Patent Publication Number: US-2021177448-A1

Title: Suction heads for vacuum-actuated surgical graspers

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to co-pending U.S. Provisional Application Ser. No. 62/720,471, filed Aug. 21, 2018, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Mechanical surgical graspers have been used for decades in surgical procedures to manipulate (e.g., retract) patient tissues. Such graspers typically take the form of forceps that include a scissors-like handle that is used to open and close opposing jaws that can grip the tissue. 
     While such mechanical graspers are generally effective, their jaws can damage delicate tissues of a patient. Because of this, vacuum-actuated surgical graspers have been developed. Such graspers use a suction head to apply gentle suction to the tissue to grip it instead of opposed jaws, which can damage the delicate tissues. Needed, however, are suction heads for vacuum-actuated surgical graspers that enable tissue to be firmly gripped and manipulated while also being capable of passing through a narrow passage to the surgical site. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure may be better understood with reference to the following figures. Matching reference numerals designate corresponding parts throughout the figures, which are not necessarily drawn to scale. 
         FIGS. 1A and 1B  are side views of an embodiment of a vacuum-actuated surgical grasper, the grasper being shown with a suction head of the grasper not deployed and deployed, respectively. 
         FIG. 2  is a side view of a first embodiment of a suction head that can be used with the grasper of  FIG. 1 . 
         FIG. 3  a distal end view of the suction head of  FIG. 2 . 
         FIG. 4  is a cross-sectional side view of the suction head of  FIG. 2 . 
         FIG. 5  is a cross-sectional perspective view of the suction head of  FIG. 2 . 
         FIG. 6  is a cross-sectional side detail view of the suction head of  FIG. 2 . 
         FIG. 7  is partial cross-sectional side view of a second embodiment of a suction head that can be used with the surgical grasper of  FIG. 1 . 
         FIG. 8  is a schematic view of a robotic system that incorporates a vacuum-actuated surgical grasper that includes a suction head. 
     
    
    
     DETAILED DESCRIPTION 
     As described above, needed are suction heads for vacuum-actuated surgical graspers that enable patient tissue to be firmly gripped and manipulated while also being capable of passing through a narrow passage to the surgical site. Examples of such suction heads are described in the disclosure that follows. In some embodiments, the suction heads have a flared configuration in which a lateral dimension (e.g., diameter) of the head increases from its proximal end to its distal end. In some embodiments, the suction heads are made of an elastomeric material that enables the head to be collapsed into a smaller size to facilitate its passage through a narrow lumen, such as a trocar. Once the suction head has passed through the lumen and reaches the surgical site (e.g., a site within the abdominal cavity), the suction head can be deployed and, therefore, enabled to expand into its natural flared shape. In such a case, the dimensions of the suction head can be substantially larger than the inner dimension (e.g., diameter) of the lumen through which the head is passed. The relatively large dimension of the suction head facilitates secure gripping of tissue. 
     In the following disclosure, various specific embodiments are described. It is to be understood that those embodiments are example implementations of the disclosed inventions and that alternative embodiments are possible, including hybrid embodiments that include aspects of separately disclosed embodiments. All such embodiments are intended to fall within the scope of this disclosure. 
       FIGS. 1A and 1B  illustrate an example embodiment of a vacuum-actuated surgical grasper  10  that can be used in a surgical procedure, such as a laparoscopic procedure. This grasper  10  is intended for manual use by a human being. As shown in the figure, the grasper  10  generally comprises a body  12  and an elongated suction tube  14  that extends from the body. The grasper  10  is configured to connect to a vacuum source (not shown) via a vacuum tube  16  and deliver suction to the suction tube  14 . In the illustrated embodiment, the body  12  includes a housing  18  from which the suction tube  14 , a grip element  20 , and an actuation lever  22  extend. With such a configuration, suction can be applied by a human user by moving the actuation lever  22  toward the grip element  20 . 
     With further reference to  FIGS. 1A and 1B , a sheath  24  is mounted to the distal end of the suction tube  14 . In some embodiments, the sheath  24  comprises a generally rigid cylindrical element that is configured to contain and deploy a suction head  26  of the vacuum-actuated surgical grasper  10 . In some embodiments, the sheath  24  has an outer dimension (e.g., outer diameter) of approximately 12 mm and an inner dimension (e.g., inner diameter) of approximately 11 mm. In  FIG. 1A , the sheath  24  is shown in an extended position in which the suction head  26  is contained within the sheath in a collapsed orientation. In  FIG. 1B , the sheath  24  is shown in a retracted position in which case the sheath has been linearly retracted along the suction tube  14  in the proximal direction (i.e., toward the body  12 ) so as to enable the suction head  26  to expand into its original natural flared shape. In some embodiments, such retraction is achieved using a wire or cable (not shown) that extends to the sheath  24  and is used to pull the sheath along the suction tube  14  in the proximal direction. Containment and deployment of the suction head  26  are facilitated by the material from which the suction head  26  is made. Specifically, the suction head  26  is made of a biocompatible elastomeric material, such as a medical-grade silicone material, that enables the suction head to be collapsed within the sheath  24  and to spring back into its original natural expanded (i.e., flared) state shown in  FIG. 1B  once the sheath is pulled back. 
       FIGS. 2-6  illustrate a first embodiment of the suction head, which is identified by reference numeral  30 . With reference first to  FIG. 2 , the suction head  30  generally comprises a proximal portion  32  and a distal portion  34  that extends from the proximal portion. In some embodiments, both portions  32  and  34  are made from the same piece of material such that the suction head  30  has a unitary construction. As mentioned above, the suction head  30  can be made of an elastomeric material, such as a medical-grade silicone material. In some embodiments, the elastomeric material has a Shore A hardness of approximately 40A to 100A (e.g., Shore 60A). 
     The proximal portion  32  is generally cylindrical and has a constant outer dimension (e.g., outer diameter) while the distal portion  34  has a flared shape in which the outer dimension (e.g., outer diameter) of the distal portion gradually increases from its proximal end to its distal end. In cases in which the suction head  30  is generally circular in cross-section, the suction head can be described as being generally trumpet shaped in that it incorporates a flared end similar to that of the “bell” of a trumpet, which can be said to form the shape of a cone that has a geometrically (i.e., nonlinearly) increasing diameter from its proximal end to its distal end. In some embodiments, the proximal portion  32  has a constant outer diameter of approximately 9 mm, while the distal portion  34  has an outer diameter that is equal to that of the proximal portion (e.g., approximately 9 mm) at its proximal end but geometrically increases to approximately 17 mm at its distal end. 
     With reference to  FIGS. 4 and 5 , the suction head  30  forms an elongated inner passage  36  that extends along the length of the head from its proximal end to its distal end. This passage  36  is placed in fluid communication with an inner passage of the suction tube  14  when the head  30  is mounted to the distal end of the tube. In some embodiments, the distal end of the suction tube  14  is received within the inner passage  36  of the proximal portion  32  with a friction fit. As shown in  FIGS. 4 and 5 , the inner passage  36  can have a constant dimension (e.g., inner diameter) within the proximal portion  32  and, like the outer surface of the head  30 , a dimension (e.g., inner diameter) that gradually (geometrically) increases from the proximal end of the distal portion  34  to the distal end of the distal portion. In some embodiments, the passage  36  has an inner diameter of approximately 5 mm within the proximal portion  32  and an inner diameter that increases from approximately 5 mm to approximately 17 mm within the distal portion  34 . As can be appreciated from  FIG. 4 , the thickness of the walls of the distal portion  34  can gradually decrease from its proximal end to its distal end. 
     With reference next to  FIGS. 4-6 , the distal portion of the inner passage  36 , which is contained within the distal portion  34  of the suction head  30 , comprises multiple internal continuous annular ribs  38  that facilitate gripping of the tissue that is drawn into the inner passage when the vacuum-actuated surgical grasper  10  is used. In the illustrated embodiment, the suction head  30  comprises 5 such ribs  38 , which are spaced from each other along the longitudinal direction of the distal portion of the inner passage  36 . In some embodiments, the ribs  38  increase in size from the distal end to the proximal end of the distal portion  34  of the head  30 . 
     As shown in  FIG. 4 , each rib  38  is generally triangular in cross-section and includes an arcuate proximal surface  40  that generally faces the proximal end of the suction head  30 , an arcuate distal surface  42  that generally faces the distal end of the head, and an arcuate edge  44  that is formed where the proximal and distal surfaces meet. As is further shown in the figure, the distal surface  42  of each rib  38  is larger (i.e., extends a farther distance from the wall of the inner passage  36 ) than the proximal surface  40 . This configuration results in each rib  38  having a swept orientation in which each rib is angled backward toward the proximal end of the suction head  30  and the arcuate edge  44  of each rib (and, therefore, the tip of the triangular cross-section) faces that end, away from an inlet  46  of the head in which tissue is drawn. This swept orientation increases the gripping force that can be applied to the tissue by the head  30 . 
     Referring next to  FIG. 6 , each rib  38  can further comprise concave arcuate groove  48  that is formed in the proximal surface  40  of the rib and, therefore, also faces the proximal end of the suction head  30 . When provided, the grooves  48  reduce the amount of material that forms the arcuate edges  44  of the ribs  38 , which enables the ribs to flex backward toward the inlet  46  of the suction head  30 . This flexure further enhances the grip of the suction head  30  on the tissue, particularly when the head is used to retract tissue. 
       FIG. 7  illustrates a further embodiment of a suction head  60 . The suction head  60  can have a configuration similar to that of the suction head  30 . Accordingly, the suction head  60  can comprise a cylindrical proximal portion  62  and a flared distal portion  64 . The suction head  60  can also be made of an elastomeric material, such as a medical-grade silicone material. 
     Also like the suction head  30 , the suction head  60  includes an elongated inner passage  66  that extends along the length of the head from its proximal end to its distal end. The inner passage  66  includes multiple internal continuous annular ribs  68  that facilitate gripping of tissue that is drawn into the inner passage when the vacuum-actuated surgical grasper  10  is used. In the illustrated embodiment, the suction head  60  comprises 12 such ribs  68 , each positioned immediately adjacent to each other along the length of the inner passage  66  within the distal portion  64  of the head. In some embodiments, the ribs  68  increase in size from the distal end to the proximal end of the distal portion  64  of the head  60 . 
     As shown in  FIG. 7 , each rib  68  is generally triangular in cross-section and includes an arcuate proximal surface  70  that generally faces the proximal end of the suction head  60 , an arcuate distal surface  72  that generally faces the distal end of the head, and a sharp arcuate edge  74  that is formed where the proximal and distal surfaces meet. As with the other embodiment, the distal surface  72  of each rib  68  is larger (i.e., extends a farther distance from the wall of the inner passage  66 ) than the proximal surface  70 . This configuration results in each rib  68  also having a swept orientation in which each rib is angled backward toward the proximal end of the suction head  60  and the arcuate edge  74  of each rib (and, therefore, the tip of the triangle cross-section) faces that end, away from an inlet  76  of the head in which tissue is drawn into the inner passage  36 . Unlike the ribs  38  of the suction head  30 , however, the ribs  68  of the suction head  60  do not include an arcuate groove. Because of this, the suction head  60  is easier and less expensive to manufacture. 
     Irrespective of the particular configuration of the suction head, the vacuum-actuated surgical grasper  10  ( FIG. 1 ) can be used to grasp patient tissues to manipulate (e.g., refract) them. During such use, a vacuum source can be connected to the vacuum tube  16  so that a fluid, such as air or another gas, can be drawn through the suction head (e.g., suction head  26 ), the suction tube  14 , and the body  12 . When the suction head is placed in contact with tissue while the vacuum is applied, a portion of the tissue is drawn into the suction head and, therefore, is securely gripped by the head. In some embodiments, tissues can be gripped with a force of approximately 10 N, which is comparable to conventional jawed graspers. Unlike jawed graspers, however, damage to the tissue is avoided as no sharp edges or hard materials come into contact with the tissue. 
     Although a vacuum-actuated surgical grasper has been described and illustrated that is configured for manual operation by a human user, it is noted that a similar vacuum-actuated surgical grasper can be used in a robotics context. This is schematically illustrated in  FIG. 8 . As shown in this figure, a vacuum-actuated surgical grasper  80  is attached to the end of a robotic manipulator  82  of a robotic system  84 . In such a case, the surgical grasper  80  functions as an end effector of the system  84  and its position and orientation can be robotically controlled using the robotic manipulator  82 . Once the suction head  86  is positioned and oriented as desired, for example, so that the head is placed in contact with tissue that is to be manipulated, suction can be applied to the head via a vacuum tube  88  that extends either along or within the robotic manipulator to a vacuum source (not shown). Accordingly, instead of moving and applying suction manually as with the embodiment shown in  FIGS. 1A and 1B , such moving and applying suction is automated by the robotic system  84 .