Implantable wireless sensor

Abstract

The progress of a endovascular aneurysm repair can be monitored by inserting a pressure transducer sensor using a catheter into the sac during endovascular aneurysm repair and then using a small, hand-held read out device to measure pressure easily, safely, inexpensively and accurately. In one aspect a sensor is introduced into the body by the steps of loading the sensor into a catheter, and deploying into the aneurysm sac. This invention also has other applications for measuring physical properties in patients or in other sites.

1 . A sensor for wirelessly determining a physical property, which sensor comprises: 
 a self-contained resonant circuit comprising a capacitor and an inductor, and    two substrates, at least one of which substrates has a recess therein,    wherein the circuit is variable in response to the physical property and wherein the substrates are hermetically sealed together.    
   
   
       2 . The sensor of  claim 1 , wherein the hermetically sealed substrates form a pressure sensitive chamber.  
   
   
       3 . The sensor of  claim 1 , wherein the substrates are comprised of glass, fused silica, sapphire, quartz, or silicone.  
   
   
       4 . The sensor of  claim 3 , wherein the substrates are comprised of fused silica.  
   
   
       5 . The sensor of  claim 1 , wherein the physical property is pressure.  
   
   
       6 . The sensor of  claim 1 , wherein there are no conductive connections or via holes to provide a direct physical conduit or connection between an upper inductor coil and a lower inductor coil.  
   
   
       7 . The sensor of  claim 1 , wherein each substrate has an inductor coil arranged therein in planar fashion.  
   
   
       8 . The sensor of  claim 7 , wherein the inductor coil of one substrate is in a plane parallel to the plane of the inductor coil in the second substrate.  
   
   
       9 . The sensor of  claim 8 , wherein the inductor coils are coextensive.  
   
   
       10 . The sensor of  claim 1 , wherein the inductor coil of the substrate with a recess is positioned in the recess.  
   
   
       11 . The sensor of  claim 10 , wherein each substrate has a recess and an inductor coil is positioned in each recess.  
   
   
       12 . The sensor of  claim 1 , wherein the inductor comprises to inductor coils and each inductor coil is a wire spiral.  
   
   
       13 . The sensor of  claim 12 , wherein each wire spiral is formed by electrodeposition.  
   
   
       14 . The sensor of  claim 1 , wherein the sensor is from about 0.5 in. to about 1 in. in length and from about 0.1 in. to about 0.5 in. in width.  
   
   
       15 . The sensor of  claim 14 , wherein the sensor has a thickness of from about 0.05 in. to about 0.30 in.  
   
   
       16 . The sensor of  claim 1 , wherein a stabilizer is arranged around the sensor.  
   
   
       17 . The sensor of  claim 16 , wherein the stabilizer stabilizes position, location, and/or orientation.  
   
   
       18 . The sensor of  claim 16 , wherein the stabilizer is a metal basket arranged around the outer surface of the sensor.  
   
   
       19 . The sensor of  claim 1 , wherein the physical property is measured in a patient.  
   
   
       20 . A system for delivering a sensor, which comprises a sensor of  claim 1  and a delivery guidewire or catheter.  
   
   
       21 . The system of  claim 21 , wherein the sensor is removable from the guidewire or catheter.  
   
   
       22 . The system of  claim 21 , wherein the sensor is removably attached to the guidewire or catheter.  
   
   
       23 . The system of  claim 21  which also comprises an instrument for measuring signals from the sensor.  
   
   
       24 . A method for measuring a physical property which comprises the steps of inserting a sensor of  claim 1  into a desired location and then measuring any signals generated by said sensor.  
   
   
       25 . The method of  claim 24 , wherein a physical property in a patient is measured.