In vivo sensor and method of making same

Abstract

Implantable in vivo sensors used to monitor physical, chemical or electrical parameters within a body. The in vivo sensors are integral with an implantable medical device and are responsive to externally or internally applied energy. Upon application of energy, the sensors undergo a phase change in at least part of the material of the device which is then detected external to the body by conventional techniques such as radiography, ultrasound imaging, magnetic resonance imaging, radio frequency imaging or the like. The in vivo sensors of the present invention may be employed to provide volumetric measurements, flow rate measurements, pressure measurements, electrical measurements, biochemical measurements, temperature, measurements, or measure the degree and type of deposits within the lumen of an endoluminal implant, such as a stent or other type of endoluminal conduit. The in vivo sensors may also be used therapeutically to modulate mechanical and/or physical properties of the endoluminal implant in response to the sensed or monitored parameter.

What is claimed is: 
     
         1 . An implantable biosensor, comprising a tubular member having a central lumen, an abluminal wall surface, a luminal wall surface, the tubular member further comprising a plurality of struts, at least one strut of the plurality of struts configured as a substrate wherein at least one electronic circuit is integrated onto the substrate and into at least one of the abluminal wall surface or luminal wall surface of the tubular member. 
     
     
         2 . The implantable biosensor of  claim 1 , wherein the tubular member is a stent. 
     
     
         3 . The implantable biosensor of  claim 2 , wherein at least some struts of the plurality of struts further include at least one recess in the abluminal wall surface of the at least some struts of the plurality of struts. 
     
     
         4 . The implantable biosensor of  claim 3 , wherein the at least one electronic circuit is integrated within the at least one recess. 
     
     
         5 . The implantable biosensor of  claim 4 , wherein the at least one electronic circuit further comprises an integrated circuit or solid-state circuit. 
     
     
         6 . The implantable biosensor of  claim 5 , further comprising at least one electrode in electrical communication with the at least one electronic circuit. 
     
     
         7 . The implantable biosensor of  claim 5 , wherein the at least one electronic circuit is configured as at least one of an antenna, a transmitter, a power source and/or an electrode. 
     
     
         8 . The implantable biosensor of  claim 7 , wherein the integrated circuit further comprises an LC circuit. 
     
     
         9 . The implantable biosensor of  claim 7 , wherein the stent is an antenna operably coupled to the at least one electronic circuit. 
     
     
         10 . The implantable biosensor of  claim 5 , wherein the at least one electronic circuit is positioned within a width and depth of the groove of at least one strut of the plurality of struts. 
     
     
         11 . A method of making an implantable biosensor, comprising the steps of:
 a. Providing a substrate for forming the implantable biosensor;   b. Vacuum depositing a device forming material onto the substrate;   c. Masking portions of the deposited device forming material to define grooves to be formed on the device forming material;   d. Forming grooves in a surface of the device forming material;   e. Depositing at least one electrical component layer of a plurality of electrical component layers into the groove; and   f. Forming surface features on a surface of at least some of the electrical component layers of the plurality of electrical component layers.   
     
     
         12 . The method of  claim 11 , wherein step b further comprises the step of depositing a shape memory metal. 
     
     
         13 . The method of  claim 12 , further comprising the step of depositing an electrically conductive layer coupling at least one electrical component layer of the plurality of electrical component layers to the device forming material. 
     
     
         14 . The method of  claim 13 , further comprising the step of depositing an electrically conductive layer coupling at least one electrical component layer of the plurality of electrical component layers to another electrical component layer. 
     
     
         15 . An implantable biosensor, comprising a tubular member having a central lumen, an abluminal wall surface, a luminal wall surface, the tubular member further comprising a plurality of struts, at least one strut of the plurality of struts configured as a substrate wherein at least one electronic circuit is integrally formed onto the substrate and into at least one of the abluminal wall surface or luminal wall surface of the tubular member. 
     
     
         16 . The implantable biosensor of  claim 15 , wherein the tubular member is a stent. 
     
     
         17 . The implantable biosensor of  claim 16 , wherein at least some struts of the plurality of struts further include at least one recess in the abluminal wall surface of the at least some struts of the plurality of struts. 
     
     
         18 . The implantable biosensor of  claim 17 , wherein the at least one electronic circuit is integrally formed within the at least one recess. 
     
     
         19 . The implantable biosensor of  claim 18 , wherein the at least one electronic circuit further comprises an integrated circuit or solid-state circuit. 
     
     
         20 . The implantable biosensor of  claim 19 , further comprising at least one electrode in electrical communication with the at least one electronic circuit.