Abstract:
In one embodiment, a needle guide is attached to the end of an ultrasonic probe in a manner such that the needle will follow a known trajectory under control of the needle guide. The surgeon then positions the needle guide by looking at the ultrasound image formed from the ultrasound radiated from the probe. In one embodiment, the needle guide has a release mechanism that allows the needle (or other medical device) that had been positioned in the guide to remain in the patient when the probe is removed. In one embodiment, the needle guide is designed to be releasably mounted to a bracket which, in turn, is releasably mounted to the end of the probe.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of, and claims priority to U.S. patent application Ser. No. 10/766,707 filed Jan. 28, 2004, entitled SYSTEMS AND METHODS FOR ASSISTING IN POSITIONING OF MEDICAL DEVICES. Which claims priority to U.S. Provisional Patent Application No. 60/528,505 filed Dec. 10, 2003, entitled DEVICE FOR ASSISTING THE POSITIONING OF MEDICAL DEVICES, and, the disclosures of which are hereby incorporated by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to medical positioning devices and more particularly to systems and methods for using imaging equipment, such as ultrasound, for assisting in the placement of a medical device. 
       BACKGROUND 
       [0003]    Proper positioning of medical devices, such as needles, catheters, drills, saws and even scalpels, is critical in the proper performance of certain medical procedures. Often the surgeon must look at a screen while trying to manually position a medical device, and thus can not look directly at the device. This is difficult at best and sometimes results in improper angles of attack and could result in improper placement of the medical device. 
       SUMMARY 
       [0004]    In one embodiment, a needle guide is attached to the end of an ultrasonic probe in a manner such that the needle will follow a known trajectory under control of the needle guide. The surgeon then positions the needle guide by looking at the ultrasound image formed from the ultrasound radiated from the probe. 
         [0005]    In one embodiment, the needle guide has a release mechanism that allows the needle (or other medical device) that had been positioned in the guide to remain in the patient when the probe is removed. 
         [0006]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized that such equivalent constructions do not depart from the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  shows one embodiment of a probe having a medical device positioning guide mounted thereon; 
           [0008]      FIG. 2  shows a view of the positioning guide of  FIG. 1 ; 
           [0009]      FIG. 3  shows one embodiment of a medical device guide and release mechanism based on the embodiment of  FIG. 1 ; 
           [0010]      FIG. 4  shows one embodiment of a needle held by the medical device guide; 
           [0011]      FIG. 5  shows details of one embodiment of the release mechanism based on the embodiment of  FIG. 1 ; 
           [0012]      FIG. 6  illustrates how the release mechanism of  FIG. 5  releasably mates with the device guide of  FIG. 1 ; 
           [0013]      FIGS. 7A ,  7 B and  7 C illustrate the releaseable mating of the device bracket with the probe; 
           [0014]      FIGS. 8A ,  8 B and  8 C illustrate the releaseable mating of the device guide with the device bracket; 
           [0015]      FIGS. 9A ,  9 B,  9 C and  9 D show dimensional relationships of embodiments of the illustrated device guide; 
           [0016]      FIGS. 10A ,  10 B and  10 C show dimensional relationships of embodiment of the illustrated release mechanism; and 
           [0017]      FIG. 11  shows one embodiment of packaging a plurality of device guides; and 
           [0018]      FIGS. 12 and 13  show alternate embodiments of the medical device guides. 
       
    
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 1  shows one embodiment of probe  10  having bracket  12  releasably attached thereto. This attachment, for example, is by fitting a first side  71  of the bracket over protrusion  13  on probe  10 , as shown in  FIG. 7A . The other side  72  of the bracket fits over the other side  15  of probe  10  as shown in  FIG. 7B , and locks between protrusions  73  and  74  up against slot  14  of probe  10  again, as shown in  FIG. 7C . Slot  702  snaps over protrusion  13  to hold bracket  12  from swinging open. Probe  10 , in the embodiment of  FIG. 1 , can be an ultrasound probe. 
         [0020]    In operation, probe  10  ( FIG. 1 ) sends ultrasound signals into the body and these signals then provide images of organs, fluids, etc which are otherwise hidden from view. When the probe is positioned properly, as determined by the images sent back by the ultrasound, the surgeon can then insert a needle, such as needle  41 , (or other surgical instrument), knowing the instrument&#39;s trajectory based upon the received images. The trajectory is a preset by the selection of the device guide. The device guide establishes an angle of attack with respect to the proximal end of the probe. By extension, this angle of attack extends below the skin of the patient. In some cases, the image may contain a projection of the needle trajectory as an aide to the surgeon. 
         [0021]    When the needle, or other device to be inserted, is positioned properly, the needle is slid forward so that its proximal end moves toward the patient and enters the patient. When the desired depth is reached, mechanism  50  is operated to release the needle thereby allowing probe  10 , bracket  12  and needle guide  20  to be removed, leaving the needle (or other device) within the patient&#39;s body. 
         [0022]      FIG. 2  shows bracket  12  having medical device guide  20  mounted thereon. Note that device  20  and device  12  can be a single structure if desired. Device  20  in the embodiment shown, is a device for holding a needle (shown in  FIG. 4 ) within groove  22 . Release control portion  50  holds the needle in position, while end portion  51  serves to release the needle when the needle has been properly positioned. If device  20  and device  12  are separate structures, they can be releasably mated as shown in  FIGS. 8A and 8B . As shown in  FIG. 8A , one end of device  20  is mated via pins  82  (shown in  FIG. 8C ) being inserted into bracket  82 . Once pin  83  is positioned in bracket  82 , guide  20  is rotated toward probe  10  and snaps in position under control of tab  81  of bracket  12  releaseably locking on edge  21  of device  20 . 
         [0023]    As shown in  FIG. 3 , device guide  30  consists of two parts: namely, guide  20  and release mechanism  50 . Guide  30  snaps into bracket  12 , as discussed above, attached to an ultrasound transducer. The device guide is manufactured to control the placement of devices, such as catheter and needles, to multiple depths, by changing the angle of attack at which the needle (or catheter) is presented to the transducer. The device guide is also manufactured to handle multiple gauges to accommodate specific diameter medical devices. 
         [0024]    As shown in  FIG. 4 , guide  20  has lead-in  43  to make insertion of the needle (such as needle  41 ) into the guide easier. Needle  41  then rests in channel  44  along the longitudinal axis of probe  10  so that the needle is positioned in a specific trajectory with respect to the surface to be probed. In effect, the medical device (which typically would be an elogated device (needle) with a substantially round cross-section forms a closing angle with the proximal end of the guide (and the probe) so that when the probe is properly placed, the proximal end, when moved down the channel, will be positioned a given distance below the skin of the patient. This trajectory intersects the patient at the target depth (such as 1.5 cm.) as indicated on the needle guide. Various angles and respective depths for 1.5, 2.5, 3.5 and 4.5 cms are shown in  FIG. 9A-9D . 
         [0025]      FIG. 4  shows mechanism  50  (discussed in more detail with respect to  FIGS. 6 and 7 ) mounted in slot  45  of guide  20 . Release portion  52  is positioned over needle  41  and exerts pressure on needle  41  within groove  44 . The pressure from portion  52  on the needle guide keeps the needle in proper orientation, but allows the user to slide the clamped needle toward the patient. The needle can then be positioned below the skin of the patient at the desired depth. 
         [0026]      FIG. 5  shows mechanism  50  having flexible tab  55  to maintain a closed position and to prevent accidental opening. The geometry of mechanism  50 , including dimension D, provides a specific amount of needle drag friction between the inserted needle and groove  44 . Once the needle has been oriented into the desired position, tab  55  is flexed inward allowing mechanism  50  (and particularly overhang  52 ) to move away from groove  44 , thereby allowing needle  41  to release from the device guide. This, then, allows needle  41  to remain in the patient when the probe is removed. 
         [0027]      FIG. 6  shows a top schematic view of mechanism  50  inserted in guide  20  with tab  55  locking against edge  42  of guide  20  prior to release of mechanism  50  from guide  20 . Tab  55  flexes into slot  53  formed by opening  54 . 
         [0028]      FIGS. 9A-9D  show dimensional relationships of embodiments of a device guide.  FIG. 9A  shows a top view of guide  20 .  FIG. 9B  is an end view of guide  20  and  FIG. 9C  is a section  9 C- 9 C taken through device  20  in  FIG. 9B .  FIG. 9D  shows typical illustrative dimensions (keyed to  FIG. 9C ) for different depth guides. 
         [0029]      FIG. 10A  shows a top view of mechanism  50 .  FIG. 10B  shows the end view of mechanism  50  and  FIG. 10C  is a section  10 C- 10 C taken through mechanism  50  in  FIG. 10B . Dimension D is keyed to the diameter of the device to be held within the guide. For 18 gauge needles, this dimension would be 0.070 in for the embodiment shown, and dimension D 1  would be 0.096 in. A typical length for mechanism  50  would be 0.564 in. If desired, portion  501  ( FIG. 10C ) can be tapered to better wedge needle  41  when in seating portion  44  of the guide. 
         [0030]      FIG. 11  shows one embodiment  1100  of the packaging for a plurality of needle guides,  50 ,  1110 ,  1111  and  1112 . Each of the needle guides can have different target depths, or they can all have the same depth. Center holder  1101  has limbs  1102  for holding each guide. Any number of limbs can be used. 
         [0031]      FIG. 12  shows one alternate device guide  1200  with latch  1201  in the open position. As shown, latch  1202  will engage protrusion  1203  for latching purposes. 
         [0032]      FIG. 13  shows guide  1200  in the latched position clamping needle  41  in position. 
         [0033]    Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.