Resistance-free trocar assembly

Abstract

The trocar assembly comprises a head, a long tubular structure having an open distal end and an open proximal end, a fixed cutting component combining a large cutter with two sharp lateral blades and a centrally located non-cutting soft end extending through the open distal end of the tubular structure, and a movable cutter safety case configured to extend through the open distal end of the tubular structure to cover the fixed cutting component and to retract from the open distal end to expose the fixed cutting component. When pressure is applied proximal to the cutter safety case, a large incision is formed in the fascia, the abdominal wall is penetrated, the reaction pressure from the abdominal wall is released, and the body cavity is safely reached.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims priority based on U.S. Provisional Patent Application No. 63 / 472,238, filed on June 9, 2023, and the entire disclosure of U.S. Provisional Patent Application No. 63 / 472,238 is incorporated herein by reference.

[0002] This disclosure generally relates to surgical instruments, and more particularly to a trocar assembly as a surgical instrument and a method of using a trocar assembly for piercing body tissue to form a conduit for inserting other medical instruments.

Background Art

[0003] The performance of laparoscopic surgery (minimally invasive surgery) in various fields of medicine has become more widespread and popular as a surgical technique. Laparoscopic surgery offers many advantages over traditional open surgery. Laparoscopic surgery is relatively precise and tends to cause less tissue damage and scarring. Laparoscopic surgery has a shorter hospital stay, less postoperative pain and discomfort, and requires less medication to relieve pain. Laparoscopic surgery causes less trauma to the patient and is more cost - effective for both the patient and the insurance company.

[0004] Trocars and Veress needles are used in minimally invasive surgery to form a path or conduit for accessing the abdominal cavity in the patient's abdominal wall. When a trocar is deployed to incise the patient's abdominal wall, the trocar is combined with a cannula to form an access port to the abdominal cavity. Thereafter, for example, to insert other medical instruments such as an endoscope, a camera, a fiber optic light, a suture needle driver, a laparoscope, an intestinal grasper, and a surgical mesh, the trocar is removed and the cannula is left behind.

[0005] However, the use of conventional trocars, such as "shield trocars," causes 75,000 complications annually in the United States alone, involving trocar-related damage to internal organs, some of which are fatal. As a result, safer alternatives to conventional trocar assemblies and methods of use are needed to create conduits into the patient's abdominal cavity.

[0006] For example, when a trocar is used to enter a body cavity and form a port via cannula insertion, the malfunctioning "safety shield" of currently available "shielded trocars" cannot completely prevent damage to vital organs by the cutter. This is because the "safety shield" is large and cannot penetrate the small opening made by a small cutter, and therefore cannot cover the sharp tip of the cutter when it enters the abdominal cavity.

[0007] The primary cause of "overshoot" events and resulting complications is the resistance of the fascia or any other body tissue against the force applied to the proximal end of any trocar. Currently, operators are increasing the proximal force, resulting in "overshoot" events and the complications reported in the literature. To reduce the fascial resistance to the proximal force, it is necessary to make larger incisions in the fascia to reduce fascial resistance, which allows for smoother and safer penetration of the abdominal wall.

[0008] According to the laws of physics, a cutter with a small tip will create a small incision in the fascia. Therefore, by the same law, a protective mechanism with a larger diameter will remain above the fascia until more pressure is applied to the proximal end of the trocar. Following this law, almost all "shielded trocars" may allow the cutter to initially penetrate the body cavity without protection. Fortunately, however, it should be noted that this has not resulted in the complete (100%) failure of these trocars. However, it should also be noted that this results in 75,000 complications per year in the United States alone, endangering patients' health and lives, and that the design of the "shielded trocar" is largely responsible for these dangerous complications because its dysfunctional "safety shield" does not provide protection to vital organs, allowing the cutter to initially penetrate the fascia without the "safety shield." For example, some trocars offer special tips that claim to allow for better or easier incision of the fascia. In reality, they have been demonstrated to fail to achieve the safe "penetration" that is expected. In fact, "overshoot" is a defect of all trocars that do not have a cutter or protective mechanism similar to those disclosed herein.

[0009] This disclosure suggests that the reason the "shielded trocar" prevents complete failure is that air (CO2 gas) flows into the body cavity, providing a protective layer of air cushion between the sharp cutter and vital organs.

[0010] The following references support the significant shortcomings of shielded trocars and trocars with small cutters. Numerous medical studies analyzing the safety of trocars of various structures, particularly shielded trocars, acknowledge the risks and inadequacies of existing trocars. These analyses conclude that, although shielded trocars have been used to reduce intrusion injury, "there is no evidence that shielded trocars reduce visceral and vascular injury in laparoscopic access."

[0011] (1) In his masterclass paper entitled “Safe Laparoscopic Abdominal Invasion,” published in the April 2022 issue of Ob.Gyn. News (Vol. 57, No. 3), Dr. Charles E. Miller provides compelling testimony that no design changes have been made to improve the safety of the trocar. He cites Dr. Javier F. Maglina's declaration that “50% of damage to the gastrointestinal tract and major blood vessels occurs at invasion,” and that “in a study of 1,500 gynecological patients, approximately 20% to 25% of complications were not recognized until the postoperative period.” In his important and very recent paper, Dr. Miller states that “the use of shielded trocars has not been shown to reduce invasion damage, i.e., it has not been shown to reduce visceral or vascular damage.”

[0012] (2) According to a recent article titled "A New Device for Safe Trocar Insertion in Laparoscopic Surgery Based on Insertion Force Characteristics," published in the International Journal of Bioscience, Biochemistry and Bioinformatics (Vol. 9, No. 1) in January 2019, approximately 75,000 trocar insertion complications occur annually in the United States.

[0013] (3) An FDA report titled "Laparoscopic Trocar Injury: A Report by the Systematic Technical Assessment of Medical Products (STAMP) Committee of the Center for Medical Devices and Radiological Health (CDRH) of the U.S. Food and Drug Administration (FDA): FDA Safety Communication" supports the problems and risks of shielded trocars. This "communication" proves the problems and risks of shielded trocars. The report was last updated in 2014, indicating that its assessment remains valid.

[0014] (4) According to the FDA, "In 1984, a trocar with a retractable shield that covers the tip before and after insertion was introduced to protect abdominal and pelvic organs from accidental puncture. Whether shielded trocars provide protection against injury is a matter of debate. A 1996 study involving the use of 386,784 trocars found that 10 of 26 serious injuries (39%) and 2 of 7 deaths (29%) were associated with shielded trocars. In 1996, based on insufficient data to support safety claims, the FDA asked manufacturers to refrain from using the term "safe trocar" to refer to shielded trocars."

[0015] The FDA stated that it has received frequent reports of trocars and trocar components being damaged, sometimes in connection with patient lacerations and fragments of the device left in patients. The FDA also believes that the debate on the effectiveness of trocars classified as "shielded, optical, and radially expanding designs" will continue because fail-safe mechanisms do not adequately prevent trocar-related damage. In addition, the FDA assesses that, along with other reasons, "the lack of proven fail-safe mechanisms may also be contributing to increased morbidity and mortality."

[0016] The FDA has further suggested that the Trocar's "design" needs to be improved in order to make it safe.

[0017] (5) The Emergency Medical Research Institute (ECRI), considered the most trusted laboratory for medical product testing in the United States, stated in its report "Trocar: Safety and Selection, 1998;27:376-98.[PubMed:9859030]" that while shielded trocars were intended to prevent the sharp tip from damaging the contents of the abdominal cavity, even when the shielded trocar functions correctly and is used according to specifications, there is a short period of time when the sharp trocar tip is exposed and vulnerable upon entry into the abdominal cavity. ECRI concluded that "this shield may create a false sense of security and lead to over-reliance on it."

[0018] Given the aforementioned shortcomings experienced with conventional trocars, improvements to the trocar design have been urgently needed for many years. It should be noted that, for many years, no inventor or researcher has been able to solve this extremely serious problem in the medical field, and that it urgently needs to be improved to save lives. [Overview of the Initiative]

[0019] In contrast to the aforementioned shortcomings experienced with conventional trocars, the improvements devised herein do not rely on any "hit or miss" artificial protection, as disclosed herein. The disclosed large cutter, the respective slits at the distal end of the trocar, the cutter safety case, and the cannula work together to provide unquestionable safety. In this, the automatic retraction function of the compression spring forces the cutter back to its original non-cutting position immediately after the large cutter has made a sufficiently large incision in the fascia, thereby retracting the cutter safety case and allowing the trocar and cannula to safely and easily enter the open cavity.

[0020] Previous modifications of the trocar in various embodiments by the prior inventors are disclosed in U.S. Patents 8,523,817, 8,838,206, 9,579,472, and 10,646,250, which are referenced herein.

[0021] Applying the design modifications described herein to the corresponding distal components of a "shielded trocar," a "non-traumatic blunt-end trocar," or any other trocar can significantly reduce the need to apply excessive pressure to the proximal end of the trocar, thereby improving safety. More importantly, the disclosed modifications do not give surgeons a false sense of security.

[0022] The modifications disclosed herein, which involve enlarging the cutter to create a larger fascial incision and allowing a redesigned cutter safety case to enter the abdominal cavity prior to or together with the cutter, are truly novel and innovative ideas. These modifications have the potential to improve the coordinated mechanical function of the cutter and protective mechanisms of all existing trocars in order to control "overshoot" events and make trocars safer.

[0023] As mentioned above, the main cause of "overshoot" is the reaction of the force applied to the proximal end of any trocar due to resistance from fascia or other body tissues. To counteract the fascial resistance to the force applied proximal, it is important that the trocar's cutter creates a larger opening in the resistant body tissues of the abdominal wall, such as fascia, and that the cutter safety case can enter the body cavity without resistance or difficulty from the tissues involved. This can be achieved by redesigning the distal end of the trocar, the cutter, the cutter safety case, and the auxiliary cannula.

[0024] Therefore, the present disclosure relates to modifications to make the cutter larger and to modify the distal end of the trocar, the cutter safety case, and the distal end of the auxiliary cannula to include two lateral slits that are diametrically opposed with 180 degrees of separation therebetween. Further, three different sets of slits are disclosed that provide unobstructed vertical passages that are precisely aligned so that the cutter can pass easily and safely through the components that communicate cooperatively therewith, forming a large incision in the fascia while remaining within the protective guard of the cutter safety case and then returning to the non-incision mode without contacting any vital organs.

[0025] Furthermore, different configurations of the cutter safety case embodiments devised herein are disclosed herein that each incorporate the diametrically opposed slits described above.

[0026] Therefore, the main purpose of the above innovative and unique modifications to the distal end of the trocar, the enlarged cutter of the fixed incision component, the cutter safety case, and the distal end of the cannula is to significantly reduce the pressure required at the proximal end of the trocar and eliminate dangerous "overshooting" events.

[0027] The above object is achieved because the lateral slits of the cutter safety case disclosed herein accommodate a large cutter housed therein, and the soft tip 138 of the cutter can easily protrude from its distal end. Also, the fixed incision component includes a large cutter having two sharp cutting edges at its lateral ends and an elongated strut (rod) terminating in the soft tip 138, and can protrude from the cooperatively aligned lateral slits of the cutter safety case, the trocar, and the cannula, so that the three sets of slits form a continuous, accurate, and unobstructed vertical path, allowing the large cutter to incise the fascia and return to the original non-incision mode without damaging any organs.

[0028] It is proposed that other advantages can be achieved by the inventor's design improvements to existing trocars disclosed herein. It is common medical device manufacturing practice to tapere the distal end of a cannula so that the cannula can access the abdominal cavity when the trocar cuts through the fascia and penetrates the incision at the surgical site. The tapering is necessary because existing trocars form a small incision in the fascia. By tapering, the cannula has a distal end that is weaker than the rest of its tubular shaft. It has been reported that the distal end of the cannula occasionally breaks off when the cannula is being handled while carrying other medical devices during use, for example, by fragments falling into the abdominal cavity.

[0029] Two features of this disclosure compensate for this drawback. Namely, the large incision on the fascia formed by the large cutter is larger than the distal end of the trocar, forming an easily accessible pathway; and the proposed diametrically opposed slits eliminate the need to tapere the distal end of the cannula, thereby eliminating the possibility of the device chipping or breaking during laparoscopic surgery.

[0030] One embodiment of the present disclosure provides a trocar assembly, the trocar assembly including a head disposed at the proximal end of the trocar assembly, an open distal end, an open proximal end, and a partial partition wall located between the open distal end and the open proximal end, defining a distal section and a proximal section respectively, the partial partition wall covering a part of the cross-section of the shaft and leaving an opening for a lumen extending from the open distal end to the open proximal end, a shaft configured to extend distally from the head, an incision component including a tang and a knife blade, the tang being fixed at a position on the distal side of the partial partition wall such that the incision component is fixed to the shaft, the knife blade having two lateral incision ends extending through the open distal end of the shaft at the distal end of the trocar assembly, a retractable protective assembly configured to be either in an extended or a contracted state through the open distal end of the shaft, the retractable protective assembly being configured to extend through the open distal end of the shaft and cover the fixed incision component in a natural biasing position, the retractable protective assembly being configured to contract from the open distal end of the shaft and expose the fixed incision component in a compressed position while pressure is applied in a proximal direction along the longitudinal axis of the retractable protective assembly, the retractable protective assembly including a movable cutter safety case configured to house the knife blade and be coupled to the partial partition wall via a biasing element fixedly attached to the partial partition wall, the cutter safety case including a central opening at its proximal end and two diametrically opposed lateral slits having a 180-degree separation at its distal end, the shaft including two slits aligned corresponding to its distal end, the incision component, the cutter safety case, and the shaft being nested together in a natural biasing position, and the knife blade being able to protrude from the aligned slits of the cutter safety case and the open distal end of the shaft in a compressed position.

Brief Description of the Drawings

[0031] [Figure 1] Shows a trocar assembly according to an embodiment of the present disclosure. [Figure 2A]A shrinkable protective assembly in a deflated state according to one embodiment of the present disclosure is shown. [Figure 2B] An extended and retractable protective assembly according to one embodiment of the present disclosure is shown. [Figure 3] An incision component according to another embodiment of the present disclosure is shown. [Figure 4] A retractable protective assembly according to one embodiment of the present disclosure is shown. [Figure 5] The distal portion of a trocar shaft according to one embodiment of the present disclosure is shown. [Modes for carrying out the invention]

[0032] The description of exemplary embodiments in accordance with the principles of this disclosure is intended to be read in conjunction with the accompanying drawings and should be considered as part of the entire description. Any reference to direction or orientation in the description of embodiments disclosed herein is intended solely for explanatory convenience and is not intended to limit the scope of this disclosure in any way. Relative terms such as “down,” “up,” “horizontal,” “vertical,” “upward,” “downward,” “up,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the orientation described or the orientation shown in the drawings discussed. These relative terms are for explanatory convenience only and do not require that the device be constructed or operated in a particular orientation unless expressly indicated as such. “Mounted,” “fixed,” “connected,” “joined,” “interconnected,” and similar terms refer to a relationship in which structures are fixed or attached to one another, directly or indirectly through intervening structures, and include both movable and rigid attachments unless expressly otherwise described. Furthermore, the features and advantages of this disclosure are shown by reference to the exemplary embodiments. Therefore, this disclosure should not be limited to such exemplary embodiments illustrating possible combinations of some non-limiting features, which may exist individually or in combination with other features; the scope of this disclosure is defined by the claims appended herein.

[0033] This disclosure describes one or more of the best possible ways of carrying out the disclosure as currently conceivable. This description is not intended to be understood restrictively, and provides examples of the disclosure presented solely for illustrative purposes to inform those skilled in the art of the merits and structure of the disclosure, with reference to the accompanying drawings. In the various drawings, identical or similar parts are denoted by the same reference numerals.

[0034] It is important to note that the disclosed embodiments are merely examples of many advantageous uses of the innovative teachings herein. In general, the descriptions contained herein do not necessarily limit any of the requested disclosures. Furthermore, some descriptions may apply to certain inventive features but not to others. In general, unless otherwise indicated, elements described in the singular form include the plural form and vice versa without loss of generality.

[0035] As stated above, the novel and innovative improvements described herein relate to and follow Sir Isaac Newton's third law of physics, which states that "for every action (force) in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A."

[0036] Therefore, when pressure is applied to the proximal end of the trocar to cut the fascia, the same amount of force is received at the distal end of the trocar, generating a reaction pressure from the body tissue. At this point, the trocar operator needs to apply further pressure to the proximal end of the trocar so that the cutting edge cuts through the abdominal wall during the "initial entry," resulting in an equal reaction force at the distal end, which is received at the proximal end. At this stage, the operator may have lost most of their control over the device. Because the small cutting edge only forms a small incision in the fascia, the protective mechanism with a larger diameter cannot enter the opening before the cutting edge and gets stuck on the fascia, and since the cutting edge has already entered the open body cavity, this results in the occurrence of an event known worldwide as "overshooting." This is a fact of the physical law known as "direct response or relationship," where "variables increase or decrease together."

[0037] Accordingly, this disclosure focuses on improvements to the distal structure of the trocar and its key internal components, proposing to redesign the cutter to a larger size to form a larger incision in the fascia; to redesign the cutter safety case to protect the sharp cutting edge during penetration by housing the larger cutter and including the narrow, extreme distal end in the cutter safety case; to redesign the open distal end of the trocar to house the larger cutter and cutter safety case; and to redesign the open distal end of the cannula accompanying the trocar to accommodate the combined diameter of all the above components. These complementary corresponding improvements aim to bring about a significant improvement in patient safety by eliminating or at least reducing the fascial resistance to the trocar to a negligible level.

[0038] To use the apparatus of this disclosure, as shown in Figure 1, the distal end of the trocar assembly is positioned relative to the skin layer 300, and the inferiorly located fascial diaphragm 304 is positioned between the muscle 302 and the peritoneum 306 covering the abdominal cavity.

[0039] Common trocar components, including all embodiments of the resistance-free trocar assembly of this disclosure, are briefly disclosed herein. Referring to Figure 1, the disclosed trocar assembly 100 includes a cylindrical head (handle) 102 extending horizontally at its proximal open end 220 and an elongated tubular structure (shaft) 106 at its open distal end 108. The head is configured to be subjected to pressure during deployment of the trocar for incising a surgical site. The head (handle) is further configured to allow for the placement or attachment of any necessary auxiliary components of a general trocar, and in particular of the disclosed trocar. Thus, the disclosed embodiments further assume proximal interfaces for the trocar and a cannula. The proximal cannula interface functions as an air supply port 181 for supplying CO2 gas into a body cavity and is located directly below the head (handle) of the trocar assembly. Another proximal trocar interface 182 functions as a port for the trocar when it is used independently for drainage purposes or other medical applications. In one embodiment, valve 181 is located at the proximal end of the cannula shaft to prevent CO2 leakage. In another embodiment, port 182 is connected to the proximal end of the trocar and penetrates the outer wall of the trocar into the lumen of the trocar. This port is used for the discharge of fluids and gases from the body cavity. Port 182 penetrates the interior of the trocar and connects to a drainage medium.

[0040] Therefore, it is disclosed that the cutting component of the trocar assembly will be further redesigned to form a larger intended incision in the fascia by focusing on improvements to the main distal component responsible for safely cutting the fascia during the “initial incision,” and by enlarging the cutting blade so that it can protrude through the lateral slits 161, 162 of the movable cutter safety case as shown in Figure 4. As shown in Figures 2A and 2B, the cutter 110 is fixed and located within the cutter safety case 123, and switching from non-cutting mode to cutting mode and vice versa depends on the movement of the cutter safety case.

[0041] The movable cutter safety case 123 has a vertical movement that is actuated and controlled by the expansion and contraction of the compression spring 124, and is moved to immediately follow and cover the large cutter at the moment the large cutter cuts through the fascia and enters the body cavity. Therefore, once the fascia is cut and the body cavity is entered, the large cutter and the cutter safety case immediately return to the non-cutting safety mode and retract to their original positions.

[0042] This specification discloses that the proximal end of the compression spring 124 is fixed, while the distal end of the compression spring is positioned in close contact with the proximal end of the cutter safety case. In such an arrangement, the compression spring cannot move laterally or be unintentionally dislodged. However, the compression spring is essentially configured to expand and contract vertically when induced (struck).

[0043] This specification discloses that in one embodiment, the cutting component 110 includes a long vertical arm (tongue) 152 and a knife blade 150. The long vertical arm (post) of the fixed cutting component 110 includes a rod having a large cutter at its tip, which includes a soft tip 138 located at the distal end of the cutter safety case 123. The sharp lateral cutting edges 134, 136 of the large cutter are formed by short segments of the cutting component rod adjacent to the non-cutting soft tip 138, so that in functional mode, the sharp lateral cutting edges protrude through the lateral slits 161, 162 of the cutter safety case.

[0044] The disclosed fixed incision component 110, compression spring 124, and cutter safety case 123 are integrated and positioned within the inner shaft of the trocar, and the nested (integrated) components and the trocar are slidably positioned within the lumen of the cannula and move smoothly without any apparent gaps or friction.

[0045] It is further disclosed that the fixed incision component is fixed to the inner wall of the trocar at the end of a long arm positioned at an appropriate distance from the distal end of the trocar. In some embodiments, the fixed incision component is fixed to a partial partition wall, which serves two functions: providing an anchor point for the incision component and providing a lumen extending from the proximal to the distal end of the trocar. To provide a larger contact surface between the long arm (tongue) of the incision component and the anchor point in the inner wall, in some embodiments the end of the long arm may have a short horizontal extension, and the long arm may have an inverted L-shaped end. The short horizontal extension provides a larger contact area when fused with the inner wall.

[0046] A compression spring 124 is attached to the long vertical arm (tongue) 152 of the fixed incision component, extending distally through a small, appropriately sized central opening at the proximal end of the cutter safety case. Thus, it is further disclosed that the cutter safety case has an open proximal end and an open distal end, and the long vertical arm (post) of the incision component extends through its internal space and can protrude slightly to incise the fascia.

[0047] Upon initial contact with the fascia, the soft tip of the distal end of the exposed large cutter does not cause harm or injury because it cannot cut or penetrate the fascia. However, this soft tip "tents" the fascia upon contact, instantly gathering it towards the edge of the sharp cutting blade of the adjacent cutter. This "tent-like" shape allows the edge of the sharp cutting blade to cut a large opening in the fascia, achieving "safe entry." The pinched skin is pulled and lifted higher than the rest of the epidermis, and after release, it takes time to return to its flat position.

[0048] In one embodiment, the incision component is a structurally extruded horizontal planar bar and includes a partial partition wall 122 that forms an extension (partial partition wall) projecting from the inner wall of the tubular trocar toward the lumen in a restrictively limited range. The planar extension (partial partition wall) defines a partial diameter of the trocar. The opening left by the partial partition allows the lumen to extend from the open distal end to the open proximal end, and the partition further divides the lumen of the trocar into two sections, the proximal and distal ends. The planar extension (partial partition wall) 122 is positioned at an appropriate distance from the distal end of the trocar.

[0049] The planar extension (partial partition wall) 122 disclosed herein includes a long vertical stabilizing post and two short vertical posts fixedly attached to the inner wall of the trocar. One short vertically projecting post 120 is directed distally and positioned midway along the length of the extension (partial partition wall) 122. A second similarly configured short post defines and terminates the horizontal boundary of the planar extension (partial partition wall). The defined structure of the planar extension (partial partition wall) can be constructed of suitable medical-grade material such as plastic or metal.

[0050] This specification further discloses that the two short vertical posts 120 enclose a space defining the horizontal boundary of the housing for the compression spring and the large cutter, stabilizing and limiting any lateral movement of the components during deployment. Within the confines of this housing formed by the two short vertical posts 120 of the planar extension (partial partition wall), a compression spring 124 is fixed, positioned in close contact with the proximal end of the cutter safety case and capable of extending distally through a small, appropriately sized central opening at the proximal end of the cutter safety case. The compression spring 124 is essentially configured to expand and contract vertically when induced (compressed). The large cutter is positioned centrally within the cavity of the compression spring 124. The cutter 110 and the compression spring 124 are fixed at their proximal ends to the distal end of the planar extension (partial partition wall) 122, projecting downward toward the distal end of the trocar.

[0051] Therefore, the large cutter 110 provides a larger incision in the fascia, and the proposed cutter safety case allows the sharp edges of the cutter to enter the abdominal cavity before they come into contact with any vital organs such as the intestines and cause damage. Once the resistance of the fascia is removed, a compression spring automatically pulls the cutter back into the protective cover of the cutter safety case.

[0052] In fact, this disclosure proposes an older surgical method of safe open surgery (laparoscopy) for minimally invasive surgery (laparoscopic surgery). This disclosure proposes a novel structure of a devised cutter safety case that covers the edge of the sharp cutting edge of the cutter for safer and more effective operation.

[0053] The improvements to the safety features of the trocar disclosed herein include, in one embodiment, the design of a funnel-shaped cutter safety case, in another embodiment, the design of a triangular cutter safety case, and in yet another embodiment, the cutter safety case may be formed from two separate members, a front section and a rear section.

[0054] In two different shapes of cutter safety cases disclosed herein, namely a funnel-shaped cutter safety case and a triangular cutter safety case, the structure includes two lateral slits 161, 162 having similar features located on the sides, while the two-member cutter safety case embodiment includes two diametrically opposed lateral slits spaced 180 degrees apart by default. The diametrically opposed slits spaced 180 degrees apart are proposed herein to form an open distal end, where the cutter safety case becomes smaller at its distal end, the sharp outer edge of the side of the cutting edge of the large cutter can protrude outward through the diametrically opposed slits, and the large cutter and the cutter safety case cooperate to form a path for entry into the abdominal cavity, and the cutter safety case enters the body cavity directly in front of the large cutter.

[0055] The cutter safety case extends through the open distal end of the trocar 108, covering the large cutter in its naturally biased position. When body pressure is applied, it contracts from the open distal end, exposing the large cutter in its compressed position until it reaches the body cavity. Once it reaches the body cavity and the opposing pressure is removed, the cutter safety case returns to its naturally biased position.

[0056] In one embodiment, the cutter safety case can be designed and constructed from two separate members, a front section and a rear section, and can function with one or two springs fixedly attached to the proximal end of each member of the cutter safety case. This embodiment may have either a funnel-shaped or triangular cutter safety case, and the cutter safety case is formed from two sections, one front member and one rear member, which have two opposing slits embedded with a 180-degree spacing by default, and further have a narrower (smaller) diameter at their distal end.

[0057] Furthermore, this disclosure also discloses that the distal end of the trocar also includes two diametrically opposed slits 171, 172 spaced 180 degrees apart, as shown in Figure 5, which interact in cooperation with the lateral slits of the cutter safety case. Thus, the distally positioned trocar slits 171, 172 work together with the corresponding parallel slits 161, 162 of the distal end of the cutter safety case to form a continuous, precisely aligned, and unobstructed path for the large cutter to temporarily extend distally to cut the fascia.

[0058] This precisely designed structure allows the trocar to be pressed against the target tissue of the patient, and when minimal pressure is applied proximal to it, a compression spring activates the cutter safety case, allowing it to move downward along with the large cutter located inside. This allows the cutter safety case and large cutter to smoothly pass through a set of vertically aligned slits, forming a large incision in the fascia, and the trocar and cannula to enter the open abdominal cavity without any obstruction or damage to any vital organs. Once the fascia is safely incised, the compression spring immediately pulls the sharp cutting edges of the cutter safety case and the large cutter inside back to their original, safe, non-incisional positions.

[0059] The slits at the distal end of the cannula, trocar, and cutter safety case can accommodate lateral cutting blades of different sizes.

[0060] Therefore, the trocar assembly proposed in this disclosure has several unique advantages over existing devices. The lateral slits on opposite sides of the distal end of the movable cutter safety case that houses the blade allow a large cutter blade to be housed within its internal space (housing compartment). The effect of the unique double-sided slits is to eliminate or significantly reduce the "overshoot" phenomenon. • The large blade reduces the force required for the proximal end of the trocar to enter the body cavity, thus eliminating the need for the distal end of the trocar to engage with the fascia. By creating a large incision in the protective layer of the body cavity, potential trauma to vital organs can be eliminated or significantly reduced. Each of the trocar's cutter safety case and cannula shaft, which house the cutter, has a set of bilateral slits at their distal ends. These precisely designed bilateral slits work together and communicate with each other, allowing the large cutter to move easily and safely through the above elements, forming an unobstructed vertical passage (conduit) for creating a large incision in the fascia. During deployment, the large cutter remains within the protective cover of the cutter safety case. After cutting the fascia, it immediately returns to non-incisional mode without any contact with vital organs. - A horizontal partial partition wall, separation wall, or compartment wall that occupies a portion of the internal cavity of the trocar. The partial partition wall, separation wall, or compartment wall can be fixedly positioned on the inner wall of the device, leaving an open path from the proximal end to the distal end. Therefore, the proposed trocar can perform many related tasks and serve as a conduit for introducing other devices into body cavities. The movable cutter safety case, with slits on both sides and a large blade embedded inside, enters the body cavity without resistance and forms a larger opening for stent placement and insertion of other medical devices in cardiac and thoracic surgery and vascular surgery, etc. The vertically open lumen allows fluids and gases (CO2) to reach any distal target site through its internal cavity, and the operator can aspirate or inject drugs or other fluids into the body cavity through the proximal opening. The trocar's mechanical design allows its proximal and distal ends to communicate seamlessly with each other via an unobstructed vertical length in an open lumen. Therefore, the structure acts as an indicator of the device's location within the body cavity, providing the operator with an early warning signal. For example, if the device comes into contact with an artery, blood will flow upward, alerting the operator that the distal end of the trocar is in the wrong space and that immediate corrective action is required. Because the parts of the device are not separated into individually inaccessible proximal and distal ends, the partial partition walls, separation walls, or compartmental walls facilitate the removal of fragments from the “non-disposable” device and cleaning for subsequent use.

[0061] In one embodiment, the trocar assembly further includes a switch assembly 200. As shown in Figure 2A, the switch assembly 200 may include components located below or above a partial partition wall 122 attached to the inner wall of the shaft 106. The components may include, for example, an automatic switch 202 located below the partial partition wall 122, an electronic storage device such as a battery 204, and a lighting device 206. The automatic switch 202, the battery 204, and the lighting device 206 communicate electronically via one or more wires 208. The lighting device may include at least one light-emitting diode (LED). The battery 204 may be an alkaline coin cell or a battery pack.

[0062] The automatic switch 202 can be configured to be in a first position when the retractable protective assembly is in its naturally biased position. Furthermore, the automatic switch 202 can be configured to be in a second position when the retractable protective assembly is in the compressed position, and the movement of the retractable protective assembly is configured to affect the movement of the automatic switch 202. The first position is either ON or OFF, and the second position is the other of ON or OFF. The lighting device 206 is configured to be illuminated when the automatic switch 202 is ON and de-illuminated when the automatic switch 202 is OFF. Thus, the LED lights up (i.e., is illuminated) when the automatic switch 202 is ON and turns off (i.e., is de-illuminated) when the automatic switch 202 is OFF.

[0063] In one embodiment (not shown), the switch assembly may include a manual switch. The manual switch may be located on the outer surface of the head of the trocar assembly, similar to the trocar assembly 100 in Figure 1, except for the manual switch and additional secondary electronic storage. The manual switch may be connected to the additional secondary electronic storage through one or more wires (e.g., a single wire) that extend from the head 102 through the open proximal end of the shaft and through a lumen that proceeds through an opening in the shaft 106 defined by a partial partition wall of the shaft.

[0064] Therefore, the switch assembly of the trocar assembly includes a manual switch, an illumination device, and an electronic storage device including a battery and a secondary electronic storage device. The electronic storage device including the battery and secondary electronic storage device, and the illumination device are located within the shaft. The battery is located distally below the partial partition wall, and the secondary electronic storage device is located proximal above the partial partition wall. In a non-limiting example, the secondary electronic storage device includes an alkaline battery pack located proximal above the partial partition wall, and the illumination device 206 includes at least one light-emitting diode (LED) located below or above the partial partition wall. The manual switch, the electronic storage device, and the illumination device 206 communicate electronically via one or more wires.

[0065] The manual switch is configured to switch between ON and OFF states through manual pressing. The LED is configured to light up when the manual switch is ON and to remain off when the manual switch is OFF.

[0066] While this disclosure describes several embodiments with some length and specificity, it is not intended to limit itself to these specific examples or embodiments or any particular embodiment, but rather to provide the broadest possible interpretation considering the relevant art, and thus effectively encompasses the various embodiments described herein. Furthermore, while the foregoing describes various embodiments foreseen and for which there are implementable descriptions by the inventors, any changes to this disclosure that are not currently foreseen may still constitute equivalents of this disclosure.

Claims

1. A trocar assembly (100), A head (102) positioned at the proximal end (104) of the trocar assembly (100), A shaft (106) extending distally from a head (102), including an open distal end (108), an open proximal end (220), and a partial partition wall (122) located between the pre-open distal end (108) and the pre-open proximal end (220), defining a distal section and a proximal section, respectively, wherein the partial partition wall (122) covers a portion of the cross-section of the shaft, leaving an opening for a lumen extending from the pre-open distal end (108) to the pre-open proximal end (220), An incision component (110) comprising a tongue (152) and a knife blade (150), wherein the tongue is fixed to the distal position of the partial partition wall such that the incision component is fixed to the shaft, and the knife blade has two lateral incision ends (134, 136) extending from the distal end of the trocar assembly through the open distal end of the shaft, A retractable protective assembly (114) configured to be in either an extended or retracted state, passing through the open distal end of the shaft, wherein the retractable protective assembly is configured to extend through the open distal end of the shaft (108) and cover the fixed cutting component (110) in a naturally biased position, and the retractable protective assembly is configured to retract from the open distal end of the shaft to expose the fixed cutting component in a compressed position while pressure is applied toward and proximal along the longitudinal axis of the retractable protective assembly, and the retractable protective assembly has a movable cutter safety case (123) configured to house the knife blade and to be coupled to the partial partition wall (122) via a biasing element (124), The cutter safety case (123) includes a central opening at its proximal end through which the tongue passes, and includes two diametrically opposed lateral slits (161, 162) spaced 180 degrees apart at its distal end, the shaft includes two slits (171, 172) aligned to correspond to its distal end, the cutting component, the cutter safety case, and the shaft are nested together in the natural biasing position, and the knife blade can protrude from the aligned slits of the cutter safety case and the open distal end of the shaft in the compressed position.

2. The trocar assembly according to claim 1, wherein the biasing element is a coil spring configured to be positioned around the tongue of the cutting component, one end of the coil spring connected to the cutter safety case, and the other end of the coil spring connected to the distal side of the partial partition wall, the distal side of the partial partition wall including a plurality of posts configured to restrict the lateral movement of the coil spring, and when the coil spring is in its natural biasing position, the cutter safety case and the open distal end of the shaft are configured to accommodate the knife blade.

3. The trocar assembly according to claim 1, wherein the two cutting ends of the knife blade terminate at a non-cutting soft tip (138) located at the distal end of the cutter safety case when the retractable protective assembly is in the natural biasing position.

4. The trocar assembly according to claim 1, wherein the distal end of the cutter safety case is funnel-shaped or triangular.

5. The trocar assembly according to claim 1, wherein the cutter safety case includes a front and a rear portion, and when the front and rear portions are combined, two diametrically opposed lateral slits with a 180-degree separation are formed.

6. CO from structure 2 The trocar assembly according to claim 1, further comprising a valve (181) for preventing leakage and an air supply port (182) for drainage.

7. The trocar assembly according to claim 1, further comprising a switch assembly (200).

8. The trocar assembly according to claim 7, wherein the switch assembly (200) is located distally below the partial partition wall, and the switch assembly comprises an automatic switch (202), an electronic memory device (204), and a lighting device (206), the automatic switch, the electronic memory device, and the lighting device communicate electronically via one or more wires.

9. The trocar assembly according to claim 8, wherein the automatic switch is configured to be set to a first position when the retractable protective assembly is in the natural biasing position and to be set to a second position when the retractable protective assembly is in the compressed position, and the movement of the retractable protective assembly is configured to affect the movement of the automatic switch.

10. The trocar assembly according to claim 8, wherein the electronic storage device includes a battery, and the lighting device includes at least one light-emitting diode (LED) positioned below or above the partial partition wall.

11. The trocar assembly according to claim 7, wherein the switch assembly includes a manual switch, an electronic memory device, and an illumination device disposed on the outer surface of the head of the trocar assembly, the electronic memory device and the illumination device being disposed within the shaft, and the manual switch, the electronic memory device and the illumination device communicating electronically via one or more wires.

12. The trocar assembly according to claim 11, wherein the electronic storage device includes a battery and a secondary electronic storage device, the battery being located below or above the partial partition wall.

13. The trocar assembly according to claim 12, wherein the secondary electronic storage device includes an alkaline battery pack positioned above the partition wall, and the lighting device includes at least one light-emitting diode (LED) positioned below or above the partial partition wall.

14. The trocar assembly according to claim 13, wherein the proximal manual switch is configured to switch between an ON state and an OFF state by manual pressing, and the LED is illuminated when the manual switch is in the ON state, and the LED is not illuminated when the manual switch is in the OFF state.

15. The trocar assembly according to claim 7, further comprising an automatic switch positioned below the partial partition wall, wherein the movement of the retractable protective assembly is configured to affect the movement of the automatic switch, the LED is configured to illuminate when the automatic switch is ON, and the LED is configured to de-illuminate when the automatic switch is OFF.

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