Method and apparatus for regulating the flow rate of a periodic flow heart prosthesis
First Claim
1. A method of regulating a heart prosthesis which includes a positive displacement pump providing a periodic flow of period T and which includes an electrical actuator driving said pump, said actuator being powered by electrical power supply means, the method comprising following operations:
- a) calculating a sequence of normal values for a physical operating parameter of said prosthesis as a function of a sequence of positions of said prosthesis, each of said positions respectively corresponding to one of said normal values of said physical operating parameter, which sequence of normal values of said physical operating parameter should be complied with during said period T;
b) then during operation prosthesis, during each of said period of said periodic flow, at time intervals T4 shorter than said period T, and preferably at time intervals T4 that are regularly spaced apart and that are such that the ratio T/T4 is greater than 10;
c) sensing values of said physical operating parameter of said prosthesis by means of a physical operating parameter sensor; and
simultaneously sensing a position of said prosthesis by prosthesis position sensor means;
d) calculating a difference (E) between said sensed value of said physical operating parameter and the normal value of said physical operating parameter in said sequence of normal values corresponding to said position of said prosthesis as sensed by said prosthesis position sensor means, ande) if said difference (E) is greater than a threshold (5), taking action on said power supply means to reduce drive speed of said heart pump.
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Accused Products
Abstract
The invention relates to a method and apparatus enabling the blood flow rate conveyed by a heart prosthesis drive by an electrical actuator (18) to be adapted to the flow rate available in the patient'"'"'s venous return. An apparatus includes a sensor (11) for measuring a physical operating parameter of the prosthesis, and having a passband which extends beyond the variation frequency of the blood flow, and it comprises an angular position sensor (10) for determining the position of the prosthesis, a central unit (15) which receives signals from the sensor (11) and from the angular position sensor (10), which central unit is capable of controlling power supply means (5) of the actuator, and a memory (16) in which normal values of the physical operating parameter of the prosthesis are stored. The apparatus of the invention is particularly intended for monitoring the operation of human heart prostheses.
82 Citations
16 Claims
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1. A method of regulating a heart prosthesis which includes a positive displacement pump providing a periodic flow of period T and which includes an electrical actuator driving said pump, said actuator being powered by electrical power supply means, the method comprising following operations:
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a) calculating a sequence of normal values for a physical operating parameter of said prosthesis as a function of a sequence of positions of said prosthesis, each of said positions respectively corresponding to one of said normal values of said physical operating parameter, which sequence of normal values of said physical operating parameter should be complied with during said period T; b) then during operation prosthesis, during each of said period of said periodic flow, at time intervals T4 shorter than said period T, and preferably at time intervals T4 that are regularly spaced apart and that are such that the ratio T/T4 is greater than 10; c) sensing values of said physical operating parameter of said prosthesis by means of a physical operating parameter sensor; and
simultaneously sensing a position of said prosthesis by prosthesis position sensor means;d) calculating a difference (E) between said sensed value of said physical operating parameter and the normal value of said physical operating parameter in said sequence of normal values corresponding to said position of said prosthesis as sensed by said prosthesis position sensor means, and e) if said difference (E) is greater than a threshold (5), taking action on said power supply means to reduce drive speed of said heart pump. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for regulating a heart prosthesis that includes a positive displacement pump providing a periodic blood flow of period T and which includes an electrical actuator driving said pump, which actuator is powered by means for supplying electrical power, further including a physical operating parameter sensor having a passband that extends beyond frequency F corresponding to said period T, the apparatus further comprising means for sensing prosthesis position, one memory in which normal values of said physical parameter are stored, one central unit means for receiving signals from said physical operating parameter sensor and from said means for sensing said prosthesis position, which central unit is further means for controlling said means for supplying the electrical power to vary speed of said actuator and/or of said pump, wherein said physical operating parameter sensor is a blood pressure sensor situated between an implantation site and an inlet of said pump, which physical operating parameter sensor is highly insensitive to acceleration, and wherein normal values of fluctuating components of blood pressure at said inlet of said pump are stored in said memory.
- 10. An apparatus for regulating a heart prosthesis that includes a positive displacement pump providing a periodic blood flow of period T and which includes an electrical actuator driving said pump, which actuator is powered by means for supplying electrical power, further including at least one physical operating parameter sensor having a passband that extends beyond frequency F corresponding to said period T, the apparatus further comprising means for sensing prosthesis position, one memory in which normal values of said physical parameter are stored, one central unit means for receiving signals from said physical operating parameter sensor and from said means for sensing said prosthesis position, which central unit means is is further for controlling said means for supplying electrical power to vary speed of said actuator and/or of said pump, and wherein said physical operating parameter sensor is responsive to an electrical parameter of said actuator.
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16. An apparatus for regulating a heart prosthesis which includes a positive displacement pump providing a periodic flow of period T and which includes an electrical actuator driving said pump, which actuator is powered by means for supplying electrical power, said apparatus further comprising:
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a physical operating parameter sensor having a passband that extends beyond frequency F corresponding to said period T; a prosthesis position sensor; a central unit means for calculating a sequence of normal values for a physical operating parameter of said prosthesis as a function of a sequence of said prosthesis positions, which sequence of normal values should be complied with during said period T; a memory for storing said normal values of said physical operating parameter; said central unit means calculating during each of said period, at time intervals T4 such that the ratio T/T4 is greater than 10, a difference (E) between sensed value of said physical operating parameter and the normal value of said physical operating parameter corresponding to prosthesis position sensed by said prosthesis position sensor, and said central unit means reduced drive speed of said heart pump when said difference (E) is greater than a threshold (S).
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Specification