Abstract:
A device for interlocking two sections such as a forearm-hand brace and a elbow-forearm medical device comprising, a circular strip of loop pile or hook fastener material attached to the outer surface of a first cylindrical section such as the custom forearm-hand brace. A sheet of thermo-formable material formed into a second cylindrical section matching the outer surface of the first cylindrical section wherein the second section includes a groove such that the first cylindrical section is held by the circular fastener strip within the groove and is free to rotate in either direction. A cooperating locking strap of hook or loop pile fastener attached to the second section and aligned with the strip of loop pile or hook fastener on the first cylindrical section such that attaching the locking strap to the strip prevents the free rotation and locks the first cylindrical section to the second section.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/040,644, filed Mar. 28, 2008, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates to interlocking cylinders and the means to lock those cylinders in any desired degree of rotation. In some fields it is necessary to adjustably interconnect cylinders. For example, in the field of medicine, it is sometimes necessary to apply an orthopedic brace over the arm of a patient to improve its alignment and function. The orthopedic brace must be adjustable to precisely locate the hand or arm as medically required. Many pathologies cause the muscles in the human forearm to tighten, which can resist or even stop active or passive rotation of the forearm. Since the human hand is attached to the forearm, any limitation of forearm movement therefore limits the positioning of the human hand for functional use. Often, these pathologies cause a patient to maintain their hand and forearm in a pronated (elbow flexed to 90 degrees and palm facing the floor) or supinated (elbow flexed to 90 degrees and palm facing the ceiling) position at rest. Common examples of such pathologies include: brachial plexus injury (BPI), elbow fractures, cerebral palsy (CP), surgical muscle lengthening, and forearm muscle contracture. 
         [0003]    Prior art methods of fixing this problem include the application of serial casts or slotted interlocking cylinder braces to a persons arm to rotate and lengthen the tightened muscles until the arm can be rotated through a normal range, either passively or actively. 
         [0004]    Serial casts are used to hold the forearm and hand at their end range to permit the forearm muscles to grow and lengthen. By applying a series of these casts a clinician can gradually increase the available range-of-motion (ROM) in the forearm, and improve the functional positioning of the hand. Serial casts have to be reapplied each week by an experienced clinician, which is both costly and time consuming for the patient and medical practice. Furthermore, once the final cast is removed there is nothing to stop the muscles from retightening over time and returning the arm and hand to the original position before the casting was initiated. 
         [0005]    Slotted interlocking cylinders and rotational step-lock orthopedic braces also have been used to position and hold the forearm and hand to achieve the same results as repeated serial casts. These devices are limited in that they require screws and mechanical joints to hold the forearm and hand in the desired position and do not allow for small degrees of adjustment, which is vital if you want to obtain full joint range of motion. In addition, the exposed metal components are a hazard to those wearing these orthopedic devices. 
         [0006]    As can be seen, there is a need for an improved apparatus and method of interlocking cylinder sections that will allow for a greater range of adjustment, easy re-adjustment, simple application and removal, and minimal mechanical parts. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  shows a view of the elbow-forearm medical device  100  with the trough-like partial cylinder  102  and lower arm partial cylinder  104  installed. 
           [0008]      FIG. 2  shows a view of the elbow-forearm-hand brace  300  with the forearm-hand brace  200  interlocked with the lower arm partial cylinder  104  and rotated into a pronated position. 
           [0009]      FIG. 3  shows a view of the forearm-hand brace  200 . 
           [0010]      FIG. 4  shows the forearm-hand brace  200  interlocked with the lower arm partial cylinder  104  by the loop pile fastener strap  120  and overlying locking strap  250 . 
           [0011]      FIG. 5  shows a view of the complete elbow-forearm-hand brace  300 . 
           [0012]      FIG. 6  shows a view of the complete elbow-forearm-hand brace  300  with the forearm-hand brace  200  interlocked with the lower arm partial cylinder  104  and rotated into a supinated position. 
           [0013]      FIG. 7  shows the fabrication flowchart  400 , which describes the steps required to make the elbow-forearm-hand brace  300   
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]      FIG. 1  shows the elbow-forearm section of a medical device that can be applied over the arm of a patient. The elbow-forearm medical device  100  includes a custom-molded trough-like partial cylinder  102  that intimately fits around the patient&#39;s upper arm. It will be understood that the use of the term cylinder is used generally to describe a shape that is similar to a cylinder, like a patient&#39;s arm. The trough-like partial cylinder  102  is fabricated by lining a cast of the patient&#39;s upper arm with a soft, compliant material, such as Plastazote or Aliplast, and then drape molding, under vacuum or another forming process, a piece of thermoplastic material, such as polypropylene, over top of it. The newly formed, lined upper arm cylinder is then cut off the cast and trimmed to form the trough-like partial cylinder. The soft compliant inner material is used to minimize abrasion to the patient&#39;s skin during use. 
         [0015]    The elbow-forearm medical device  100  also includes a lower arm partial cylinder  104 . The elbow-forearm medical device  100  includes a commercial, adjustable orthotic elbow joint  110  that allows the trough-like partial cylinder  102  to be angularly adjusted relative to the lower-arm partial cylinder  104 . The lower arm partial cylinder  104  and trough-like partial cylinder  102  are fastened to the elbow-forearm medical device  100  by copper rivets  112 . The lower arm partial cylinder  104  is formed by drape molding, under vacuum or another forming process, a piece of thermoplastic material, such as polypropylene, over the previously fabricated forearm-hand brace  200  ( FIG. 3 ) that had been put back on the cast of the patient&#39;s forearm and hand. This enables the forearm-hand brace  200  to intimately fit within the lower arm partial cylinder  104  and is able to rotate freely in either direction. The trough-like partial cylinder  102  and lower arm partial cylinder  104  can include multiple loop pile fastener straps  120  attached via rivets  122 . The pile-hook fastener straps  120  can include cooperating ‘D’ rings  128  attached to the opposite side of the trough-like partial cylinder  102  and lower arm partial cylinder  104 . The trough-like partial cylinder  102  has an opening  102   a  that allows a patient&#39;s upper arm to be placed inside. The lower arm partial cylinder  104  has an opening  104   a  that allows the forearm-hand brace  200  to be connected to the lower arm partial cylinder  104 . The lower arm partial cylinder  104  includes at least one cylindrical groove  130  which, is formed when the lower arm partial cylinder  104  is drape molded, under vacuum or another forming process, over the forearm-hand brace  200 . The groove assists the forearm-hand brace  200  to be held within the lower arm partial cylinder  104  and to stop it sliding forward or backward during use. Furthermore, the grove enables the forearm-hand brace  200  to be rotated in either direction about the approximate axis of the lower arm partial cylinder  104 . This ability to rotate is shown by the double headed arrow ‘A’ in  FIG. 2 . 
         [0016]      FIG. 3  shows a view of the forearm-hand brace  200 . The forearm-hand brace  200  is created in five steps. Step  1 ,  402  is to line the outside of a cast of the patient&#39;s lower arm, wrist and hand with a soft, compliant material, such as Plastazote or Aliplast. The soft compliant inner material is used to minimize friction to the patient&#39;s skin during use. Step  2 ,  404  is to glue and wrap firm thermo-moldable foam, such as Pelite, about the forearm section and grind this outer layer into a cylindrical shape until it has the same diameter from the patient&#39;s wrist to the end of the patient&#39;s forearm (this ensures that the inside of the forearm-hand brace  200  matches the shape of the patient&#39;s arm while the outside is a cylindrical shape to permit rotation). Step  3 ,  406  is to form the outer plastic skin of the forearm-hand brace  200  by drape molding, under vacuum or another forming process, a thermoplastic material, such as polyethylene, over top of it. Step  4 ,  408  is to add one or more strips of thermo-moldable foam around the circumference of the forearm-brace  200  to form the corresponding groove(s)  130  in the lower arm partial cylinder  104 . Step  5 ,  410  is to trim off the forearm-hand brace  200  from the underlying cast and form the top opening  202  so that the forearm-hand brace  200  can be applied around the patient&#39;s forearm and hand and held closed by loop-pile strap  204 . 
         [0017]    Once the groove(s)  130  have been formed during the fabrication of the lower arm partial cylinder  104  the cylindrical strip(s) of foam are removed from the outside of the forearm-hand brace  200  and are replaced by a adhesive backed strip(s) of pile material  206 . The adhesive backed strip(s) of pile material  206  enables the forearm-hand brace  200  to not only, remain within the lower arm partial cylinder  104  but also, be able to rotate either direction with  360  degrees of rotational freedom ( FIGS. 2 and 6 ). 
         [0018]    When the overlying locking strap  250  ( FIG. 5 ) with its underlying section of hook material  252  is tightened through the ‘D’ ring  128  it not only, locks the forearm-hand brace  200  into the lower arm partial cylinder  104 , but also stops the forearm-hand brace  200  from rotating any direction. If multiple grooves  130  are used on the forearm-hand brace  200  then there will be a corresponding number of adhesive backed strips of pile material  206  and overlying locking straps  250 . 
         [0019]    The ability to infinitely adjust the rotation position of the forearm-hand brace  200  within the lower arm partial cylinder  104  and then to be able to lock it in place is the essence of the infinitely adjustable loop pile controlled rotation and locking invention. 
         [0020]      FIG. 4  shows a view of the forearm-hand brace  200  locked down inside the lower arm partial cylinder  104 . The remaining parts of the elbow-forearm medical device  100  have been cut away. The loop pile fastener strap  120  has been looped through a ‘D’ ring  128  and fastened back on itself. The overlying locking strap  250  has been looped through a ‘D’ ring  128  and fastened back on itself and its underlying section of hook material  252  has attached to the adhesive backed strip of pile material  206  which runs around the circumference of the forearm-hand brace  200 . 
         [0021]      FIG. 5  shows a view of the elbow-forearm-hand brace  300  which is made by placing the forearm-hand brace  200  inside of the elbow-forearm medical device  100 . The overlying locking strap  250  includes an underlying section of hook material  252  that will adhere to the corresponding adhesive backed strip of pile material  206  that has been fastened around the forearm-hand brace  200 . 
         [0022]      FIG. 6  shows a view of the complete elbow-forearm-hand brace  300  with the forearm-hand brace  200  interlocked with the lower arm partial cylinder  104  and rotated into a supinated position. The double arrow ‘B’ indicates that the forearm-hand brace  200  can be rotated in either direction from its current position. 
         [0023]      FIG. 7  shows the fabrication flowchart  400 , which describes the steps required to make the elbow-forearm-hand brace  300 . The elbow-forearm-hand brace  300  is made up of two interconnecting parts: the elbow-forearm medical device  100  and the forearm-hand brace  200 . There are 17 fabrication steps in all. Step  1 ,  402  is to line the outside of a cast of the patient&#39;s lower arm, wrist and hand with a soft, compliant material, such as Plastazote or Aliplast. The soft compliant inner material is used to minimize friction to the patient&#39;s skin during use. Step  2 ,  404  is to glue and wrap firm thermo-moldable foam, such as Pelite, about the forearm section and grind this outer layer into a cylindrical shape until it has the same diameter from the patient&#39;s wrist to the end of the patient&#39;s forearm (this ensures that the inside of the forearm-hand brace  200  matches the shape of the patient&#39;s arm while the outside is a cylindrical shape to permit rotation). Step  3 ,  406  is to form the outer plastic skin of the forearm-hand brace  200  by drape molding, under vacuum or other forming process, a thermoplastic material, such as polyethylene, over top of it. Step  4 ,  408  is to add one or more strips of thermo-moldable foam around the circumference of the forearm-brace  200  to form the corresponding groove(s)  130  in the lower arm partial cylinder  104 . Step  5 ,  410  is to trim off the forearm-hand brace  200  from the underlying cast and form the top opening  202  so that the forearm-hand brace  200  can be applied around the patient&#39;s forearm and hand and held closed by loop-pile strap  204 . Step  6 ,  412  is to replace the completed forearm-hand brace  200  back over the cast of the patient&#39;s arm and hand. Step  7 ,  414  is to wrap the upper arm section of the patient&#39;s cast with a soft, compliant material, such as Plastazote or Aliplast, and trim it to length. Step  8 ,  416  is to form the trough-like partial cylinder  102  and the lower arm partial cylinder  104  by drape molding, under vacuum or by another forming process a piece of thermoplastic material, such as polypropylene, over the top of the soft material upper arm section and the forearm-hand brace  200 . Step  9 ,  418  is to remove the newly formed trough-like partial cylinder  102  and the lower arm partial cylinder  104  from the cast and the forearm-hand brace  200  and trim them to size. Step  10 ,  420  is to remove the strips of thermo-moldable foam from the outside of the forearm-hand brace  200  and replace them with adhesive backed strip(s) of pile material  206 . Step  11 ,  422  is to attach a metal hinge  106  ( FIG. 1 ) and a commercial, adjustable orthotic elbow joint  110  to the trough-like partial cylinder  102  and the lower arm partial cylinder  104  with rivets  112 . By connecting the trough-like partial cylinder  102  to the lower arm partial cylinder  104  it forms the elbow-forearm medical device  100 . Step  12 ,  424  is to rivet  112  the loop-pile fastener straps  120  and their adjacent ‘D’ rings  128  to the trough-like partial cylinder  102  and the lower partial arm cylinder  104 , and to rivet  112  the overlying locking strap(s)  250  and adjacent ‘D’ ring(s) to the lower arm partial cylinder  104  in line with the adhesive backed strip(s) of pile material  206  that are attached to the circumference of the forearm-hand brace  200 . Step  13 ,  426  is to attach the forearm-hand brace  200  over the patient&#39;s forearm and hand. Step  14 ,  428  is to take the forearm-hand brace  200 , with the patient&#39;s forearm and hand inside, and snap it down inside the lower-arm partial cylinder  104 . Step  15 ,  430  is to take the patient&#39;s upper arm and place it inside of the trough-like partial cylinder  102  and secure it with the loop-pile fastener straps  120  through their respective ‘D’ rings  128 . Step  16 ,  432  is to rotate the patient&#39;s forearm and hand by turning the forearm-hand brace  200  within the lower arm partial cylinder  104  until the desired position is obtained. Step  17 ,  434  is to lock the hand and forearm in the desired position by feeding the overlying locking strap(s)  250  through their corresponding ‘D’ rings  128  and tightening them down so that the underlying section of hook material  252  adheres to the corresponding adhesive backed strip of pile material  206  that is around the forearm-hand brace  200 . 
         [0024]    It will be obvious to those skilled in the art that modifications may be made to the embodiments described above without departing from the scope of the invention. Thus the scope of the invention should be determined by the claims in the formal application and their legal equivalents, rather than by the examples given.