Patent Publication Number: US-2020279510-A1

Title: Systems and methods for simulating surgical procedures

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     None. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH &amp; DEVELOPMENT 
     None. 
     FIELD OF THE INVENTION 
     The invention relates to systems for simulating surgical procedures and methods of performing the surgical procedures on the systems. 
     BACKGROUND OF THE INVENTION 
     The teaching and practice of surgical procedures on live patients can be risky for many reasons. One such reason is that components of the body may be subject to harmful contact by an instrument in use by a physician, veterinarian, student, nurse, or other health professional when performing the surgical procedure. To reduce harmful contact to bodily components, it would be desirable to have systems that allow health professionals to teach and practice surgical procedures prior to operating on a live patient. In particular, it would be highly desirable to have systems for simulating surgical procedures that are capable of informing users when sensitive bodily components have been contacted or have been contacted in a harmful manner with an instrument. 
     SUMMARY OF THE INVENTION 
     The present invention comprises systems for simulating surgical procedures with an instrument. The systems have a first material for manipulation with the instrument and a second material extending through the first material, wherein the second material is electrically conductive. The present invention also comprises methods for simulating a surgical procedure. The methods include manipulating a first material, and contacting a surgical instrument with a second material, the second material extending within the first material, the surgical instrument and the second material being components of an electrical circuit. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a front view of a system according to the invention. 
         FIG. 2  shows a front view of a model of a system according to the invention. 
         FIG. 3  shows a front view of a component of the model of  FIG. 2 . 
         FIG. 4  shows a flow chart of a method for making a model for a system according to the invention. 
         FIG. 5  shows a view of components used to make a model according to the flow chart of  FIG. 4 . 
         FIG. 6  shows a flow chart of a method for using a system according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiment shown in  FIG. 1  is a system  100  comprising a model  101  in the shape of a portion of the human head and neck. System  100  is used to simulate surgery on a patient, and in this case, to simulate parotid surgery on a patient. System  101  is in use. In other words, model  101  of system  100  has been cut and opened by a user of system  100  who is practicing parotid surgery. In alternative embodiments, the system can be used to practice a wide range of surgeries on human or animal patients. 
     Model  101  includes a first region  110  that is made of a soft material. In this embodiment, the soft material of first region  110  is silicone based and non-conductive. In alternative embodiments, first region  110  may be made from latex, acrylic, or another material. First region  110  represents the skin and flesh of a patient undergoing parotid surgery. In some embodiments, one or more physical characteristics of first region  110  are set to simulate physical characteristics of the skin and flesh of a patient. For example, the density of the soft material of first region  110  may be set at or near the density of flesh. In this embodiment, the color of the soft material of the first region  110  is tan. 
     Model  101  of  FIG. 1  is in use. In  FIG. 1 , first region  110  has been opened along line  110   a , and flap  110   b  of first region  110  has been pulled open. 
     Model  101  includes a second region  120  that is made of a soft material. In this embodiment, the soft material of second region  120  is also silicone based and non-conductive. In alternative embodiments, second region  120  may be made from latex, acrylic, or another material. Second region  120  represents the parotid gland of a patient undergoing parotid surgery. In alternative embodiments, second region  120  may represent the thyroid gland, cervical lymph nodes, cystic neck masses, or another bodily component. In some embodiments, one or more physical characteristics of second region  120  are set to simulate the physical characteristics of the parotid gland of a patient. The color and/or one or more physical characteristics of the soft material of second region  120  may be different from those of the soft material of first region  110  so that the regions can be easily differentiated by a user of system  100 . In this embodiment, the density of the soft material of second region  120  is less than the density of the soft material of first region  110 , and the color of the soft material of the second region  120  is yellow. 
     Model  101  of  FIG. 1  is in use. In  FIG. 1 , second region  120  has been opened along line  120   a , and flap  120   b  of second region  120  has been pulled open. In this embodiment, first region  110  and second region  120  adhere to one another such that flap  110   b  of first region  110  and flap  120   b  of second region  120  generally move together. Flap  120   a  and flap  120   b  may be held open by a surgical retractor, Lone Star® Hook, or another instrument during the simulated surgery. 
     Model  101  includes a third region  130 . In this embodiment, third region  130  is soft and silicone based. Third region  130  represents a tumor of a patient undergoing parotid surgery. In some embodiments, one or more physical characteristics of third region  130  are set to simulate the physical characteristics of a tumor in a patient. The color and/or other physical characteristics of the material of third region  130  may be different form those of the soft material of second region  120  so that the regions can be easily differentiated. In this embodiment, the density of the material of third region  130  is substantially the same as the density of the soft material of the first region  110 . The material of third region  130  is blue. In some embodiments, one or more physical characteristics of the material of third region  130  may be chosen so that third region  130  can be palpated through first region  110  and second region  120 . For example, the material of third region  130  may be denser than the soft material of first region  110  and the soft material of second region  120 . 
     Model  101  includes a conductive material  140  that extends through first region  110  and second region  120  to an electrode  155 . In this embodiment, the conductive material  140  comprises a partially braided metallic wire. Conductive material  140  is braided at end  140   a  (which extends through first region  110  to electrode  155 ) and unbraided at ends  140   b ,  140   c ,  140   d ,  140   e , and  140   f . Conductive material  140  is made from five strands of 15 cm long 24-gauge bare copper wire. At end  140   a , conductive material  140  comprises branded strands of wire. Ends  140   b ,  140   c ,  140   d ,  140   e , and  140   f  comprise the unbraided strands of the branded strands of wire at end  140   a . Conductive material  140  represents the facial nerve of a patient. In alternative embodiments, conductive material  140  may represent the recurrent laryngeal nerve, vagus nerve, spinal accessory nerve, jugular vein and/or tributaries, carotid artery and/or tributaries, or another bodily component. As explained below, system  100  is configured so that when a user of system  100  contacts conductive material  140  with an instrument, such as a surgical blade or knife, dissection forceps, pickup forceps, tissue scissors, or other instrument, alarm  152  is activated. 
     In model  101 , conductive material  140  is coated with a non-conductive material  145  (shown in  FIG. 3 ), such as a wax or non-conductive polymer. The use of non-conductive material  145  to coat conductive material  140  allows the user of system  100  to put some pressure on conductive material  140 , through non-conductive material  145 , without resulting in activation of alarm  152 . In this way, system  100  can be used to simulate surgeries where, for example, organic material must be peeled away from the nerve without severing or damaging the nerve. One or more physical characteristics of non-conductive material  145  may be chosen to prevent direct contact between an instrument of the user of system  100  and conductive material  140 , and thereby activation of alarm  152 , up to a threshold. Conductive material  140  need not be coated with a non-conductive material over its entirety but may be coated only where the user is likely to contact it with an instrument. Model  101  also includes a gauge  190  on the surface of first region  110 . In this embodiment, gauge  190  is attached to conductive material  140 . Gauge  190  measures tension in or pressure exerted on conductive material  140  and will signal the user of model  101  if tension above a certain threshold is measured on conductive material  140 . In alternative embodiments, model  101  need not include a conductive material  140  with non-conductive coating  145  or a gauge  190 . Importantly, embodiments where conductive material  140  is not coated with a non-conductive material can also be used to simulate surgeries where, for example, organic material must be peeled away from the nerve without severing or damage the nerve. In these embodiments, the system simply alerts the user that contact has been made with the simulated organic component and that the user should proceed cautiously. 
     Model  101  of system  100  also includes simulated blood vessels  160  in first region  110  and second region  120 . The simulated blood vessels in model  101  are red. 
     Model  101  includes electrode  155  that is in electrical communication with conductive material  140 . In model  101 , electrode  155  lies on the surface of first region  110 . In alternative embodiments, electrode  155  may lie underneath the first region  110 . In model  101 , electrode  155  is in electrical communication with first terminal  158  of battery  151  on component  150  via wire  153 . Component  150  also includes alarm  152 . In this embodiment, alarm  152  includes a light  156  for generating a visual signal and a buzzer  157  for generating an audio signal. Alarm  152  is in electrical connection with second terminal  159  of battery  151  via wire  154 . In alternative embodiments, a power source other than a battery may be used. 
       FIG. 1  also includes tissue scissors  170  for use on model  101 . Tissue scissors  170  are in electrical communication with alarm  152  via wire  171  and alligator clip  172 . In this embodiment, tissue scissors  170  are also electrically conductive. When tissue scissors  170  contact conductive material  140  the electrical circuit with battery  151  and alarm  152  is completed and light  156  and buzzer  157  are activated. In this embodiment, light  156  and buzzer  157  are deactivated when tissue scissors  170  lose contact with conductive material  140 . In alternative embodiments, one or more of battery  151 , light  156 , and buzzer  157  may be located inside or on top of model  101 . In still further embodiments, system  100  may record user contact with conductive material  140  with or without generating an alarm. 
       FIG. 1  also includes surgical knife  180  for use on model  101 . Surgical knife  180  is in electrical communication with alarm  152  via wire  181  and alligator clip  182 . In this embodiment, surgical knife  180  is electrically conductive. When surgical knife  180  contacts conductive material  140  the electrical circuit with battery  151  and alarm  152  is completed and light  156  and buzzer  157  are activated. In this embodiment, light  156  and buzzer  157  are deactivated when surgical knife  180  loses contact with conductive material  140 . In this embodiment, surgical knife  180  and tissue scissors  170  are both in electrical communication with battery  151  and alarm  152  to facilitate an efficient surgical simulation and to prevent a user of system  100  from having to stop and connect a new instrument to the battery  151  each time the user wishes to use a new instrument on model  101 . In alternative embodiments, more than two instruments may be connected to battery  151  and alarm  152  at one time. 
       FIG. 2  shows model  101  prior to use for simulation of parotid surgery. First region  110  of model  101  has not been opened, and second region  140  is not visible from this view. 
       FIG. 3  shows a front view of conductive material  140 . 
       FIG. 4  shows a flow chart  200  for a method for making a model for use in a system. In this embodiment, step  210  includes making a first mold from a mixture of Alja-Safe® Acrobat® powder and water. The first mold is used to make a first component of the model. In alternative embodiments, the first mold is made from a 3-D printer. 
     At step  220 , the first component is made using the first mold of step  210 . In this embodiment, the first component is made by mixing approximately 15 ml of Dragon Skin® part A, 15 ml of Dragon Skin® part B, 80 ml of Slacker®, 0.25 ml of yellow pigment, and 0.15 skin tone pigment and pouring the mixture into the first mold. The first component will represent a gland in a patent in the finished model. 
     At step  221 , a conductive material is formed by partially braiding 5 strands of wire. All five strands are braided at one end of the conductive material and all 5 strands remain unbraided at the other ends of the conductive material. 
     At step  225 , before the mixture of the first component of step  220  has cured, a second component and the conductive material are placed within the mixture. The second component may represent a tumor or other object that is to be removed from the first component of the model by a user of the model. The conductive material may represent an object, such as a nerve, that is subject to damage during the surgery to be simulated on the model. In this embodiment, the conductive material extends outside of the first component. In this embodiment, the conductive material is not coated. In alternative embodiments, the conductive material may be coated with a non-conductive material that allows a user simulating surgery with the model to apply pressure, up to a threshold, to the conductive material through the non-conductive material with an instrument without directly conducting the conductive material. 
     At step  230 , the first component is allowed to cure for approximately one hour. At step  235 , the first component is removed from the first mold. 
     At step  240 , a second mold is made from a mixture of Alja-Safe® Acrobat® power and water. The second mold is used to make a third component of the model. In alternative embodiments, the second mold is made from a 3-D printer. 
     At step  250 , the third component is made using the second mold of step  240 . The third component is made by mixing 250 ml of Dragon Skin® part A, 250 ml of Drag Skin® part B, 80 ml of Slacker®, 3 ml of THI-VEX®, and 3 ml of skin tone flesh pigment and pouring the mixture into the second mold and on top of the cured first component. The third component will represent the skin and flesh of a patient in the finished model. 
     At step  255 , before the mixture of step  250  has cured, the conductive material extending outside of cured first component is arranged in the third component to represent an object, such as a nerve, that is subject to damage during the surgery to be simulated on the model. In this embodiment, one end of the conductive material extends outside of the third component. 
     At step  260 , the third component is allowed to cure for approximately one hour. At step  265 , the first component, second component, third component, and conductive material are removed from the second mold. 
       FIG. 5  shows partial model  300 . Partial model  300  comprises first component  310 , second component  320 , and conductive material  330 . Also visible is first mold  340  after first component  310  has been removed from the first mold  340  in step  235  of flow chart  200 . The conductive material  330  includes braided end  330   a , which comprises five braided strands of wire, and unbraided ends  330   b ,  330   c ,  330   d ,  330   e , and  330   f , which each comprise one strand of the strands of braided end  330   a.    
       FIG. 6  shows a flowchart  400  for simulating a surgery with a system. In this embodiment, step  410  comprises cutting a first material of a model, the first material being soft and silicone-based. 
     Step  420  comprises contacting a surgical instrument with a second material that extends through the first material, the contact resulting in the second material and the surgical instrument forming an electrical circuit with an alarm and a battery, the contact also resulting in the alarm generating a signal. 
     Step  430  comprises removing a third material from the first material.