Implantable vascular structures and methods for their use

Abstract

Devices, systems and methods are described by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably a baroreceptor located in the carotid sinus. A control system may be used to modulate the baroreceptor activation device. The control system may utilize an algorithm defining a stimulus regimen which promotes long term efficacy and reduces power requirements/consumption. The baroreceptor activation device may utilize electrodes to activate the baroreceptors. The electrodes may be adapted for connection to the carotid arteries at or near the carotid sinus, and may be designed to minimize extraneous tissue stimulation.

1 . An implantable vascular pressure measuring assembly comprising:
 an elastic base adapted to be mounted on the outer wall of a blood vessel under circumferential tension; and   a strain measurement sensor mounted on the elastic base so that changes in circumferential stress resulting from changes in blood pressure within the vessel may be detected.   
   
   
       2 . An implantable assembly as in  claim 1 , wherein the base is sufficiently elastic to conform to the outer wall of the blood vessel. 
   
   
       3 . An implantable assembly, as in  claim 2 , wherein the base comprises a silicone sheet. 
   
   
       4 . An implantable assembly as in  claim 1 , wherein the elastic base is adapted to be wrapped around the entire circumference of the blood vessel. 
   
   
       5 . An implantable assembly as in  claim 2 , wherein only a portion of the base is elastic. 
   
   
       6 . An implantable assembly as in  claim 1 , wherein the base is secured to a patch on the wall of the blood vessel. 
   
   
       7 . An implantable assembly as in  claim 6 , wherein the base is adapted to be secured by stapling, gluing, or clipping to the blood vessel wall. 
   
   
       8 . An implantable assembly as in  claim 1 , wherein the base is a silicone base wrapped around the blood vessel. 
   
   
       9 . An implantable assembly as in  claim 1 , wherein the base is adapted to be wrapped around an artery. 
   
   
       10 . An implantable assembly as in  claim 9 , wherein the base is adapted to be wrapped around a carotid artery. 
   
   
       11 . An implantable assembly as in  claim 1 , wherein the strain measurement sensor comprises a foil strain gauge or a force-sensing resistor. 
   
   
       12 . An implantable assembly as in  claim 1 , wherein the strain measurement sensor comprises a strain gauge or a micro machined sensor. 
   
   
       13 . A system comprising:
 an implantable vascular pressure measuring assembly as in  claim 1 ; and   a physiologic transducer comprising any one of a piezoelectric pressure transducer; an ultrasonic flow velocity transducer, an ultrasonic volumetric flow rate transducer, a thermodilution flow velocity transducer, and a capacitive pressure transducer, wherein said physiologic transducer is adapted to be implanted in or on a blood vessel or within a chamber of the heart; and   a control system connected to the pressure measuring assembly and the physiologic transducer.   
   
   
       14 . A system as in  claim 13 , further comprising a baroreceptor activation device. 
   
   
       15 . A system as in  claim 14 , wherein the baroreflex activation device comprises:
 a base having a length sufficient to extend around at least a substantial portion of the circumference of the carotid sinus, wherein said base is sufficiently elastic to conform to said circumference; and   one or more electrodes connected to the base, the electrodes having a length which is at least partly in the circumferential direction and which is sufficiently stretchable to conform to the carotid sinus with the base.