beat of a patient,

• means for providing signals representing a reference heart beat of the patient on a recurrent basis,
• means for providing signals representing the actual heart beat of the patient,
• means for comparing the rates of recurrence of the signals representing the reference heart beat and the actual heart beat to provide an error signal representing any differences in rate,
• means responsive to the error signal for adjusting the recurrent rate of the signals representing the reference heart beat in a direction to minimize such error signals, and
• means responsive to the error signal for providing an output signal when the error signal varies at a rate above a particular value.