Patent Publication Number: US-2020275989-A1

Title: Flexible holding device

Description:
The invention relates to a flexible holding device, in particular a flexible holding device for preferred use in magnetic resonance imaging (MRI), as well as to a locking unit, to a tool mount and to an instrument holder for use in magnetic resonance imaging (MRI). 
     The current possibilities of MRI have not yet been exhausted, especially in interventional applications. This is mainly due to the fact that not enough medical devices are available that can be used in MRI. In this context, many patients could benefit from an operation conducted using MRI, for example when taking tissue samples. Nowadays, such biopsies are often carried out with the assistance of ultrasound (US) or computer tomography (CT), although these methods are considerably inferior to the options afforded by MRI. This relates in particular to the detectability of different tissues, which can be significantly increased by means of MRI, and thus to the precision of taking samples. Providing more MRI-compatible instruments would result in a significant improvement in treatment options. 
     In the prior art, various instruments and holding devices are known for medical use and specifically for use in the MRI sector. A drawback of these instruments and thus the prior art is that the known holding devices, in particular in the MRI sector, are highly complex in structure. This means that the appliances cannot be operated without prior training. In addition, the complicated handling increases the length of time the patient has to spend in the MRI, which is undesired and disadvantageous both for the patient and the hospital. Not least, known holding devices are often very expensive, because of the technology used. Known appliances thus have a large number of options that are often neither used nor desired. These additional options result in the above-mentioned drawbacks, such as difficult, counter-intuitive operation, reduced patient safety, and high purchase and maintenance costs. 
     The problem addressed by the invention is therefore to provide a holding device, a locking unit, a tool mount, and an instrument holder which are easy to handle and at the same time provide comprehensive options for positioning. 
     Another problem addressed by the invention is therefore to provide a holding device, a locking unit, a tool mount, and an instrument holder which are particularly suitable for use in magnetic resonance imaging (MRI). In addition, they can be used with other diagnostic systems and as a device for assistance during operations. 
     This problem is solved by an invention having the features of claims  1 ,  15 ,  19  and  22 . Advantageous embodiments are found in the dependent claims. It should be noted that the features that are set out individually in the claims can also be combined with one another in any technologically viable manner, and thus demonstrate further embodiments of the invention. 
     A holding device according to the invention comprises at least one locking unit comprising at least two sockets. The holding device may further comprise at least one locking unit comprising a socket. The sockets are designed to make it possible for joint heads received in the sockets to each pivot about at least one pivot axis, and preferably precisely one pivot axis. Embodiments comprising a plurality of pivot axes are also conceivable, however. 
     An advantageous configuration provides that the sockets are designed to be rotatable relative to one another such that the orientation of the pivot axes of the sockets relative to one another can be changed. This can be achieved for example by the locking unit being divided between the two sockets and the two parts of the locking unit being designed to be rotatable relative to one another. For this purpose, a cuff which comprises two circumferential notches on the side facing the locking unit can be placed around the two-part locking unit in the region of the division, for example. The two parts of the locking unit engage in this notch in a form-fitting manner with outwardly directed projections, which notch thus serves as a guide rail for the rotational movement of the two parts of the locking unit. Other options for configuring rotation of the sockets relative to one another according to the invention are known to a person skilled in the art. 
     In a preferred embodiment, the holding device comprises at least one connector element having at least two joint heads, wherein at least one joint head of the connector element is received in a socket of the locking unit. 
     In a particular configuration, the holding device preferably comprises at least two locking units and at least one connector element, wherein the joint heads of the connector element are each received in a socket of a locking unit. 
     The socket and joint heads may for example be designed as ball-and-socket joints, but other types of joint are also conceivable, and a person skilled in the art would select a suitable joint construction here. 
     The invention further relates to a locking unit, as is described in greater detail above and in the following. The locking unit comprises at least two sockets, wherein the sockets are designed to make it possible for joint heads received in the sockets to each pivot about at least one pivot axis, and preferably precisely one pivot axis. Furthermore, the locking unit comprises at least two locking elements, wherein the locking elements lock joint heads received in the sockets in a locking position and allow joint heads received in the sockets to move freely about the pivot axes in an open position. Furthermore, locking units comprising one socket are also conceivable. 
     An advantageous configuration of the locking unit provides that the sockets are designed to be rotatable relative to one another in an open position such that the orientation of the pivot axes of the sockets relative to one another can be changed. The locking elements lock the sockets relative to one another in the locking position, such that the position of the pivot axes can be fixed in the locking position. 
     In order to make it possible to adjust the joint heads by up to 90° relative to the longitudinal axis of the locking unit, the sockets may comprise a cut-out at the ends of the locking unit which is suitable for receiving the shaft of the joint heads. 
     A particular embodiment of the locking unit provides that, in the locking position, the locking elements are pressed against joint heads received in the sockets by eccentrically arranged eccentric elements of a locking lever. By means of this pressure, both the joint heads are fixed in the sockets and the position of the pivot axes relative to one another is also fixed. 
     The substantially rod-shaped locking lever is preferably arranged perpendicularly to the longitudinal axis of the locking unit at a point between the two sockets of the locking unit. The two ends of the locking lever are rotatably mounted in a tubular casing of the locking unit, at least the first end also penetrating through the casing towards the outside. This first end comprises a rotary lever or at least an attachment point for a rotary lever in the region of the outside of the casing. The portion of the locking lever inside the cavity in the casing comprises at least two eccentric projections, which are opposite one another based on the axis of the locking element. If the locking lever is then rotated by 90° by means of the rotary lever, the eccentric projections can be moved from a position along the longitudinal axis of the locking unit, referred to in the following as the locking position, into a position perpendicular to the longitudinal axis of the locking unit, referred to in the following as the open position. 
     A movably mounted locking element, the external diameter of which preferably substantially corresponds to the internal diameter of the tubular casing, is positioned on either side of the locking lever within the tubular casing. The length of the locking element is coordinated with the eccentric projections of the locking lever such that the locking elements do not lock the joint heads and pivot axes in the open position and the locking elements lock the joint heads and pivot axes in the locking position of the locking lever. The locking is carried out by the locking elements being pushed against the joint heads by the eccentric projections of the locking element, as a result of which said joint heads are in turn pushed against the sockets of the locking unit and the projections of the two parts of the locking unit are pushed into the notch. Accordingly, by adjusting the locking lever simultaneously using a handle, both locking elements are moved and are locked or released using a handle. In particular, the ends of the locking elements that extend as far as the joint heads may be coated with a material that additionally prevents the joint heads from slipping, for example an elastomer. Alternatively, the material of the locking elements may consist of an elastomer in part. Other options for the locking are known to a person skilled in the art. 
     In another preferred embodiment, the locking unit is adjustable in length between the sockets. 
     An advantageous configuration of the locking unit provides that the locking unit comprises a casing made up of at least two casing parts, wherein at least two casing parts are designed to be adjustable relative to one another for the length adjustment of the locking unit. 
     A particular configuration of the locking unit provides that the at least two casing parts can be latched into one another by latching elements. 
     In addition, according to an advantageous configuration of the locking unit, at least one of the locking elements comprises a first and a second locking element part, wherein the first and the second locking element part are designed to be adjustable relative to one another for the length adjustment of the locking unit and can be latched into one another by latching elements. 
     According to a particular configuration, the latching elements of the casing parts and the locking element parts are preferably designed as form-fitting elements that are formed in part in the circumferential direction. These form-fitting elements may for example be formed as screw threads, hooks or teeth, wherein the latching elements may also be designed as teeth that are formed in the longitudinal direction in part. 
     According to a particularly advantageous embodiment, the latching elements are arranged on the corresponding casing parts and locking element parts such that at least one casing part and one of the locking element parts can be adjusted together relative to the other casing and locking element parts. By the coupling of the length adjustment of casing parts and locking element parts, when adjusting the length of the locking unit, locking is also made possible by means of the locking elements, since the locking element changes its length analogously to the length adjustment of the casing. 
     In another preferred embodiment, the holding device comprises a tool mount as described in the following. The tool mount described is preferably intended for use on a holding device according to the invention, but it is not limited thereto. 
     The tool mount comprises at least one hole for receiving a tool. In a closed position, at least one locking shaft engages in the hole and the tool can thus be fixed in the hole. In an open position, the locking shaft does not engage in the hole and the tool can be removed from the hole. 
     According to an advantageous configuration of the tool mount, the locking shaft can preferably be moved from a closed position into an open position by an unlocking mechanism that can be released by an unlocking element. 
     According to a particular configuration, the unlocking mechanism comprises a spring, which moves the locking shaft into the closed position by means of spring force. 
     In another preferred embodiment, the holding device also comprises, in addition to the tool mount, an instrument holder as described in the following. The instrument holder described is preferably intended for use with the holding device according to the invention, but it is not limited thereto. 
     The instrument holder according to the invention comprises a housing, in which at least one rotatable flat thread is arranged. A plurality of sliders, preferably three sliders, are arranged on the flat thread and penetrate through the housing through first openings in the housing. The first openings in the housing are preferably designed as T-shaped guide rails, which extend in the manner of spokes in a straight line from the central cut-out to the edge of the cylinder. The three guide rails are preferably arranged at an angle of 120° relative to one another. A slider runs in each of the T-shaped guide rails. Each slider comprises lateral protrusions, which are received by the T-shaped guide rails of the cover. The sliders can be moved towards one another by rotation of the flat thread in a first rotational direction and can be moved away from one another by rotation of the flat thread in a second rotational direction counter to the first rotational direction. 
     According to an advantageous configuration of the instrument holder, the flat thread has rotary means that make it possible to rotate the flat thread. The rotary means are preferably accessible from the outside via at least one second opening in the housing of the instrument holder. 
     Cut-outs may preferably be arranged centrally in the base and cover of the housing and at a corresponding point in the flat thread such that an instrument to be clamped, for example a needle, in particular a biopsy needle, can extend through this cut-out in the instrument holder. 
     One end of the slider, the inner end, which is within the housing, extends into the flat thread and engages with a protrusion therein. The other end of the slider, the outer end, extends out of the housing. The slider comprises gripping surfaces towards the center of the instrument holder, which surfaces can be enlarged in order to provide a larger projecting surface for holding an instrument. 
     The instrument holder described is preferably intended for use with the holding device according to the invention, but it is not limited thereto. 
     The holding device according to the invention may also comprise a fixing unit. The fixing unit comprises at least one joint head for making it possible to connect the fixing unit to a socket of a locking unit of the holding device in an articulated manner. Furthermore, the fixing unit comprises means for fixing the fixing unit to a surface underneath and thus serves to detachably fasten the entire holding device to said surface. A person skilled in the art will select the means used for fixing depending on the surface to which the fixing unit is to be detachably fastened. These means may for example be screw connections, clamped connections, suction connections, or other connections. 
     In another preferred embodiment, the holding device as well as the tool mount and the instrument holder are suitable for use in MRI. This is achieved by selecting suitable materials during production. A particularly preferred material here is polycaprolactam (nylon 6), but many other materials that are known to a person skilled in the art are also suitable for use in MRI. 
     The invention and the technical field are described in greater detail in the following with reference to the drawings. It should be noted that the drawings show a particularly preferred variant of the invention; however, the invention is not limited to the variant shown. Provided that it is technically viable, the invention in particular includes any combination of the technical features that are set out in the claims or are described in the description as being relevant to the invention. 
    
    
     
       In the drawings: 
         FIG. 1  is a view of a first embodiment of the holding device according to the invention. 
         FIG. 2  is a longitudinal section through a first embodiment of the locking element comprising a connecting element. 
         FIG. 3  is a view of the tool mount according to the invention. 
         FIG. 4  is a partial cross section through the tool mount. 
         FIG. 5  is a view of a second embodiment of the locking element. 
         FIG. 6  is a longitudinal section through the second embodiment of the locking element. 
         FIG. 7  is a view of a detail of a first casing part. 
         FIG. 8  is a view of a detail of a first locking element part. 
         FIG. 9  is a view of a detail of a second locking element part. 
         FIG. 10  is a view of a preferred embodiment of the instrument holder. 
         FIG. 11  is a partial section through the housing of a preferred embodiment of the instrument holder. 
         FIG. 12  shows the flat thread of the instrument holder together with two sliders. 
     
    
    
       FIG. 1  shows a first embodiment of the holding device  1  according to the invention, comprising a connector element  4 , two locking units  2 , a tool mount  12 , an instrument holder  17  and a fixing unit  24 . The fixing unit  24  is suitable for being fastened to a surface by means of a guide and a screw. A person skilled in the art will select suitable means depending on the surface. The fixing unit  24  also has a joint head  5  ( FIG. 2 ), which engages in a socket  3  ( FIG. 2 ) of one locking unit  2 . The locking element  2  is connected to a second locking element  2  by a connector element  4 . The connector element  4  comprises two joint heads  5  ( FIG. 2 ), which each engage in one socket  3  ( FIG. 2 ) of the two locking units  2 . The locking units  2  are each locked by a locking lever  8 , with only one being shown in  FIG. 1 . A tool mount  12  that has already been described and is described in greater detail in the following is received in a socket of one locking unit  2  by its own joint head. An instrument holder  17  that has already been described and is described in greater detail in the following is received in the tool mount  12  shown. 
       FIG. 2  is longitudinal section through a first embodiment of the locking unit  2 . The substantially rod-shaped locking lever  7  is preferably arranged perpendicularly to the longitudinal axis of the locking unit  2  at a point between the two sockets  3  of the locking unit  2 . The two ends of the locking lever  7  are rotatably mounted in the tubular casing  9  of the locking unit  2 , with at least the first end also penetrating through the casing  9  towards the outside. This first end comprises a rotary lever  8  or at least an attachment point for a rotary lever in the region of the outside of the casing. The portion of the locking lever  8  inside the cavity in the casing comprises at least two eccentric projections  7 , which are opposite one another based on the axis of the locking element. If the locking lever  8  is then rotated by 90°, the eccentric projections  7  can be moved from a locking position into an open position. A movably mounted locking element  6 , the external diameter of which preferably substantially corresponds to the internal diameter of the tubular casing  9 , is positioned on either side of the locking lever  8  within the tubular casing  9 . The length of the locking element  6  is preferably coordinated with the eccentric projections  7  of the locking lever  8  such that the locking elements  6  do not lock the joint heads  5  and pivot axes in the open position and the locking elements  6  lock the joint heads  5  and pivot axes in the locking position of the locking lever  8 . The locking is carried out by the locking elements  6  being pushed against the joint heads  5  by the eccentric projections  7  of the locking element  8 , as a result of which said joint heads are in turn pushed against the sockets  3  of the locking unit  2  and the projections  27  of the two parts of the locking unit  2  are pushed into the notch  28 . Accordingly, by adjusting the locking lever  8  simultaneously using a handle, both locking elements  6  are moved and are thus locked or released. 
       FIG. 3  shows a preferred embodiment of the tool mount  12 , comprising a square hole  13 , a locking shaft  14  and an unlocking element  15 . 
       FIG. 4  is a partial section through the tool mount  12  according to  FIG. 3 , comprising a square hole  13 , a locking shaft  14 , an unlocking element  15  and a spring  16 . The locking shaft  14  engages in the hole  13  with one end and thus fixes a tool inserted therein. In order to release the fixing, the locking shaft  14  is moved out of the hole  13  by means of the unlocking element  15 . A spring  16  moves the locking shaft  14  into the closed position such that, without pressure on the unlocking element  15 , the tool mount  12  remains in the closed position. 
       FIG. 5  shows another preferred embodiment of the locking unit  2  having length adjustment. The joint ball  5  ( FIG. 2 ) can be pivoted in at least one axis  29  in the socket  3  ( FIG. 2 ). The joint ball  5  ( FIG. 2 ) can, however, be adjusted in a plurality of pivot axes. The axis  29  defined by the joint ball  5  ( FIG. 2 ) and the socket  3  ( FIG. 2 ) can be rotated for this purpose. In addition, depending on the opening width of a pocket formed in the socket  3  ( FIG. 2 ), the joint ball  5  ( FIG. 2 ) can be rotated relative to the socket  3  ( FIG. 2 ) in all three spatial axes within a certain range. The ability to pivot about the axis  29  is limited by means of the lateral guides in the socket  3  ( FIG. 2 ). By means of a wider opening in the socket  3  ( FIG. 2 ), the joint ball  5  ( FIG. 2 ) and the socket  3  ( FIG. 2 ) can also pivot all the way around. This feature is also implemented in the embodiment described above in  FIGS. 1 and 2 . 
       FIG. 6  is a longitudinal section through the preferred embodiment of the locking unit  2  having length adjustment. The locking unit  2  comprises a casing made up of two casing portions  30   a ,  30   b , with the casing portion  30   a  being formed in one piece and the casing portion  30   b  being formed in at least two pieces. The casing parts  9   a ,  9   b  of the casing portion  30   b  are designed to be adjustable relative to one another for the length adjustment of the locking unit  2  and can be latched into one another by first latching elements  10 . In addition, at least one of the locking elements  6  of the locking unit  2  comprises a first and a second locking element part  6   a ,  6   b , wherein the first and the second locking element part  6   a ,  6   b  are likewise designed to be adjustable relative to one another for the length adjustment of the locking unit  2  and can be latched into one another by second latching elements  11 . 
     The latching elements  10 ,  10   a ,  10   b  of the casing parts  9   a ,  9   b  and the latching elements  11 ,  11   a ,  11   b  of the locking element parts  6   a ,  6   b  are preferably designed as screw threads  31  that are formed in part in the circumferential direction or as teeth that are formed in part. The latching elements  10 ,  10   a ,  10   b ,  11   a ,  11   b  are arranged on the corresponding casing parts  9   a ,  9   b  and locking element parts  6   a ,  6   b  such that at least one casing part  9   a  and one of the locking element parts  6   a  can be adjusted together relative to the other casing and locking element parts  9   b ,  6   b . By the coupling according to the invention of the length adjustment of casing parts  9   a  and locking element parts  6   a , when adjusting the length of the locking unit  2 , locking is also made possible by means of the locking elements  6 , since the locking element  6  changes its length analogously to the length adjustment of the casing  9 . 
       FIG. 7  is a view of a detail of the casing part  9   a  together with the latching elements  10  in the form of screw threads or teeth  31  that are formed in part. The screw threads  31  are only formed on two opposite sides of the casing part  9   a . In the corresponding casing part  9   b  according to  FIG. 6  that is also shown, the screw threads  31  are accordingly likewise only formed on two opposite sides of the casing part  9   b . In one casing part  9   a , the screw threads  31  form an outer thread, and in the other casing part  9   b , the screw threads  31  form an inner thread or inner teeth. In the closed position, the screw threads  31  or teeth of the two casing parts  9   a ,  9   b  engage in one another and thus do not allow any length adjustment. For the length adjustment, the position of the casing parts  9   a ,  9   b  is rotated by 90°, such that the screw threads precisely no longer engage in one another and length adjustment is possible. 
       FIG. 8  is a view of a detail of the locking element part  6   a  together with the latching elements  11   a  in the form of screw threads or teeth  31  that are formed in part in the circumferential direction as an outer thread/outer teeth. 
       FIG. 9  is a view of a detail of the locking element part  6   b  together with the latching elements  11   b  in the form of screw threads  31  that are formed in part in the circumferential direction as an inner thread/inner teeth. 
     The interaction between the inner and outer threads/teeth  31  of the locking element parts  6   a ,  6   b  functions similarly to the interaction of the casing parts  9   a ,  9   b . In a latching position, the screw threads  31  of the two locking element parts  6   a ,  6   b  engage in one another and thus do not allow any length adjustment. For the length adjustment, the position of the locking element parts  6   a ,  6   b  is rotated by 90°, such that the screw threads  31  precisely no longer engage in one another and length adjustment is possible. The rotational movements of the locking element parts  6   a ,  6   b  and the casing parts  9   a ,  9   b  are coupled via a connection of the casing part  9   a  and the locking element parts  6   a , such that a length adjustment of the locking unit  2  always causes a length adjustment of the casing portion  30   b  and the corresponding locking element  6   a ,  6   b.    
       FIG. 10  is a view of a preferred embodiment of the instrument holder  17  according to the invention, comprising a housing  18  and preferably three sliders  20 . In addition, a holder is provided below the housing  18 , by means of which the instrument holder  17  can be received in the hole  13  ( FIG. 3 ) in the tool mount  12  ( FIG. 3 ), which has already been described. 
       FIG. 11  is a partial section through the housing  18  of the instrument holder  17 . The housing  18  comprises first openings  21 , which are preferably designed as T-shaped guide rails  21  and extend in the manner of spokes in a straight line from the central cut-out  30  to the edge of the housing  18 . The guide rails  21  are preferably arranged at an angle of 120° relative to one another. A substantially cuboid slider  20  runs in each of the T-shaped guide rails  21 . Each slider comprises two lateral protrusions  32 , which are received by the T-shaped guide rails  21  of the housing  18 . 
       FIG. 12  shows the flat thread  19 , which is arranged so as to be rotatable in the housing  18  of the instrument holder  17 . The flat thread  19  has rotary means  22  that make it possible to rotate the flat thread  19 . The rotary means  22  are preferably accessible from outside the housing  18  via at least one second opening  23  in the housing  18  of the instrument holder  17 . 
     The inner end of the slider  20 , which is within the housing  18 , extends into the flat thread  19  and engages with a protrusion therein. The outer end of the slider  20  extends out of the housing  18 . The slider comprises gripping surfaces  33  towards the center of the instrument holder  17 , which surfaces can be enlarged in order to provide a larger projecting surface for holding an instrument. 
     The sliders  20  can be moved towards one another by rotation of the flat thread  19  in a first rotational direction and can be moved away from one another by rotation of the flat thread  19  in a second rotational direction counter to the first rotational direction. 
     Cut-outs  31  may preferably be arranged centrally in the base and cover of the housing  18  and at a corresponding point in the flat thread  19  such that an instrument to be clamped, for example a needle, can extend through this cut-out in the instrument holder  17 . 
     The holding device  1  according to the invention can be formed by a plurality of locking units  2 , both according to the first embodiment and the second embodiment. For this purpose, the locking units  2  can be combined with one another in the form of an assembly to form the holding device  1 . A connector element  4  comprising at least two joint heads  5  is arranged between each of the thus combined locking units  2 , with one joint head  5  being received in a socket  3  of the combined locking units  2  in each case. 
     LIST OF REFERENCE SIGNS 
     
         
           1  holding device 
           2  locking unit 
           3  sockets 
           4  connector element 
           5  joint head 
           6  locking element ( 6   a ,  6   b =locking element parts) 
           7  eccentric element 
           8  locking lever 
           9  casing ( 9   a ,  9   b =casing parts) 
           10  first latching element 
           11  second latching element 
           12  tool mount 
           13  hole 
           14  locking shaft 
           15  unlocking element 
           16  spring 
           17  instrument holder 
           18  housing 
           19  flat thread 
           20  slider 
           21  first openings 
           22  rotary means 
           23  second openings 
           24  fixing unit 
           25  guide 
           26  screw 
           27  projection 
           28  notch 
           29  pivot axis 
           30  casing portions (a, b) 
           31  cut-out ( FIG. 11 ) and thread ( FIGS. 6, 7, 8 and 9 ) 
           32  lateral protrusions 
           33  gripping surface