Abstract:
An apparatus for holding a needle such as a medical needle, during exposure to radiation, such as X-ray radiation. The apparatus includes a needle collar and a control bar. The needle collar attaches to the needle shaft and has a first attachment point while the control bar has a second attachment point, where the first and second attachment points cooperate to releasably engage the needle collar and the control bar. In use, when the needle collar and the control bar are engaged, the user grasps the control bar to control the needle while releasing the needle and maintaining the hands of the user outside of a field of the radiation, e.g., outside of a field of the X-ray radiation. The control bar is dimensioned such that its proximal end (i.e., the end to be grasped by the user) is outside the field of radiation.

Description:
RELATED APPLICATION INFORMATION  
       [0001]    This is a continuation-in-part application of U.S. patent application Ser. No. 09/594,151 filed Jun. 15, 2001. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This relates to a medical device and more particularly to a needle control device to obviate or mitigate exposure of excessive radiation to the hand of a user.  
         BACKGROUND OF THE INVENTION  
         [0003]    Several medical treatments involve the use of needles and continuous applied doses of radiation while a medical practitioner is within the range of the radiation. An example of such a procedure is vertebroplasty.  
           [0004]    Percutaneous vertebroplasty involves the injection of a bone cement or other suitable biomaterial into a vertebral body via a percutaneous route under X-ray guidance. The cement is injected as a semi-liquid substance through a needle that has been passed into the vertebral body, generally along a transpedicular or posterolateral approach.  
           [0005]    Percutaneous vertebroplasty is intended to provide structural reinforcement of a vertebral body through injection, by a minimally invasive percutaneous approach, of bone cement into the vertebral body. See, for example, Cotten, A., et al “Percutaneous vertebroplasty: State of the Art.”  Radiographics  1998 March-April; 18(2):311-20; discussion at 320-3. Percutaneous vertebroplasty can result in increased structural integrity, decreased micromotion at the fracture site and possibly a destruction of pain fibers due to the heat of the bone cement as it polymerizes and sets. Complete pain relief can be achieved in up to 80% of patients.  
           [0006]    Generally, when performing vertebroplasty, a needle of an appropriate gauge (such as 11 gauge or 13 gauge in a smaller vertebral body) is passed down the pedicle until it enters the vertebral body and reaches the junction of the anterior and middle thirds. Great skill is usually required to insert the needle at a suitable angle and pass the needle through the periosteum, down the pedicle and into the vertebral body. A suitable cement is prepared and injected through the needle and into the vertebral body, under lateral X-ray projection fluoroscopy imaging. The injection is stopped as the cement starts to extend into some unwanted location such as the disc space or towards the posterior quarter of the vertebral body, where the risk of epidural venous filing and hence spinal cord compression is greatest. The injection is also discontinued if adequate vertebral filling is achieved.  
           [0007]    The procedure usually requires the user (typically a physician) to hold the needle in position while (at least a portion of) the body is being radiated. This is normally needed since the needle should be stabilized and oriented in the correct position in order for the intended target in the body to be reached. This protocol leads to the creation of a field of radiation within which the user&#39;s hands typically are placed. Consequently, the user will received repeated doses of radiation which can lead to one or more occupational health hazards (e.g., health problems) and/or can shorten the career of the user due to the user receiving quantities of radiation beyond the allowable limits.  
           [0008]    Accordingly, there is a need in the art for a means by which radiative medical procedures such as percutaneous vertebroplasty may be performed while obviating or mitigation the deleterious effects of exposure of the physician or other user to excessive radiation.  
         SUMMARY OF THE INVENTION  
         [0009]    It is an object of the present invention to provide a novel needle control device for holding a needle that obviates or mitigates at least one of the disadvantages of the prior art.  
           [0010]    Accordingly, in one of its aspects, the present invention provides an apparatus for control of a needle (i.e., a needle control device) used in a field of radiation, the apparatus comprising:  
           [0011]    a needle collar for attachment to the needle, the needle collar comprising a first attachment point; and  
           [0012]    as control bar having a second attachment point, the first attachment point and the second attachment point cooperating to releasably engage the needle collar and the control bar.  
           [0013]    In another of its aspects, the present invention provides a needle comprising:  
           [0014]    a handle;  
           [0015]    a cannula attached to the handle;  
           [0016]    a needle collar attached to the needle, the needle collar comprising a first attachment point; and  
           [0017]    a control bar having a second attachment point, the first attachment point and the second attachment point cooperating to releasably engage the needle collar and the control bar.  
           [0018]    In yet another of its aspects, the present invention provides a kit of parts comprising:  
           [0019]    a needle comprising: a handle; a cannula attached to the handle; a needle collar attached to the needle, the needle collar comprising a first attachment point; and  
           [0020]    a control bar having a second attachment point, the first attachment point and the second attachment point cooperating to releasably engage the needle collar and the control bar.  
           [0021]    Thus, the present invention is an apparatus for a physician to safely hold a needle, during exposure of the treatment site and the needle to radiation, such as X-ray radiation. The apparatus includes a needle collar and a control bar. The needle collar attaches to the needle and has a first attachment point. The control bar has a second attachment point. The first attachment point and the second attachment point cooperate to releasably engage the needle collar and the control bar. In use, the needle collar and the control bar are engaged and the user grasps the control bar to control the needle are engaged and the user grasps the control bar to control the needle whi 9 le maintaining the hands of the user outside of a field of the radiation, e.g., outside of a field of the X-ray radiation. The control bar is dimensioned such that its proximal end (i.e., the end to be grasped by the user) is outside of the field of radiation. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0022]    [0022]FIG. 1 illustrates an isometric view of a PRIOR ART vertebroplasty needle;  
         [0023]    [0023]FIG. 2 illustrates an isometric view of a portion of the present needle control device with the control bar removed;  
         [0024]    [0024]FIG. 3 illustrates an isomeric schematic view of the present needle control device in use; and  
         [0025]    [0025]FIG. 4 shows an alternative needle collar and control bar.  
     
    
     DETAILED DESCRIPTION  
       [0026]    Before discussing the specific embodiments of the invention, a needle suitable for use with the needle control device will be described with reference to FIG. 1. A vertebroplasty needle is indicated generally at  10  and is preferably used for expressing bone cement or a suitable biomaterial into a vertebral body. For vertebroplasty, it is preferred that needle  10  be constructed of surgical stainless steel, although those of skill in the art will appreciate that needle  10  may be constructed of any other suitable materials. Vertebroplasty needle  10  generally consists of a cannula (also referred to as a sheath or a trocar)  12  and an insert  14  receivably removable within the sheath. Cannula  12  has a handle  16  for grasping by an operator. Insert  14  has a connector  18  operable to releasably attach to handle  16 . Insert  14  is receivable within cannula  12  for insertion of needle  10  into a vertebral body via percutaneous routes. Insert  14  is removable from cannula  12  to allow for a conventional injector (not shown), suitable for cement delivery, to be releasably attached to handle  16  to facilitate the injection of cement through cannula  12  into a vertebral body. The injector can be a syringe or a cement delivery needle or other suitable injector as will occur to those of skill in the art.  
         [0027]    Referring now to FIGS. 2 and 3, a needle control device for holding a needle is indicated generally at  20 . Device  20  includes a needle collar  22  that is releasably attachable to a control bar  24 .  
         [0028]    In a presently preferred embodiment, needle collar  22  has an opening  26  for releasably engaging with needle  10  when needle  10  is passed through opening  26 . Needle collar  22  may preferably serve as a depth marker and may be made from medical grade plastic or from other suitable materials. Other embodiments of needle collar  22  will occur to those of skill in the art, such as depth markers that include a gasket which can be constricted or loosened about the needle in order to adjust the grip of the depth marker on the needle. The interior diameter of opening  26  in needle collar  22  is slightly larger than the exterior diameter of needle  10 , and the size and material of needle collar  22  cooperates to create a friction or interference fit around needle  10 . Other suitable depth markers can be used.  
         [0029]    Needle collar  22  has a first attachment point  28 . First attachment point  28  protrudes from needle collar  22  and is operable to connect with control bar  24 . In a first embodiment, first attachment point  28  comprises a post  30  with a pair of bosses  32  substantially perpendicular to post  30 .  
         [0030]    Control bar  24  is made from medical grade plastic or other suitable materials can be used. Preferably, control bar  24  is radiolucent, so as not to interfere with the X-ray image. Control bar  24  is operable to connect with first attachment point  28 . In a presently preferred embodiment, control bar  24  has a second attachment point  34  that releasably engages with first attachment point  28 . Second attachment point  34  is seen to be a female receptacle or cavity to receive post  30  thereinto, and that has a pair of axially extending slots  36  and a pair of recesses  38 , extending laterally from respective slots  36 . Recesses  38  are substantially perpendicular to each slot  36  to releasably retain a respective boss  32 . Recesses  38  extend substantially in opposite directions, so that when control bar  24  is twisted each boss  32  is received and retained within its respective slot  36 .  
         [0031]    Preferably, control bar  24  is from about 10 cm to about 40 cm in length. More preferably, control bar  24  is between about 20 to 30 cm in length. It will be understood, however, that the length of control bar  24  may vary depending on the size of the needle that is used and the medical process in which it is being used. In particular, the length of control bar  24  is chosen to ensure that it can be grasped in a position that is outside the field of radiation generated during the procedure.  
         [0032]    The operation of device  20  will now be described with reference to the foregoing and to FIG. 3. More specifically, a method for performing vertebroplasty in accordance with an embodiment of the invention, will now be discussed, utilizing a needle  10  and needle control device  20  and performed on a patient having a vertebra  40 . The patient would be placed in the prone position so that vertebra  40  is within the radiation field generated by an imaging device (not shown). In most such cases, the imaging device is an X-ray projection fluoroscopy imaging device.  
         [0033]    Needle  10  is inserted into the vertebral body of the patient. Bar  24  is attached to needle  10  by post  30  being received into female end  34  of control bar  24  with bosses  32  engaging in axially extending slots  36  and rotating control bar  24  until bosses  32  are releasably engaged in laterally extending recesses  38  in communication with slots  36 . Control bar  24  is oriented to position the user&#39;s hand outside of the field of X-ray radiation. Control bar  24  is grasped by the user, who then may release the needle while maintaining positional control thereover by control bar, and the X-ray device is turned on and an image is taken. The X-ray only exposes the vertebral body, the needle and the adjacent portions of the needle control device.  
         [0034]    While the embodiments discussed herein are directed to particular implementations of the present invention, it will be apparent that variations to these embodiments are within the scope of the invention. For example, needle control device  20  can be made from any material that is suitable for surgical procedures and is radiolucent.  
         [0035]    Further, it is contemplated, as seen in FIGS. 2 and 3, that first attachment point  28  can be a male luer lock and second attachment point  34  can be a female luer lock (or vice versa). Alternatively, first attachment point  28  can be a male luer slip and second attachment point  34  can be a female luer slip (or vice versa).  
         [0036]    Another embodiment of the needle control device of the present invention is disclosed in FIG. 4. Needle collar  50  is shown having a C-shaped needle-clamping section  52  whereby the collar may be slipped over the needle (prior to beginning the vertebroplasty procedure) from the needle&#39;s distal end (not shown) until it is positioned at the desired location, such as to demark a selected insertion depth by the collar&#39;s distalmost side. The inside diameter of needle-clamping section  52  is preferably selected to be incrementally smaller than the outside diameter of the shaft of the needle with which it is to be used, therefore providing for a force fit to self-retain on the needle shaft. Cylindrical protrusion  54  extends laterally from collar  50  to define a male first attachment point  28 . Control bar  56  is shown to be an elongate member having a second attachment point  34  defined in a female cavity  58  complementary to protrusion  54  and thereby be adapted to releasably and detachably receive protrusion  54  thereinto in a force fit. The force fit can easily be defined by the protrusion having an outside diameter selected to be incrementally larger than the inside diameter of the female cavity  58 , and can be of sufficient force to avoid inadvertent detachment but be easily overcome manually for desired detachment by axial pulling of the control bar away from the needle without resulting in undesirable movement of the needle relative to the patient. Both collar  50  and control bar  56  can for example be extruded and/or molded of plastic material such as, for example, polyethylene or nylon.  
         [0037]    The present invention provides a novel needle control device for holding a needle during exposure to radiation, such as X-ray radiation. Of course, those of skill in the art will recognize that the present needle control device has a number of applications and uses in image guided procedures (e.g., magnetic resonance imaging (MRI) and the like). The device includes a needle collar for retaining the needle and a control bar for allowing the user to hold the needle in position prior to and/or during and/or after the X-ray process. The needle collar includes a first attachment point that, preferably, is complementary to a second attachment point positioned on the bar for releasable attachment to the control bar. The control bar allows the user to maintain control over the needle while taking an X-ray image and avoid exposing the user to the excessive X-ray radiation.  
         [0038]    While the present invention has been described with reference to preferred and specifically illustrated embodiments, it will of course by understood by those skilled in the arts that various modifications to these preferred and illustrated embodiments may be made without departing from the spirit and scope of the invention.  
         [0039]    All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extend as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.