Monitoring the hemodynamic state of a patient from measurements of myocardial contractility using doppler ultrasound techniques

Claim 3

An apparatus in accordance with claim 1, further comprising: means for generating electrical stimulation pulse events, and means for adjusting said pulse generating means as a function of said at least one heart performance parameter.

Claim 4

An apparatus in accordance with claim 2, wherein said means for adjusting said pulse generating means adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 5

A hemodynamic control apparatus for determining a patient's hemodynamic status and adjusting the hemodynamic output of the patient's heart to correspond to the patient's metabolic needs, comprising: means for generating electrical stimulation pulse events, ultrasonic means adapted to be implanted within the patient's heart for monitoring movement of a plurality of individual cardiac myofibrils, means for determining a cardiac performance parameter based on said monitored movement of a plurality of individual cardiac myofibrils, and means for adjusting said pulse generating means as a function of said cardiac performance parameter.

Claim 6

A hemodynamic control apparatus for determining a patient's hemodynamic status and adjusting the hemodynamic output of the patient's heart to correspond to the patient's metabolic needs, comprising: means for generating electrical stimulation pulse events, ultrasonic means adapted to be implanted within the patient's heart for monitoring movement of a plurality of individual cardiac myofibrils, means for determining a cardiac performance parameter based on said monitored movement of a plurality of individual cardiac myofibrils, and means for adjusting said pulse generating means as a function of said cardiac performance parameter.

Claim 7

A hemodynamic control apparatus in accordance with claim 4, wherein said ultrasonic means is adapted to be implanted within the patient's right heart and adjacent to the septum separating the right from the left ventricle for ensonifying the patient's septum with ultrasonic energy and detecting returning ultrasonic energy from a plurality of individual cardiac myofibrils within the septum.

Claim 8

A hemodynamic control apparatus in accordance with claim 4, wherein said means for adjusting said pulse generating means adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 9

A hemodynamic control apparatus in accordance with claim 4, wherein said pulse generating means includes means for generating ventricular pacing pulses, wherein said means for determining cardiac performance comprises a means for deriving a cardiac performance index, and wherein said apparatus further comprises: means for sensing atrial heartbeats, means for determining a metabolic indicator rate as a function of said cardiac performance index and independent of the rate of sensed natural atrial heart beats, means for classifying whether the sensed natural atrial heart rate is physiological or pathological based on the sensed natural atrial heart rate, the metabolic indicator rate and the cardiac performance index, and control means operative when the sensed natural atrial heart rate is physiological for keying the operation of said ventricular pacing pulse generating means to the operation of said atrial heart beat sensing means, and operative otherwise for keying the operation of said ventricular pacing pulse generating means to said metabolic indicator rate.

Claim 10

A hemodynamic control apparatus in accordance with claim 7, wherein said classifying means includes means for defining an atrial tracking rate which is proportional to said metabolic indicator rate, and wherein said classifying means classifies the sinus heart rate as pathological when the sensed natural atrial heart rate is faster than said atrial tracking rate and the cardiac performance index is decreasing.

Claim 11

A hemodynamic control apparatus in accordance with claim 8, wherein said means for adjusting said pulse generating means adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 12

A hemodynamic control apparatus in accordance with claim 7, further including: means for determining a cardiac performance index minimum value characterizing the threshold level of cardiac myofibril motion resulting from generated ventricular pacing pulses which successfully stimulate the heart, means for comparing subsequent cardiac performance indices resulting from ventricular pacing pulses to said cardiac performance index minimum value, and control means responsive to said comparing means for adjusting the energy level of said generated ventricular pacing pulses to safely stimulate the heart so that the cardiac performance indices will consistently exceed the cardiac performance index minimal value.

Claim 15

A method of operating an apparatus for monitoring performance of a patient's heart in accordance with claim 11, further comprising the steps of : generating electrical stimulation pulse events, and adjusting pulse generating operating parameters as a function of said at least one heart performance parameter.

Claim 16

A method of operating an apparatus for monitoring performance of a patient's heart in accordance with claim 12, wherein said adjusting step adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 19

A method of operating a hemodynamic control apparatus in accordance with claim 14, wherein said step of ultrasonically monitoring cardiac myofibril motion includes the steps of ensonifying cardiac myofibrils within the septum separating the right from the left ventricle with ultrasonic energy and detecting returning ultrasonic energy from the plurality of individual cardiac myofibrils within the septum.

Claim 20

A method of operating a hemodynamic control apparatus in accordance with claim 14, wherein said adjusting step adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 21

A method of operating a hemodynamic control apparatus in accordance with claim 14, wherein said pulse generating step includes the step of generating ventricular pacing pulses, wherein said step of determining cardiac performance includes the step of deriving a cardiac performance index, and wherein said method further comprises the steps of: sensing atrial heartbeats, determining a metabolic indicator as a function of said cardiac performance index and independent of the rate of sensed natural atrial heart beats, classifying whether the sensed natural atrial heart rate is physiological or pathological based on the sensed natural atrial heart rate, the metabolic indicator rate and the cardiac performance index, and keying the operation of said ventricular pacing pulse generating step to the operation of said atrial heart beat sensing when the sensed atrial heart rate is physiological, and otherwise keying the operation of said ventricular pacing pulse generating step to said metabolic indicator rate.

Claim 22

A method of operating a hemodynamic control apparatus in accordance with claim 17, wherein said classifying step further includes the steps of: defining an atrial tracking rate which is proportional to said metabolic indicator rate, and categorizing a sinus heart rate as pathological when the sensed natural atrial heart rate is faster than said atrial tracking rate during a time when the cardiac performance index is decreasing.

Claim 23

A method of operating a hemodynamic control apparatus in accordance with claim 18, wherein said adjusting step adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 24

A method of operating a hemodynamic control apparatus in accordance with claim 17, further including the steps of : determining a cardiac performance index minimum value characterizing the threshold level of cardiac myofibril motion resulting from generated ventricular pacing pulses which successfully stimulate the heart, comparing subsequent cardiac performance indices resulting from ventricular pacing pulses to said cardiac performance index minimum value, and adjusting the energy level of said generated ventricular pacing pulses according to the results of said comparing step in such a manner that the cardiac performance indices will consistently exceed the cardiac performance index minimal value, whereby the heart is safely stimulated by said generated ventricular pulses.

Claim 25

A hemodynamic control apparatus for determining a patient's hemodynamic status and adjusting the hemodynamic output of the patient's heart to correspond to the patient's metabolic needs, comprising: means for generating electrical stimulation pulse events, ultrasonical means adapted to be implanted within the patient's heart for monitoring cardiac myofibril motion, wherein said ultrasonic means is adapted to be implanted within the patient's right heart and adjacent to the septum separating the right from the left ventricle for ensonifying the patient's septum with ultrasonic energy and detecting returning ultrasonic energy from cardiac myofibrils within the septum, means for determining cardiac performance based on said monitored cardiac myofibril motion, and means for adjusting said pulse generating means as a function of said cardiac performance.

Claim 26

A hemodynamic control apparatus for determining a patient's hemodynamic status and adjusting the hemodynamic output of the patient's heart to correspond to the patient's metabolic needs, comprising: means for generating electrical stimulation pulse events, ultrasonical means adapted to be implanted within the patient's heart for monitoring cardiac myofibril motion, wherein said ultrasonic means is adapted to be implanted within the patient's right heart and adjacent to the septum separating the right from the left ventricle for ensonifying the patient's septum with ultrasonic energy and detecting returning ultrasonic energy from cardiac myofibrils within the septum, means for determining cardiac performance based on said monitored cardiac myofibril motion, and means for adjusting said pulse generating means as a function of said cardiac performance.

Claim 27

A hemodynamic control apparatus for determining a patient's hemodynamic status and adjusting the hemodynamic output of the patient's heart to correspond to the patient's metabolic needs, comprising: means for generating electrical stimulation pulse events, ultrasonical means adapted to be implanted within the patient's heart for monitoring cardiac myofibril motion, wherein said ultrasonic means is adapted to be implanted within the patient's right heart and adjacent to the septum separating the right from the left ventricle for ensonifying the patient's septum with ultrasonic energy and detecting returning ultrasonic energy from cardiac myofibrils within the septum, means for determining cardiac performance based on said monitored cardiac myofibril motion, and means for adjusting said pulse generating means as a function of said cardiac performance, wherein said pulse generating means includes means for generating ventricular pacing pulses, wherein said means for determining cardiac performance comprises a means for deriving a cardiac performance index, and wherein said apparatus further comprises: means for sensing atrial heartbeats, means for determining a metabolic indicator rate as a function of said cardiac performance index and independent of the rate of sensed natural atrial heart beats, means for classifying whether the sensed natural atrial heart rate is physiological or pathological based on the sensed natural atrial heart rate, the metabolic indicator rate and the cardiac performance index, and control means operative when the sensed natural atrial heart rate is physiological for keying the operation of said ventricular pacing pulse generating means to the operation of said atrial heart beat sensing means, and operative otherwise for keying the operation of said ventricular pacing pulse generating means to said metabolic indicator rate.

Claim 28

A hemodynamic control apparatus for determining a patient's hemodynamic status and adjusting the hemodynamic output of the patient's heart to correspond to the patient's metabolic needs, comprising: means for generating electrical stimulation pulse events, ultrasonical means adapted to be implanted within the patient's heart for monitoring cardiac myofibril motion, wherein said ultrasonic means is adapted to be implanted within the patient's right heart and adjacent to the septum separating the right from the left ventricle for ensonifying the patient's septum with ultrasonic energy and detecting returning ultrasonic energy from cardiac myofibrils within the septum, means for determining cardiac performance based on said monitored cardiac myofibril motion, and means for adjusting said pulse generating means as a function of said cardiac performance, wherein said pulse generating means includes means for generating ventricular pacing pulses, wherein said means for determining cardiac performance comprises a means for deriving a cardiac performance index, and wherein said apparatus further comprises: means for sensing atrial heartbeats, means for determining a metabolic indicator rate as a function of said cardiac performance index and independent of the rate of sensed natural atrial heart beats, means for classifying whether the sensed natural atrial heart rate is physiological or pathological based on the sensed natural atrial heart rate, the metabolic indicator rate and the cardiac performance index, and control means operative when the sensed natural atrial heart rate is physiological for keying the operation of said ventricular pacing pulse generating means to the operation of said atrial heart beat sensing means, and operative otherwise for keying the operation of said ventricular pacing pulse generating means to said metabolic indicator rate.

Claim 29

A hemodynamic control apparatus in accordance with claim 22, wherein said classifying means defines an atrial tracking rate which is proportional to said metabolic indicator rate, and wherein said classifying means classifies the sinus heart rate as pathological when the sensed natural atrial heart rate is faster than said atrial tracking rate and the cardiac performance index is decreasing.

Claim 30

A hemodynamic control apparatus in accordance with claim 23, wherein said means for adjusting said pulse generating means adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 31

A hemodynamic control apparatus in accordance with claim 22, further including: means for determining a cardiac performance index minimum value characterizing the threshold level of cardiac myofibril motion resulting from generated ventricular pacing pulses which successfully stimulate the heart, means for comparing subsequent cardiac performance indices resulting from ventricular pacing pulses to said cardiac performance index minimum value, and control means responsive to said comparing means for adjusting the energy level of said generated ventricular pacing pulses to safely stimulate the heart so that the cardiac performance indices will consistently exceed the cardiac performance index minimal value.

Claim 34

A method of operating a hemodynamic control apparatus in accordance with claim 26, wherein said pulse generating step includes the step of generating ventricular pacing pulses, wherein said step of determining cardiac performance includes the step of deriving a cardiac performance index, and wherein said apparatus further comprises the steps of: sensing atrial heartbeats, determining a metabolic indicator rate as a function of said cardiac performance index and independent of the rate of sensed natural atrial heart beats, classifying whether the sensed natural atrial heart rate is physiological or pathological based on the sensed natural atrial heart rate, the metabolic indicator rate and the cardiac performance index, and keying the operation of said ventricular pacing pulse generating step to the operation of said atrial heart beat sensing when the sensed atrial heart rate is physiological, and otherwise keying the operation of said ventricular pacing pulse generating step to said metabolic indicator rate.

Claim 35

A method of operating a hemodynamic control apparatus in accordance with claim 27, wherein said classifying step further includes the steps of: defining an atrial tracking rate which is proportional to the said metabolic indicator rate, and categorizing a sinus heart rate as pathological when the sensed natural atrial heart rate is faster than said atrial tracking rate during a time when the cardiac performance index is decreasing.

Claim 36

A method of operating a hemodynamic control apparatus in accordance with claim 28, wherein said adjusting step adjusts at least one of the pulse generation parameters from the group of pulse generation parameters comprising electrical stimulation pulse timing, electrical stimulation pulse duration, electrical stimulation pulse amplitude, electrical stimulation pulse polarity, pacing mode and pacing rate.

Claim 37

A method of operating a hemodynamic control apparatus in accordance with claim 27, further including the steps of: determining a cardiac performance index minimum value characterizing the threshold level of cardiac myofibril motion resulting from generated ventricular pacing pulses which successfully stimulate the heart, comparing subsequent cardiac performance indices resulting from ventricular pacing pulses to said cardiac performance index minimum value, and adjusting the energy level of said generated ventricular pacing pulses according to the results of said comparing step in such a manner that the cardiac performance indices will consistently exceed the cardiac performance index minimal value, whereby the heart is safely stimulated by said generated ventricular pulses.