Pressure sensor for therapeutic delivery device and method

Abstract

The present invention is an apparatus for treating a selected patient tissue or organ region, at the surface of such region. The apparatus has an accessing tool for accessing the patient region, the tool having a distal end, and a proximal end at which the tool can be manipulated to place the distal end adjacent to the patient region. The apparatus also has a probe carried on the distal end and defining a contact surface that may be urged against the patient region thereby creating contact pressure. A pressure transducer is operatively coupled to the probe and is capable of producing a measurable response to the contact pressure. A monitoring device is operatively connected to the pressure transducer, for determining the contact pressure. An effector is operatively disposed on the probe for producing a given effect on the patient region when the effector is activated, and an activator operatively connected to the effector, by which the effector can be activated.

what is claimed:  
     
         1 . Apparatus for treating a selected patient tissue or organ region, at the surface of such region, comprising 
 an accessing tool for accessing the patient region, said tool having a distal end and a proximal end at which the tool can be manipulated to place the distal end adjacent such patient region,    a probe carried on said distal end and defining a contact surface that may be urged against said patient region thereby creating contact pressure,    a pressure transducer operatively coupled to said probe and capable of producing a measurable response to the contact pressure,    a monitoring device operatively connected to said pressure transducer, for determining the contact pressure,    an effector operatively disposed on said probe for producing a given effect on the patient region when effector is activated,    an activator operatively connected to said effector, by which said effector can be activated.    
     
     
         2 . The apparatus of    claim 1   , wherein said monitor is operatively connected to a user readable display.  
     
     
         3 . The apparatus of    claim 1   , wherein said activator is operatively connected to said monitor and activates said effector at a pre-selected range.  
     
     
         4 . The apparatus of    claim 1   , wherein said monitoring device is operable to measure the range over which the pressure transducer is responsive to changes in the force applied to the transducer, and to determine from such range, a contact-pressure range within which activation of the effector is optimized for treatment effect.  
     
     
         5 . The apparatus of    claim 1   , wherein said pressure transducer is responsive to the magnitude and direction of force applied to the transducer, and said monitor is operable to determine both the contact pressure and the approximate incidence angle of said tool with respect to the surface of the patient region.  
     
     
         6 . The apparatus of    claim 5   , wherein said pressure transducer includes a plurality of pressure-transducer units, each carried on the probe's contact surface, and said monitoring device is operable to determine from the force applied to each unit, the orientation of the said tool with respect to the surface of patient tissue with which said is in contact.  
     
     
         7 . The apparatus of    claim 5   , wherein said pressure transducer defines an axis of least strain along which force can be applied to the tool's head, and the transducer is responsive to force components applied along the axis and off axis.  
     
     
         8 . The apparatus of    claim 5   , wherein said probe is movably mounted on the distal end of said tool, and the pressure transducer includes position-sensing means for sensing the position of the probe with respect to the distal end of the tool.  
     
     
         9 . The apparatus of    claim 1   , wherein said pressure transducer includes (i) first and second conductors, (ii) an insulating layer adjacent the first conductor, said layer having perforations therein, and (iii) a conductive elastomer disposed between the insulating layer and the second conductor and in constant contact with the second conductor; wherein, during operation of the transducer, an electrical excitation signal applied to the two conductors and the impedance therebetween varies with a force applied to the contact surface of the transducer to generate an information signal indicative of whether or not the force applied to the contact surface is above a predetermined threshold, and, if so, the magnitude of the applied force.  
     
     
         10 . The apparatus of    claim 9   , wherein said conductive elastomer temporarily flows through the perforations in the non-conductive layer and makes contact with the first conductor, when the applied force is above the predetermined threshold.  
     
     
         11 . The apparatus of    claim 1   , wherein said monitoring device is operably connected to said activator, to activate said effector when such contact pressure is within a selected pressure range.  
     
     
         12 . The apparatus of    claim 1   , for use in promoting angiogenesis in an under-oxygenated region of a patient's heart, wherein the accessing tool is designed to access an exterior or interior surface of such heart region from an external body site, and said effector is designed to produce an angiogenic stimulus in the myocardial layer of such region, upon activation of the effector.  
     
     
         13 . A pressure transducer comprising 
 means defining a contact surface,    first and second conductors;    an insulating layer having perforations therein, the non-conductive material being adjacent to the first conductor; and    a conductive elastomer between the insulating layer and the second conductor and in constant contact with the second conductor;    wherein, during operation of the transducer, an electrical excitation signal applied to the two conductors and the impedance therebetween varies with a force applied to the contact surface of the transducer to generate an information signal indicative of (i) whether or not the force applied to the contact surface is above a predetermined threshold, and, if so, (ii) the magnitude of the applied force.    
     
     
         14 . The transducer of    claim 13   , wherein the information signal is provided continuously and in real-time.  
     
     
         15 . The transducer of    claim 13   , wherein the conductive elastomer temporarily flows through the perforations in the non-conductive layer and makes contact with the first conductor, when the applied force is above the predetermined threshold.  
     
     
         16 . The transducer of    claim 15   , wherein the electrical excitation signal remains substantially unchanged when the applied force is below the predetermined threshold.