Rate-responsive pacemaker with circuitry for processing multiple sensor inputs

Claim 2

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; second processing means for processing said second signal to provide a second switch matrix input signal indicative of one or more characteristics of said second signal; an addressable switch matrix having as inputs said first and second switch matrix input signals and having as an output a unique set of numerical coefficients indicated by the values of said first and second switch matrix input signals; and means for computing a selected rate signal based on said first and second signals and said unique set of numerical coefficients, said selected rate signal being supplied to said pulse generating means.

Claim 3

A rate-responsive pacemaker as defined in claim 1, wherein said addressable switch matrix comprises: memory for storing a plurality of sets of numerical coefficients; and rate memory logic means for selecting the one of said plurality of sets of numerical coefficients stored in said memory which corresponds to the values of said first and second switch matrix input signals.

Claim 4

A rate-responsive pacemaker as defined in claim 2, wherein the values of said plurality of sets of numerical coefficients stored in said memory are programmable.

Claim 5

A rate-responsive pacemaker as defined in claim 2, wherein each of said plurality of sets of numerical coefficients comprises two numerical coefficients.

Claim 6

A rate-responsive pacemaker as defined in claim 4, wherein said numerical coefficients are weighting factors for said first and second signals.

Claim 7

A rate-responsive pacemaker as defined in claim 4, wherein said selected rate signal is calculated according to the formula X·S 1 +Y·S 2 where X and Y are the unique set of numerical coefficients, S 1 is the first signal, and S 2 is the second signal.

Claim 8

A rate-responsive pacemaker as defined in claim 2, wherein each of said plurality of sets of numerical coefficients comprises three numerical coefficients.

Claim 9

A rate-responsive pacemaker as defined in claim 7, wherein two of said numerical coefficients are weighting factors for said first and second signals, and the third of said numerical coefficients is an offset factor.

Claim 10

A rate-responsive pacemaker as defined in claim 8, wherein said selected rate signal is calculated according to the formula X·S 1 +Y·S 2 +Z were X and Y are the two weighting factors in the unique set of numerical coefficients, S 1 is the first signal, S 2 is the second signal, and Z is the offset factor in the unique set of numerical efficients.

Claim 11

A rate-responsive pacemaker as defined in claim 1, wherein said first sensor means comprises: an activity sensor.

Claim 12

A rate-responsive pacemaker as defined in claim 10, wherein said second sensor means comprises: a temperature sensor.

Claim 13

A rate-responsive pacemaker as defined in claim 10, wherein said second sensor means comprises: a respiratory minute volume sensor.

Claim 14

A rate-responsive pacemaker as defined in claim 10, wherein said second sensor means comprises: a QT interval sensor.

Claim 15

A rate-responsive pacemaker as defined in claim 10, wherein said second sensor means comprises: a respiratory rate sensor.

Claim 16

A rate-responsive pacemaker as defined in claim 10 wherein said second sensor means comprises: a stroke volume sensor.

Claim 17

A rate-responsive pacemaker as defined in claim 10, wherein said second sensor means comprises: a blood pressure sensor.

Claim 18

A rate-responsive pacemaker as defined in claim 1, wherein one of said first and second sensor means comprises: a blood oxygen saturation sensor.

Claim 19

A rate-responsive pacemaker as defined in claim 1, wherein one of said first and second sensor means comprises: a blood oxygen partial pressure sensor.

Claim 20

A rate-responsive pacemaker as defined in claim 1 wherein said first sensor means has a relatively fast response and said second sensor means has a relatively slow response.

Claim 21

A rate-responsive pacemaker as defined in claim 19, wherein said first sensor means comprises one of the sensors from the group consisting of an activity sensor, a blood oxygen saturation sensor, a blood oxygen partial pressure sensor, and a p CO 2 sensor.

Claim 22

A rate-responsive pacemaker as defined in claim 19, wherein said second sensor means comprises one of the sensors from the group consisting of a respiratory minute volume sensor, a temperature sensor, a pH sensor, and a respiration rate sensor.

Claim 23

A rate-responsive pacemaker as defined in claim 1, wherein said first sensor means has a highly accurate response for low levels of exercise and said second sensor means has a highly accurate-response for high levels of exercise.

Claim 24

A rate-responsive pacemaker as defined in claim 22, wherein said first sensor means comprises one of the sensors from the group consisting of an activity sensor, a blood oxygen saturation sensor, a blood oxygen partial pressure sensor, and a pCO 2 sensor.

Claim 25

A rate-responsive pacemaker as defined in claim 22, wherein said second sensor means comprises one of the sensors from the group consisting of a respiratory minute volume sensor, a pH sensor, and a temperature sensor.

Claim 26

A rate-responsive pacemaker as defined in claim 1, wherein said first conversion means comprises: a first amplifier for amplifying said first signal, said first amplifier having a first amplifier output; a first filter for filtering said first amplifier output, said first filter having a first filter output; and first linearizing means for linearizing said first filter output.

Claim 27

A rate-responsive pacemaker as defined in claim 1, wherein said second conversion means comprises: a second amplifier for amplifying said second signal, said second amplifier having a second amplifier output; a second filter for filtering said second amplifier output, said second filter having a second filter output; and second linearizing means for linearizing said second filter output.

Claim 28

A rate-responsive pacemaker as defined in claim 1, additionally comprising: a reaction and recovery time circuit installed between said addressable rate matrix and said pulse generating means, said reaction and recovery time circuit for limiting the rate at which said selected rate signal supplied to said pulse generating means will be allowed to rise and fall.

Claim 29

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; second processing means for processing said second signal to provide a second switch matrix input signal indicative of one or more characteristics of said second signal; an addressable switch matrix having as inputs said first and second switch matrix input signals, said addressable switch matrix containing a plurality of sets of numerical coefficients therein, said addressable switch matrix having as an output a particular set of two numerical coefficients which is indicated in said addressable switch matrix by the values of said first and second switch matrix input signals; and means for computing a selected rate signal by first computing the product of one of said two numerical coefficients and said first signal, secondly computing the product of the other of said two numerical coefficients and said second signal, and thirdly adding the products together, said selected rate signal being supplied to said pulse generating means.

Claim 30

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; second processing means for processing said second signal to provide a second switch matrix input signal indicative of one or more characteristics of said second signal; an addressable switch matrix having as inputs said first and second switch matrix input signals, said addressable switch matrix containing a plurality of sets of numerical coefficients therein, said addressable switch matrix having as an output a particular set of two numerical coefficients which is indicated in said addressable switch matrix by the values of said first and second switch matrix input signals; and means for computing a selected rate signal by first computing the product of one of said two numerical coefficients and said first signal, secondly computing the product of the other of said two numerical coefficients and said second signal, and thirdly adding the products together, said selected rate signal being supplied to said pulse generating means.

Claim 31

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; a third sensor means for sensing a third physiological parameter of a patient and producing a third signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; second processing means for processing said second signal to provide a second switch matrix input signal indicative of one or more characteristics of said second signal; third processing means for processing said third signal to provide a third switch matrix input signal indicative of one or more characteristics of said third signal; an addressable switch matrix having as inputs said first, second, and third switch matrix input signals and having as an output a unique set of numerical coefficients indicated by the values of said first, second, and third switch matrix input signals; and means for computing a selected rate signal based on said first, second, and third signals and said numerical coefficients, said selected rate signal being supplied to said pulse generating means.

Claim 32

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; a third sensor means for sensing a third physiological parameter of a patient and producing a third signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; second processing means for processing said second signal to provide a second switch matrix input signal indicative of one or more characteristics of said second signal; third processing means for processing said third signal to provide a third switch matrix input signal indicative of one or more characteristics of said third signal; an addressable switch matrix having as inputs said first, second, and third switch matrix input signals and having as an output a unique set of numerical coefficients indicated by the values of said first, second, and third switch matrix input signals; and means for computing a selected rate signal based on said first, second, and third signals and said numerical coefficients, said selected rate signal being supplied to said pulse generating means.

Claim 33

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; an addressable switch matrix having as an input said first switch matrix input signal and having as an output a unique set of numerical coefficients indicated by the value of said first switch matrix input signal; and means for computing a selected rate signal based on said first and second signals and said numerical coefficients, said selected rate signal being supplied to said pulse generating means.

Claim 34

A rate-responsive pacemaker for stimulating the heart of a patient, said pacemaker comprising: pulse generating means for generating and delivering stimulation pulses to the patient's heart in response to a selected rate signal; a first sensor means for sensing a first physiological parameter of a patient and producing a first signal in response thereto; a second sensor means for sensing a second physiological parameter of a patient and producing a second signal in response thereto; first processing means for processing said first signal to provide a first switch matrix input signal indicative of one or more characteristics of said first signal; an addressable switch matrix having as an input said first switch matrix input signal and having as an output a unique set of numerical coefficients indicated by the value of said first switch matrix input signal; and means for computing a selected rate signal based on said first and second signals and said numerical coefficients, said selected rate signal being supplied to said pulse generating means.