Nosepiece configured for use with ultrasound probes

Abstract

A system for producing an ultrasound image comprises a scan head having a transducer capable of generating ultrasound energy at a frequency of at least 20 megahertz (MHz), and a processor for receiving ultrasound energy and for generating an ultrasound image at a frame rate of at least 15 frames per second (fps).

1 . A nosepiece for use with an ultrasound probe, comprising:
 a housing having a proximal end and a distal end, wherein the housing defines an enclosure configured to receive an ultrasound transducer; and   an acoustic window removably secured to the distal end of the housing, wherein the acoustic window includes a membrane that is acoustically penetrable at frequencies of 20 MHz or greater.   
     
     
         2 . The nosepiece of  claim 2  wherein the acoustic window includes an outer surface, and wherein the membrane is positioned on the outer surface. 
     
     
         3 . The nosepiece of  claim 1 , further comprising a raised lip protruding from the housing, wherein the acoustic window includes a groove configured to receive the lip when the acoustic window is secured to the housing. 
     
     
         4 . The nosepiece of  claim 3  wherein the groove and the lip form an interference fit when the acoustic window is secured to the housing. 
     
     
         5 . The nosepiece of  claim 1  wherein the membrane is at least partially formed from low density polyethylene. 
     
     
         6 . The nosepiece of  claim 1  wherein the membrane comprises a material selected from one or more of: polyester, polycarbonate, acrylic, thermoplastic elastomer, silicone elastomer, latex elastomer, ethylene copolymer, polyimide, polymethyl pentene, polyethylene, polytetrafluoroethylene, polycarbonate, polypropylene, and polyurethane films. 
     
     
         7 . The nosepiece of  claim 1  wherein the membrane has a thickness of approximately 25 microns or less. 
     
     
         8 . The nosepiece of  claim 1  wherein the membrane has an acoustical impedance between about 1.3 and 1.7 MegaRayles. 
     
     
         9 . The nosepiece of  claim 1  wherein the housing includes a fill port configured to receive an acoustic coupling fluid therethrough. 
     
     
         10 . The nosepiece of  claim 1  wherein the acoustical window has a generally rectangular shape. 
     
     
         11 . The nosepiece of  claim 1  wherein the housing comprises a base portion at least proximate the proximal end, a shoulder portion at least proximate the distal end, and an intermediate portion therebetween, wherein the intermediate portion includes a first surface opposite a second surface, wherein the first and the second surfaces extend from the base portion to the shoulder portion, and wherein the first and the second surfaces have a conic section shape. 
     
     
         12 . The nosepiece of  claim 1 , further comprising a plurality of apertures at the proximal end and configured to receive corresponding locking members. 
     
     
         13 . The nosepiece of  claim 12  wherein the apertures form a portion of a bayonet-type locking mechanism. 
     
     
         14 . The nosepiece of  claim 1 , further comprising a sheath releasably attached to the housing. 
     
     
         15 . A scanhead for use with an ultrasound imaging system, comprising:
 an ultrasonic transducer configured to transmit ultrasound signals into a subject at a frequency of at least 20 MHz and to receive ultrasound energy from the subject;   an elongate member having a first end and a second end, wherein the elongate member is configured to pivot about a pivot axis spaced from the first end, and wherein the transducer is removably attached to the first end;   a nosepiece having a proximal end and a distal end, wherein the nosepiece defines an enclosed volume sized to receive the transducer in the enclosed volume, wherein the nosepiece includes a fill port in fluid communication with the enclosed volume and configured to receive an acoustic coupling fluid therethrough, and wherein the nosepiece includes an acoustic window having an acoustically penetrable membrane;   a motor coupled to the elongate member and configured to oscillate the transducer along a reciprocating path; and   a position encoder configured to produce a signal indicative of an angular position of the elongate member as the elongate member rotates about the pivot axis for use in determining the position of the transducer along its reciprocating arcuate path.   
     
     
         16 . The scanhead of  claim 15  wherein the enclosed volume is configured to be at least partially filled with the acoustic coupling fluid. 
     
     
         17 . The scanhead of  claim 15  wherein the membrane is positioned in front of the transducer such that at least a portion of the transmitted ultrasound passes through the membrane into the subject. 
     
     
         18 . The scanhead of  claim 15  wherein the window is releasably attached to the nosepiece. 
     
     
         19 . The scanhead of  claim 15  wherein the nosepiece includes a raised lip protruding from the distal end, wherein the window includes a groove configured to sealably engage the lip when the window is engaged with the housing. 
     
     
         20 . The scanhead of  claim 15  wherein the ultrasonic transducer has a first face, and wherein the acoustic window is normal to the first face along the full extent of the reciprocating path.