Abstract:
A laparoscopic device that includes an outer rod having a end connected to a handle and an end having an articulated section formed from links joined with non-diametrical hinges; an actuation rod within the outer rod, having an end connected to the handle and an end connected to a tension element within the articulated section, configured to cause the articulated section to bend when tension is applied; and an attachment rod within the actuation rod having an end connected to the handle and an end having a flexible section connected to a tool. The handle includes an actuator configured to apply tension to the attachment rod such that the tool is activated; a rod actuator configured to apply tension to the actuation rod such that the articulated section of the outer rod bends; and a lockable rotator, configured to rotate the outer rod with respect to the handle.

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to laparoscopic devices and, more particularly, to a flexible laparoscopic device having modular parts. 
     2. Description of the Related Art 
     Laparoscopy is a surgical procedure that involves making a small incision, e.g., in a person&#39;s abdomen, and performing an operation using tools inserted through said insertion. To accomplish such surgeries, surgeons use a variety of laparoscopic tools that are designed to provide visual feedback and allow for the manipulation of internal tissues. However, existing laparoscopic manipulators suffer from certain disadvantages. 
     In particular, laparoscopic manipulators are designed to allow a certain degree of maneuverability once inside a body cavity. To accomplish this, many existing devices use a system of wires and joints, allowing a surgeon to change the shape of the manipulator during an operation. However, these wires are delicate and their use involves a large number of moving parts, such that there is a significant chance of failure during use. Furthermore, such devices are often single-use, where parts are not interchangeable, and so the entire device must be thrown away after it is used in a surgery if it cannot be adequately sterilized. This leads to substantial waste. 
     SUMMARY 
     A laparoscopic device is shown that includes an outer rod having a proximal end connected to an actuating handle and an end distal to said handle, the distal end having an articulated section formed from a plurality of links joined with non-diametrical hinges; an actuation rod disposed within the outer rod, having a proximal end connected to the actuating handle and a distal end connected to a tension element disposed within the articulated section of the outer rod, configured to cause an angular displacement of said articulated section when tension is applied; and an attachment rod disposed within the actuation rod having a proximal end connected to the actuating handle and a distal end having a flexible section and being connected to a tool. The actuating handle includes a tool actuator configured to apply tension to the attachment rod such that the tool is activated; a rod actuator configured to apply tension to the actuation rod such that the articulated section of the outer rod undergoes an angular displacement; and a lockable rotator, configured to rotate the outer rod with respect to the actuating handle. 
     A laparoscopic device is shown that includes an outer rod having a proximal end connected to an actuating handle and an end distal to said handle, the distal end having an articulated section formed from a plurality of links joined with non-diametrical hinges configured to have a greater angular range in a first direction than in an opposite direction; and an actuation rod disposed within the outer rod, having a proximal end connected to the actuating handle and a distal end connected to a tension element disposed within the articulated section of the outer rod, configured to cause an angular displacement of said articulated section when tension is applied. The actuating handle includes a rod actuator configured to apply tension to the actuation rod such that the articulated section of the outer rod undergoes an angular displacement. 
     A laparoscopic device is shown that includes an outer rod having a proximal end connected to an actuating handle and an end distal to said handle, the distal end having an articulated section; an actuation rod disposed within the outer rod, having a proximal end connected to the actuating handle, configured to cause an angular displacement of said articulated section when tension is applied; and an attachment rod disposed within the actuation rod having a proximal end connected to the actuating handle and a distal end having a flexible section and being connected to a tool. The outer rod, the actuation rod, the attachment rod, and the actuating handle are each separable and removable. 
     These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The disclosure will provide details in the following description of preferred embodiments with reference to the following figures wherein: 
         FIG. 1  is a diagram of an exemplary laparoscopic manipulator according to the present principles. 
         FIG. 2  is an exploded diagram of an exemplary laparoscopic manipulator according to the present principles. 
         FIG. 3  is a diagram of an articulated rod section according to the present principles. 
         FIG. 4  is a diagram of an individual link of the articulated rod section according to the present principles. 
         FIG. 5  is a diagram illustrating the articulation of two links. 
         FIG. 6  is a diagram of a length of articulated links with tension elements. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present principles provide a modular design using tensioned rods. As compared to existing wire-based designs, the present principles provide a laparoscopic device that has a longer effective life by having fewer points of potential failure and by allowing for the replacement of individual parts that have become dirty or worn out. 
     Referring now to the drawings in which like numerals represent the same or similar elements and initially to  FIG. 1 , a laparoscopic manipulator  100  according to the present principles is illustrated. An actuator handle  102  connects to the proximal end of a rod  104 , the rod having a tool portion  106  extending from its distal end. The handle  102  includes an actuating grip  108  that allows the tool portion  106  to be used. Exemplary tools  106  include, e.g., a claw or pincer device configured to grasp and a scissors or other cutting device. The handle  102  further includes a lockable rotator  110  that rotates the rod  104  and tool  106  portions with respect to the actuating handle  102 . The lockable rotator  110  may be locked using locking knob  111 . Locking knob may be a threaded screw that prevents the rod  104  from rotating, or may be any other suitable device for mechanically preventing rotation. The handle  102  further includes an articulation actuator  112  that causes the distal end of the rod to undergo an angular displacement. The present principles thereby allow a surgeon to achieve three degrees of freedom: one from the angular displacement of the rod, one from the rotation of the rod relative to the handle, and one from the insertion/removal of the rod from the body cavity. 
     Referring now to  FIG. 2 , an exploded diagram of the laparoscopic manipulator  100  is shown. An outer rod  202  is shown that has an optional coating  204  and an articulated section  206  at the distal end. The proximal end of the outer rod  202  may have a flanged portion  207  that provides an attachment point between the outer rod and the handle  102 . The outer rod  202  may be formed from, for example, stainless steel such as 304 medical-grade steel, or another appropriate material. Inside the outer rod  202  is an actuator rod  208 . Actuator rod may also be formed from medical-grade stainless steel or other appropriate material. The coating  204  is, for example, a thin heat-shrink material such as polyester or Teflon®, but it is contemplated that any appropriate, biologically neutral material may be employed. The actuator rod  208  connects to a tension element inside the articulated section  206 . When tension is applied to the actuator rod  208 , the articulated section  206  deforms and produces an angular displacement. The limits of the angular displacement are controlled by the structure of the articulated section  206 , as described below. 
     An attachment rod  210  passes inside the actuator rod  208  and the outer rod  202  and may be formed from medical-grade stainless steel or other appropriate material. The proximal end of the attachment rod  210  extends into the handle  102  and connects to the actuating grip  108 . The distal end of the attachment rod  210  has a flexible portion  212  with an optional coating  214 . As above, the coating  214  may be an appropriate heat-shrink material applied so as to form a thin, flexible, and durable covering to prevent wear. The flexible portion  212  may be, for example, a braided stainless steel wire or any other durable material that can withstand bending and tension. The tool portion  106  is attached to the distal end of the flexible portion and has a threaded portion  215  configured to couple with a threaded portion of the outer rod  202  at the end of the articulated section  206 . The threading of portion  215  is configured to provide a specific coupling angle with respect to the outer rod  202 , such that the tool portion  106  has a specific, fixed rotational orientation relative to the outer rod  202 . The rotator  110  and the articulation actuator  112  fit to the handle  102  over the outer rod  202  and are held in place by safety knob  216 . The safety knob  216  twists off, allowing the rods  202 ,  208 , and  210  to be detached from the handle  102  and replaced. The safety knob  216  holds the flanged portion  207  of outer rod  202  to the handle  102 . 
     When the actuating grip  108  is moved, the attachment rod  210  moves forward or backward with respect to the outer rod  202 . Because the tool portion  106  is fixed to the distal end of the outer rod  202 , the movement of the attachment rod  210  with respect to the tool portion causes the tool  106  to activate by, e.g., closing and opening two clamp jaws. When rotator  110  is turned, the entire assembly rotates relative to the handle. This is accomplished by, for example clamping the proximal end of the actuating rod  208  within the rotator  110  and/or the articulation actuator  112 . When the articulation actuator  112  is rotated, the actuating rod  208  is moved transversely with respect to the outer rod  202 , applying a tension to the rod and thereby to the articulating section  206 . This causes the articulating section  206  to bend. 
     Referring now to  FIG. 3 , the articulated section  206  of outer rod  202  is shown in detail. The articulated section is made up of individual links  302 , each having a cylindrical cross-section and being attached to the next link by a hinge  304 . At the end of the articulated section  206  is a threaded interior  306  that couples to the threaded part of tool portion  106 . 
     Referring now to  FIG. 4 , an individual link  302  is shown from a distal perspective. The link  302  is a hollow cylinder  400  having a male coupling portion  402  that has a first side  404  substantially aligned along a radius of the cylinder  400  and a second side  406  that is aligned parallel to the radius of the cylinder. This is one illustrative position of the male coupling portion  402  and should not be construed as limiting—the male coupling portion  402  may be disposed anywhere along the cylinder  400  as long as it is not centrally aligned with a radius of said cylinder  400 . The cylinder  400  has a central hole  408 , a first spring slot  410 , and a second spring slot  412 . The central hole  408  accommodates the flexible portion  212  of attachment rod  210 , while the two spring slots  410  and  412  accommodate springs formed from, e.g., a memory metal. 
     Referring now to  FIG. 5 , an exemplary illustration of the bending of two articulated links  302  is shown. A first link  502  is depicted as being joined with a second link  504  in three different positions. In a first position  506 , the two links  502  and  504  have zero angular displacement with respect to one another. A small gap  505  exists between the two links  502  and  504 . This small gap  505  allows a small amount of movement. It should be noted that, in the depiction of  FIG. 5 , the male coupling portion  402  lines up with a female coupling portion  512 , depicting their non-diametrical arrangement. The male coupling portion  402  of link  504  is disposed within the female coupling portion  512  of link  502 , forming a hinge  304 . 
     When the links are in position  508 , the small gap  505  is pinched on the long side. Because of the relatively distance between the link edge and the hinge  304 , only a small angular displacement  506  is created. Contrast this to the links in position  510 . In position  510 , there is a much shorter distance between the hinge  304  and the link edges that contact, which results in a much larger angular displacement  508 . Thus, by creating a hinge along a non-diametrical axis, articulated links  302  naturally bend in one direction much more than in the other. In this way an articulated structure  206  can be created with unidirectional bending without cutting away portions of the cylinders  400 . 
     Referring now to  FIG. 6 , an exemplary illustration of a portion of the flexible portion  206  of attachment rod  210  is shown. A series of coupled links  302  are shown, with spring rods  602  and  604  running through the respective spring holes  410  and  412 . Said spring rods  602  and  604  may, for example, be formed from a memory metal such as a nickel-titanium alloy. The spring rods  602  and  604  provide support to the flexible portion  206 , preventing disengagement of the links  302  and may be biased in a curved configuration or a straight configuration. A curved bias is advantageous because it permits actuator rod  208  to extend the flexible portion  206  when tension is applied, and permits the spring rods  602  and  604  to return to a curved configuration when tension is released. This avoids a possible malfunction when a tension is applied to a straight spring, effectively applying only a longitudinal force without a transverse (bending) force. An alternative embodiment may comprise only a single spring rod, but the second spring rod lends superior support and reliability. 
     Having described preferred embodiments of a laparoscopic device (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments disclosed which are within the scope of the invention as outlined by the appended claims. Having thus described aspects of the invention, with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.