Abstract:
A clamping apparatus of the present invention is used in a medical environment to rotationally and releasably secure a device to a support member. The clamping apparatus includes a device clamp having first and second clamp elements and a connector interconnecting the clamp elements. The clamp elements define a first receptacle for receiving a support and a second receptacle for receiving a mounting structure. At least one clamping element defines a device catch in the second receptacle. The connector is selectively moveable between a first position in which relative rotation between the flexible shaft, device clamp and device is resisted, and a second position in which the device is permitted to rotate without releasing connection to the support. A method of supporting a medical device on a support to permit selective rotation of the medical device relative to a flexible shaft without loss of interconnection is also disclosed.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to the field of support apparatus for medical devices and more particularly to a medical device mounting apparatus having a clamping apparatus. 
   BACKGROUND OF THE INVENTION 
   Medical devices such as enteral feeding pumps are typically attached to an IV pole or other support member by a pole clamp or other attachment device that holds the pump in a fixed position relative to the support member. One existing pole clamp design permits one degree of freedom of motion of the pump relative to the pole by allowing the pump to be rotated or indexed between fixed orientations relative to the IV pole. The indexing requires a substantial portion of the fixture be located on the clamp. Another existing pole clamp design permits two or more degrees of freedom of motion such that the pump may be moved horizontally, vertically, or laterally relative to the IV pole for easier viewing and operation. An example is embodied in co-assigned application Ser. No. 11/138,200 entitled Flexible Clamping Apparatus for Medical Devices filed May 26, 2005, the disclosure of which is incorporated herein by reference. 
   Furthermore, such existing pole clamps are typically mounted directly on the housing of the pump so that the pump housing is in close proximity to the IV pole. As such, the pumps mounted by conventional pole clamps take up more vertical space on the IV pole that may be needed for other devices and/or medical fluid containers. These existing designs are ill-equipped for moving equipment in and out of the way at bedside as needed when providing medical care. Therefore, a need exists for a simple effective means of releasably securing a pump or similar device to a support while also allowing adjustment of the pump without releasing the pump&#39;s connection to the support. 
   SUMMARY OF THE INVENTION 
   In one aspect of the present invention, a clamping apparatus used in a medical environment to releasably secure a device to a support member generally comprises a flexible shaft having a first end for attachment to the support member and a second end for attachment to the device. A device clamp is adapted to connect the device to the flexible shaft. The device clamp comprises first and second generally opposed clamp elements and a connector interconnecting the first and second clamp elements. The first and second clamp elements define a first receptacle for receiving the second end of the flexible shaft therein and a second receptacle for receiving a mounting structure of the device therein. At least one of the first and second clamp elements defines a device catch in the second receptacle. The connector is selectively moveable between a first position in which the clamp elements are adapted to frictionally engage the second end of the flexible shaft and the mounting structure of the device to resist relative rotation between the flexible shaft, device clamp and device; and a second position in which the clamp elements are relatively farther apart than in the first position and the device catch is position to prevent withdrawal of the mounting structure of the device from the second receptacle thereby permitting the device to be rotated with respect to the flexible shaft without releasing connection to the flexible shaft. 
   In another aspect, a clamp for use in connecting a medical device to a support generally comprises first and second generally opposed clamp elements and a connector interconnecting the first and second clamp elements. The first and second clamp elements define a first receptacle for receiving an end of the support therein and a second receptacle for receiving a mounting structure of the medical device therein. At least one of the first and second clamp elements defines a device catch in the second receptacle. The connector is selectively movable between a first position in which the clamp elements are adapted to frictionally engage the end of the support and the mounting structure of the device to resist relative rotation between the support, clamp and medical device; and a second position in which the clamp elements are relatively farther apart than in the first position and the device catch is positioned to prevent withdrawal of the mounting structure of the medical device from the second receptacle thereby permitting the device to be rotated with respect to the support without releasing connection to the support. 
   In yet another aspect, a method of supporting a medical device on a flexible shaft to permit selective rotation of the medical device relative to the flexible shaft without loss of interconnection with the shaft generally comprises rotating a connector to move first and second clamp elements to an open position. Inserting a mounting structure of the medical device into a second receptacle defined by the first and second clamp elements. Then rotating the connector to move the first and second clamp elements to a fully closed position thereby clamping the mounting structure in a receptacle defined by the first and second clamp elements for resisting relative rotation of the mounting structure relative to the flexible shaft. Lastly, loosening the clamp to a position in which the mounting structure and medical device are free to rotate, while the medical device is retained from moving out of the receptacle. 
   Other objects and features will be in part apparent and in part pointed out hereinafter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective of a clamping apparatus mounting an enteral feeding pump to an IV pole; 
       FIG. 2  is a left side elevation of  FIG. 1  with adjusted position of pump shown in phantom; 
       FIG. 3  is a rear perspective of the clamping apparatus and medical device with the clamping apparatus exploded; 
       FIG. 4  is a perspective of a flexible shaft and device clamp of the clamping apparatus; 
       FIG. 4A  is a side elevation of the flexible shaft; 
       FIG. 5  is an end view of the flexible shaft; 
       FIG. 6  is a section of the flexible shaft taken in the plane including line  6 - 6  of  FIG. 5 ; 
       FIG. 6A  is an enlarged detail of  FIG. 6  showing a sleeve of the flexible shaft; 
       FIG. 7  is an enlarged perspective of the device clamp showing additionally a stem and a sleeve of the clamping apparatus received in the device clamp; 
       FIG. 8  is a section of the device clamp taken in the plane including line  8 - 8  of  FIG. 7 ; 
       FIG. 8A  is the section of the device clamp in  FIG. 8  with the stem and sleeve shown in phantom; 
       FIG. 8B  is an enlarged view of a portion of  FIG. 8A  showing the connection between the device clamp and the stem; 
       FIG. 9  is a side elevation of a lever and screw attachment of the device clamp; 
       FIG. 10  is an enlarged detail of  FIG. 9  in section to reveal internal threads on the screw; 
       FIG. 11  is an enlarged perspective of a clamping member of the clamping apparatus; 
       FIG. 12  is a horizontal section of the clamping member of  FIG. 11 ; 
       FIG. 13  is a perspective of the clamping member with the flexible shaft removed and a fragmentary portion of a cylindrical pole received in the clamping member; 
       FIG. 13A  is a cross-section taken along the plane including  13 A- 13 A of  FIG. 13 ; 
       FIG. 14  is a perspective similar to  FIG. 13  but with a fragmentary portion of a planar table top received in the clamping member; and 
       FIG. 14A  is a cross-section taken along the plane including  14 A- 14 A of  FIG. 14 . 
   

   Corresponding reference characters indicate corresponding parts throughout the drawings. 
   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings and in particular to  FIGS. 1-3 , a powered medical device assembly  1  includes a clamping apparatus  3  releasably attached to a support member S to support a medical device  5  on the support member (the reference numerals designating their subjects generally). In the embodiment of  FIG. 1 , the support member S is a vertical IV pole having a cylindrical rod R extending up from a stand (not shown) that is commonly used to support medical paraphernalia such as IV bags (not shown) in a hospital or other healthcare environment. As discussed further below, the clamping apparatus  3  is capable of mounting the medical device  5  on support members having other than cylindrical shapes. The clamping apparatus  3  is configured to allow full range of motion (i.e., six-degrees of freedom of motion) of the medical device  5  relative to the support member S so the medical device can be positioned for better viewing and adjustment. The clamping apparatus  3  may be more broadly described as “mounting apparatus”, as it will be understood that an apparatus that mounts a medical device without clamping (e.g., including even a permanent attachment) falls within a broader scope of the present invention. 
   The medical device  5  may be any medical device used in diagnosing, monitoring, or treating a patient. In the illustrated embodiment, the medical device  5  is an enteral feeding pump used to regulate the delivery of nutritional fluids to a patient from a container (not shown) but it is understood that the medical device could be any other type of device that is typically mounted on a support. In the illustrated embodiment, the pump  5  has a housing  11 , a display screen  13  at the front of the housing for monitoring the operational status of the pump and a control knob  15  for making adjustments to the pump. As shown in  FIG. 3 , the pump  5  has a mounting stem  19  (broadly, “mounting structure”) attached to the back of the housing  11  for releasable attachment to the clamping apparatus  3 . The mounting stem  19  is cylindrical and extends from the housing  11 . It is understood that the pump  5  may be battery operated or may have a power cord (not shown) connection. The pump may be powered in any suitable manner, such as by fluid or air power. It is envisioned that the pump  5  may also be fluid (e.g., air) powered. 
   The clamping apparatus  3  includes a clamp, generally indicated  37 , having a clamping member, generally indicated  41 , for releasable attachment of the assembly  1  to the support member S and a securing rod  51  releasably attached to the clamping member for attaching the apparatus to the IV pole. The clamping apparatus  3  further includes a flexible shaft, generally indicated  43 , attached to the clamping member  41  at a first end  45  and releasably attached to the medical device  5  at a second end  47  through a sleeve  97 . The flexible shaft  43  is selectively configurable while connected to the pump  5  to allow the pump to have complete freedom of motion relative to the support member S. The complete freedom of motion of the pump  5  relative to the support member S includes translation of the pump in any of the three dimensions (e.g., x, y, and z-axis) relative to the support as well as rotation or the ability to change the angle of orientation of the pump relative to any of the three axes so that the pump has six degrees of freedom of motion relative to the support. Moreover, once moved the clamping apparatus  3  retains the medical device  5  in its new selected position. 
   As shown in  FIGS. 4 ,  4 A and  6 , the flexible shaft  43  has a generally tubular body, generally indicated  61 , with an internally threaded bushing  63  mounted on the body at the first end  45  of the shaft and a device clamp, generally indicated  65 , mounted on the body at the second end  47  of the shaft. As shown in  FIG. 6 , the tubular body  61  includes a coil spring, generally indicated  69 , having a plurality of coils  71  extending from the first end  45  to the second end  47  of the shaft  43 . A stiffener  75  is disposed between the coils  71  to provide stiffness to the flexible shaft  43  and allow the shaft to be set in a stationary position when bent. In the illustrated embodiment, the stiffener  75  comprises a wire having a triangular cross-section but it is understood that the stiffener may have other shapes. The stiffener  75  is pliable to allow the spring  69  to bend and twist in any direction but provides sufficient resistance to prevent the spring from returning to its original position and shape. A sheath  77  covers the spring  69  and the stiffener  75  to provide a thin outer layer for the flexible shaft  43 . The sheath  77  may be made from plastic, rubber, vinyl, or any other flexible material. It is understood that the flexible shaft  43  may include a tube stiffener made out of a rigid material (e.g. copper, plastic, etc.) or an internal stiffener received through the coil spring without departing from the scope of the invention. 
   Referring now specifically to  FIG. 6 , the threaded bushing  63  mounted on the first end  45  of the flexible shaft  43  has a threaded axial bore  81  at its outer end that opens to an axial cavity  85  at its inner end that receives the spring  69  and the stiffener  75  of the flexible shaft  43 . The threaded bushing  63  includes a collar  87  having an external surface  89  of the flexible shaft  43  covered by the sheath  77  that may be grasped for connecting the flexible shaft  43  to the clamping member  41 . As shown in  FIG. 3 , the outer axial surface of the bushing has a rectangular protrusion  93  slightly greater in width than the diameter of the threaded bore  81 . At the second end  47  of the flexible shaft  43  the sleeve  97  has a first annular recess  141  which will be explained later in greater detail. 
   Referring now to  FIGS. 7 and 8 , the device clamp  65  is an intermediate connector for rotational and releasable connection between the flexible shaft  43  and the stem  19  of the pump  5 . The device clamp  65  includes a clamp collar  99  having a first (top) clamp element  101  and a second (bottom) clamp element  103 . The first clamp element  101  has an opening  105  therein. The opening  105  is shaped like a counterbore and therefore also includes a first shoulder  107 . The second clamp element  103  has a threaded, counterbore opening  109  with a second shoulder  111 . 
   The device clamp  65  also includes an adjustment member, indicated generally at  113 . The adjustment member comprises of a lever  115  and a screw  117  ( FIG. 8 ). The lever  115  is rigidly attached to the screw  117  by a threaded fastener  119 . The screw comprises a head  121  and a shank  122  including a threaded end portion  123  that has a hole  125  (see,  FIG. 10 ). The screw  117  passes through the opening  105  in the first clamp element  101  and is received in the threaded opening  109  in the second clamp element  103  where the threads on the distal end portion  123  of the shank  122  and the threaded opening in the second clamp element engage. The head  121  of the screw  117  rests on the first shoulder  107  in the first clamp element  101  acting as a brace for the clamping force between the first clamp element and the second clamp element  103  as will be explained in greater detail below. 
   A threaded fastener  127  passes through the bottom end of opening  109  in the second clamp element and is threadedly received in the hole  125  in the screw  117 . The threaded fastener  127  mounts a washer  129  on the free end of the distal end portion  123  of the shank  122 . The washer  129  has a sufficiently large diameter to engage the second shoulder  111  of the opening  109  in the second clamp element  103  during operation of the connector  65 . A compression spring  131  is positioned around the shank  122  of the screw  117  and its opposite ends bear against the first clamp element  101  and the second clamp element  103 , holding the spring in place within the device clamp  65 . The compression spring  131  biases the first and second clamp elements  101 ,  103  away from each other. 
   At each end of the clamp elements  101 ,  103  the space formed between the two elements define receptacles  133 ,  135  (see,  FIG. 8A ). A first receptacle  133  includes a first annular lip  137  (broadly, “a shaft catch”) projecting radially inward and extending substantially continuously around the receptacle. A second receptacle  135  includes a second (shallow) annular lip  139  (broadly, “a device catch”), smaller than the first annular lip  137  but also projecting radially inward and extending substantially continuously around the receptacle. The first receptacle  133  is sized and shaped for receiving the sleeve  97  on the second end  47  of the flexible shaft  43 , and the second receptacle  135  is sized and shaped for receiving the stem  19  in the pump  5 . The sleeve  97  of the flexible shaft  43  includes the first annular recess  141 . When the sleeve  97  is received in the first receptacle  133 , the annular lip  137  extends into the annular recess  141  allowing the first receptacle to resist withdrawal of the flexible shaft  43 . Similarly, the stem  19  in the pump  5  has a second annular recess  143 . When the stem  19  is received in the second receptacle  135 , the second annular lip  139  extends into the second annular recess  143  providing a mechanical interlock and allowing the second receptacle to resist withdrawal of the pump  5  (see,  FIG. 8B ). 
   The device clamp  65  operates in three positions. In a first position, the threaded connection between the screw  117  and the second clamp element  103  is at its tightest. In this position, the first and second clamp elements  101 ,  103  are closer together so that the elements bear against the sleeve  97  of the flexible shaft  43  and the stem  19  of the pump  5 . The two clamp elements  101 ,  103  fictionally engage the flexible shaft  43  and stem  19 , thus prohibiting relative rotation between the flexible shaft  43 , clamp collar  99  and the pump  5 . 
   In a second position, the lever  115  is turned a sufficient degree to loosen the thread connection between the screw  117  and the second clamp element  103  so that the first and second clamp elements move apart from one another aided by the bias of the spring  131 . This second position will result in a reduction in the frictional force between the clamp collar  99  and the stem  19  permitting the pump  5  to be rotated, within the second receptacle  135 , with respect to the flexible shaft  43 . The first annular lip  137  in the first receptacle  133  will still extend into the first annular recess  141  on the sleeve  97  thus maintaining connection to the flexible shaft  43 . The second annular lip  139  also retains connection of the pump  5  to the flexible shaft  43  in this position. This allows the pump  5  to be rotated to a desired orientation and then secured in that position by turning the lever  115  in the opposite direction. This will tighten the threaded connection between the screw  117  and the second clamp element  103 , thus, restoring the frictional engagement between the collar  99  and the stem  19 . Those skilled in the art will see that as the first and second elements move apart the frictional force will also be reduced between the clamp collar  99  and the sleeve  97  permitting the collar  99  to rotate in relation to both the pump  5  and the flexible shaft  43 . This has the advantage that when the clamp  37  must be attached to a support in an attitude that would otherwise place the lever  115  in a less accessible location the clamp  99  can be rotated around the shaft  43  to place the lever  115  in a more convenient position for operation. 
   In a third position, the lever  115  is further turned a sufficient additional degree from the second position to loosen the thread connection between the screw  117  and the second clamp element  103  such that the first and second clamp elements move further apart from one another aided by the bias of the spring  131 . In this position the second annular lip  139  clears the second annular recess  143 . This will result in the complete removal of all circumferential interference between the second annular lip  139  and the stem  19  permitting the pump  5  to move freely into and out of the second receptacle  135 . This position will allow the user to handle the pump  5  free from connection to the flexible shaft  43  or allow the pump  5  to be changed out for another device. In this third position the first annular lip  131  will still extend into the first annular recess  141  maintaining connection between the flexible shaft  43  and the device clamp  65 . 
   As shown in  FIGS. 11 and 12 , the clamping member  41  is generally C-shaped and has an inner surface, generally indicated  161 , for contact with the IV pole or other support member S, an opening  163  for receiving the support member, and an outer surface generally indicated at  165 . It is to be understood that clamping members (not shown) having configurations other than described herein may be used within the scope of the present invention. Moreover, the clamping member may be eliminated entirely without departing from the scope of the present invention. Referring to  FIG. 12 , the clamping member  41  has an upper portion  169  at the top (as oriented in  FIG. 12 ) of the clamping member intersecting a middle portion  171  generally at a right angle. The inner surface  161  on the middle portion  171  has a recess  175 . A threaded hole  177  of the clamping member  41  passes through the upper portion  169  and a cylindrical, non-threaded opening  179  passes through the recess  175  in middle portion  171 . The middle portion has projecting walls  184  spaced to define a recess  185  that is sized to receive the rectangular protrusion  93  ( FIG. 3 ) on the threaded bushing  63  at the first end  45  of the flexible shaft  43  when the flexible shaft is connected to the clamping member  41 . 
   A first lower portion  187  of the clamping member  41  intersects the middle portion  171  generally at right angles. A second lower portion  190  is downwardly bent relative to the first lower portion  187  so that the first lower portion and the second lower portion meet at a bend  191  having an angle less than 90 degrees. A third lower portion  193  is upwardly bent relative to the second lower portion  190  so that the second and third lower portions meet at a lower bend  195  in the clamping member  41 . The second and third lower portions  190 ,  193  define a “V” to receive an IV pole or support member S (see,  FIG. 13 ). A fourth lower portion  197  is downwardly bent relative to the third lower portion  193  so that the third and fourth lower portions meet at a bend  199 . A portion of the inner surface  161  on the fourth lower portion  197  that faces the upper portion  169  is disposed substantially along the same plane as a corresponding surface portion of the first lower portion  187 . 
   As shown in  FIGS. 11 and 12 , the first lower portion  187  has two roughly semi-cylindrical arms  205 ,  207  on its outer surface that form a cylindrical recess  211  in the first lower portion. The cylindrical recess  211  provides structure for holding for an AC power adapter cord (not shown) when the cord is not in use. The two arms  205 ,  207  are separated by an axial slot  213  that allows the power adapter cord or other cord of the pump  5  to be received in the recess  211 . 
   As shown in  FIG. 3 , the flexible shaft  43  is attached to the clamping member  41  by a threaded bolt  261  or other fastener that is received through the opening  179  in the recess  175  on the middle portion  171  of the clamping member and is in threaded engagement with the internally threaded bushing  63  on the first end  45  of the flexible shaft. The recess  175  is configured to receive the head of the bolt  261  so that the head does not interfere with the support member S when the clamping member  41  is connected to the flexible shaft  43 . When the axially outer surface of the threaded bushing  63  on the flexible shaft  43  abuts the outer surface  165  of the middle portion  171  of the clamping member  41 , the recess  185  on the middle portion of the clamping member receives the protrusion  93  on the threaded bushing. The engagement of the protrusion  93  on the threaded bushing  63  with the walls  184  prevents the bushing from rotating when the threaded fastener  261  is threadably advanced into the bushing. The threaded connection between the flexible shaft  43  and the clamping member  41  allows the flexible shaft and the clamping member to be disassembled and interchanged with other parts (e.g., a flexible shaft having a longer or shorter length, a flexible shaft having an increased or decreased stiffness, or a clamping member having a different shape) by removing the threaded fastener  261 . It is understood that the flexible shaft  43  may be connected to the clamping member  41  with other attachment mechanisms (e.g., quick-disconnect connector, rivet, etc.) without departing from the scope of this invention. 
   It is understood that the clamping member  41  of the present invention allows the pump  5  to be mounted on either a cylindrical surface S ( FIGS. 13 and 13A ) or a planar surface PS ( FIGS. 14 and 14A ). Thus the pump  5  may be conveniently mounted in a healthcare environment on an IV pole, horizontal or vertical bed rail, wheelchair tubing, or other support typical of a hospital or other medical facility. In addition, the pump  5  may be mounted on a table top PS or other structure for use in a home or other setting outside of a medical facility. Other suitable support structures for mounting the pump  5  include, but are not limited to, powered medical scooters or mobility chairs, multi-parameter carts, doors, tables, cabinets, bed stands, countertops, chairs, medical trays, television trays, and desks. Further, the clamping member  41  may receive a pole S having a first thickness T 1  ( FIG. 13A ) or a table top PS having a generally planar surface with a thickness T 2  ( FIG. 14A ) that may be greater than or less than the thickness of the pole. 
   As shown in  FIGS. 14 and 14A , the clamping apparatus  3  may be configured for clamping the medical device  5  to a table top or other planar support member PS. In this arrangement, the securing rod  51  is threadably received through the threaded hole  177  of the clamping member  41  to contact the upper surface US of the table top PS. The lower surface LS of the table top PS contacts the inner surface  161  of the first lower portion  187  and fourth lower portion  197  of the clamping member  41  so that the table PS is held in clamped engagement between the securing rod  51  and the clamping member. The clamping apparatus  3  is secured to the table PS by turning the knob  325  on the securing rod  51  so that the rod engages the upper surface US of the table and urges the lower surface LS of the table into secure contact with first and fourth lower portions  187 ,  197 . The substantially co-planar relationship of the first and fourth portions  187 ,  197  provides stability and orients the middle portion  171  generally perpendicular to the upper and lower surfaces US, LS of the table top PS. 
   The flexible shaft  43  of the present invention allows six degrees of freedom of motion of the pump  5  relative to the support member S. The pump  5  may be mounted in a first position ( FIGS. 1 and 2 ) in which the pump is retained by the flexible shaft  43  in a stationary position so that a point on the housing  11  (e.g., the front of the housing) is a first distance D 1  away from the support. By applying a force to the housing  11  of the pump  5 , the flexible shaft  43  may be manipulated so that the pump is moved to a second position (shown in phantom in  FIG. 2 ) in which the pump is retained by the flexible shaft in a stationary position so that the point on the housing is a second distance D 2  greater than the first distance D 1  from the support member S. It is understood that the pump  5  may be positioned closer to the pole S at the second position such that the distance D 2  is less than the first distance D 1 . Also, the pump  5  may be tilted up or down about a horizontal axis (e.g., x-axis  FIGS. 1 and 2 ) perpendicular to the support S and passing through the pump to allow better viewing of the display screen  13  on the pump. Further, the pump  5  may be tilted left or right about a vertical axis (e.g., y-axis  FIGS. 1 and 2 ) to allow the display screen  13  to be viewed or the controls  15  to be accessed. The pump  5  may be rotated using the device clamp  65  about the horizontal axis A 2 . The device clamp  65  helps to prevent the spring  69  of the flexible shaft  43  from being unwound by rotation, which can cause a loss of functionality of the flexible shaft. The flexible shaft  43  also allows the pump  5  to be moved anywhere along a line intersecting the support S and the pump so that the only factor limiting the position of the pump relative to the support is the length of the flexible shaft. 
   Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. 
   When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
   In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. 
   As various changes could be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.