Patent Publication Number: US-2016235442-A1

Title: Magnetic based device for retrieving a misplaced article

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of Ser. No. 13/672,370, filed Nov. 8, 2012, which is a continuation-in-part of U.S. patent application Ser. No. 13/303,050, filed Nov. 22, 2011, which claims the benefit of U.S. patent application Ser. No. 61/416,814, filed Nov. 24, 2010, and U.S. patent application Ser. No. 61/537,358, filed Sep. 21, 2011, each of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to medical equipment, and in particular, to a device or probe for retrieving an article (foreign body) that is attracted to a magnetic field and has been misplaced during a surgical procedure, such as during a minimally invasive surgical procedure (e.g., a laparoscopic, robotic, endoscopic or arthroscopic procedure). 
     BACKGROUND 
     As technology advances, the manner in which surgical procedures are conducted and the instruments/tools that are used have greatly changed and the field of minimally invasive surgery has spawned many types of surgical procedures including laparoscopic, robotic, endoscopic and arthroscopic surgery. Laparoscopy (laparoscopic surgery) is an operation performed in (but not limited to) the chest, abdomen, pelvis, or retroperitoeneum through small incisions (usually 0.5-1.5 cm) with the aid of a camera. It can either be used to inspect and diagnose a condition or to perform surgery. The laparoscope allows doctors to perform both minor and complex surgeries with a few small incisions. There are a number of advantages to the patient with laparoscopic surgery versus an open procedure. These include reduced pain, decreased blood loss, and faster recovery time. Robotic surgery is the latest advance in minimally invasive surgery which is similar to laparoscopic surgery in that surgery is performed through (but not limited to) small incisions in the chest, abdomen, pelvis or retroperitoneum but uses a robotic system to perform surgery. 
     Endoscopic surgery is any surgery through a scope or instrument into a body cavity such as endoscopy in the upper gastro-intestinal tract or cystoscopy in the lower genitor-urinary tract. This is a minimally invasive procedure that allows for the examination and treatment of tissues, organs, etc with a scope that has a camera and a working channel. 
     Arthroscopy (also called arthroscopic surgery) is a minimally invasive surgical procedure in which an examination and sometimes treatment of damage of the interior of a joint is performed using an arthroscope, a type of endoscope that is inserted into the joint through a small incision. Arthroscopic procedures can be performed either to evaluate or to treat many orthopaedic conditions including torn floating cartilage, torn surface cartilage, ACL reconstruction, and trimming damaged cartilage. 
     Despite guidelines to improve practice, the occurrence of retained items during or after surgery remains problematic. Perioperative nurses perform surgical counts of items to be used during a procedure before surgery begins and at specified times during and at the end of surgery to ensure that items are not left in a patient unintentionally. In its statement on the prevention of retained foreign bodies after surgery, the American College of Surgeons recommends consistent application and adherence to standardized counting procedures and performance of methodical wound exploration before closure of the surgical site. 
     All surgical sponges and instruments utilized during any surgical procedure must be accounted for at the end of the operation to ensure no foreign body is inadvertently left inside the patient. Individual institutions establish their own counting policies based on guidelines from the Association of Peri-operative Registered Nurses. Retained surgical foreign bodies are most frequently reported in the chest, abdomen, pelvis or vagina. 
     Current practice regarding the misplacement of intra abdominal foreign bodies involves meticulous and systematic examination of the peritoneal cavity with some sources recommending that the ability to have visual and tactile recognition of the foreign body being particularly important. The potential for a needle stick injury is amplified by this technique. If the object is not found, the next step involves getting a radiographic imaging study and the patient remains in the operating room until the film is reviewed by a radiologist. However, in many institutions, the act of ordering an x-ray is viewed cautiously and as an act of last resort since most times when an x-ray is ordered, an internal report must be generated as to why the x-ray is needed. This exposes all those involved to at least a note in one&#39;s professional record or institution and possibly to reprimand since the cause of the need for the x-ray is the misplacement of a foreign body. 
     While there has been suggestions and recommendations including providing x-ray detectable (radiographic) packs, gauze, and needles, there is a need for an improved device that is configured to be used with a port or instrument that is used in a surgical procedure (e.g., a minimally invasive procedure) and configured to retrieve a misplaced foreign body that is attracted to a magnetic field. 
     SUMMARY 
     In one embodiment, a device for locating and retrieving a misplaced foreign body that has metallic characteristics includes a shaft connected to a handle and a retrieval tool that is coupled to the shaft and moves between a deployed position and collapsed position. The tool has a magnetic element that generates a magnetic field, wherein the magnetic field extends over a greater area in the deployed position and is of sufficient strength to attract the foreign body such that it is held in contact with the tool. 
     In another embodiment, a device for locating and retrieving a misplaced foreign body that has metallic characteristics includes a shaft connected to a handle and an electro-magnetic element that is disposed about the shaft and is configured to generate a magnetic field when electric current passes therethrough. The shaft and electro-magnetic element have a width of about 20 mm or less to allow the device to be used in ports associated with minimally invasive surgery. 
     The above-described device can be part of an automated robotic system and can also include a metal detector to assist in locating the misplaced foreign body. 
     These and other aspects, features and advantages shall be apparent from the accompanying Drawings and description of certain embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective side view of a device for retrieving an article that has been misplaced during a surgical procedure showing a tool in a retracted position; 
         FIG. 2  is perspective side view of the device of  FIG. 1  with the tool in the fully extended position; 
         FIG. 3  is an exploded perspective view of the device of  FIG. 1  showing inner working components according to a first embodiment; 
         FIG. 4  is a cross-sectional view taken along the line  4 - 4  of  FIG. 2 ; 
         FIG. 5  is a cross-sectional view taken along the line  5 - 5  of  FIG. 1 ; 
         FIG. 6  is a cross-sectional view of the tool of  FIG. 1  in a partially extended position; 
         FIG. 7  is a cross-sectional view of the tool of  FIG. 1  in a fully extended position; 
         FIG. 8  is a close-up of a portion of the tool of the device showing magnets disposed within recesses formed in the tool; 
         FIG. 9  is a close-up of a portion of the tool of the device showing magnets disposed within holes formed in the tool; 
         FIG. 10  is a close-up of a portion of the tool of the device showing magnet strips disposed longitudinally along a length of the tool; 
         FIG. 11  is side perspective view of the tool of the device of the  FIG. 8  being inserted through a trocar and delivered to a surgical site for retrieving an article that has been misplaced during a minimally invasive surgical procedure; 
         FIG. 12  is a side perspective view of a tool according to another embodiment being inserted through a trocar and delivered to a surgical site for retrieving an article that has been misplaced during a minimally invasive surgical procedure; 
         FIG. 13  is a perspective side view of another device for retrieving an article that has been misplaced during a surgical procedure showing a tool in a retracted position; 
         FIG. 14  is perspective side view of the device of  FIG. 13  with the tool in the fully extended position; 
         FIG. 15  is a cross-sectional view taken along the line  15 - 15  of  FIG. 14 ; 
         FIG. 16  is an exploded perspective view of a tool according to one embodiment; 
         FIG. 17  is top view of the tool of  FIG. 16 ; 
         FIG. 18  is a perspective view of a tool according to another embodiment; 
         FIG. 19  is a perspective view of a tool according to yet another embodiment; 
         FIG. 20  is a perspective view of a tool according to another embodiment with magnetic splines (fingers) in an extended (deployed) state; 
         FIG. 21  is cross-sectional view taken along the line  21 - 21  of  FIG. 20 ; 
         FIG. 22  is a cross-sectional view showing the magnetic splines in a retracted position; 
         FIG. 23  is a perspective view of an electro-magnetic device for retrieving an article that has been misplaced during a surgical procedure; 
         FIG. 24  is a perspective view of another electro-magnetic device for retrieving an article that has been misplaced during a surgical procedure; 
         FIG. 25  is a perspective view of another magnetic device for retrieving an article that has been misplaced during a surgical procedure, with the device being in the closed or retracted position; 
         FIG. 26  is a perspective view of the device of  FIG. 25  in an opened or extended position; 
         FIG. 27  is a close-up perspective view of the magnetic element at the distal end of the device showing the magnetic element in a number of different pivoted positions; 
         FIG. 28  is a close-up perspective view of the magnetic element with an outer sheath being removed; 
         FIG. 29  is another close-up perspective view of the magnetic element with the outer sheath being removed; 
         FIG. 30  is a close-up perspective view of a proximal end of the device with the device in an opened (extended) position; 
         FIG. 31  is a close-up perspective view of the proximal end, with the device being shown in the closed (retracted) position; 
         FIG. 32  is a schematic of a robotic system incorporating a retrieval device of the present invention; and 
         FIG. 33  is a perspective view of a retrieval device incorporating a metal detector. 
     
    
    
     DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION 
     In accordance with the present invention, a device is provided that is configured to be used in minimally invasive surgical procedures and is constructed to retrieve misplaced foreign bodies to prevent the retention of foreign bodies in the patient after surgery. 
       FIGS. 1-7  illustrate a device  100  according to a first embodiment for insertion into a conventional trocar/port  101  ( FIG. 11 ) that provides access to the inside of the patient during minimally invasive surgery and for locating and retrieving a misplaced foreign body. As is known in the industry, a trocar is a medical instrument with a sharply pointed end, often three-sided, that is used inside a hollow cylinder (cannula) to introduce the trocar into blood vessels or body cavities. Trocars are also used to introduce ports in the abdomen, such as during laparoscopic surgery. Trocar sites are the small entry sites made though abdomen for the entry of surgical instruments. After a small incision is made in the skin, the trocar is the instrument inserted to penetrate the abdominal wall. Trocars of different sizes can create entry sites ranging from 5 to 20 mm in diameter. The diameter size depends on whether the removal of a specimen is anticipated and its size and other considerations, such as the size/age of the patient. In conventional laparoscopic surgery, 3-5 ports are typically used; however, single port laparoscopy (also known as “single port surgery”) is the newest frontier in laparoscopic surgery. Laparoscopic surgery involves inflating the abdomen with an inert gas (CO 2 ) and performing an operation seen through a thin camera tube along with several long thin instruments inserted through separate “ports” or trocars. Single port laparoscopy uses just one port buried in the belly button to accommodate both the instruments and the camera. This would eliminate the use of up to 3 to 5 separate trocars for the performance of typical laparoscopic procedures and would potentially leave the patient with no visible scars. 
     In order to be an effective tool in locating and retrieving misplaced foreign bodies and have wide surgical applicability, the device of the present invention is constructed (e.g., sized and shaped) so that it can be both inserted and removed through conventional medical equipment, such as the above-described trocars/ports that are used in minimally invasive surgeries. 
       FIG. 11  illustrates a trocar/port  101  that is inserted into the patient to provide access to the surgical site, such as a body cavity (e.g., abdomen). The trocar  101  has a first end  103  and an opposite end  105  that remains outside of the patient. A bore is formed through the trocar  101  that permits instruments to be passed therethrough to the surgical site, such as a body cavity. 
     It will be appreciated that the misplaced foreign bodies can include but are not limited to needles, sponges, gauze and other surgical instruments that are used during the surgical procedure. Many of these items have a metallic nature and in particular, needles and surgical instruments that are used in minimally invasive surgery have a metallic nature since at least a portion of the device is formed of a metal. The conventional radioscopic technique of locating misplaced foreign bodies takes advantage of this fact since the misplaced foreign body appears in the x-ray and its location can thus be determined. 
     As shown in  FIGS. 1-7 , the device  100  has an elongated body that has a first end  112  and an opposing second end  114 . The first end  112  is in the form of a distal end, while the second end  114  represents a proximal end of the device. The device  100  generally can be thought of as including a shaft  120  that extends to and terminates at the distal end  112  and a handle  150  that is located at the proximal end  114  of the device  100 . The shaft  120  includes a free distal end  122  (which can be the first end  112 ) and an opposing proximal end  124  that is coupled to the handle  150 . The shaft  120  is a hollow structure (e.g., a cannula) that has a working center bore that extends the length of the shaft  120  and is open at the distal end  122 . The size and shape of the shaft  120  is complementary to the trocar bore since the shaft  120  must be able to be introduced into and pass the length of the trocar bore to the surgical site. Typically, both the trocar bore and the shaft  120  have a circular shape; however, other shapes are possible so long as the shapes are complementary. 
     The device  100  has a retrieval member or mechanism  170  for locating and retrieving a misplaced foreign body. The retrieval mechanism  170  is configured so that it moves between a fully extended (deployed) position and a fully retracted (collapsed) position and in some embodiments can also be placed into a position therebetween, namely, an intermediate, partially extended position. In the fully extended (deployed) position, an increase in exposed surface area of the mechanism  170  preferably results so as to create additional contact points that emit a magnetic field and can attract and retain the misplaced foreign body. 
     The retrieval mechanism  170  includes at least one magnetic element that attracts and retains the misplaced foreign body as described in detail herein. As is known, a magnet is a material or object that produces a magnetic field. The magnetic field is responsible for generating a force that pulls on other ferromagnetic materials like iron and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. 
     The permanent magnets for use herein can be in the form of any conventional permanent magnet that is suitable for the intended application. In particular, permanent magnets can be form of ferromagnetic materials, including iron, nickel, cobalt, some alloys of rare earth metals, and some naturally occurring minerals such as lodestone. Ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic. Permanent magnets are made from “hard” ferromagnetic materials which are subjected to special processing in a powerful magnetic field during manufacture, to align their internal microcrystalline structure, making them very hard to demagnetize. 
     Another type of conventional magnet is an electromagnet that is made from a coil of wire which acts as a magnet when an electric current passes through it, but stops being a magnet when the current stops. Often an electromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil (the core acts like a bar (permanent) magnet). Thus, the coiling of the wire amplifies the wire&#39;s magnetic field. Typically, the more turns of wire results in a greater magnetic field being generated. The electric current can come from any number of different energy sources. 
     The retrieval mechanism  170  of the embodiment of  FIGS. 1-7  is part of an inner elongated member  172 , such as a tube, cannula, shaft or rod, that is received within the center bore of the shaft  120 . For example, the retrieval mechanism  170  can be located at or near a distal end  174  of the elongated member  172 . As mentioned above, the retrieval mechanism  170  includes a magnetic element and is configured so that it can be received and stored within the bore of the shaft  120 . The illustrated retrieval mechanism  170  is formed along a length of the inner member  172  and includes at least two flexible splines  180  that are constructed so that they move between a fully collapsed position and a fully deployed position. 
     In one embodiment, the splines  180  thus represent a longitudinal section of the inner member  172  or can be located at the distal end  174  thereof and represents an extension of the inner member  172 . In the illustrated embodiment, each spline  180  has a first end  182  that is attached to a tip member  186  and a second end  184  that is attached to a plug  187  or the like that is securely attached to the distal end  174  of the inner member  172 . When two splines  180  are used, the splines  180  are located opposite one another. The splines  180  are designed so that that they naturally move between a fully deployed (extended) position and a fully collapsed (retracted) position. In particular, in a normal, rest position, the splines  180  assume the fully deployed position in which the splines  180  are bent along their lengths. As illustrated, the splines  180  can assume a convex form with the convex surfaces facing outward from one another. This results in a space  181  that is formed between the splines  180 . When a force is applied to the splines  180  (e.g., an inwardly directed force), the splines  180  flex inward and this result in the splines  180  straightening out and assuming a more linear form. In other words, as the inward force is applied to the splines  180 , the splines  180  move toward the fully collapsed position in which the splines  180  are more linear in shape and parallel and can be received within the bore of the shaft  120 . 
     Each spline  180  is constructed so that it has magnetic properties to facilitate locating and retrieving a misplaced foreign body that itself has metallic properties and thus is attracted to a magnetic field. For example, the spline  180  can have one or more permanent magnets incorporated therein, with the permanent magnets being capable of being provided in different forms, such as strips, pads, etc. For example, each spline  180  can have at least one magnetic element  185  that is supported by a substrate and in particular, the spline  180  can be a layered structure with a flexible substrate  183  that is formed of a material that is outwardly biased and supports the at least one magnetic element  185 . 
     Any number of different materials can be used to form the flexible substrate  183 . For example, a shape memory alloy (SMA, smart metal, memory metal, memory alloy, etc.) is an alloy that “remembers” its original, cold forged shape. One of the commercial uses of shape memory alloy involves using the pseudo-elastic properties of the metal during the high temperature (austenitic) phase. Frames or supports can be made of a shape memory alloy as they can undergo large deformations in their high temperature state and then instantly revert back to their original shape when the stress is removed. This is the result of pseudoelasticity; the martensitic phase is generated by stressing the metal in the austenitic state and this martensite phase is capable of large strains. With the removal of the load, the martensite transforms back into the austenite phase and resumes its original shape. This property of the shape memory alloy allows the metal to be bent, twisted and pulled, before reforming its shape when released. Based on the foregoing, the splines  180  can be formed from a shape memory alloy that has characteristics that permit the intended function to be performed. 
     The splines  180  not only provide a flexing action to permit movement between the fully deployed position and the fully collapsed position but also acts as a carrier for the magnetic element(s)  185 . The magnetic element  185  can be carried and supported by the spline substrate  183  by any number of different techniques including bonding or otherwise fastening the magnetic elements  185  to the substrate  183 . It will be appreciated that the magnetic element(s)  185  can be countersunk within a recess formed in the substrate  183  so that the exposed surface of the spline  180  is relatively smooth ( FIG. 8 ). This facilitates the splines  180  moving to the fully collapsed position where the splines  180  overlap one another. 
     The magnetic element  185  can take any number of different forms including but not limited to a strip, pad, etc. and it will be appreciated that the magnetic element  185  does not have to extend the entire length of the substrate  183  but rather can be provided only in a local area(s). For example, a plurality of magnetic elements  185 , such as circular shaped permanent magnets, can be provided along the length of the spline  180  and positioned to face outwardly when the spline  180  is in the fully deployed position so as to generate an outwardly directed magnetic field. 
       FIG. 8  shows the magnetic element  185  being received within a recess  189  formed in the spline  180  such that the outer surface of the magnetic element  185  can be flush relative to the outer surface of the spline  180 . Each spline  180  can include a plurality of recesses  187  formed along the length of the spline  180 . The recesses  187  do not pass completely through the body of the spline  180 .  FIG. 9  shows a different embodiment where the magnetic elements  185  are received within complementary openings (through-holes)  189  formed in the spline  180 . The through-holes  189  pass completely through the body of the spline  180  and thus, the magnetic elements  185  are inserted into the through-holes  189  and adhered therein.  FIG. 10  shows the magnetic elements in the form of strips  185  disposed along the exterior surface of the spline  180 . The strips  185  can come in any shape and size. 
     It will be appreciated that the magnetic element(s)  185  are designed and positioned so that they do not interfere with the ability of the spline  180  to flex and move between the fully collapsed and fully deployed positions as described herein. 
       FIGS. 2 and 7  shows the splines  180  in the fully deployed position, while  FIGS. 1 and 5  show the splines  180  in the fully collapsed position. The interaction and relative positions and/or movements between the inner member  172  and the shaft  120  result in the splines  180  moving between the fully deployed position and the fully retracted position. In the fully collapsed position, the splines  180  are positioned adjacent one another and are linearly arranged. 
     The device  100  can be of a disposable type and therefore after a single use, can be disposed of after the misplaced foreign body has been located and retrieved. 
     The handle  150  includes an actuator  190  for deploying the retrieval mechanism  170  and moving the retrieval mechanism  170  between the fully deployed and fully collapsed positions. The actuator  190  can come in any number of different forms and is designed so that the user can easily operate the device  100  with his or her hand. In the illustrated embodiment, the actuator  190  is in the form of a slide mechanism that includes a slider  192  that moves within a slot  153  that is formed in the handle  150 . The slider  192  is operatively connected to the inner member  172  using a conventional mechanical attachment or linkage. For example, a pivotable link can be provided between the slider  192  and the inner member  172 . The slider  192  is coupled to the inner member  172  such that linear movement of the slider  192  is translated into linear movement of the inner member  172  relative to the outer shaft  120  which in this embodiment is fixedly attached to the handle  150 . 
     The length of the inner member  172  is such that when the slider  192  is moved to the most forward position which corresponds to the fully deployed position, the distal end  164  of the inner member  172  extends beyond the distal end of the outer shaft  120  so as to expose the retrieving mechanism  170 . In the embodiment of  FIG. 1 , as the slider  192  is moved from the most rearward position, which corresponds to the fully collapsed (retracted) position, to the most forward position, the inner member  172  is moved forward within the bore of the shaft  120  resulting in the retrieving mechanism  170  (a tool) being exposed. Continued forward movement of the inner member  172  results in more of the retrieving mechanism  170  being exposed and due to the biasing (elastic) properties of the splines  180 , the splines  180  flex radially outward away from one another. Once the slider  192  is moved into the most forward position, the splines  180  are at least substantially or completely exposed and have completely “sprung” open due to the material characteristics of the splines  180 . 
     It will be appreciated that the actuator  190  can include a thumbwheel and be operated by rotation of the thumbwheel which causes movement of either the outer shaft  120  or the inner member  172 . In addition, the handle can include a locking mechanism for locking the slider  192  in one of the positions. 
       FIG. 3  also shows that that the retrieval mechanism  170  can be rotated. For example, the handle  150  can include a knob  159  at the proximal end. The knob  159  can be connected to the inner member  172  using a connector shaft  177  such that when the connector shaft  177  rotates, the inner member  172  likewise rotates, thereby causing rotation of the connected retrieval mechanism (tool  170 ). 
     It will also be appreciated that the retrieval mechanism  170  can be constructed so that additional other movements are possible. For example, in addition to being deployable and linearly movable and rotatable, the retrieval mechanism  170  can be constructed so that it can pivot in a different direction than the deployment direction. 
     As can be seen in the figures, once the retrieval mechanism  170  is fully deployed, the magnetic elements thereof are positioned for locating and retrieving a metal-based (metal-containing) misplaced foreign body due to an increased exposed surface area in the deployed position. Using cameras and the like, the device  100  is manipulated to cause the retrieval mechanism  170  to move within the surgical site and the magnetic field generated by the magnetic element  185  generates a force that attracts and draws a metal article, such as the metal-based misplaced foreign body, into contact with the magnetic element  185  when the metal article enters the magnetic field. 
     The strength of the magnetic field can be measured and the gauss (G) is the cgs unit of measurement of the magnetic field. It will be understood that the strength of the magnetic field is determined by a number of factors including the type of magnet since the material the permanent magnet is made from has a significant effect on the overall strength of the magnet. The magnetic field produced by deployment of the splines  180  is of sufficient strength to cause a metal-based misplaced foreign body to be drawn toward the splines  180  when the splines  180  are placed in a position proximate the foreign body during the search for the misplaced foreign body at the surgical site. As mentioned herein, once the misplaced foreign body is located, another tool can be used to remove the foreign body from the patient&#39;s body. In one embodiment the strength of the magnetic field is between 5 G to 100 G and in particular, 10 G to 90 G, etc. However, these values are merely exemplary and not limiting of the present invention since the strength of the desired magnetic field can depend upon the particular application and characteristics of the misplaced article. 
     The strength of the magnetic field can depend upon the particular application and can be selected depending upon different circumstances. The magnetic field is preferably of a strength that will attract a metallic foreign body that is within a prescribed radius from the foreign body. For example, the magnetic field strength can be selected so that a metallic foreign body that is within a distance of up to about 4 inches from the magnetic element is attracted towards the magnetic element for retrieval of the foreign body. It will be appreciated that this range is merely one exemplary embodiment and the magnetic field strength can be selected to achieve a different objective and attract an object that is at a different distance from the magnetic element; however, in general, the magnetic field should be selected so that metallic foreign bodies that are within a distance from the magnetic element are attracted to the magnetic element, wherein the distance is representative of a distance that the foreign body may travel from the surgical site when misplaced. In other words, the magnetic field strength should be selected so that metallic foreign bodies that are commonly used in the surgical procedure are attracted and retrieved when they migrate away from the surgical entry point but remain within a zone of travel that would be expected when the metallic foreign body is misplaced. 
     To return the tool (retrieval mechanism  170 ) to the fully collapsed position, the slider  192  is moved in the opposite direction (rearwardly) to cause the inner member  172  to move rearwardly within the shaft  120 , thereby drawing the splines  180  toward the outer shaft  120 . As the open splines  180  are drawn toward the shaft  120 , the outer shaft  120  contacts and applies a force against the splines  180  to cause inward flexing of the splines  180 . As the splines  180  are continuously drawn into the bore of the outer shaft  120 , the splines  180  collapse into the fully collapsed position once the splines  180  are entirely contained within the shaft  120 . 
     When used in minimally invasive surgery where a metal-based foreign body has been misplaced, the device  100  is inserted into the bore of the trocar/port  101  in the fully collapsed position and once at least the distal end of the device  100  clears the trocar/port and is located at the surgical site, the actuator  190  can be manipulated to cause deployment of the retrieving mechanism  170 . Once the retrieving mechanism  170  is deployed and the misplaced foreign body is located and retained, another tool (e.g., a gripper) can be delivered to the surgical site through another port and brought into position to engage and remove the foreign body through the other port. 
     It will also be understood that instead of placing permanent magnets along the splines  180 , each spline  180  can function as or include an electro-magnetic element such as the ones described herein. For example, a coil of wire can be disposed about each spline  180  and be operatively connected to an energy source, thereby providing an actuatable electro-magnet when current is passed therethrough. In this embodiment, after outward deployment of the splines  180 , a current can be passed through the coil of wire to generate a magnetic field. The characteristics, including strength, of the magnetic field can be varied by altering the current that is passed through the coil of wire. 
     Yet another embodiment and variation of the splines  180  of  FIG. 1  is shown in  FIG. 12  where a mesh or net-like structure  191  is disposed and coupled to the two splines  180 . In the fully collapsed position, the mesh  191  likewise collapses and folds over itself so at to permit the mesh  191  and splines  180  to be retracted within the shaft  120 . It will be appreciated that the mesh  191  can either carry one or more permanent magnets or can support one or more electro-magnets (not shown) that are connected to an energy source as by passing wires along or within the splines  180  or by passing wires directly from the inner member  172  to the mesh  191 . 
     The mesh  191  increases the surface area that is available for carrying magnetic elements and for generating a magnetic field having greater coverage. By increasing the scope of the magnetic field, the likelihood of finding the misplaced foreign body increases due to the increased coverage of the magnetic field. 
     It will be appreciated that in the embodiment of  FIG. 12  where a mesh  191  is provided, the splines  180  can include a magnetic element (such as permanent magnets  185 ) or the splines  180  can be free of the magnetic element  185 . 
       FIGS. 13-17  illustrate a device  200  according to another embodiment. The device  200  is similar to the device  100  and therefore, like elements are numbered alike. The device  200  includes the outer shaft  120  and the inner member  172 ; however, the actuator means for the device  200  are different in that the tool (e.g., a retrieval mechanism  250 ) is deployed using a different action than in the device  100 . In addition, the tool  250  of the device  200  is different than the tool  170  of device  100 . 
     In the illustrated embodiment, the device  200  includes an actuator  210  that is in the form of a slide mechanism that includes slider  192  that moves within the slot  153  that is formed in the handle  150 . Unlike the embodiment of  FIG. 1 , the slider  192  in  FIGS. 13-17  is operatively connected to the outer shaft  120  using a conventional mechanical attachment or linkage. The slider  192  is coupled to the outer shaft  120  such that linear movement of the slider  192  is translated into linear movement of the shaft  120  over and relative to the inner member  172  which in this embodiment is fixedly attached to the handle  150 . In other words, in the first embodiment of  FIG. 1 , the inner member  172  is linearly advanced in a push/pull manner, whereby in the second embodiment of  FIG. 13 , the outer sheath  120  is the member that is linearly advanced in a push/pull manner so as to expose the tool  250 . 
     The tool  250  has the same intended function as the tool  170 ; however, the tool  250  has a different construction. In particular, the tool  250  is formed of first and second fingers or blades  260 ,  270  that are biased open relative to one another by means of a biasing member  275 . Each blade  260 ,  270  has a first end  272  and an opposing second end  274  with the first end  272  being an end that is closer to the inner member  172  and the second end  274  being a distal end of the blade  260 ,  270 . The blades  260 ,  270  are coupled to the inner member  172  at their first ends  272  in such a way that the blades  260 ,  270  can pivot open and closed. For example, the first ends  272  of the blades  260 ,  270  can be received within a slot  273  formed in the inner member  172  at the distal end  174  thereof. A pivot pin  277  passes through the inner member  272  through the slot  273  and likewise passes through holes  279  formed in the blades  260 ,  270  near the ends  272  thereof. The blades  260 ,  270  thus pivot open and closed about the pin  277 . 
     Since the blades of the various tools described herein are introduced into the human body and can contact soft tissue, the blades can be treated or configured so as to not adversely impact the tissue if contact is made. For example, at least the edges of the blades  260 ,  270  can coated or can be formed so that they are smooth or curved so as to not pierce or scratch internal tissue if contact is made therewith. The edges of the blades can thus be rounded or coated with a pliable material that is more giving and can be placed in contact with tissue without adversely impacting the tissue. 
     The blades  260 ,  270  can come in any number of different forms so long as when the blades  260 ,  270  are in a collapsed position, the blades  260 ,  270  are complementary to one another and can be contained within the outer shaft  120 . For example, the two blades  260 ,  270  in the collapsed position can overlie one another (stacked relationship). 
     Each blade  260 ,  270  has a magnetic property in that the blades  260 ,  270  generate a magnetic field as discussed herein. For example, each blade  260 ,  270  can be at least substantially formed of a permanent magnet and can be an elongated structure, such an oblong shaped structure or a rectangular shaped structure or even a rod shaped structure. However, the blades  260 ,  270  can have other shapes so long as they are complementary to one another and can be disposed within the bore of the outer shaft  120  when placed in the fully collapsed position. The blade  260 ,  270  can thus be formed entirely of a magnetic material. 
     It will also be appreciated that similar to the blades/splines of the first embodiment, the blade  260 ,  270  can be formed of a structure that includes a substrate that carries one or more permanent magnets. For example, permanent magnets in the form of one or more strips, pads, discrete shaped magnets, etc., can be provided along a length of the blade  260 ,  270 . As with the previous embodiment, the permanent magnets do not have to extend the entire length of the blade  260 ,  270  and instead can be located in only one or more discrete sections of the blade  260 ,  270 . For example, a series of circular shaped magnets can be formed along the outwardly facing surface of the blades  260 ,  270 . The permanent magnets can be attached the blades using conventional processing techniques including bonding the magnets to the blades, embedding the magnets within the blade structure, etc. 
     In this embodiment, the substrates of the blades  260 ,  270  face one another, with the magnetic components thereof facing outward to generate an outwardly facing magnetic field for locating and retrieving the misplaced foreign body. 
     The biasing member  275  can be in the form of a spring or the like as shown. The biasing member  275  is coupled to the first blade  260  and the second blade  270  for generating a biasing force that forces the two blades to separate from one another. In the illustrated embodiment, the biasing member  275  can be a bent spring (e.g., V-shaped spring) that is attached at its opposite ends to the two blades  260 ,  270 . In this configuration, the spring  275  can be thought to have two legs with one leg attached to the first blade  260  and the other leg attached to the second blade  270 . In the natural, rest position, the legs of the spring  275  flex outwardly and therefore, the blades  260 ,  270  that are coupled thereto likewise flex outwardly. When the tool  250  is drawn into the shaft  120  or the outer shaft  120  is advanced forwardly over the tool  250 , an inward force is applied to the blades  260 ,  270  to cause the biasing member  275  to flex inwardly and collapse upon itself and store energy. This results in the blades  260 ,  270  being drawn toward one another toward the fully collapsed position where the blades  260 ,  270  are disposed adjacent one another and can be received and contained within the outer shaft  120 . In the fully collapsed position of the blades  260 ,  270 , the spring  275  contains stored energy that is released as soon as a sufficient amount (length) of the blades  260 ,  270  is free from the influence of the surrounding outer shaft  120 . More specifically, as the tool  250  becomes more and more exposed, the spring  275  begins to release its stored energy to the blades  260 ,  270  which increasingly have the ability to pivot open. This continues until the tool  250  is completely exposed and extended beyond the outer shaft  120  and all of the stored energy of the spring  275  is released. 
     It will also be understood that the blades  260 ,  270  can alternatively be in the form of blades that are non-magnetic in nature; however, an electro-magnetic component can be incorporated into or associated with the blades  260 ,  270  that act as carriers or substrates (support member). For example, a coil of wire can be wrapped around the blades  260 ,  270  to form an electro-magnetic element that is operatively connected to an energy source. 
     In  FIG. 18 , a mesh or net-like structure  280  is disposed and coupled to the blades  260 ,  270 . In the fully collapsed position, the mesh  280  likewise collapses and folds over itself so at to permit the mesh  280  and blades  260 ,  270  to be retracted within the shaft  120 . It will be appreciated that the mesh  280  can either carry one or more permanent magnets (not shown) or can support one or more electro-magnets (not shown) that are connected to an energy source as by passing wires along or within the blades  260 ,  270  or by passing wires directly from the inner member  172  to the mesh  280 . 
     The mesh  280  increases the surface area that is available for carrying magnetic elements and for generating a magnetic field having greater coverage. 
     It will be appreciated that in the embodiment of  FIG. 18  where a mesh  280  is provided, the blades  260 ,  270  can include a magnetic element (such as permanent magnets) or the blades  260 ,  270  can be free of a magnetic element. 
       FIG. 19  illustrate a device  300  that is similar to the devices previously described and therefore like elements are numbered alike. In this embodiment, the distal end of the inner member (shaft)  172  is coupled to one or more flexible blades (fingers)  310 . In the illustrated embodiment, there are four blades  310  that are disposed adjacent one another (e.g., stacked orientation). 
     As with the splines described above with reference to the device  100 , the blades  310  are naturally biased to a bent position. More specifically, the blades  310  are designed so that that they naturally move between a fully deployed (extended) position and a fully collapsed (retracted) position. In particular, in a normal, rest position, the blades  310  assume the fully deployed position in which the blades  310  are bent along their lengths. When a force is applied to the blades  310  (e.g., an inwardly directed force), the blades  310  flex inward and this result in the blades  310  straightening out and assuming a more linear form. In other words, as the inward force is applied to the blades  310 , the blades  310  move toward the fully collapsed position in which the blades  310  are more linear in shape and can be received within the bore of the shaft  120 . 
     Each blade  310  is constructed so that it has magnetic properties to facilitate locating and retrieving a misplaced foreign body. For example, the blade  310  can have one or more permanent magnets incorporated therein, with the permanent magnets being capable of being provided in different forms, such as strips, pads, discrete magnets, etc. For example, each blade  310  can have at least one magnetic element that is supported by a substrate (blade part) and in particular, the blade  310  can be a layered structure with a flexible substrate  310  that is formed of a material that is outwardly biased and supports the magnetic element. The blades  310  can be formed of the same materials that are suitable for forming the splines. For example, a shape memory alloy can be used to form the blade  310  (at least the substrate part thereof) and impart the desired elastic properties and create the naturally biased position. 
     It will also be appreciated that, as shown in  FIG. 19 , each blade  310  can carry and support an electro-magnet  311 , such as a coiled wire. More specifically, a wire is coiled around the blade  310  and is operatively connected to an energy source to permit current to pass through the coiled wire to generate the magnetic field. In this manner, the device includes four electro-magnetic elements that create individual magnetic fields and due to the deployment of the blades  310 , the scope or extent of the magnetic fields is expanded. 
     To increase the magnetic field, the blade  310  can be a layered structure that includes the memory alloy and also include a metal layer about which the coiled wire is disposed, thereby increasing the strength of the magnetic field generated by the electro-magnet  311  as described hereinbefore. 
       FIGS. 20-22  illustrate a device  301  that is similar to device  300  and includes a plurality of blades  313  that are similar to blades  310  and are arranged in a stack relationship. The blades  313  are pivotally attached to the shaft  120  using a pivot  315  that passes through the blades  313 . When the blades  313  are deployed, the blades  313  pivot outwardly to produce splayed blades  313 . As shown, each blade  313  includes a cam slot  317  that are at least partially aligned with one another when the blades  313  are stacked. 
     In the illustrated embodiment, the inner member  172  includes a pin  165  that extends outwardly therefrom. The pin  165  is sized to be disposed within and through the cam slots  317  of the stacked blades  313 . It will be appreciated that since the blades  313  are fixedly attached to the shaft  120  at the pivot  315 , linear movement of the inner member  172  causes the pin  165  to ride within the cam slots  317  and cause pivoting of the blades  313  about the pivot  315 .  FIGS. 20 and 21  show the blades  313  in a deployed position and  FIG. 22  shows the blades  313  in a retracted position. 
     The actuator mechanism in this device is similar to  FIG. 1  in which manipulation of the actuator causes the linear movement of the inner member  172 , thereby resulting in the blades  313  pivoting open and closed. 
       FIGS. 23-24  show a device  400  according to another embodiment that is similar to the other embodiments. As a result, like components are numbered alike. The device  400  is an electro-magnetic based device in which an electro-magnet  410  is disposed along the inner member  172  ( FIG. 24 ). The electro-magnet  410  can be in the form of a coiled wire that is disposed about the inner member  172 . The electro-magnet  410  is operatively connected to an energy source to permit the electro-magnet  410  to be energized. For example, the handle of the device  400  can include a plug outlet into which a plug can be plugged or a cord  409  extends therefrom, with the plug being connected to a cord that is attached to an energy device, such as a device that generates an electric current that is delivered to the device. The electro-magnet  410  can be coupled to the plug outlet using conventional means, such as wiring that is routed through the device  400  from the handle to the tool. Circuitry within the external current generating device permits control and the ability to vary the characteristics of the current. 
     As with the other embodiments, the device  400  ( FIG. 24 ) can be actuated in any number of different ways so to expose the electro-magnet  410 . For example, the previously described actuation means can be used including move the outer shaft  120  relative to the inner member  172  to expose the tool or the inner member  172  can be advanced forward relative to the fixed outer shaft  120  so as to expose the tool. 
     It will further be appreciated that, as shown in  FIG. 23 , the electro-magnet  410  can be disposed about a fixed member in that the device can simply have the elongated outer shaft  120  which is fixed to the handle  150 , with the electro-magnet  410  being disposed about the outer shaft  120  in an exposed position all the time. In this embodiment, the instrument is inserted into the trocar/port and is advanced to the surgical site and then the energy source is delivered to the electro-magnet  410  resulting in the generation of a magnetic field. The user then simply moves the electro-magnet  410  about the surgical site until the misplaced foreign body is within the influence of the magnetic field and thereby is drawn into contact with electro-magnet  410  due to magnetic attraction between the metal-based foreign body and the electro-magnet. 
     It will also be understood that with all of the electro-magnet based devices described herein, the handle of the respective device can include one or more controls that are specific to the operation of the electro-magnet. For example, the handle can include an on/off button for supplying energy to the coil. It is envisioned that control over the characteristics of the current can be performed by controls that are part of the external device that is the energy source; however, it is within the scope of the present invention, that the handle can include a means for altering the characteristics of the energy (current) that is delivered to the coil. 
       FIGS. 11 and 12  show the devices of the present invention in use.  FIG. 11  shows the device  100  being inserted into the trocar  101  for locating and retrieving a misplaced foreign body  10 , such as a needle. Once the retrieval mechanism (tool)  170  is within the body, it is deployed so as to create a magnetic field of greater dimensions due to the deployment of the tool  170 . It will be appreciated that the device of the present invention, including device  100 , can be used in combination with another tool/instrument  20  that performs the actual removal of the misplaced foreign body  10  from the body cavity. More specifically, once the device  100  of the present invention successfully locates and is coupled to the misplaced foreign body  10  as by magnetic attraction, another instrument, such as a gripping device, can be introduced to the site (as by another port) and can be moved into position to grasp and remove the misplaced foreign body  10 . 
     It will be appreciated that the devices discloses herein are intended for use with conventional equipment that is used in a minimally invasive surgical procedure and therefore, the device in the collapsed position is sized and shaped to permit it to be received within conventional trocars/ports used during the procedure. The device, in the collapsed position, can have a width of about 10 mm or less. Other dimensions are possible and may be preferred depending upon the particular application that the device is being used in; however, the devices of the present invention are particularly suited for use in a minimally invasive surgical environment. 
     It will also be further appreciated that the internal mechanism for causing the retrieval tool to move between the deployed position and the collapsed position can be any number of different mechanical attachment or linkage mechanism, including those described in U.S. Pat. Nos. 5,195,505; 5,199,419; 5,271,385; 5,381,788; 5,391,180; 5,490,819; 5,414,517; 5,554,101; 5,607,450; and 5,766,205, each of which is hereby incorporated by reference in its entirety. 
     In yet another embodiment, the deployable member that is part of the retrieval tool and that carries the magnetic element can be in the form of a single blade structure as opposed to the multiple blade structures described herein. In this embodiment, the single blade can be deployed and when deployed will change its shape compared to the collapsed position. For example, the blade can be formed of a shape memory alloy, etc., as described herein, and will curl or bend when deployed. In addition, the blade can be a single blade structure but when deployed can occupy a greater area. For example, the blade can be formed to have a bellows type structure (fan-fold design) and when deployed, the bellows structure unfolds and therefore, the magnetic elements that are associated with the bellows structure unfold and/or are spaced over a greater area, thereby generating a magnetic field that occupies a greater coverage area. 
     In accordance with the present invention, the various retrieval tools described herein are in some way manipulated to cause a change in at least one characteristic or property of the tool which results in a magnetic field being generated and/or being generated over a greater area. For example, one type of manipulation is the activation of an electro-magnetic device to cause a current to flow through the device, thereby generating the magnetic field. Yet another type of manipulation is the deployment or altering of the physical characteristics of the magnetic element such that the generated magnetic field extends over a greater area. This action can either be the bending, upon deployment, of one or more fingers that carry the magnetic elements as described or it can be another action, such as the above-described unfolding of a fan-fold or bellows type structure that results in the magnetic elements occupying a greater footprint and thereby, generating a magnetic field that has greater coverage. 
       FIGS. 25-31  illustrate a device  500  according to another embodiment for insertion into a conventional trocar/port for locating and retrieving a misplaced magnetic foreign body. The device  500  is similar to the other devices disclosed in the related &#39;814 application and is designed to perform the same functions described therein. 
     The device  500  can include an outer sheath or shaft  510  that is open at both proximal and distal ends  512 ,  514 , respectively, and thus represents a hollow structure. As shown, the proximal end  512  can include an enlarged body or handle member  520 . The illustrated outer sheath  510  is in the form of a tubular structure and the length and shape thereof can be selected depending upon the particular application. However, the dimensions of the outer sheath  510  are selected in view of the trocar dimensions since the outer sheath  510  is inserted into and passes through the hollow bore of the trocar. In one embodiment, the outer sheath  510  has a diameter of about 12 mm; however, other dimensions are possible depending in part on at least the dimensions of the trocar. In addition, other factors can influence selection of the outer sheath  510 . 
     The device  500  further includes an inner member  600  which is designed to slidingly move within the outer sheath  510  and be positioned between an extended (opened) position ( FIG. 26 ) in which a distal end  604  of the member  600  extends beyond the distal end  514  of the outer sheath  510  and a retracted (closed) position in which the distal end  604  of the member  600  is at least partially retracted within the outer sheath  510 . In the retracted (closed) position, the distal end  604  of the member  600  can be fully contained within the outer sheath  510 . 
     The dimensions of the inner member  600  are thus such that it can be received within the hollow bore of the outer sheath  510 . 
     The inner member  600  also includes a proximal end  602  which can include a handle component  630  and an actuator  640  which causes controlled movement of the inner member  600  as described below. The handle component  630  can be a knob-like structure that has ribs to assist the user in grasping the inner member  600  and manipulating the inner member  600  relative to the outer sheath  510 . For example, the user can rotate the inner member  600  within and relative to the outer sheath  510  by rotating the handle component  630 . The handle component  630  has a greater size than the member  520  and thus the member  520  serves as a stop that limits the longitudinal movement of the inner member  600  within the hollow bore of the outer sheath  510 . For example and as illustrated, in the closed (retracted) position of  FIG. 25 , the handle component  630  is spaced from the member  520 , while in the opened (extended) position of  FIG. 26 , the handle component  630  is in contact with or proximate to the member  520 . The handle component  630  is thus fixed to the elongated body that defines the inner member  600 . 
     The actuator  640  is shown in  FIGS. 30 and 31  and is configured to permit at least a portion  625  of the distal end  604  of the inner member  600  to move (e.g., to pivot) as described below. The actuator  640  can take any number of different forms including a lever or pull member (pull knob) as shown which is coupled to a mechanical linkage that is coupled to the movable distal end portion  625 . The actuator  640  is thus intended to allow the user to easily cause controlled movement of the distal end portion  625 . It will be appreciated and better understood in view of the below discussion that the illustrated actuator  640  is part of a pull wire mechanism in which a pull wire  635  is coupled to a pull knob  645  at the proximal end and at the distal end is coupled to the distal end portion  625 . 
     As shown best in  FIGS. 28 and 29 , the inner member  600  is an elongated structure that includes a main portion  605  and the distal end portion  625  which is coupled to a distal end  607  of the main portion  605 . 
     The distal end portion  625  of the inner member  600  which is controllable is in the form of an articulating member and in particular, an articulating magnetic element  650  similar to the other embodiments described in the &#39;814 application. The coupling between the magnetic element  650  and the distal end  607  of the main portion  605  can be accomplished using any number of different types of mechanical couplings. In the illustrated embodiment, the magnetic element  650  is attached to the main portion  605  using a mechanical link  660  that allows the magnetic element  650  to pivot relative to the main portion  605 . 
     The pull wire  635  is attached to the link  660  and the proximal end of the magnetic element  650  is pivotally coupled to the distal end of the main portion  605  about the link  660  such that translational movement of the pull wire  635  causes a pivoting of the magnetic element  650 . As shown in  FIG. 30 , in the open position (extend position) in which the magnetic element  650  is pivoted, the pull knob  645  is pulled from the handle component  630  and the pull wire  635  is exposed.  FIG. 31  shows the closed (retracted) position in which the magnetic element  650  is not pivoted but instead lies linearly along the axis of the main portion  605  and as shown, the pull knob  645  is in contact with the handle component  630  and the pull wire  635  is not visible. 
     In one embodiment, the magnetic element  650  pivots over a range of 90 degrees; however, in other embodiments, the magnetic element  650  can pivot over a range greater than 90 degrees. However, since the inner member  600  is freely rotatable, a 90 degree pivot range is generally sufficient. 
     It will be understood that any number of other mechanical linkages can be used to caused the controlled movement of the magnetic element  650  besides the illustrated linkage. In particular, the user simply needs to be able to control the magnetic element from a location outside the body and be able to easily use a slider or control knob or some other actuator to cause the controlled movement (pivoting) of the magnetic element. 
     The magnetic element  650  includes a magnetic component  655  and can include a casing or housing or end caps  657 , etc. As with the other embodiment in the &#39;814 application, the strength of the magnetic component  650  should be such that magnetic foreign material within a body is attracted to and drawn into contact with the magnetic component  650 . The magnetic component  650  can be in the form of a permanent magnet. For example, one type of permanent magnet that is particularly suited for the present invention and the intended applications of the device  500  is a neodymium magnet (also known as NdFeB, NIB, or Neo magnet), the most widely-used type of rare-earth magnet, is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd 2 Fe 14 B tetragonal crystalline structure. As is known in the industry, the magnetic strength (field) is in part based on the characteristics of the magnet, such as its diameter (width) and length. The greater the diameter, the stronger the magnetic field and similarly, the longer the magnet, the stronger the magnetic field. 
     In one embodiment, the magnetic component  655  includes a neodymium magnet having a diameter of about ⅜ inch and a length of about 2 inch. It will be appreciated that other dimensions are equally possible for the magnet depending upon the intended application and the overall design and dimensions of the device. It will be appreciated that the width of the magnet cannot exceed the width of the inner bore formed in the outer sheath  510  and obviously is less than the width of the trocar through which the device  500  is fed. 
     Preferably, the strength of the magnet is such that magnetic material that is at least 1 inch away or greater is attracted to and drawn into contact with the magnet and more preferably, material that is at least 2 inches away or greater is attracted to and drawn into contact with the magnet. This objective and the above field of attraction distances relate to foreign magnetic material that may be accidentally misplaced in the body during the course of a surgery as discussed in the &#39;814 application. 
     In order to permit coupling to the link  660 , a proximal cap or housing is provided and is attached to the magnet itself using conventional means, including bonding, etc. A distal end protective cap can also be provided as illustrated. The proximal part is the portion that is pivotally connected to the main portion  605  using the link or some other mechanical attachment such as a pin, etc. 
     It will also be appreciated that the mechanical linkage that is operatively coupled to the magnetic element  650  can include one or more locking positions to allow the user to lock the magnetic element  650  in any one of several pivoted positions. For example, the magnetic element  650  can be locked in a 45 degree position; a 90 degree position, etc. Such lock can lock the mechanical linkage in a fixed position, thereby preventing the accidental movement of the magnetic element  650 . 
     It will also be appreciated that the device  500  can consist solely of the inner member  600  and in that case, the outer sheath  510  is eliminated and the inner member  600  is the only member that is inserted and passed through the inner bore of the trocar. 
     The operation and use of the device  500  are described below. 
     As with the other embodiments described in the &#39;814 application, the device  500  is inserted into and passed through the trocar until at least the distal tip of the instrument extends beyond the trocar distal tip within the patient&#39;s body. When the device  500  include outer sheath  510 , the user then manipulates and directs the inner member  600  forward toward the patient to cause at least the magnetic element  650  to extend beyond the distal end of the sheath  510 . In this initial position as shown in  FIGS. 28 and 29 , the magnetic element  650  is in-line (axially aligned) with the main portion  605 . Since the magnetic element  650  has cleared the outer sheath  510 , it can be manipulated by the user and this includes the ability to fully rotate the magnetic element 360 degrees and the ability to move (pivot) the magnetic element  650  so that it is out of the plane of the main portion  605 . As discussed hereinbefore, the magnetic element  650  can be pivoted into different position so as to allow the user to position the magnet and thus the associated magnetic field in different positions so as to attract the magnetic foreign material that is to be located and recovered by the device  500 . 
     Further aspects of the misplaced foreign material and the patient&#39;s anatomy and potential applications for the device  500  are set forth in the &#39;814 application and therefore are not repeated herein. It will therefore be understood that the device  500  is in intended to be used in the manner described and in all of the applications described in the &#39;814 application. Also, a retrieval tool, such as grippers or the like can be used in combination with the device  500  to actually remove the misplaced foreign material once it has been located and retrieved by the device  500 . 
     As mentioned above, when the outer sheath  510  is eliminated, the inner member  600  is passed through the trocar and then manipulated in the same manner described above. 
     In yet another aspect of the present invention, the retrieval devices according to the present invention are not limited being used in a manual setting and instead, the retrieval device can be used as part of an automated system that is controlled by a person. 
     More specifically and as shown in  FIG. 32 , an automated robotic system  1000  can be provided and in one embodiment, is designed to operate in response to user commands. For example, the surgeon can control the robotic system  1000  using a user interface  1010 . The user interface  1010  can come in any number of different forms and can include a keyboard or keypad (touch screen) and also other user manipulable controls, such as members that respond to the user&#39;s movements, such as movements of the user&#39;s hand, fingers, etc. By manipulating these controls, the user can control with precision certain robotic tools as described herein and in particular can control one of the retrieval devices disclosed herein. 
     The robotic system  1000  has particular utility in laparoscopic procedures and other similar procedures as will be appreciated by the below discussion. The robotic system  1000  can thus be implemented in any of the surgical procedures discussed herein with reference to one of the retrieval devices in accordance with the present invention. 
     The robotic system  1000  includes a number of working components and in accordance with one design, the robotic system  1000  includes a robotic arm  1100  that is capable of moving in a number of different directions (multiple degrees of freedom) based on the commands of the user. A display  1200  is also provided to allow the user to view the target location as the surgical procedure. In particular, one of the tools of the robotic system  1000  can be an endoscope or some other type of imaging device that permits the user to directly view the surgical site (target location). 
     The robotic system  1000  is a computer based system that contains a processor that executes code (software) to allow precise control of the movable robotic parts of the system  1000  and to allow imaging to be displayed (live video feed on display  1200 ) as discussed herein. 
     In  FIG. 32 , retrieval device  1300  constitutes one of the retrieval devices disclosed herein for using in locating a misplaced foreign body that has metallic characteristics. As will be appreciated, the retrieval device  1300  is operatively coupled to a moving part of the robotic system so as to allow the retrieval device  1300  to be moved in a precise manner as part of a surgical procedure as described herein. Based on operating software and the user&#39;s commands, the retrieval device  1300  can be manipulated both in terms of its operating state (i.e., is it opened or closed) and also its location (i.e., it can be manipulated into the body (i.e., through a trocar) and also manipulated once inside the body. 
     The operation of the individual retrieval devices  1300  is described hereinbefore and it should be understood that the purpose and characteristics of the devices  1300  does not substantively change due to the fact that it is implemented in an automated system (robotic). 
     In yet another embodiment shown in  FIG. 33 , a retrieval device  1400  in accordance with the present invention can include a metal detector  1500 . The retrieval device  1400  can share a number of characteristics as the retrieval devices described hereinbefore and accordingly, the retrieval  1400  can be in the form of one or more of the other retrieval devices described herein, such as the device  500 . The retrieval device  1400  is thus designed to be operable for retrieving the misplaced article (metal). 
     The metal detector  1500  can be a micro-sized unit to allow it to be part of the retrieval device  1400  that is constructed for laparoscopic use and therefore, is, in this embodiment, of a size that passes through a trocar or the like to pass into the patient&#39;s body. 
     As shown in  FIG. 33 , the metal detector  1500  and retrieval mechanism can be incorporated into the distal end of the device. For example, in a construction in which the magnetic element travels through a bore in an outer body (i.e., outer sheath, etc.), the outer body can incorporate the metal detector  1500  therein (e.g., the coils can be incorporated into the cylindrical wall of the outer sheath or the coils can be disposed at and protruding beyond the distal end of the outer sheath). In this manner, the metal detector  1500  can be isolated from the magnetic element of the retrieval device. More particularly, the outer sheath with the metal detector  1500  at its distal end can be fed through a trocar to the target site and the metal detector  1500  is operated to determine the approximate location of the misplaced article. Once this location is determined, the magnetic element is fed through the central bore of the outer sheath until it extends beyond the distal end of the outer sheath and can be operated as described above in order to search and retrieve the misplaced article. The metal detector  1500  can be turned off as the magnetic element is delivered to the target site. In this construction, the magnetic element of the retrieval device can be magnetically isolated from the metal detector so as to not interfere with operation thereof. 
     Other alternative constructions are equally possible between the metal detector and the magnetic element of the retrieval device. 
     The metal detector  1500  measures a change in an observed magnetic field and when is configured to alert the user as to the presence of a metal object within the vicinity of the metal detector  1500 . The range and sensitivity of the metal detector  1500  can be tailored according to the intended application. In the case of the present invention in which the metal detector  1500  is part of a retrieval device  1400  that is introduced into the body, the sensitivity of the metal detector  1500  is programmed accordingly and more particularly, given the environment, the detector  1500  can be programmed and constructed to detect the presence of a magnetic field within a very short range, such as several inches (i.e., within 3 inches; or alternatively, within 2 inches; or alternatively within 1 inch from the detector). 
     It will also be appreciated that the detector  1500  can be constructed so as to give feedback to the user on the approximate location of the misplaced article. In other words, the metal detector  1500  can determine approximately how far away the misplaced article is based on the strength of the magnetic field it generates. The closer to the metal detector an object is, the stronger the magnetic field picked up by the metal detector (e.g., by a receiver coil thereof) and the stronger the electric current generated. The farther from the detector, the weaker the field. This information can be processed by a processor that is part of the device and can be relayed to the user, as by auditory and/or visual feedback. It is also possible for the device to include a display (a screen) on which information can be displayed such as graphic information indicating the approximate distance to the misplaced article based on the measured magnetic field). 
     The control software for the metal detector  1500  can be and is preferably configured to generate at least one of auditory feedback and visual feedback. For example, as the observed magnetic field increases, an increasing audible signal is heard (e.g., a beeping of increasing frequency) and/or a display light can be illuminated with increasing frequency or can blink with increasing frequency as the detector is moved towards the misplaced article). This allows the user to understand whether the device  1400  is moving in a direction towards or away from the misplaced item (magnetic) and thus, the user can use this information to move the retrieval device  1400  in the proper desired direction. In one embodiment, the metal detector  1500  is a small pico-detector or is another coil based micro-sized metal detector that is disposed at or near the tip of the device  1400 . As is understood, as metal is brought into proximity with a coil (e.g., a receiving coil at the tip) of the detector, the frequency of an oscillator changes and this signal can be processed by a processor to alert the user to the presence of a metal object (the misplaced article) in the manners described herein. 
     In the case of where the retrieval device is an electro-magnetic device as described herein, the power source of the electro-magnetic tool and the metal detector can be the same. However, the electronics of the device are configured to allow each of these components to be independently powered to allow independent operation of the retrieval device and the metal detector. In addition, the device can include conventional current reducing/amplifying parts where needed in order to regulate the current to each of these different parts. 
     The combination of a metal detector with a magnetic retrieval device allows the device to sense the misplaced metal material using the metal detector and then the retrieval mechanism is used to attract and collect the misplaced article. 
     While the invention has been described in connection with certain embodiments thereof, the invention is capable of being practiced in other forms and using other materials and structures. Accordingly, the invention is defined by the recitations in the claims appended hereto and equivalents thereof.