Surgical training model for laparoscopic procedures

FIELD OF THE INVENTION

0001This application is generally related to surgical training tools, and in particular, to simulated models for teaching and practicing various surgical techniques and procedures related but not limited to laparoscopic, endoscopic and minimally invasive surgery.

BACKGROUND OF THE INVENTION

0002Medical students as well as experienced doctors learning new surgical techniques must undergo extensive training before they are qualified to perform surgery on human patients. The training must teach proper techniques employing various medical devices for cutting, penetrating, clamping, grasping, stapling, cauterizing and suturing a variety of tissue types. The range of possibilities that a trainee may encounter is great. For example, different organs and patient anatomies and diseases are presented. The thickness and consistency of the various tissue layers will also vary from one part of the body to the next and from one patient to another. Different procedures demand different skills. Furthermore, the trainee must practice techniques in various anatomical environs that are influenced by factors such as the size and condition of the patient, the adjacent anatomical landscape and the types of targeted tissues and whether they are readily accessible or relatively inaccessible.

0003Numerous teaching aids, trainers, simulators and model organs are available for one or more aspects of surgical training. A surgical training device, of the general type to which the present invention relates, is disclosed US patent application, publication number <patcit id="pcit0001" dnum="US4371345A"><text>US 4371345A</text></patcit>. In laparoscopic or minimally invasive surgery, a small incision, as small as 5-10 mm is made through which a trocar or cannula is inserted to access a body cavity and to create a channel for the insertion of a camera, such as a laparoscope. The camera provides a live video feed capturing images that are then displayed to the surgeon on one or more monitors. At least one additional small incision is made through which another trocar/cannula is inserted to create a pathway through which surgical instruments can be passed for performing procedures observed on the monitor. The targeted tissue location such as the abdomen is typically enlarged by delivering carbon dioxide gas to insufflate the body cavity and create a working space large enough to safely accommodate the scope and instruments used by the surgeon. The insufflation pressure in the tissue cavity is maintained by using specialized trocars. Laparoscopic surgery offers a number of advantages when compared with an open procedure. These advantages include reduced pain, reduced blood and shorter recovery times due to smaller incisions.

0004Laparoscopic or endoscopic minimally invasive surgery requires an increased level of skill compared to open surgery because the target tissue is not directly observed by the clinician. The target tissue is observed on monitors displaying a portion of the surgical site that is accessed through a small opening. Therefore, clinicians need to practice visually determining tissue planes, three-dimensional depth perception on a two-dimensional viewing screen, hand-to-hand transfer of instruments, suturing, precision cutting and tissue and instrument manipulation. Typically, models simulating a particular anatomy or procedure are placed in a simulated pelvic trainer where the anatomical model is obscured from direct visualization by the practitioner. Simulated pelvic trainers provide a functional, inexpensive and practical means to train surgeons and residents the basic skills and typical techniques used in laparoscopic surgery such as grasping, manipulating, cutting, knot tying, suturing, stapling, cauterizing as well as how to perform specific surgical procedures that utilize these basic skills. Simulated pelvic trainers are also effective sales tools for demonstrating medical devices required to perform these laparoscopic procedures.

0005One of the techniques mentioned above that requires practice in laparoscopic or minimally invasive surgery is cutting and suturing. Therefore, it is desirable to present a model for practicing cutting and suturing. It is also desirable to have a model that not only simulates the particular anatomy but also presents the anatomy at a particular step or stage of the procedure or isolates a particular step of a procedure for the trainee to practice in a simulated laparoscopic environment. The model is then disposed inside a simulated laparoscopic environment such as a laparoscopic trainer in which it is at least partially obscured from direct visualization. A camera and monitor provide visualization to the practitioner as in real surgery. After a technique is practiced, it is furthermore desirable that such a model permits repeatable practice with ease, speed and cost savings. In view of the above, it is an object of this invention to provide a surgical training device that presents an anatomy at a particular stage or step of a procedure that also enables repeatable practice. It has been demonstrated that the use of simulation trainers greatly enhances the skill levels of new laparoscopists and are a great tool to train future surgeons in a non-surgical setting. There is a need for such improved, realistic and effective surgical training models.

SUMMARY OF THE INVENTION

0006According to the present invention, there is provided a surgical training device as recited in Claim 1 of the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

0007<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> illustrates a top perspective view of a surgical training device according to the present invention.</li><li><figref idref="f0002">FIG. 2</figref> illustrates a top perspective, partially transparent view of a surgical training model according to the present invention.</li><li><figref idref="f0003">FIG. 3</figref> illustrates a top perspective view of a model without a simulated tissue portion according to the present invention.</li><li><figref idref="f0004">FIG. 4</figref> illustrates a top perspective, partially transparent view of a model with two tissue simulation portions according to the present invention.</li></ul>

DETAILED DESCRIPTION OF THE INVENTION

0008A surgical training device 10 that is configured to mimic the torso of a patient such as the abdominal region is shown in <figref idref="f0001">FIG. 1</figref>. The surgical training device 10 provides a body cavity 12 substantially obscured from the user and configured for receiving simulated or live tissue or model organs or training model of the like described in this invention. The body cavity 12 is accessed via a tissue simulation region 14 that is penetrated by the user employing devices to practice surgical techniques on the tissue or organ model found located in the body cavity 12. Although the body cavity 12 is shown to be accessible through a tissue simulation region, a hand-assisted access device or single-site port device may be alternatively employed to access the body cavity 12.

0009Still referencing <figref idref="f0001">FIG. 1</figref>, the surgical training device 10 includes a top cover 16 connected to and spaced apart from a base 18 by at least one leg 20. <figref idref="f0001">FIG. 1</figref> shows a plurality of legs 20. The surgical training device 10 is configured to mimic the torso of a patient such as the abdominal region. The top cover 16 is representative of the anterior surface of the patient and the space between the top cover 16 and the base 18 is representative of an interior of the patient or body cavity where organs reside. The surgical trainer 10 is a useful tool for teaching, practicing and demonstrating various surgical procedures and their related instruments in simulation of a patient undergoing a surgical procedure. Surgical instruments are inserted into the cavity 12 through the tissue simulation region 14 as well as through pre-established apertures 22 in the top cover 16. Various tools and techniques may be used to penetrate the top cover 16 to perform mock procedures on model organs placed between the top cover 16 and the base 18. The base 18 includes a model-receiving area 24 or tray for staging or holding a simulated tissue model or live tissue. The model-receiving area 24 of the base 18 includes frame-like elements for holding the model (not shown) in place. To help retain simulated tissue model or live organs on the base 18, a clip attached to a retractable wire is provided at locations 26. The wire is extended and then clipped to hold the tissue model in position substantially beneath the tissue simulation region 14. Other means for retaining the tissue model include a patch of hook-and-loop type fastening material (VELCRO^®) affixed to the base 18 in the model-receiving area 24 such that it is removably connectable to a complementary piece of hook-and-loop type fastening material (VELCRO^®) affixed to the model.

0010A video display monitor 28 that is hinged to the top cover 16 is shown in a closed orientation in <figref idref="f0001">FIG. 1</figref>. The video monitor 28 is connectable to a variety of visual systems for delivering an image to the monitor. For example, a laparoscope inserted through one of the pre-established apertures 22 or a webcam located in the cavity and used to observe the simulated procedure can be connected to the video monitor 28 and/or a mobile computing device to provide an image to the user. Also, audio recording or delivery means may also be provided and integrated with the trainer 10 to provide audio and visual capabilities. Means for connecting a portable memory storage device such as a flash drive, smart phone, digital audio or video player, or other digital mobile device is also provided, to record training procedures and/or play back pre-recorded videos on the monitor for demonstration purposes. Of course, connection means for providing an audio visual output to a larger screen other than the monitor is provided. In another variation, the top cover 10 does not include a video display but includes means for supporting a laptop computer, a mobile digital device or tablet such as an IPAD^® and connecting it by wire or wirelessly to the trainer.

0011When assembled, the top cover 16 is positioned directly above the base 18 with the legs 20 located substantially around the periphery and interconnected between the top cover 16 and base 18. The top cover 16 and base 18 are substantially the same shape and size and have substantially the same peripheral outline. The internal cavity is partially or entirely obscured from view. In the variation shown in <figref idref="f0001">FIG. 1</figref>, the legs include openings to allow ambient light to illuminate the internal cavity as much as possible and also to advantageously provide as much weight reduction as possible for convenient portability. The top cover 16 is removable from the legs 20 which in turn are removable or collapsible via hinges or the like with respect to the base 18. Therefore, the unassembled trainer 10 has a reduced height that makes for easier portability. In essence, the surgical trainer 10 provides a simulated body cavity 12 that is obscured from the user. The body cavity 12 is configured to receive at least one surgical model accessible via at least one tissue simulation region 14 and/or apertures 22 in the top cover 16 or sides through which the user may access the models to practice laparoscopic or endoscopic minimally invasive surgical techniques.

0012A surgical training model 30 according to the present invention is shown in <figref idref="f0002">FIG. 2</figref>. The model 30 is configured to be placed inside the surgical training device 10 described above or other surgical trainer similar to the one described above. The model 30 may also be used by itself without a laparoscopic trainer to train or practice certain procedures and surgical techniques. The model 30 includes a base 32, a plurality of posts 34, and at least one simulated tissue portion 36.

0013The base 32 of the model 30 is a platform that serves as a bottom support for the rest of the model 30 and it is sized and configured such that the model 30 does not tip over. The platform is made of any material such as metal or plastic. The base 32 is of sufficient heft to maintain the stability of the model 30 in the upright position while being manipulated by a user. The base 32 may include holes for receiving posts 34. Alternatively, the posts 34 may be integrally form with the base 32 as a unitary body. The model 30 is sized and configured to be placed into the body cavity 12 of the surgical trainer 10 in the location of the model receiving area 24. The underside of the base 32 is provided with means to affix the model 30 inside the surgical trainer 10. Such means to affix the model 30 inside the trainer 10 include but are not limited to adhesive, suction cup, snap-fit, magnet, and a hook-and-loop type fastener material attached to the bottom surface of the base 32 and configured to connect with a complementary hook-and-loop type fastener material or adhesive attached to the base 18 of the surgical trainer 30.

0014Still referencing <figref idref="f0002">FIG. 2</figref>, four posts 34 are connected to the base 32 of the model 30 or, alternatively, the posts 34 are integrally formed with the base 32. Each post 34 is elongate and cylindrical in shape having a proximal end connected to the base 32 and a distal end that extends upwardly from the base 32. In one variation, the distal end includes a tapered section 38 that terminates at a blunt tip surface 40 so as to not injure a user but is sharp enough to puncture holes in simulated tissue. In one variation, as shown in <figref idref="f0002">FIG. 2</figref>, the distal end is conical or tapered and has smoothly curved, rounded or flat tip. Each post 34 includes at least one circumferential notch 42 or cut that extends radially inwardly from the outer surface and into the post 34. In the variation shown in <figref idref="f0002">FIG. 2</figref>, each post 34 includes three notches 42a, 42b, 42c spaced apart along the length of the post 34 although any number of notches may be included in the post 34. The notches 34 are perpendicular to the longitudinal axis of the each post 34. In one variation, all of the posts 34 have the same number of notches 34 in the same locations or distances along the longitudinal axis. The posts 34 are spaced apart and located in substantially the four corners of the base 32. The posts 34 may be oriented perpendicular to the base 32 or angled outwardly as shown in <figref idref="f0002">FIG. 2</figref> to help retain a tensioned simulated tissue portion 36 or to allow for varied tension in the simulated tissue portion 36. In one variation, the posts are movable with respect to the base 32 such that their angle with respect to the base 32 can be selected by the user in order to vary the tension on the simulated tissue portion 26. In another variation, the angle of the posts 34 are not fixed but vary within constrained parameters upon manipulation of the connected simulated tissue portion 36 thereby increasing the difficulty for the clinician in performing the surgical technique. At least one of the posts 34 angulates, shifts, tilts, wobbles or is movable with respect to base 32 in response to forces applied to the simulated tissue portion 36 by the practitioner. The proximal end of at least one post 34 is connected to the base 32 and configured such that the post angulates polyaxially or rotates polyaxially with respect to the base. In another variation at least one of the posts 34 is a flexible gooseneck which can be adjusted with the position being maintained by the gooseneck post 34 following the adjustment. The gooseneck post 34 is advantageous in adjusting the tension in the simulated tissue portion 36. The posts 34 are configured to support the simulated tissue portion 36 and to selectively locate and position the simulated tissue portion 36 in the notches 34. If the simulated tissue portion 36 is in the form of a sheet as shown in <figref idref="f0002">FIG. 2</figref>, then the thickness of the notches 42 is at least as thick as the thickness of the sheet forming the simulated tissue portion 36 such that the simulated tissue portion 36 is supported within and by the notches 42 and retained in the notches 42 along the posts 34 and thereby prevented from slipping or moving along the length of the post 34 as a clinician manipulates the simulated tissue portion 36. In one variation, the simulated tissue sheet 36 is approximately 0.13cm (0.05 inches) thick and the notches are approximately 0.25cm (0.1 inches) thick and the notches 42 are spaced apart by approximately 0.64cm (0.25 inches). In another variation, the notches 42 are thinner than the sheet 36 to slightly compress the sheet in position within the notch 42. For example, the notch 42 is approximately 0.20cm (0.08 inches) and the sheet is approximately 0.25cm (0.1 inches). One variation includes mounting posts that have notches that are formed at the same height. For example, a post 34 is approximately 10.1cm (4.0 inches) long and includes first, second, third and fourth notches located at approximately 2.54cm (1.0 inch), 4.57cm (1.8 inches), 6.9cm (2.7 inches), and 9.4cm (3.7 inches), respectively. The outer diameter of the posts 34 are approximately 0.76cm (0.3 inches) and the inner diameter of the posts 34 in the location of the notches is approximately 0.58cm (0.23 inches).

0015In one variation, the posts 34 are removable from the base 32. The base 32 includes four apertures and the posts 34 are passed into the apertures from underneath the base 32. Each post 34 is provided with a flange and each aperture is keyed for allowing the flanged post 34 to pass into the aperture. Once inserted into the aperture of the base 32, the post 34 is twisted relative to the base 32 to lock the post 34 in position relative to the base 32. To remove the post 34, the post 34 is twisted in the opposite direction and pushed down through the aperture. The underside of the base 32 includes an alcove provided with detents into which the posts 34 may be snapped into for flat storage of the model. Of course, rigid posts 34 may be interchangeable with flexible/movable ones.

0016Still referencing <figref idref="f0002">FIG. 2</figref>, the simulated tissue portion 36 includes a sheet of simulated tissue material. In another variation, the simulated tissue portion can take the form and shape of a particular organ. The simulated tissue portion 36 is connected to the posts 34 and in essence suspended from the upper surface of the base by a distance defined by the distance of the notch 42 to which the simulated tissue portion is attached. The simulated tissue portion 36 is free on all sides except at the points of support at the posts 34. The simulated tissue portion 36 is mounted in tension being slightly stretched between and connected to the posts 34. The tension of the sheet may be adjusted by angulating the posts 34 or by stretching and piercing the simulated tissue portion 36 in locations closer together along the simulated tissue portion. In one variation, the simulated tissue portion 36 is a sheet of silicone. In another variation the simulated tissue portion is a sheet of fabric or mesh coated with silicone on at least one side. The fabric or mesh is a 2-way or 4-way stretch material such as stretch nylon or spandex or a stretch nylon/spandex blend mesh or fabric. The fabric or mesh material is stretchable and porous and weighs approximately 79 grams per square yard. The material of the sheet can be any polymeric material that is flexible and can stretch and may include a mesh or other reinforcement material or fiber. The silicone coating on the mesh provides a realistic tissue feel and may include a textured surface to provide the user with tactile feedback and to allow the user to grab onto the surface with graspers. The mesh, fabric, fiber or other filler material provides reinforcement to the silicone such that the sheet can hold a suture without tearing or be stretched without tearing when being manipulated or connected to the posts 34. The simulated tissue portion 36 may also be made of KRATON^® or other thermoplastic elastomer.

0017In one variation, the simulated tissue portion 36 includes a marking or a predetermined pathway drawn on the upper surface of the at least one simulated tissue portion 36 with ink for example for the user to cut along. A shape may also be drawn which the user can practice cutting out. A pre-marked simulated tissue portion 36 provides a starting point for the user. Also, a blank simulated tissue portion 36 allows the user to draw their own line, path or shape on the simulated tissue portion 36 that then the user can cut along employing laparoscopic scissors and dissectors to practice precision cutting and then practice suturing the cut or opening closed. Furthermore, in one variation, the simulated tissue portion 36 includes pre-formed apertures 44 located along the perimeter at the four corners as shown in <figref idref="f0002">FIG. 2</figref>. These apertures are approximately 0.32cm (0.125 inches) in diameter and are set back from the edges by approximately 1.05cm (0.413 inches). The apertures 44 are located in the four corners of the sheet 36 and are used for mounting the simulated tissue portion 36 onto the four posts 34 as shown. The simulated tissue portion 36 in the form of a sheet is approximately 1 to 10 mm thick for example. In another variation, the simulated tissue portion 36 that is formed in a sheet includes a textured upper surface and a smooth lower surface. The texturing can include protrusions or other realistic organ details. If desired, the user may flip the sheet such that the smooth surface is facing upwardly on the posts. The smooth surface may increase the difficulty in grasping and manipulating the simulated tissue portion with instruments. In another variation, the sheet of simulated tissue 36 includes several pre-cut paths and/or holes which forces the user to maintain tension on the simulated tissue portion drawing opposite sides of the hole or pre-cut path close together for suturing.

0018In use, a user will mount at least one simulated tissue portion 36 onto the posts 34. If the simulated tissue portion 36 includes preformed apertures 44 then mounting the simulated tissue portion 36 includes placing the apertures 44 over each post 34 and sliding the simulated tissue portion 36 to rest within one of the at least one notches 42 formed in the post 34. The simulated tissue portion 36 is mounted on all four posts 34. Fewer posts may be employed to suspend the simulated tissue portion 36. The notches 42 advantageously permit the entire sheet 36 to be mounted at an angle such that one side or at least one corner of the simulated tissue portion 36 is mounted on a higher or lower notch relative to the other corners and posts. For example, one side of the simulated tissue portion 36 is connected to two posts 34 by positioning the simulated tissue portion 36 along that first side to rest in notches 42a and the other side of the simulated tissue portion 36 is connected to two posts 34 by positioning the simulated tissue portion 36 along that second side to rest in notches 42c which are lower than notches 42a thereby angulating the simulated tissue portion 36. If the simulated tissue portion 36 is not provided with preformed apertures 44, the tapered distal ends 38 of the posts 34 can be used to puncture apertures 44 anywhere into the sheet 36. Hence, the tension in the simulated tissue portion 36 can be selected by the user when the user mounts the simulated tissue portion 36 onto the posts 34. For example, when the simulated tissue portion 36 is mounted by piercing an aperture 44 into the simulated tissue portion 36, it can then be selectively stretched making the simulated tissue portion 36 as tense or loose as the user wishes before piercing at least a second aperture 44 to mount the simulated tissue portion on another post 34 and so forth. The fabric reinforced silicone material prevents the aperture 44 from propagating. Multiple preformed apertures 44 can be included in the sheet 36 to provide different degrees of tension when the sheet is mounted using a specific set of preformed apertures 44. As the simulated tissue portion 36 in the form of a sheet is stretched over a post, it then snaps into place inside one of the notches 42. The posts 34 may include barbs, a shoulder or flange (not shown) extending outwardly from the outer surface to help retain the simulated tissue portion 36 in position together with or without notches 42. The posts 34 allow the user to set the sheet to different tensions to allow for different levels of difficulty as well as different angles to represent different structures or locations within the body.

0019<figref idref="f0003">FIG. 3</figref> shows a variation of the model 30 that includes more than four posts 34. In particular, there is a first or outer set of posts 34 and a second inner set of posts 46. There are four outer posts 34 and four inner posts 46 for a total of eight posts. The inner posts 46 are shorter relative to the outer posts 34. Both sets of posts are generally positioned in the four corners of the base 32 and adjacent to each other. Having two sets of posts allows greater variation or selectability in the tension or angles for mounting the simulated tissue portion 36. The second set of posts 46, like the first set of posts 34, includes notches 42 for positioning the simulated tissue portion 36. Although one notch 42 is shown in all of the posts 34, 46, the invention is not so limited and any number of notches at varying heights can be formed in the posts 34, 42. <figref idref="f0003">FIG. 3</figref> does not illustrate the simulated tissue portion 36.

0020Turning now to <figref idref="f0004">FIG. 4</figref>, there is shown a model 30 according to the present invention having two simulated tissue portions 36a, 36b mounted on the posts 34. As shown the simulated tissue portions 36a, 36b are formed as sheets but are not so limited and may include shapes that simulate organs and other tissue structures. A first simulated tissue portion 36a is mounted onto the posts 34 and placed into notches 42c and a second simulated tissue portion is shown mounted onto posts 34 and placed into notches 42a. Of course, the second sheet 36b can be placed into the same notches as the first sheet 36a or angled in any manner with respect to the first sheet 36a which may also be angled and placed in different notches. Placing the sheets 36a, 36b in the same notches creates a layered tissue that can be used to mimic muscle tissue as found in the abdominal region. The sheets of simulated tissue 36 can be any color and include markings and vascular structures drawn on the simulated tissue structure 36 to mimic real tissue structures. The multiple sheets may all be connected together and retained with adhesive selectively applied in selected areas between the sheets. Although, two sheets 36a, 36b are shown, the invention is not limited to the number of sheets that can be mounted on the posts 34. The posts 34 can be accordingly constructed to be longer and include more notches 42 to accommodate more sheets and a wider selection of angulations. <figref idref="f0004">FIG. 4</figref> illustrates a simulated tumor 48 located between the two sheets 36a, 36b. The tumor 48 can be attached to one or both of the layers 36a, 36b or not be attached. The clinician can practice making an incision in the second layer 36b to uncover the tumor 48, then practice excising the tumor 48 and then practice suturing the defect left behind in the first layer 36a if the tumor 48 was attached to the first layer 36a and then practice suturing the second layer 36b closed as well.

0021The model 30 is also suitable for use as a blunt dissection model. The simulated tissue sheet 36 for blunt dissection is made of silicone with no fabric reinforcement which allows the dissectors or trocars to puncture and separate the material. Multiple sheets may be layered together and attached together by means of silicone adhesive or thinner layers of silicone to allow for tissue dissections and separations of tissue planes.

0022The model 30 provides a realistic platform for presenting simulated tissue structures for training in a laparoscopic environment. As the clinician practices certain techniques such as cutting and suturing, the clinician will use certain instruments such as graspers, cutters, suture needles, sutures, laparoscopes, endoscopes, trocars and the like. When the simulated tissue structure that is supported on the posts in the model of the present invention is contacted with such instruments, the simulated tissue structure will give and flex under the force, deflecting a certain degree depending upon the tension with which it is mounted. This dynamism of the simulated tissue structure advantageously mimics real live tissue that gives way, moves and flexes upon manipulation in real life. Also, cutting and suturing feels differently when performed on simulated tissue structure that is suspended, that is in tension and that allows for a certain amount of deflection. These simulation advantages are provided by the model 30 of the present invention and are particularly useful when practicing laparoscopic surgical techniques that allow the user to fine tune depth perception and tissue manipulation skills while suturing, cutting and puncturing in a simulated laparoscopic environment.

0023While certain embodiments have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the following claims.