Abstract:
A versatile needle guide for attachment to an ultrasound transducer probe. The needle guide includes an open topped generally vertical passageway formed between a base member and a gauge top which is hingedly mounted to the base member. A spring urges a grooved face on the gauge top into abutment with a flat face on the base member. The gauge top may be pivoted about the hinge mounting to separate the grooved face from the flat face to open the side of the passageway to allow a needle to be removed from the needle guide. The gauge top may be easily disassembled from the base for interchange with another gauge top having a different size of groove.

Description:
CROSS REFERENCES 
     This is a continuation-in-part of Ser. No. 29/103,098, filed Apr. 8, 1999, now Des. Pat. No. 424,693. 
    
    
     BACKGROUND 
     In the field of medicine, procedures are done to obtain biopsy samples or to place drainage tubes within the body. To assist in such procedures, an ultrasound image may be obtained to guide the biopsy needle or drainage tube into proper position. Ultrasound imaging of this sort is accomplished by use of an ultrasound transducer probe touching the body near the location for puncture of the skin and tissues by the needle or cannula. In order to assist in placement of the needle or tube, needle guides have been developed to fastened to or be incorporated within the ultrasound transducer probe. The biopsy needle or drainage cannula can be guided by the attached or incorporated guide. Many of such prior art devices either require the needle to remain attached to the transducer until the needle is withdrawn from the body or else they utilize traps or complex pathways for the needle to travel to be released from the transducer probe after the transducer probe is no longer needed. Such prior art devices result in the operator having to keep the transducer resting on the body while the biopsy sample is retrieved or else they give rise to discomfort for the patient and inconvenience for the physician performing the procedure while disconnecting the placed needle or cannula from the ultrasound transducer probe. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a needle guide which allows easy release of a biopsy needle from an ultrasound transducer probe after the needle has been guided into place by visualization of ultrasound images generated by use of the ultrasound transducer probe. 
     The needle guide snaps onto the ultrasound transducer probe and may be removed by hand operation. The needle guide includes a passageway through which a biopsy needle may be passed to aim it into the body at a target location. The needle guide is formed such that the passageway directs the leading end of the biopsy needle into the image field of the transducer probe. The user may cause the needle guide to release the biopsy needle bilaterally by squeezing one side of the needle guide with the thumb and forefinger. 
     A mounting bracket which is retained to the ultrasound transducer probe includes a band snugly surrounding the probe such that its transmission face is not obstructed. The band includes a generally elongate protrusion, to which the needle guide member may be frictionally or mechanically retained such that the needle guide may be removed by manual effort without the use of tools. The needle guide includes a mounting body equipped with a pair of rails which receive the protrusion on the band around the transducer wand. A rotatable lock lever is rotatively operated to insert a blade through a slot in one rail to impinge the blade upon the protrusion. 
     The base member is fashioned to allow it to be snap fitted to the mounting body and to fit on the mounting body in a defined orientation. The base is equipped with a flat face adjacent a hinge element comprising spaced ears with indentations which become part of a hinge when a gauge top member is mounted to the base member. A gauge top member has a wall with a triangular groove which abuts the flat face of the base member when longitudinally spaced stubs on the gauge top member are captured in the indentations in the opposing ears of the base member. The stubs serve as an axis about which the gauge top member may pivot on the base member over a limited range. A spring is interposed between the base and the gauge top member to urge the grooves containing wall of the gauge top member to remain in abutment with the flat face of the base member. 
     The gauge top includes a handle which may be depressed toward the base against the bias of the spring in order to move the groove away from the flat face such that a needle which has been passed through the passageway may be released from the needle guide. 
     It is a further object of the invention to provide a disposable needle guide for attachment to a transducer probe which facilitates removal of the ultrasound transducer probe from a needle which has been passed through the needle guide. 
     It is also an object of the invention to provide a needle guide constructed of stainless steel which may be sterilized and reused. 
     It is a further object of the invention to provide a needle guide which may be easily disassembled to permit use of different diameter needles or cannula by exchanging only the outermost member of the needle guide without disengaging the remaining parts of the needle guide from the transducer probe. 
     It is another object to provide a needle guide which may be mounted to varying shapes of ultrasound transducer probes by use of a flexible or elastic strap. 
     It is a further object of the Invention to provide a needle guide for fixed attachments to an ultrasound transducer probe which permits release of a needle from the needle guide with the use of a user&#39;s thumb and forefinger of one hand. 
     It is also an object of the invention to provide a one piece assembled needle guide which is ready for use after mounting to a bracket on a transducer probe. 
     It is another object to provide a needle guide which has a funnel-shaped opening to facilitate insertion of the tip of a biopsy needle into the guide. 
     It is yet a further object of the invention to provide a needle guide for mounting to a transducer probe which has a rounded lower surface to reduce discomfort of patients who are touched by the guide. 
     These and other advantages and objects of the invention will be understood through examination of the detailed description which follows. 
    
    
     DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a perspective view of the preferred embodiment needle guide retained to an ultrasound transducer probe and having a needle passing thorough the barrel of the needle guide. 
     FIG. 2 is an exploded view in perspective of the preferred embodiment needle guide. 
     FIG. 3 is a front elevation of the needle guide shown detached from the mounting bracket thereof. 
     FIG. 4 is a top plan view of the needle guide detached from the mounting bracket thereof. 
     FIG. 5 is a rear elevation of the gauge top member of the needle guide. 
     FIG. 6 is top plan view of the mount body of the invention with the lock lever installed thereon. 
     FIG. 7 is a rear right perspective of the mount body of the invention with the lock lever installed thereon in its locked position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows the preferred embodiment needle guide  2  mounted to a mounting bracket  6  fixed to an ultrasound transducer probe  4 . A biopsy needle  12  is shown being guided by needle guide  2  at an angle such that the lower end of the needle  12  will intersect the vertical axis of the probe  4 . By so guiding the needle  12 , the needle guide  2  allows the lower end of the needle  12  to enter the image field of the transducer probe  4  such that the operator of the instrument may position the lower tip of the needle at a location being viewed on the ultrasound imaging system of which transducer probe  4  is a part. 
     The needle guide  2  is mounted to a protrusion  10  which is formed on band  8  of mounting bracket  6 . In the configuration shown in FIG. 1, the band  8  surrounds and conforms to the shape of the generally rectangular transducer probe  4 . Band  8  may be fabricated of a flexible material such that it may be fitted conformingly to other shapes of transducer probe but it is to be understood that band  8  must fit tightly around the transducer probe  4  such that it will remain firmly in position during use of the needle guide  2 . Band  8  may also be constructed as a belt or strap, the ends of which may be joined by hook and loop fasteners, or by buckle, or hook and catch fastening means. 
     Preferably needle guide  2  is fabricated from plastic materials and is intended to be disposable. However, the needle guide  2  may be constructed of stainless steel and hence may be sterilized and reused. 
     FIGS. 2-7 illustrate the members which are assembled into the preferred embodiment needle guide  2  to accomplish the advantages provided by the invention. The band  8  is provided with protrusion  10  along its circumference such that protrusion  10  extends outwardly from band  8 . Protrusion is shaped to have a tapered body  50  having a top wall  52  which extends further from band  8  than its lower wall  54 . 
     A mounting body  14  fits onto protrusion  10  when desired, by receiving protrusion  10  between the spaced apart rails  16 ,  18  of mounting body  14 . Rails  16 ,  18  have rear edges  64  which incline corresponding to the taper of protrusion  10  such that protrusion  10  may fit snugly in channel  66  formed by rails  16 ,  18 . 
     Flange  106  of mounting body  14  is provided with an opening  20  into which a male snap member on base member  24  (not shown) may be received when base member  24  is fixed to mounting body  14 . Other mechanical attachment means may be used to fix base member  24  to mounting body  14 , or these two members may be fabricated as a single unit. Base member  24  is provided with a hollow  78  on its first side  68  into which the upper section  70  of mounting body  14  is received. 
     Referring particularly to FIGS. 6 and 7, detail of the first side  56  of mount body  14  can be seen to include the lock lever  22  mounted to mount body  14  and rotatable thereon. Specifically, in the preferred embodiment, mount body  14  includes first rail  16  spaced apart from generally parallel second rail  18 , leaving channel  66  therebetween for receiving the body  50  of protrusion  10 . A notch  100  is provided in the top edge of flange  106  into which may be snapped a pin  48  which depends from lock lever  22 . Pin  48  has an enlargement or knob  102  at its free end to retain lock lever adjacent flange  106 . Lock lever  22  may rotate about its pin  48  within notch  100  over a range limited in a counterclockwise direction (as seen in FIG. 7) by the slot  32  of second rail  18 . Blade  96  of lock lever  22  may enter slot  32  thereby encroaching into channel  66  at its free edge  108 . A ridge  60  is disposed upon first rail  16  within channel  66  opposing slot  32  of second rail  18 . When mount body  14  is to be placed upon protrusion  10 , lock lever  22  is rotated clockwise (as viewed from first side  56 ) to remove blade  96  from slot  32 . Once protrusion  10  is received in channel  66 , lock lever  22  is rotated so that blade  96  impinges on the side of protrusion  10 . Lock lever  22  is manipulated by movement of lock handle  98 . A detent may be installed on lock lever  22  to be received in a recess on the face of flange  106 , in order to restrict the rotation of lock lever  22  about pin  100 . 
     Referring again to FIGS. 2-5, opposing wall  72  of base member  24  is provided with a planar face  74  which diametrically opposes hollow  78 . Opposing wall  72  also includes an recess containing face  76  lateral to planar face  74 . Recess containing face  76  is provided with a shallow rectangular recess  80  into which one wing  30  of spring element  28  may be received. 
     Opposing wall  72  of base member  24  includes spaced apart ears  42  disposed generally midway laterally along opposing wall  72 . Each of ears  42  is provided with an inwardly directed cylindrical indentation  82  facing opposingly the cylindrical indentation  82  of the other ear  42 . 
     Gauge top  34  includes a retention end  84  and a handle end  86  on opposing sides of central segment  88  on which axle stubs  44  are mounted. The opposing cylindrical indentations  82  of ears  42  are disposed to receive axle stubs  44  on gauge top  34  such that axle stubs  44  and cylindrical indentations  82  may cooperate to provide a hinge around which gauge top  34  may rotate. Alternate structures for the pivot axle may be employed. 
     Retention end  84  of gauge top  34  is provided with V-shaped or triangular groove  38  which extends the vertical length of gauge top  34 . Alternatively, groove  38  may be of rectangular or semi-cylindrical shape. When gauge top  34  is fixed to base  24  by snapping axle stubs  44  of gauge top  34  into cylindrical indentations  82  of base  24 , triangular groove  38  abuts planar face  74  of base  24  and an open ended passageway  90  is formed between triangular groove  38  and planar face  74  of base  24 . Spring  28  is captured between base  24  and gauge top  34  and biases retention end  84  of gauge top  34  toward planar face  74  of base  24 . Alternatively, spring  28  may be incorporated in base  24  or gauge top  34  or permanently fixed to one of them. Handle end  86  of gauge top  34  includes lever  36  which is angularly displaced from recess containing face  76  of base  24  when gauge top  34  is fixed to base  24 . Lever  36  may be curved upward to provide a convenient area for placement of a forefinger thereon. Because lever  36  is spaced from recess containing face  76  and urged therefrom by spring  28 , finger pressure urging lever  36  toward recess containing face  76  causes gauge top  34  to pivot about the hinge created by the interaction of indentations  82  and axle stubs  44 . When needle guide  2  is operated like an alligator clip or spring-type clothes pin, triangular groove  38  separates from planar face  74  and a needle located within passageway  90  may easily be separated from needle guide  2  and the transducer probe  4  to which needle guide  2  is attached. 
     The conical or funnel shaped opening  40  in top side  92  is coaxial with triangular groove  38  such that the insertion of the tip of a biopsy needle  12  is facilitated by the centering action of the funnel shaped opening  40  of the passageway  90 . 
     Lever  36  may be marked with a part number or other indicator  94  which may indicate the size of needle  12  which may be passed through the passageway  90 . Should a larger or smaller needle need to be substituted for the first needle chosen, it can be seen that gauge top  34  may be disconnected from base member  24  without tools and an alternative gauge top  34  may be attached to base  24 , with such alternative gauge top  34  having a triangular groove  38  which has a different width and depth. 
     In preparation for a biopsy, amniocentesis, or other puncturing procedure, the physician is provided with a fully assembled needle guide  2  ready for attachment to an elastic mounting bracket  6  already attached to a transducer probe  4 . The indicator  94  informs the physician whether the needle guide  2  is provided with the proper sized passageway  90  for the gauge of needle  12  to be used. Once the needle guide  2  has been mounted to the protrusion  10  of the band  8 , the procedure may be commenced. 
     It can be easily understood that a physician may place the ultrasound transducer probe  4  equipped with a mounted needle guide  2  against the skin of the patient on whom a procedure is to be performed. Once the target (tumor to be biopsied or site to be drained) is visualized on the ultrasound system monitor, a biopsy needle or cannula may be inserted into the conical opening  40  of passageway  90  and directed therethrough toward the patient&#39;s body. Once a puncture has been accomplished, the needle  12  may be inserted toward the identified target to intersect therewith. Once placed, the lever  36  of the needle guide  2  may be depressed, allowing the transducer probe  4  and needle guide  2  to be separated from the sited needle  12  by drawing the transducer probe  4  and attached needle guide  2  laterally such that planar face  74  is passed along the needle  12  and the needle  12  is freed from the needle guide  2 .