Self-aiming directable acoustic transducer assembly for invasive medical device applications

Abstract

A directable acoustic transducer assembly is presented for use in a medical insertion device (MID). In an embodiment, the assembly aims an acoustic signal in response to a sensed or detected force or load imposed on the MID. The directable acoustic transducer assembly includes a switch array and a plurality of directional acoustic transducer elements. The switch array responds to the force or load and activates the directional acoustic transducer elements closest to the source of the force or load. The switch array may include a plurality of switches, at least one of which responses to a force or load and may activate directional acoustic transducer elements having a target tissue in the field of view. The assembly includes embodiments that are responsive to various loads. A directable acoustic transducer assembly may be part of a diagnostic and/or therapeutic system, such as an RF ablation system.

1 .- 22 . (canceled) 
     
     
         23 . In a system including a medical device having a body, a tip configured to articulate relative to the body in response to a force applied to the tip, and a switch array that includes a plurality of switches wherein one or more of the plurality of switches are closed when the tip articulates relative to the body, a method of determining the applied force comprising:
 detecting when one or more of the switches have been closed;   determining at least the number of closed switches; and   determining the applied force based on the determined number of closed switches and predetermined data that relates an increasing number of closed switches to the applied force.   
     
     
         24 . The method of  claim 23  wherein the determined applied force comprises at least a magnitude thereof. 
     
     
         25 . The method of  claim 24  further comprising a plurality of magnitudes in steps. 
     
     
         26 . The method of  claim 23  wherein said detecting when one or more of the switches have been closed comprises determining when the switch closures occurred simultaneously. 
     
     
         27 . The method of  claim 23  wherein said detecting when one or more of the switches have been closed comprises determining when the switch closures occurred sequentially with increasing tip articulation. 
     
     
         28 . The method of  claim 23  wherein said plurality of switches comprises electromechanical switches and wherein detecting when one or more of the switches have been closed comprises determining when the one or more switches have been electrically closed. 
     
     
         29 . The method of  claim 23  wherein determining the applied force comprises an indication that a specific minimum force has been applied to the tip. 
     
     
         30 . The method of  claim 23  wherein the predetermined data that relates the increasing number of closed switches to the applied force is determined empirically. 
     
     
         31 . The method of  claim 30  wherein the predetermined data that relates the increasing number of closed switches to the applied force is determined is bench calibrated during a design of the medical device. 
     
     
         32 . The method of  claim 23  wherein the plurality of switches in the switch array are arranged relative to the tip and body such that the identity of the closed switches determined during tip articulation is indicative of a direction of the applied force. 
     
     
         33 . The method of  claim 32  wherein the medical device comprises a longitudinal axis and wherein the direction of the applied force comprises at least a vector component thereof that is perpendicular to the longitudinal axis. 
     
     
         34 . The method of  claim 23  wherein the medical device comprises means for a directed therapy, diagnostic measurement, or monitoring of selected tissue, and wherein closure of the one or more switches enables or activates the directed therapy, diagnostic measurement, monitoring of selected tissue. 
     
     
         35 . The method of  claim 23  wherein at least one of the switches comprises an element whose distortion or mechanical loading causes it to change conductance. 
     
     
         36 . A medical device comprising:
 a body;   a tip configured to articulate relative to the body in response to a force applied to the tip; and   a switch array that includes a plurality of switches wherein one or more of the plurality of switches are closed when the tip articulates relative to the body; and   wherein said device is configured to determining the applied force bearing on the tip by (i) detecting when one or more of the switches have been closed; (ii) determining at least the number of closed switches; and (iii) determining the applied force based on the determined number of closed switches and predetermined data that relates an increasing number of closed switches to the applied force.   
     
     
         37 . The device of  claim 36  wherein the determined applied force comprises one of (i) a magnitude thereof and (ii) a direction of the applied force, wherein the plurality of switches in the switch array are arranged relative to the tip and body such that the identity of the closed switches determined during tip articulation is indicative of the direction of the applied force. 
     
     
         38 . The device of  claim 36  wherein said detecting when one or more of the switches have been closed comprises determining when the switch closures occurred sequentially with increasing tip articulation. 
     
     
         39 . The device of  claim 36  wherein the predetermined data that relates the increasing number of closed switches to the applied force is determined empirically. 
     
     
         40 . The device of  claim 36  wherein the switch array comprises:
 a first substrate or support configured to support at least one first electrical contact; 
 a second substrate or support generally opposed to the first substrate or support and configured to support at least one second electrical contact; 
 wherein the at least one first electrical contact and the at least one second electrical contact together form a contact pair corresponding to one of the plurality of switches in the switch array. 
 
     
     
         41 . The device of  claim 40  wherein the first substrate or support, the second substrate or support, or a combination thereof comprise a generally cylindrical, disc-shaped, or annular substrate or combination thereof, and wherein the switch array further comprises:
 a deformable material or member configured to join or space the first and second substrates or supports in a manner not interfering with contacting of one or more contact pairs comprising the first electrical contact and the second electrical contact, 
 wherein the contact pairs corresponding to the switches of the switch array are separated by a gap, thereby forming open circuits, 
 wherein the deformable material or member is configured to allow for one or more loading states on the switch array to cause the first and second substrates or supports to move relative to each other via distortion of the deformable material or member in a manner configured to close one or more contact pairs corresponding to the specific load state, and 
 wherein the switch array further includes interconnections to each first and second electrical contact which can be wired to circuits or connections outside of the switch array in a manner providing the desired switching relationship between specific load state and specific contact pairs, which enables or activates a directed therapy, diagnostic measurement or monitoring of selected tissue. 
 
     
     
         42 . The device of claim  19  wherein the medical device comprises one of an introducer, a catheter, a sheath, a scope, and a combination thereof.