Abstract:
An apparatus and method of use for a wrist extension brace, intended to be used to position, secure, stabilize, and extend a patient&#39;s wrist for the purpose of assisting cannulation of blood vessels in the wrist and forearm. The apparatus generally includes a frame having a fixed dorsiflexion angle and means for cushioning a patient&#39;s hand, wrist and forearm and means of attaching such to the wrist extension brace. The method of use includes the steps of attaching the apparatus to a patient&#39;s wrist and adjusting it after such attachment.

Description:
[0001]    This Non-Provisional Utility patent application claims benefit of Provisional Patent Application 61/403,525, which has a filing date of Sep. 17, 2010. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to wrist braces and supports and, more particularly, to novel apparatuses and methods for positioning, stabilizing, securing and extending the wrist of a human patient for the purpose of cannulating a blood vessel in the wrist and forearm. 
       BACKGROUND OF THE INVENTION 
       [0003]    Cannulation of patients&#39; blood vessels occurs for many reasons, including catheterization for the purpose of inserting catheters for imaging and repairing coronary and other arteries, inserting indwelling lines for the purpose of monitoring the patient, for example to obtain continuous blood pressure or measure blood gasses, or for infusing medications. Such cannulation involves locating a blood vessel in which to create a puncture and then inserting a cannula, which may be sheaths for catheterizations or arterial or venous “lines” for monitoring (these may also be known as “art-lines” or “a-lines”), in some cases for an extended period of time. Such sheaths or lines may also provide vascular access for other procedures, for example, drawing blood, inserting a pacemaker lead or performing electrophysiology tests. Blood vessels commonly used for these purposes include the femoral, brachial, jugular, subclavian and radial arteries and veins. The present invention relates to cannulation of the blood vessels in the wrist, more particularly the radial artery or vein. 
         [0004]    Immediately prior to cannulating the radial artery, the operator, who is a medical professional, extends the patient&#39;s wrist so as to put it into dorsiflexion. Dorsiflexion of the wrist results in lengthening the vessels therein, thereby making them more taut and less susceptible to movement when accessing the vessel for the purpose of puncturing it and inserting a cannula. The radial artery in particular tends to “roll” or move less when performing the puncture, when it is thusly lengthened. It is also thought that sometimes the vessel moves closer to the skin surface when the wrist is put into dorsiflexion. A dorsiflexion angle in the range of 20° to 45° is thought to provide optimal extension for this purpose. 
         [0005]    The patient&#39;s hand and forearm are also stabilized prior to cannulation, so that the opportunity for the wrist to move is minimized. The hand is usually placed with the dorsal surface facing down, so that the palmar aspect faces up. In this position, the hand naturally tends to pronate, which causes the area of the forearm to be punctured to often be positioned at a disadvantageous angle relative to the longitudinal axis of movement of the needle used to initially gain vascular access. 
         [0006]    Properly extending the wrist into dorsiflexion and securement of the forearm and hand such that the puncture site is stable and facing upward with the proper aspect exposed are therefore requirements that must be addressed for safe, successful cannulation to occur. 
         [0007]    Use of materials such as rolled up gauze, rolled up towels and surgical drapes, adhesive tape, and other disposable soft goods are often employed to address these requirements. For catheterizations the wrist is often strapped or taped to an arm-board attached to the procedure table. When inserting a-lines for monitoring, cardboard or other relatively stiff materials are often used in an attempt to address these requirements. Increasingly, braces specifically designed to address these requirements have been developed, including the Hand-Aid product marketed by Kimberly-Clark. Though somewhat effective, the Hand-Aid does not provide good stability or securement since it has rounded ends that encourage side-to-side rolling when placed on a flat surface, and also permits rolling of the forearm and hand when it is deployed onto the patient. Further, it has a relatively shallow dorsiflexion angle. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    A useful tool for stabilizing, securing and extending the hand, wrist and forearm of a patient whose blood vessels in that area are about to be cannulated would have the following characteristics: i) usable for the varied usage environments including cardiac catheterization or interventional radiology laboratory, where the patient&#39;s arm, with a brace attached, would be secured to an arm-board; ii) provide stability by avoiding pronation or rolling of the forearm, wrist and hand within the brace; iii) provide stability by avoiding rolling of the brace on the arm-board or other flat surface to which it may be attached; iv) usable for critical care nursing, clinic, hospital transport bed, and surgery environment by providing compact size and shape, and comfortable contours; v) provide proper wrist extension; vi) be quick and easy to deploy; vii) be comfortable for the patient. 
         [0009]    The present invention, to be known as the “Brace”, is intended to be used to position, secure, stabilize, and extend a patient&#39;s wrist for the purpose of assisting cannulation of blood vessels in the wrist and forearm. For example, this may be employed when inserting an arterial or venous line or a sheath or catheter into a blood vessel of the wrist or forearm. More particular examples include inserting an arterial line into a patient&#39;s radial artery for the purpose of monitoring certain signs, including continuous blood pressure or blood gasses, or when inserting a sheath into such radial artery to provide access for catheters. 
         [0010]    Use of the Brace will make the process of achieving a puncture into a blood vessel in the wrist or forearm easier and safer. When deployed onto a patient, the Brace device puts the wrist into dorsiflexion, which lengthens the vessels therein, thereby making them more taut and less susceptible to movement when accessing the vessel. Thus the Brace helps to reduce opportunity for misplaced punctures. 
         [0011]    In addition to its wrist extension feature, the Brace includes features for stabilizing the patient&#39;s hand, wrist and forearm during and after cannulation. Composed at least partially of a rigid material to enable a consistent dorsiflexion angle and stable securement. The hand is secured to the Brace in a fashion so as to hold it flat, with minimal if any opportunity for pronation. This is caused by the hand strap extending from the proximal phalanx of the thumb or the metacarpophalangeal joint, to be known as the “MCP”, of the thumb across the palm of the hand to the MCP or proximal phalanges of the little finger. When used for catheterization procedures using the radial artery in a cardiac catheterization laboratory, the Brace, deployed onto the hand, is often secured on to an arm board with a strap. The arm board is attached to the procedure table and provides a resting place for the patient&#39;s arm. The bottom surface of the Brace frame has flat surfaces extending along the width at each end so that it stays flat on the Arm board, with minimal if any opportunity for rolling side to side. Further, the Brace may remain deployed onto the patient following completion of the cannulation procedure, concurrently with a hemostatic device that may be deployed onto the patient&#39;s wrist during and after removal of the cannula for the purpose of achieving hemostasis at the site from which the cannula was removed. Such hemostatic devices, for example, the RadAR (Advanced Vascular Dynamics, Portland, Oreg., USA) or TR-Band (Terumo, Tokyo, Japan) devices may be in the form of a strap or bracelet that attaches around the wrist to provide external compression for the purpose of achieving such hemostasis. The tip of such a device may be threaded around the Brace or between the Brace and dorsal surface of the patient&#39;s forearm or wrist, and then secured and adjusted. The shape of the Brace may include a narrower width in its middle section to facilitate such hemostatic device deployment. 
         [0012]    The Brace may also be deployed onto patients for monitoring patients in their hospital or clinic beds, since the shape of the Brace permits the hand and forearm to comfortably rest wherever the patient desires to place it. Thus the Brace provides the flexibility of having either proper securement and stability when placed on a flat surface, for example on an arm-board, or comfortable placement when it is desired that the patient be able to move their forearm and hand and place it, for example on their lap or next to them in the confines of a hospital or clinic bed while restricting movement of the wrist. 
         [0013]    The Brace has a top surface and a bottom surface, and a front end and a back end, and a “dorsiflexion angle”. When the deployed, this angle, generally between 10° and 60°, or more particularly between 20° and 45°, extends the patient&#39;s wrist into dorsiflexion. The brace may include a rigid frame, which has structural features to provide sufficient strength and rigidity to prevent breakage and excessive flexing or twisting. Further, the frame has stabilization feet, features to prevent the brace, with the patient&#39;s hand attached, from rolling when placed on a flat surface, i.e. an armboard used during a catheterization procedure. These may include flat surfaces at the front and back ends of the frame, or a flat strut extending between the front and back ends of the frame. At least one optional tie-down hole may also be included, which extends through the frame at its perimeter. A narrowed waist may also be included in the middle area of the frame so as to enable devices to be deployed around the wrist at the end of the cannulation procedure to more easily enable hemostasis, when the cannulas are removed, or other manipulations in the cannulation area. Such narrowed waist avoids interference with components of such devices, making their deployment easier. One or more ribs may optionally be included in the construction of a frame to enable rigidity and torsional stability while at the same time minimizing consumption of materials in its construction. 
         [0014]    Optionally, at least one arm-board strap may be threaded through the tie-down holes for the purpose of wrapping around an arm board on which the Brace, with the patient&#39;s hand attached, is placed, e.g. at time of a catheterization procedure. These tie-down holes can also be used to help guide at least one securement strap, which hold the patient&#39;s hand in the Brace. 
         [0015]    An optional cushion pad having generally the same shape as the frame, or simply a generally rectangular or oval shape, is placed on top of the frame to provide a cushion between the frame and the patient&#39;s hand for the purpose of patient comfort. The cushion pad, if formed separately from the frame, covers the frame and is composed of a pliable material, which is attached to the frame. Such attachment may be achieved by using adhesive or a hook-and-loop means, e.g. Velcro, or other means. Alternatively the cushion pad may be formed as a unitary part of the frame. 
         [0016]    The frame has attachment means, e.g. Velcro, on its underside for attaching at least one securement strap. A preferred embodiment may include two securement straps, using Velcro or other similar means for attachment, to secure the patient&#39;s hand and forearm to the Brace device. A forearm strap secures the forearm to the Brace. A hand strap secures the hand to the Brace. The straps attach to the frame using the attachment means. Other examples of attachment means include snaps, hooks, or holes with which to attach the straps. Such attachment means may further enable subsequent removal and replacement of the cushion pad and straps onto the frame. 
         [0017]    The method of use of the Brace is that it is deployed onto the patient in advance of a cannulation procedure. The hand is placed onto the Brace with its palmar aspect facing up and the dorsal aspect placed flat, directly onto the Brace in a fashion familiar to clinicians performing these cannulation procedures. The dorsal aspects of the patient&#39;s wrist and forearm are also placed against the cushion pad. Those skilled in the art of cannulating blood vessels in patient&#39;s arm will have a thorough understanding of the mechanics and anatomy involved in this procedure. 
         [0018]    The hand, wrist and forearm is then secured to the Brace. The hand strap extends generally diagonally across the palm of the hand, from the thumb MCP or thumb proximal phalanx bone, crossing the little finger MCP or phalanges, to hold the hand flat on the Brace. The forearm strap is wrapped around the forearm proximal to the wrist joint. By placing the hand strap in this fashion, the patient&#39;s hand is prevented from rolling and counters the natural tendency of the hand to pronate when placed in the palm-up position. 
         [0019]    The forearm and hand straps are then firmly but removably secured using the attachment means, which in a preferred embodiment may be located on the underside of the frame. Tie-down holes may be used to guide and secure the straps. 
         [0020]    The Brace, with the patient&#39;s hand firmly secured in place, is then placed onto the arm board. In a preferred embodiment, an optional arm board strap is wrapped across the patient&#39;s hand (across the fingers), and around the bottom of the arm board, to be secured to an attachment means on the frame or on itself. In some instances, the Brace will not be secured to an arm board at the discretion of the cath lab staff. Tie-down holes may be used to guide and also to secure the arm-board strap. 
         [0021]    Preparation of the access site may be performed following deployment of the Brace device onto the patient. 
         [0022]    In the case that the Brace is used for placement of an arterial or venous line that will stay in place for an extended period of time, the Brace may be deployed as described above, with an additional activity performed following such placement comprising: loosening the hand, placing a separate padding material between the dorsal surface of the hand and the Brace to decrease the dorsiflexion angle and then re-securing the hand, for purposes of patient comfort. 
         [0023]    It will be understood by those skilled in the art that, although the following drawings and Detailed Description of the Invention disclose further aspects and advantages of the Brace and its method of use, and describes preferred embodiments, the present invention is not intended to be limited only to these preferred embodiments. It will be apparent that other changes in form and detail may be made therein without departing from the spirit and scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS 
         [0024]    FIG.  1 —A perspective view of the Brace  10  shows a cushion pad  30  placed on the top surface of the frame  20 , included in which tie-down holes  60  and to which are attached a forearm strap  40 , a hand strap  41 . At the front end of the frame  20  is shown a front stabilization foot  70 , and in the middle of the frame  20  is shown the narrowed waist  21 . 
           [0025]    FIG.  2 —A perspective exploded view of the Brace  10  shows attachment means  50  and  51 , for example adhesively-attached pieces of Velcro hook material, to be placed on the bottom and top surfaces of the frame  20 , respectively. A front stabilization foot  70  and a rear stabilization foot  71  are also shown on frame  20  at the front and rear ends, respectively. Structural ribs  72  are also shown integrally formed into the frame  20 . Also shown are the tie-down holes  60 , the pad  30 , the forearm strap  40 , the hand strap  41  and an arm-board strap  42 . 
           [0026]    FIG.  3 —A bottom view of the frame  20  shows the front stabilization foot  70  and rear stabilization foot  71 , both of which lie flat to provide overall stability when the Brace  10  is placed onto a flat surface, for example an arm-board. Also shown is a narrowed waist  21  of the frame  20  and structural ribs  72  and tie-down holes  60  integrally formed into the frame  20 . 
           [0027]    FIG.  4 —A perspective view of the frame  20 , shows a front stabilization foot  70  and rear stabilization foot  71 , which may have flat edges at the tips of the frame  20  so as to provide a stable platform by preventing rocking side to side. Also shown are tie-down holes  60  located along the perimeter of the frame  20 , the narrowed waist  21  and ribs  72  integrally formed into the frame  20 . 
           [0028]    FIG.  5 —A side view of the frame  20  shows the locations of the front stabilization foot  70  and rear stabilization foot  71  at the front and rear ends of the frame  20 , respectively. In addition, the dorsiflexion angle A is shown. In a preferred embodiment the dorsiflexion angle A is between 10° and 60°, more particularly between 20° and 45°. A structural rib  72  is shown integrally formed into the frame  20 . 
           [0029]    FIG.  6 —A perspective view of the Brace  10  as deployed shows a hand  100  placed onto the Brace  10  with its dorsal surface placed flat onto the cushion pad  30 . The forearm strap  40  is shown secured around the forearm  101  and the hand strap  41  is shown secured around the hand  100 . Notably, the hand strap  41  wraps around the thumb proximal phalanx  102  and extends across the palm of the hand  100  and around the little finger MCP  104 . Alternatively, the hand strap  41  can wrap around the thumb MCP  103  instead of the thumb proximal phalanx  102 . The forearm  101 , up to the wrist  105 , lies over the cushion pad  30  covering the narrowed waist  21  of the frame  20 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    The frame  20  may be composed of a generally rigid material, for example: a thermoplastic such as a polystyrene, polyethylene, polypropylene, nylon or polycarbonate or ABS; a fiber material; or, a metal. The attachment means  50  or  51  may be an adhesive, for example: a double-sided adhesive tape; or, a hook-and-loop material such as Velcro. The attachment means  50  or  51  may be permanently attached to the frame  20 , or be formed as a unitary element of the frame  20 , for example, it may be molded into the frame  20  during injection molding. The cushion pad  30  may composed of a material, preferably having a characteristic of pliancy and flexibility, for example: a synthetic foam; a hydrogel; a cloth composed of either natural or synthetic fibers; a silicone or similar moldable material; a composite or lamination of more than one material; or, a thermoplastic. The material of the cushion pad  30  may further include the property, on the side contacting the patient skin, of wicking away moisture from the skin. The cushion pad  30  may further include on one side a loop material to removably attach to hook material adhesively placed onto or molded into the frame  20 . The straps  40  and  41  may further include on one side a loop material to removably attach to hook material, for example, attachment means  51 , adhesively placed onto or molded into the frame  20 . The forearm strap  40  and hand strap  41  may be composed of a material, preferably having a characteristic of flexibility, for example: a synthetic foam; a hydrogel; a cloth composed of either natural or synthetic fibers; a composite or lamination of more than one material; or, a thermoplastic. The straps  40  and  41  may further include on one side a loop material to removably mate with hook material located on the frame  20 , for example, attachment means  50 . The arm-board strap  42  may be composed of a material, preferably having a characteristic of flexibility, for example: a synthetic foam; a fabric composed of natural or synthetic fibers; a composite or lamination of more than one material; or, a thermoplastic. The material of arm-board strap  42  may further include the characteristic of a hook-and-loop material wherein the hook portion is on one side and the loop portion is on the opposite side such that the arm-board strap  42 , when wrapped around the hand  100 , Brace  10  and arm-board to secure it in place, for example in the catheterization laboratory, it attaches to itself. Construction of these components may be separately, or in combination as a unitary piece. If constructed and provided separately from the frame  20 , the cushion pad  30  and straps  41  and  42  may be provided unattached to the frame  20  such that the user would assemble these components using the attachment means  50  and  51 . In this embodiment, the cushion pad  30  would have a shape that conforms to the outline of the frame  20  or alternatively it may have a generally rectangular or oval shape. 
         [0031]    When cannulating a vessel in a patient&#39;s wrist  105  for the purpose of a catheterization procedure, the hand  100  and forearm  101  are placed onto the Brace  10  with the hand&#39;s  100  palmar aspect facing up and the dorsal aspects placed flat, directly onto the cushion pad  30 . 
         [0032]    The hand  100  is then secured to the Brace  10 . The hand strap  41  crosses the distal aspect of the thumb MCP  103 , over the palm of the hand  100  and extending generally diagonally from the thumb MCP  103  or the thumb proximal phalanx  102  and across the little finger MCP  104 . By placing the hand strap  41  in this fashion, the patient&#39;s hand  100  is held flat against the Brace  10  and prevented from rolling, thus countering the natural tendency of a hand to pronate when placed in the palm-up position. The forearm strap  40  is wrapped around the forearm  101 . The forearm strap  40  and hand strap  41  are firmly secured by attaching them to the attachment means  50 , which in a preferred embodiment may be located on the underside of the frame  20 . Tie-down holes  60  may optionally be used to guide and the straps  40  and  41 . The tie-down holes may also be used to attach the straps  40  and  41  to the Brace  10 . 
         [0033]    The Brace  10 , with the patient&#39;s hand  100  firmly secured in place, may then placed at the discretion of the user onto an arm board. In a preferred embodiment, an optional arm board strap  42  is wrapped across the patient&#39;s hand  100  (across the fingers), and around the bottom of the arm board, to be secured to an attachment means on the frame or onto itself. In some instances, the Brace  10  may not be secured to an arm board, at the discretion of the user. Tie-down holes  60  may be used to guide and secure the arm-board strap  42 . 
         [0034]    The Brace  10  may remain deployed onto the patient following completion of the cannulation procedure, concurrently with a separately provided hemostatic device (for example, the RadAR or TR-Band devices) that may be deployed onto the patient&#39;s wrist  105  during and after removal of the cannula for the purpose of achieving hemostasis at the site from which the cannula was removed. The tip of such a device may be threaded around the outside surface of the frame  20  or between the pad  30  or frame  20  and the dorsal surface of the patient&#39;s forearm  101  or wrist  105 . The hemostatic device may then be secured. The shape of the Brace  10  or more particularly frame  20  may include a narrowed waist  21  generally in the middle section to facilitate such hemostatic device deployment. 
         [0035]    When placing arterial lines or venous lines into a vessel in a patient&#39;s wrist  105 , the hand  100  and forearm  101  are placed onto the Brace  10  with the hand&#39;s  100  palmar aspect facing up and the dorsal aspects placed flat, directly onto the cushion pad  30 . 
         [0036]    The hand  100  and forearm  101  is then secured to the Brace with the hand strap  41  and forearm strap  40  as described in the foregoing. Following arterial line placement, the hand strap  41  may at the discretion of the user be released and a padding, which may optionally be included with the Brace  10 , placed between the dorsal surface of the hand  100  and the cushion pad  20  to decrease the dorsiflexion angle A, for the purpose of increasing patient comfort. The hand strap  41  would then be re-secured to hold the hand  100  in place.