Method and apparatus for delivering an implantable wireless sensor for in vivo pressure measurement

Abstract

An apparatus for implanting an implant device having a corkscrew-type anchor associated therewith into a patient includes an elongated, flexible shaft. A retention mechanism is located at the distal end of the shaft for retaining the device at the distal end of the shaft. The apparatus includes means selectively operable for disengaging the retention mechanism from the implant device when the anchor has been anchored into tissue at a target site. In another aspect, an apparatus for releasing an implant into a vessel within a patient includes an elongated shaft for inserting into the vessel of the patient. A tether wire extends through the proximal portion of a secondary lumen, exits a first port, engages a portion of the implant, enters a second port, and extends through at least a portion of a distal portion of the secondary lumen. The implant is thereby tethered to the side of the elongated shaft, and pulling the tether wire disengages the tether wire from the distal portion of the secondary lumen and the implant so as to release the implant from the shaft.

1 . An apparatus for implanting into a patient an implant device having a corkscrew-type anchor associated therewith, comprising: 
 an elongated, flexible shaft having proximal and distal ends;    a retention mechanism disposed at the distal end of said shaft for retaining said device at the distal end of said catheter; and    means selectively operable for disengaging said retention mechanism from said implant device when said anchor has been anchored into tissue at a target site.    
     
     
         2 . The apparatus of  claim 1 , wherein said elongated, flexible shaft comprises a helical coil.  
     
     
         3 . The apparatus of  claim 2 , wherein said helical coil comprises a first helical coil, and wherein said elongated flexible shaft further comprises a second helical coil nested within said first helical coil.  
     
     
         4 . The apparatus of  claim 3 , wherein said second helical coil comprises turns formed in the opposite direction from said first helical coil.  
     
     
         5 . The apparatus of  claim 1 , wherein said means selectively operable for disengaging said retention mechanism from said implant device comprises a flexible rod disposed within said flexible shaft, said flexible rod being operably associated with said retention mechanism at a distal end, and a proximal end of said flexible rod being accessible from a distal portion of said shaft to selectively disengage said retention means.  
     
     
         6 . The apparatus of  claim 1 , wherein said retention mechanism comprises a plurality of fingers for gripping said implant device.  
     
     
         7 . The apparatus of  claim 6 , wherein said means selectively operable for disengaging said retention mechanism from said implant device comprises a flexible rod disposed within said flexible shaft, said flexible rod being operably associated with said plurality of fingers at a distal end, and a proximal end of said flexible rod being accessible from a distal portion of said shaft to selectively disengage said plurality of fingers from said implant device.  
     
     
         8 . The apparatus of  claim 7 , wherein said flexible rod comprises a spreader at a distal end thereof, said spreader upon proximal displacement of said flexible rod engaging said plurality of fingers to bias said fingers outward, 
 whereby pulling on a proximal end of said flexible rod causes said plurality of fingers to release said implant device.    
     
     
         9 . The apparatus of  claim 1 , wherein said retention mechanism comprises a plurality of clamshell members for gripping said implant device.  
     
     
         10 . The apparatus of  claim 9 , wherein said means selectively operable for disengaging said retention mechanism from said device comprises a screw, said screw and said clamshell members being arranged such that rotating said screw in a tightening direction with respect to said corkscrew-type anchor causes said screw to open said clamshell members so as to release said device.  
     
     
         11 . The apparatus of  claim 10 , wherein the resistance between said screw and said clamshell device is greater than the resistance imparted by screwing said anchor into the tissue of the patient, and wherein rotation of said elongated shaft beyond what is needed to tighten the anchor into the tissue of the patient will overcome the resistance between the screw and the clamshell device and cause the screw to open said clamshell members so as to release said device.  
     
     
         12 . The apparatus of  claim 11 , wherein said screw is reverse-threaded from said corkscrew-type anchor, and wherein rotation of said elongated shaft beyond what is needed to tighten the anchor into the tissue of the patient will cause said screw to retract.  
     
     
         13 . An apparatus for releasing an implant into a vessel within a patient, comprising: 
 an elongated shaft for inserting into a vessel of a patient, said shaft defining a central lumen, a secondary lumen comprising proximal and distal sections, a first port for placing the proximal section of said secondary lumen in communication with the ambient surrounding said shaft, and a second port for placing the distal section of said secondary lumen in communication with the ambient surrounding said shaft;    a tether wire extending through the proximal portion of said secondary lumen, exiting said first port, engaging a portion of said implant, entering said second port, and extending through at least a portion of said distal portion of said secondary lumen;    whereby said implant is tethered to the side of the elongated shaft; and    whereby pulling said tether wire disengages said tether wire from said distal portion of said secondary lumen and said implant so as to release said implant from said shaft.    
     
     
         14 . The apparatus of  claim 13 , further comprising a core wire disposed within a portion of the main lumen of the shaft for providing that portion of the shaft with additional stiffness.  
     
     
         15 . The apparatus of  claim 13 , wherein said main lumen extends to the distal end of said shaft, and wherein said shaft further defines a first aperture placing a distal portion of said main lumen in communication with the ambient surrounding the distal portion of the shaft and a second aperture placing an intermediate portion of said main lumen in communication with the ambient surrounding an intermediate portion of the shaft.  
     
     
         16 . The apparatus of  claim 15 , further comprising a guide wire extending generally along the outside proximal portion of the shaft, entering the main lumen through the second aperture, and exiting the main lumen through the first aperture.