Ultrasonic sensors for monitoring the condition of a vascular graft
First Claim
1. A graft adapted to be coupled into a patient'"'"'s vascular system, comprising:
- (a) a biocompatible material formed into a generally cylindrical shape and having a circular wall defining a lumen extending along a longitudinal axis of the graft, said lumen being adapted to convey a fluid through the graft;
(b) a first transducer disposed within the wall of the graft, said first transducer producing a signal indicative of a parameter of the fluid flowing through the lumen; and
(c) a coil coupled to the first transducer for conveying the signal to a point external to the patient'"'"'s body, for use in evaluating a condition of the graft.
3 Assignments
0 Petitions
Accused Products
Abstract
A parameter indicative of the status of fluid flow is remotely monitored in a vessel, a natural graft, or a synthetic graft. One or more transducers are provided either in a wall of a synthetic graft or adjacent to a vessel or natural graft to monitor the parameter. A conformal array transducer or a tilted element is used to monitor fluid flow or velocity through the graft or vessel based on the effect of the fluid on ultrasonic waves produced by the transducers. The conformal array transducer comprises a plurality of elements that curve around the graft or vessel and are excited with an input signal provided by an implantable electronics circuit, producing ultrasonic waves that propagate into the fluid flowing within the graft or vessel. Transit time or Doppler measurements are made using an appropriate number of these transducer to determine either fluid flow or velocity. Various implantable electronic circuits are provided that enable a selected transducer to be driven and to receive an ultrasonic signal or a pressure signal indicative of the status of fluid flow monitored by the transducer. The implanted electronic circuit is connected to an implanted radio frequency (RF) coil. An external coil that is connected to a power supply and monitoring console is coupled to the implanted RF coil to convey power and receive data signals from the transducer that are indicative of the parameter being monitored.
249 Citations
32 Claims
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1. A graft adapted to be coupled into a patient'"'"'s vascular system, comprising:
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(a) a biocompatible material formed into a generally cylindrical shape and having a circular wall defining a lumen extending along a longitudinal axis of the graft, said lumen being adapted to convey a fluid through the graft; (b) a first transducer disposed within the wall of the graft, said first transducer producing a signal indicative of a parameter of the fluid flowing through the lumen; and (c) a coil coupled to the first transducer for conveying the signal to a point external to the patient'"'"'s body, for use in evaluating a condition of the graft. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for remotely determining a condition of a graft that is disposed within a patient'"'"'s body, for an extended period of time, comprising the steps of:
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(a) providing a first pressure sensor that is disposed in a wall of the graft, said first pressure sensor producing a signal indicative of a first pressure of a fluid flowing through the graft; (b) transmitting the signal produced by the first pressure sensor to a point external to the patient'"'"'s body; and (c) receiving the signal and producing an indication of the condition of the graft as a function of the signal. - View Dependent Claims (22)
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23. A method for remotely determining a condition of a graft disposed within a patient'"'"'s body, for an extended period of time, comprising the steps of:
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(a) providing a first transducer that includes a plurality of elements for producing ultrasonic waves, disposed in one of two locations, said two locations including; (i) within a wall of the graft, wherein said plurality of elements are spaced apart along one side of a lumen of the graft; and (ii) carried on a band fitted about an exterior surface of the wall, said plurality of elements being sufficiently flexible to conform to a curved shape of the wall and being spaced apart along one side of the graft; (b) producing ultrasonic waves with the first transducer that are directed into the lumen of the graft, a fluid within the lumen affecting the ultrasonic waves; (c) receiving the ultrasonic waves after they have been affected by the fluid in the lumen of the graft, and producing a signal in response thereto that is indicative of a parameter related to the flow of the fluid through the lumen; (d) transmitting the signal to a point outside the patient'"'"'s body; and (e) producing an indication of the parameter and thus of the condition of fluid flow through the graft, as a function of the signal. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification