Suction cup design for capsulotomy device

Abstract

The present invention describes a device for performing a capsulotomy that improves the uniformity of suction and produces a rolled capsulotomy edge. The device includes a suction cup forming a tapered circumferential suction chamber that is capable of applying suction to tissue along a first direction. The cross-sectional area of ​​the tapered circumferential suction chamber decreases from the proximal end of the device toward the distal end of the device. The device also includes a rod coupled to the suction cup to provide suction to the suction cup. The rod forms a neck that enables fluid to flow toward the suction cup in a direction substantially perpendicular to the first direction. The device also includes a cutting element configured to excise tissue.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 078,128, filed on September 14, 2020, and U.S. Patent Application No. 17 / 112,759, filed on December 4, 2020, which are hereby incorporated by reference in their entireties for all purposes. Background Art

[0003] This specification relates generally to medical devices and, more particularly, to microsurgical instruments for capsulotomy.

[0004] Current tissue cutting devices often experience uneven suction, which can lead to inadequate sac cutting. Uneven suction is particularly problematic for tissue cutting devices that deliver suction to the suction cup through a single orifice located at one peripheral location. Furthermore, current tissue cutting devices often produce inconsistent edges in the cut tissue, which may not be sufficient to withstand the remaining steps of cataract surgery. Furthermore, with current tissue cutting devices, it is difficult to align the center of the device with the desired surgical landmark. Finally, with current tissue cutting devices, it is difficult to visually monitor the suction level within the device. Summary of the Invention

[0005] Embodiments relate to a microsurgical device for tissue cutting that produces consistent capsulotomies and improves upon current tissue cutting devices. The microsurgical device provides uniform suction across the entire circumference of the suction cup and produces a strong, tear-resistant crimp. Furthermore, the microsurgical device consistently produces a complete capsulotomy without residual growth adhering to the edges of the capsulotomy. Additionally, the device may include features that aid the surgeon during device placement, allowing for visual monitoring of the amount of suction generated in the suction cup, and the like.

[0006] The design of the suction cup ensures that a uniform suction is applied to the tissue to be removed. For example, the suction cup can form a tapered circumferential suction chamber, the cross-sectional area of ​​which decreases from the proximal end of the device to the distal end of the device. In addition, the central portion of the suction cup can have a shorter height than the circumferential portion of the suction cup (e.g., the tapered circumferential suction chamber). By having a tapered circumferential suction chamber and / or a shorter central portion, the amount of material to be evacuated under suction is reduced, ensuring a more uniform suction. In addition, in some embodiments, the suction cup may include one or more struts that create a channel for the flow of material. Due to the formed channel, a uniform suction is generated throughout the suction cup.

[0007] In addition to the design of the suction cup, the configuration of the rod coupled to the suction cup ensures that uniform suction is applied to the tissue to be excised. Suction is applied to the suction cup through the orifice of the rod that is coupled to the tapered side of the suction cup. In some embodiments, the neck of the rod enables fluid to flow toward the rod and into the suction cup in a direction substantially perpendicular to the direction of the suction to be applied to the tissue. For example, the fluid flow through the neck can be substantially horizontal, and the suction applied to the tissue can be substantially vertical. Different flow directions help ensure that uniform suction is applied to the tissue.

[0008] Furthermore, the configuration of the suction cup helps ensure a consistent curled edge. The suction cup is configured to ensure that only a portion of the cutting element is in physical contact with the tissue to be resected. For example, in some embodiments, only the inner bottom edge of the cutting element is in physical contact with the tissue to be resected. The outer bottom edge of the cutting element is physically isolated from the tissue, but is located at a sufficient distance from the tissue to remotely affect the tissue via a change in temperature. This change in temperature helps form the curled edge.

[0009] Furthermore, the manufacture, transportation, and use of the device are facilitated by the design of the suction cup. For example, the suction cup can include a containment bag that collapses between a horizontal and a vertical position. The containment bag can be molded in a vertical position and assembled and / or transported in a horizontal position. Furthermore, different portions of the suction cup can have varying thicknesses to reduce the amount of material used in the suction cup. By reducing the amount of material used in the suction cup, the force required to insert the suction cup through the incision is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A A microsurgical device is shown connected to its console according to one embodiment.

[0011] Figure 1B-1C According to one embodiment, Figure 1A A cross-sectional view of the microsurgical device is shown.

[0012] Figure 1D According to one embodiment, Figure 1A Bottom view of the microsurgical device shown.

[0013] Figure 1E According to one embodiment, Figure 1A A bottom perspective view of the microsurgical device is shown.

[0014] Figure 1F According to one embodiment, Figure 1A A top perspective view of the microsurgical device is shown.

[0015] Figure 2 According to one embodiment, Figure 1AThe flow of electrical current in the cutting element of a microsurgical device is shown.

[0016] Figure 3A-3F A method for using a Figure 1A The steps of the device are shown.

[0017] The accompanying drawings depict various exemplary embodiments of the present technology for illustrative purposes only. Those skilled in the art will readily recognize from the following description that other alternative embodiments of the structures and methods shown herein may be employed without departing from the technical principles described herein. DETAILED DESCRIPTION

[0018] Figure 1A-1F Various views of a microsurgical device 100 for tissue cutting are shown. Figure 1A An embodiment of a microsurgical device 100 is shown. Figure 1B-1C A cross-sectional view of microsurgical device 100 is shown. Figure 1D A bottom view of microsurgical device 100 is shown.

[0019] Figure 1E A bottom perspective view of the microsurgical device 100 is shown. Figure 1F A top perspective view of microsurgical device 100 is shown.

[0020] Figure 1A The device 100 shown includes a suction cup 105, a cutting element 110 (also referred to herein as a "cutting ring"), one or more suction tubes 115, electrical leads 120A, 120B, and a rod 125. The suction cup 105 and cutting element 110 are located at the distal end of the rod 125, which houses the one or more suction tubes 115 and electrical leads 120A, 120B. The device 100 also includes a console 130 (also referred to herein as a "controller") that is configured to provide suction to the suction cup 105 and electrical power to the cutting element 110. The suction cup 105 is connected to the console 130 via the one or more suction tubes 115 and a suction connector 135. The cutting element 110 is connected to the console 130 via the electrical leads 120A, 120B, one or more sets of electrical conductors (e.g., electrical conductors 140A, 140B), and an electrical connector 145.

[0021] The suction cup 105 is a foldable structure that can provide a waterproof seal between the edge of the suction cup 105 and the tissue to be removed (e.g., the lens capsule, corneal tissue, connective tissue, etc.). Due to the fluid seal between the suction cup 105 and the tissue, vacuum pressure can be applied to the suction cup 105 and the tissue, so that the resulting pressure presses the cutting element 110 against the tissue. Pressing the cutting element 110 against the tissue facilitates more precise and smoother cutting. The foldable structure of the suction cup 105 is reversibly collapsible, so that the cross-section of the suction cup 105 can be reduced for insertion of the device 100 through the incision. Thus, the suction cup 105 can be made of a compliant material, such as silicone, polyurethane, etc. In one embodiment, the material of the suction cup 105 is medical-grade silicone (e.g., Nusil MED-4960) with a Shore A durometer of 60. In addition, the silicone can be transparent, which can facilitate the placement of the suction cup 105.

[0022] Cutting element 110 is an element designed to cut tissue by applying pressure and / or applying an electrical current via one or more electrical leads 120A, 120B coupled to cutting element 110. Cutting element 110 can be made from a variety of materials. In some embodiments, the metal components of cutting element 110 can be made from a suitable electroformed material, such as nickel, nickel-titanium alloy, gold, steel, copper, platinum, iridium, molybdenum, tantalum, etc. When cutting element 110 is configured to perform electroresection of tissue, the material used for cutting element 110 is electrically conductive. In addition, cutting element 110 is reversibly collapsible, allowing the cross-section of cutting element 110 to be reduced for insertion through an incision into device 100. Therefore, the material of cutting element 110 is generally elastic, allowing it to return to its original shape after insertion through an incision into device 100. An example of a typical configuration is a superelastic nitinol ring having a wall thickness of 0.075 mm, a height of 0.140 mm, and a protrusion. Another strategy is to add a thin film (e.g., 0.0001 mm to 0.002 mm) of a more conductive material to this superelastic body. This more conductive material does not have to be superelastic because it is very thin. Examples of materials include, but are not limited to, spring steel, stainless steel, titanium nickel alloy, graphite, nitinol, nickel, nickel-chromium alloy, tungsten, molybdenum, tantalum, gold, silver, or any other material that allows the cutting element 110 to return to its previous shape.

[0023] The device 100 is capable of delivering a wide range of energies (e.g., from 0 joules to 3 joules, or more) via the cutting element 110. The energy consumed by the cutting element 110 during surgical use can be determined by experience with the specific tissue of interest. For example, in capsulotomy of the anterior lens capsule in adults, approximately 1.2 joules was found to produce satisfactory results. Examples of some specific applications of capsulotomy include pediatrics as well as adults and other animals (e.g., dogs), listed in order of increasing energy requirements. To accommodate varying energy requirements, the amount of energy consumed by the cutting element 110 can be controlled by control parameters, such as the number of pulses, the duration of each pulse, the time between pulses, and / or the energy of each pulse applied to the tissue via the cutting element 110. These parameters can be determined empirically for each tissue application and / or via computational modeling. In addition, the temperature gradient in the cutting element 110 can be designed and / or modified for different tissues.

[0024] One or more suction tubes 115 are located within the rod 125 of the device 100. The one or more suction tubes 115 are configured to provide suction to the suction cup 105. The one or more suction tubes 115 provide suction to the suction cup 105 to press the suction cup 105 against the resected tissue. The one or more suction tubes 115 can also be configured to reverse the suction and / or fluid flow applied to the suction cup 105 to disengage the suction cup 105 and the cutting element 110 from the resected tissue. In some embodiments, the material of the suction tubes 115 is medical grade silicone with a Shore A hardness of 60 (e.g., Nusil MED-4960). In some embodiments, electrical leads 120A, 120B, anchor wires and / or rigid extensions pass through the one or more suction tubes 115 to reach the suction cup 105.

[0025] One or more straws 115 can also be configured to function as a fluid path. For example, one or more straws 115 can be primed with a solution, such as a balanced salt solution, prior to use. Priming the fluid path of one or more straws 115 can help ensure that there is little or no compressible air in the device 100. Additionally, after tissue resection is complete, one or more straws 115 can be hydraulically released to release the suction cup 105 from the tissue. In some embodiments, the hydraulic release comprises forcing 0.05 ml to 0.2 ml of balanced salt solution from the straws 115 back into the suction cup 105.

[0026] The configuration of the one or more suction tubes 115 along the inner surface of the suction cup 105 can vary. For example, when there are two or more suction tubes 115, the suction tubes 115 can be located at antipodal points of the suction cup 105. This configuration can ensure that the suction force is equally distributed throughout the suction channel of the suction cup 105. In other embodiments, the suction tubes 115 can be positioned adjacent to each other within a threshold angle relative to each other, within a threshold distance, and so on. In addition, the suction tubes 115 can be positioned along the outer surface of the suction cup 105, along the bottom surface of the suction cup 105, along the top surface of the suction cup 105, and so on. In embodiments where the device 100 includes a single suction tube 115, the suction tube can be located at any point along the inner surface of the suction cup 105. For example, the orifice of the suction tube 115 can be located at the top of the suction cup 105, at the proximal end of the suction cup 105, at the distal end of the suction cup 105, and so on.

[0027] Electrical leads 120A, 120B are configured to provide electrical energy to cutting element 110. Electrical leads 120A, 120B are located within rod 125 of device 100 and are coupled to the surface of cutting element 110. In some embodiments, electrical leads 120A, 120B are silver wires. In other embodiments, electrical leads 120A, 120B are made of copper, aluminum, gold, etc. Additionally, electrical leads 120A, 120B may be insulated.

[0028] The console 130 is configured to provide suction to the suction cup 105 and electrical power to the cutting element 110. In addition, the operator of the device 100 can control the cutting depth via the console 130 by modifying the suction and / or electrical parameters of the device 100.

[0029] Suction is provided to the suction cup 105 via one or more suction tubes 115 connected to a console 130 and a suction connector 135. Using the console 130, the operator of the device 100 can provide suction to the suction cup 105, reverse the suction during detachment of the device 100, and / or flush the fluid path of the one or more suction tubes 115 with a solution. In addition, the operator of the device 100 can modify the amount of suction applied to the suction cup 105 based on the procedure being performed. In some embodiments, the operator of the device 100 can manually modify the amount of suction applied to the suction cup 105, for example using a vacuum valve and / or vacuum gauge of the console 130. Alternatively or additionally, the console 130 can include predetermined suction parameters determined through experimentation, modeling, and / or a combination thereof, each of which is associated with a procedure. In addition, using the console 130, different amounts of suction can be provided to different suction tubes. For example, a suction pressure of 19 + / - 1 inches of Hg vacuum has been successfully used. The suction pressure is gauge pressure, not absolute pressure, so the console 130 can establish the same pressure differential along the suction cup wall regardless of the altitude used.

[0030] The console 130 delivers electrical energy to the cutting element 110 via electrical leads 120A, 120B, one or more sets of electrical conductors 140A, 140B, and an electrical connector 145. The first set of electrical conductors 140A can be configured to provide power to the cutting element 110. The second set of electrical conductors 140B can be used for resistance measurement and can be connected to a measurement device, such as a Kelvin probe (also known as a 4-wire resistance measurement). In some embodiments, the first set of electrical conductors 140A and / or the second set of electrical conductors 140B are copper wires, such as 24 ga copper wire, 30 ga copper wire, etc. (respectively). In other embodiments, the first set of electrical conductors 140A and / or the second set of electrical conductors 140B are constructed of aluminum, gold, silver, etc. The electrical energy can be provided to the cutting element 110 as one or more electrical waveforms. The one or more electrical waveforms discharge through the cutting element 110 to heat the cutting element 110 for a short period of time, such as 0.0001 to 0.05 seconds, depending on the applied voltage and current.

[0031] Using the console 130, the cutting depth can be controlled by controlling the amount of discharge applied to the cutting element 110. For example, the cutting depth can be controlled by modifying one or more of the following: the energy of each pulse, the number of pulses in the pulse train, the interval between pulses, etc. As with the suction force, the operator of the device 100 can manually modify these parameters using the control elements of the console 130. Alternatively or in addition, the console 130 can include predetermined parameter groups, each of which is associated with a different cutting depth, a different patient type, etc. These parameter groups can be determined by experiment, modeling, and / or a combination thereof. The console 130 can be a controller, a microprocessor, programmable hardware logic, etc.

[0032] In some embodiments, console 130 can automatically change operating parameters of device 100. For example, console 130 can change operating parameters based on a predetermined set of operating steps associated with a procedure. Alternatively or additionally, console 130 can change operating parameters of device 100 based on feedback from device 100 itself. For example, console 130 can change operating parameters of device 100 during use in response to detection of device resistance, pressure, pressure changes, temperature, temperature changes, a determined depth of cut, etc.

[0033] Figure 1B 1 shows a cross-sectional view of the device 100. In the embodiment shown, the height of the proximal end of the suction cup 105 is greater than the height of the distal end of the suction cup 105, thereby forming a tapered circumferential suction chamber 150 in the suction cup 105. The tapered circumferential suction chamber 150 helps ensure that uniform suction is applied, in part because the height of the chamber decreases as the volume to be evacuated decreases.

[0034] In some embodiments, the first height of the tapered circumferential suction chamber 150 can have a first height at the orifice of the suction cup 105 and a second height at the antipodal point of the suction cup. In these embodiments, the first height can be greater than the second height. For example, the height of the suction cup 105 can be greatest at the proximal end and shortest at the distal end. In some embodiments, the relative heights of the proximal end of the suction cup 105 and the distal end of the suction cup 105 can be based on a number of factors, including but not limited to: the amount of total volume to be evacuated, the amount of suction to be applied, the type of surgery to be performed, the type of tissue to be resected, the amount of electrical energy to be applied, features included on the underside of the suction cup 105 (e.g., struts and / or visual guides), etc. For example, the tapered circumferential suction chamber 150 can be tilted at an angle such that the volume removed from the suction cup is proportional to the volume of the tapered circumferential suction chamber 150 along the horizontal axis of the suction cup 105. Examples of tilt angles include, but are not limited to, 0 degrees, 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees, or 15 degrees.

[0035] Additionally, the geometry and dimensions of the suction cup 105 may be modified to prevent the suction cup 105 from collapsing when suction is applied. Figure 3A As shown, the top of the tapered circumferential suction chamber 150 can be domed to prevent collapse. The rise and span of the domed portion can vary based on factors including, but not limited to, the amount of suction to be applied, the type of procedure to be performed, and the like.

[0036] Additionally, the thickness of the suction cup 105 can be modified to prevent the suction cup from collapsing when suction is applied. In some embodiments, the thickness of the entire suction cup 105 is uniform, which prevents the overall collapse of the suction cup (e.g., 200 microns or greater, 175 microns or greater, 150 microns or greater, 125 microns or greater, 100 microns or greater, 75 microns or greater, 25 microns or greater, etc.). In other embodiments, portions of the suction cup can have varying thicknesses. For example, portions that should not collapse during use (e.g., the arched portion of the suction cup 105) can be relatively thicker than other portions of the suction cup 105 that can collapse during use. In these embodiments, the portion having the increased thickness can have a thickness of approximately 200 microns or greater. Other portions of the suction cup can have a thickness of approximately 200 microns or less, such as 175 microns or less, 150 microns or less, 125 microns or less, 100 microns or less, 75 microns or less, 50 microns or less, 25 microns or less, etc. By limiting the portion of the suction cup 105 having thickenings, the total amount of silicon required to manufacture the suction cup 105 is reduced, and collapse of the suction cup 105 is prevented. Furthermore, by reducing the amount of silicon, the force required to insert the suction cup 105 through the incision is reduced.

[0037] The rod 125 is connected to the proximal end of the suction cup 105 via an opening in the tapered side of the suction cup 105. The neck 155 of the rod 125 enables the fluid to flow toward the rod 125 and out of the rod 125 into the suction cup 105 in a direction substantially perpendicular to the suction force to be applied to the tissue. For example, the angle between the flow of fluid into and out of the rod 125 and the direction of the suction force to be applied to the tissue can be between 85 degrees and 95 degrees, between 80 degrees and 100 degrees, etc. The substantially vertical flow helps to ensure an even distribution of the suction force. In alternative embodiments, the neck 155 of the rod 125 can be configured to provide a substantially vertical flow. In these embodiments, an additional mechanism can be coupled to the neck 155 of the rod 125 so that the suction force and / or fluid flow horizontally from the rod 125 to the suction cup 105.

[0038] As previously discussed, the device 100 can include a rigid extension (not shown) for extending the cutting element 110 for insertion of the device 100 through an incision (e.g., a corneal incision). The end of the rigid extension can include one or more prongs to which the cutting element 110 is coupled. The one or more prongs can substantially prevent the rigid extension and the cutting element 110 from separating during transport. However, the length of the one or more prongs may need to prevent the one or more prongs from piercing the receiving pocket 160 of the suction cup 105.

[0039] A fundamental principle of injection molding in device manufacturing is that the desired molded part must not have features that create significant undercuts, prevent separation of the mold halves, and prevent molded part recovery. In some cases, the use of side pins can produce the desired molded features, but this involves significant cost and may reduce precision. Horizontal containment pockets can have significant undercuts and cannot be manufactured using standard molding techniques that separate vertically separated mold halves.

[0040] To eliminate the undercut created by the horizontal containment bag, containment bag 160 can be collapsed between a vertical and horizontal position. In some embodiments, the material of containment bag 160 is flexible, allowing containment bag 160 to collapse between the horizontal and vertical positions. In alternative embodiments, containment bag 160 can be collapsible due to one or more joints or any other suitable collapsing mechanism. For ease of manufacturing, containment bag 160 can be molded in a vertical position. The vertical position of containment bag 160 helps ensure that the containment bag is easily released when the two mold halves are pulled apart in a vertical direction. When containment bag 160 collapses to a horizontal position, it can receive the end of the rigid extension. In some embodiments, containment bag 160 is restrained in a horizontal position during transport. When suction cup 105 and cutting element 110 are extended via the rigid extension, it can remain horizontal. When the rigid extension is retracted, containment bag 160 returns to its as-molded vertical position due to the elasticity of the silicone.

[0041] Figure 1C Another cross-sectional view of the device 100 is shown. Figure 1B As discussed, the suction cup 105 can form a tapered circumferential suction chamber 150 that slopes downwardly in a direction from the proximal end of the suction cup 105 to the distal end of the suction cup 105. Additionally, the center portion 165 of the suction cup 105 can have a shorter height than the tapered circumferential suction chamber 150 of the suction cup 105. Shortening the height of the center portion 165 can reduce the amount of material that needs to be evacuated from the space enclosed by the suction cup 105, which facilitates a more even distribution of suction. In some embodiments, the entire center portion 165 can have a uniform height. In alternative embodiments, the center portion 165 can be sloped at the same angle as the tapered circumferential suction chamber 150 or at a different angle than the tapered circumferential suction chamber 150. Additionally, the height of the center portion 165 can vary based on the amount of total volume to be evacuated, the amount of suction to be applied, the type of surgery to be performed, the type of tissue to be resected, the amount of electrical energy to be applied, features included on the underside of the suction cup 105 (e.g., supports and / or visual guides), etc.

[0042] like Figure 1C As shown, the suction cup 105 includes a sealing contact 170 and a tapered edge 175 along a skirt 180 of the suction cup 105. The compliant skirt 180 enables the sealing contact 170 to remain on the capsule even if the operator of the device 100 rotates or translates the handpiece of the device 100. For example, for procedures involving small pupils, the tapered edge 175 can facilitate placement of the compliant skirt 180 under the iris. In some embodiments, the tapered edge 175 is where the mold parting line is located. The distance between the tapered edge 175 and the sealing contact 170 can be such that flash from the molding process is not long enough to reach the sealing contact 170. For example, flash up to 0.25 mm long will not get between the seal and the capsule and cause leakage.

[0043] like Figure 1C As further shown, the proximity of the cutting element 110 to the suction cup 105 can help ensure that only the inner bottom edge 181 of the cutting element 110 is in physical contact with the tissue to be resected (e.g., the capsule). For example, the cutting element can be coupled to the surface of the suction cup such that only the inner bottom edge 181 of the cutting element is in contact with the tissue to be resected. In these embodiments, when suction is applied to the suction cup 105, the outer diameter of the cutting element 110 is not in physical contact with the tissue to be resected. In these embodiments, the outer diameter of the cutting element 110 remotely affects tissue resection through conduction. For example, the outer diameter of the cutting element 110 can be located at a sufficient distance from the capsule to remotely affect the capsule through temperature changes. The temperature change can help produce a consistent curl, which will be referenced below. Figures 3A-3FIn other embodiments, the coupling of the cutting element 110 to the suction cup 105 can be configured such that the outer bottom edge 183 of the cutting element resects tissue, the inner bottom edge 181 and the outer bottom edge 183 both resect tissue, or any other suitable portion of the cutting element 110 resects tissue.

[0044] Figure 1D-1F Another view of the device 100 is shown. Figure 1D As shown, cutting element 110 and electrical leads 120A, 120B are installed. In some embodiments, the electrical leads are electrically insulated silver wires (e.g., a 6 micron thick polyimide layer). In some embodiments, electrical leads 120A, 120B are pushed back near the top of the internal flow chamber so as not to interfere with the cutting edge (e.g., inner bottom edge 181) of cutting element 110.

[0045] The suction cup 105 shown includes one or more features. The features shown may include hollow struts (e.g., hollow struts 185) and aiming guides (e.g., aiming guides 190). In the illustrated embodiment, the hollow struts are disposed on the inner surface of the suction cup 105. The hollow struts prevent the central portion 165 of the suction cup 105 from completely sealing against the bladder surface, thereby forming a channel for material flow and evenly distributing suction. In addition, the hollow struts can provide a visual indication of the level of suction within the suction cup 105. As suction is generated, trapped bubbles are removed from the interior of the hollow struts. The escape of the bubbles can serve as a visual signal that sufficient suction has been generated. The size of the struts and aiming guides can be varied to select a size that captures bubbles and allows them to escape only when the desired level of suction has been applied. In some embodiments, the size of the struts can be varied so that they provide a visual indication of different suction levels.

[0046] In the illustrated embodiment, the suction cup 105 includes ten struts. In alternative embodiments, the suction cup 105 can include any suitable number of struts, such as one strut, five struts, etc. In some embodiments, the struts have air traps with a high aspect ratio (e.g., a diameter of 0.2 mm and a height of 0.3 mm). In alternative embodiments, the struts have air traps with a low aspect ratio, air traps with a medium aspect ratio, etc. In addition, the aspect ratio can be modified to ensure that air is always trapped. Because silicone rubber is stretchable, the strut openings can have a smaller diameter than the trap cavity and still be moldable. Reducing the diameter at the stent opening helps ensure that air is not trapped until the suction reaches the pressure required to successfully perform the capsulotomy. However, the diameter of the cavity can include a size that is smaller than and / or equal to the strut opening.

[0047] In some embodiments, the strut includes slots, such as slot 195. The slots face away from the stem 125 and / or straw 115. In alternative embodiments, the slots can face the stem and / or straw 115, each slot can face a different direction, etc. The slots can be modified to allow air to be exhausted at different suction levels.

[0048] Performing a capsulotomy at a precise location on the lens surface is critical because an eccentric capsulotomy may result in less IOL stability and poor IOL optical performance. The surgeon can use a number of different surgical landmarks to center the capsulotomy. These include the position of certain Purkinje images or light reflections that can be used to indicate the patient's visual axis position. An automated capsulotomy device (e.g., device 100) should allow the cutting element 110 aligned with such a Purkinje image to be easily centered. In the illustrated device 100, alignment of the center of the suction cup 105 with a desired surgical landmark (e.g., Purkinje light reflection) is facilitated by placing an aiming guide (e.g., aiming guide 190) near the center of the suction cup 105. The aiming guide can have a variety of geometric shapes and helps the surgeon visually identify the center position of the suction cup 105 and / or cutting element 110. The aiming guide can be manufactured on the suction cup 105 using silicone micromolding techniques well known in the art.

[0049] Once it has been determined that the suction cup 105 is in the desired alignment, the activation of the suction force must not cause a substantial shift in the position of the cutting element 110, which could result in decentration of the capsule. If the cutting element 110 is merely inserted into the hole of the suction cup 105, but the suction cup 105 is unable to fully restrict the movement of the cutting element 110 as the internal volume of the suction cup 105 decreases under the action of the suction force, the cutting element 110 may undergo undesirable movement. To prevent undesirable movement, the cutting element 110 may be physically coupled to the suction cup 105, such as Figure 1E shown.

[0050] Cutting element 110 is made of conductive metal, and suction cup 105 can be made of silicone, so they are made into two separate parts. Hollow bag (for example bag 197) is arranged in suction cup 105 to receive one or more protrusions protruding from cutting element 110. During manufacture, these protrusions are located in corresponding hollow bags, and silicone is injected into the hollow bags to fix the attachment protrusions in place. In certain embodiments, silicone is potted from the top side of suction cup 105. In alternative embodiments, silicone is potted from the bottom side of suction cup 105. For example, during bottom potting, liquid silicone can be distributed in each bag. Then, cutting element 110 is placed on suction cup 105, electrical leads 120A, 120B are passed through the inner cavity of rod 125, and the attachment protrusions are immersed in the liquid silicone in the potting bag. Then, the assembly can be heated to solidify the silicone. In certain embodiments, the bag includes a film to prevent liquid silicone from reaching the cutting element 110. When the attachment tab is placed into the hollow bag, the attachment tab may pierce the film.

[0051] Figure 2 The path of current flow within the cutting element 110 is shown. When entering the cutting element 110 through the electrical lead 120A, a portion of the current (e.g., half of the current (i 1 / 2 )) is transmitted along one half of the cutting element 110, while the other portion of the current (e.g., the other half of the current (i 1 / 2 )) is transmitted along the other half of cutting element 110. The current then exits cutting element 110 at the other electrical lead 120B. Due to the resistance of cutting element 110, the current flow causes the temperature of cutting element 110 to increase rapidly. Due to the rapid increase in temperature, water molecules near or adjacent to cutting element 110 and the tissue to be resected rapidly evaporate and mechanically disrupt along the path dictated by the portion of tissue to be resected.

[0052] Figures 3A-3F A method for using a Figure 1A The steps of the apparatus 100 are shown. Figure 3A 3 is a cross-section of the capsular membrane 305 of the device 100 immediately surrounding the lens capsule 310. In the cross-section shown, the suction cup 105 has a flow channel in which the silicone is arched and sufficiently thick to prevent collapse when suction is applied (e.g., along the tapered circumferential suction chamber 150 of the suction cup 105). Struts (e.g., struts 185) maintain an open flow path under the center of the membrane during suction. The body of the cutting element 110 is shown to have a rectangular cross-section. In alternative embodiments, the cutting element 110 can be of any suitable shape, such as conical, elliptical, etc.

[0053] The sealing contact 170 of the skirt 180 of the suction cup 105 abuts the capsule 305 surrounding the lens 310. The operator of the device centers the device 100 on the patient's visual axis. Once centered, the rigid extension has been retracted from its extended position so that the end of the rigid extension is within the neck 155 of the device 100. The rigidity of the rigid extension enables the surgeon to position the suction cup 105 on the visual axis over a wide range of anterior chamber depths (ACDs), for example, 1.9 mm to 4.0 mm ACDs.

[0054] Figure 3B 10. The lens 310 and suction cup 105 are shown deformed when suction is applied to the suction cup 105. The suction pulls the capsular membrane 305 into the interior of the suction cup 105 and creates a contact force against the inner bottom edge 181 of the cutting element 110. Simultaneously, the surface of the suction cup 105 is pulled against the outer surface of the cutting element 110. The skirt 180 of the suction cup 105 prevents contact between the capsular membrane and the outer bottom edge 183 of the cutting element 110, thereby limiting cutting of the inner bottom edge 181 of the cutting element 110. In alternative embodiments, cutting can occur at the outer bottom edge 183 of the cutting element 110, at both the inner bottom edge 181 and the outer bottom edge 183 of the cutting element 110, etc.

[0055] A small volume 315 is formed where the liquid is trapped between the capsule 305, the cutting element 110, and the suction cup 105. The tensile force caused by the suction creates a significant tensile stress in the capsule 305. There is a concentration of tensile stress where the capsule 305 contacts the inner bottom edge 181 of the cutting element 110. Because this tensile stress builds up before the cutting discharge, it is already there, waiting to act, at the moment the discharge occurs, adding a brief burst of heat. In some embodiments, the small volume 315 separating the outer diameter of the cutting element 110 from the capsule 305 is sufficiently small to allow the cutting element 110 to remotely induce a temperature change in the capsule 305, thereby aiding in the capsule's reeling after the cutting procedure is complete.

[0056] Figure 3C The figure shows the situation when an electric discharge is being conducted through cutting element 110. During the first few microseconds of the cutting event, cutting element 110 heats to a temperature that is hotter than the critical temperature of water. As a result, water molecules located within a few microns of cutting element 110 evaporate. The steam within trapped small volume 315 cannot escape during this short period of time, so the pressure within trapped small volume 315 increases. The increase in pressure causes the curvature in capsule 305 to change. This may also cause the volume of small volume 315 to change.

[0057] At the same time, heat flows from the cutting element 110 into the capsule 305 at the point of contact with the cutting element 110 (e.g., the inner bottom edge 181 of the cutting element 110). As heat flows into the collagen at the point of contact between the capsule 305 and the cutting element 110, the capsule 305 becomes brittle. Due to the symmetry of the device 100, equal forces and temperatures are applied around the circumference of the cutting element 110 in contact with the capsule 305. When the strength of the capsule 305 is less than the force that tears it apart, the capsule 305 ruptures. The force that tears the capsule 305 can be caused by: 1) tensile stress from the suction being applied, and / or 2) increased pressure in the small volume 315 due to steam heating.

[0058] Because the cutting event occurs on a millisecond time scale (e.g., 1 to 10 milliseconds), it is the inertia of the mass surrounding the material that limits the steam. A large force is required to accelerate the mass surrounding the material during this short time interval. During the millisecond time interval, the steam pressure builds up and the material will begin to move, but by this time the capsulotomy is complete. For example, the discharge can consist of 12 pulses that are each on for 66 microseconds and off for 305 microseconds, for a total time of 4 milliseconds. This may not be enough time for the material mass to accelerate and move. Note that capsules or other tissues of different thicknesses can be cut by varying the number of pulses, the duration of each pulse, the interval between pulses, and the energy of each pulse. In addition, the base width of the cutting loop can be adjusted to change the spatial extent of the remote temperature effect (e.g., curling).

[0059] Figure 3D A pullback region 325 is shown where the stretched capsule 305 is pulled back from the inner bottom edge 181 of the cutting element 110, which occurs after the discharge is complete. In some embodiments, the inertial mass involved in this motion is small.

[0060] Figure 3E The edge of the capsule 305 is shown to curl up as the edge cools. Because the heating method used by the device 100 creates a temperature gradient across the thickness of the capsule 305, the edge of the capsule 305 will curl up. Figure 3B As discussed, the outer surface of the capsule 305 will receive heat from the cutting element 110 through the steam (e.g., steam confined within the small volume 315) that contacts it. The heat causes the collagen to shrink. The collagen shrinks more at the outer surface 305A of the capsule 305 than at the inner surface 305B of the capsule 305 because the cutting event is too brief so that a large amount of heat cannot pass through the steam layer and cannot shrink the inner surface 305B of the capsule 305 as much as the outer surface 305A. This creates a tensile stress gradient across the entire thickness of the capsule 305 as it cools. The shrinking of the collagen in the top layer pulls the edges inward, causing them to curl up. The edges of the capsule can only curl up to the point where they contact the cutting element 110 and / or the bottom of the suction cup 105.

[0061] Figure 3F Flow direction 330 is shown implementing fluid release to release suction and lift suction cup 105 from lens 310. Because the edge of the capsular bag is rolled up against the bottom of cutting element 110 and suction cup 105, flow at this location is between the capsular membrane 305 and lens 310. This implements hydrodissection to separate the capsular membrane 305 from the lens 310.

[0062] As the fluid release proceeds, the edge of the capsular bag remains rolled up against the bottom of the suction cup 105, thereby still directing fluid between the capsular membrane 305 and the lens 310 to complete hydrodissection. In some embodiments, the fluid release occurs rapidly (e.g., 0.5 seconds or less). If the released flow is fast enough, the inertia of the surrounding fluid above the suction cup 105 can delay the rise of the released flow long enough to allow the released flow to follow the path of hydrodissection rather than simply causing the suction cup 105 to float. Once the edge of the capsular bag is no longer held down by the suction cup 105, the capsular bag is free to roll up under the influence of the surface stresses generated by the brief heat that reached it during the ablation event.

[0063] Additional configuration information

[0064] The foregoing description of the embodiments of the present invention has been presented for illustrative purposes; it is not intended to be exhaustive or to limit the invention to the precise form disclosed. Those skilled in the relevant art will appreciate that many modifications and variations are possible in light of the above disclosure.

[0065] The language used in the specification is mainly selected for the purpose of readability and guidance, and it may not be selected to describe or limit the subject matter of the present invention. Therefore, the scope of the present invention is not intended to be limited by this detailed description, but to be limited by any claims issued in the application based thereon. Therefore, the disclosure of the embodiment is intended to illustrate but not to limit the scope of the disclosure set forth in the appended claims. As used herein, any reference to "one embodiment" or "embodiment" means that the specific elements, features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment. The phrase "in one embodiment" appearing in different places in the specification does not necessarily refer to the same embodiment.

Claims

1. A device for removing tissue, the device comprising: a suction cup, the suction cup forming a tapered circumferential suction chamber capable of applying suction to the tissue along a first direction, the tapered circumferential suction chamber comprising a first tapered portion, the first tapered portion tapering from a circumferential edge of the tapered circumferential suction chamber to a center of the tapered circumferential suction chamber at a second height at a first height, the second height being smaller than the first height, so as to be capable of applying suction to the tissue along the first direction, and wherein the suction cup comprises a second tapered portion, the second tapered portion continuously tapering from the first height at the circumference of the suction cup at a proximal end of the suction cup to a third height at a distal end of the suction cup, the third height being smaller than the first height and larger than the second height; a stem coupled to the proximal end of the suction cup via an opening in the tapered side of the suction cup such that a neck of the stem enables fluid to flow toward the stem and from the stem into the suction cup in a second direction substantially perpendicular to the first direction, wherein the neck of the suction cup has a first diameter and the proximal end of the stem has a second diameter, and wherein the second diameter is greater than the first diameter; and A cutting element is coupled to the inner surface of the suction cup and is configured to resect the tissue.

2. The device of claim 1, further comprising a receiving bag located at a distal end of the suction cup, the receiving bag being collapsible between a horizontal position and a vertical position.

3. The device of claim 2, further comprising a rigid extension coupled to the rod and configured to extend the suction cup to insert the device into the incision, wherein The receiving pocket is configured to retain at least a portion of the rigid extension when the rigid extension is in the extended position.

4. The device according to claim 1, wherein The tapered circumferential suction chamber has a first height at the orifice of the suction cup and a second height at the antipodal point of the suction cup.

5. The device according to claim 1, wherein The suction cup has a tapered edge.

6. The device according to claim 1, wherein The suction cup comprises one or more membranes.

7. The device of claim 1 , further comprising one or more protrusions protruding from the cutting element, wherein The one or more pockets of the suction cup are configured to receive the one or more protrusions.

8. The device according to claim 1, wherein The cutting element is coupled to the surface of the suction cup such that an inner bottom edge of the cutting element contacts the tissue to be resected.

9. The device according to claim 1, wherein The surface of the suction cup includes one or more aiming guides to provide an indication of the approximate center of the suction cup.

10. A device for removing tissue, the device comprising: a suction cup forming a tapered circumferential suction chamber, the tapered circumferential suction chamber comprising a first tapered portion that tapers from a circumferential edge of the tapered circumferential suction chamber at a first height to a center of the tapered circumferential suction chamber at a second height, the second height being smaller than the first height, thereby enabling suction to be applied to tissue in a first direction, and wherein the suction cup comprises a second tapered portion that tapers continuously around the circumference of the suction cup at a proximal end of the suction cup from the first height at the circumferential edge of the suction cup to a third height at a distal end of the suction cup, the third height being smaller than the first height and larger than the second height; a stem coupled to the proximal end of the suction cup via an opening in the tapered side of the suction cup such that a neck of the stem enables fluid to flow toward the stem and from the stem into the suction cup in a second direction substantially perpendicular to the first direction; and A cutting element is coupled to a surface of the suction cup and is configured to resect the tissue.

11. The apparatus according to claim 10, further comprising: a receiving bag located at a distal end of the suction cup, the receiving bag being collapsible between a horizontal position and a vertical position; as well as A rigid extension is coupled to the shaft and is configured to extend the suction cup to insert the device into the incision in the tissue, wherein the receiving bag is configured to retain at least a portion of the rigid extension when the rigid extension is in the extended position.

12. The device according to claim 10, wherein The suction cup has a tapered edge.

13. The device of claim 10, further comprising one or more protrusions protruding from the cutting element, wherein The one or more pockets of the suction cup are configured to receive the one or more protrusions.

14. The device according to claim 10, wherein The first portion of the rod has a first diameter and the second portion of the rod has a second diameter, and wherein the second diameter is greater than the first diameter.

15. The device according to claim 10, wherein The surface of the suction cup includes one or more aiming guides to provide an indication of the approximate center of the suction cup.

16. A device for removing tissue, the device comprising: a suction cup forming a tapered circumferential suction chamber, the tapered circumferential suction chamber comprising a first tapered portion that tapers from a circumferential edge of the tapered circumferential suction chamber at a first height to a center of the tapered circumferential suction chamber at a second height, the second height being less than the first height, thereby enabling suction to be applied to tissue in a first direction, and wherein the suction cup comprises a second tapered portion that tapers continuously around the circumference of the suction cup at a proximal end of the suction cup from a first height at the circumferential edge of the suction cup to a third height at a distal end of the suction cup, the third height being less than the first height and greater than the second height; and A stem is coupled to the proximal end of the suction cup via an opening in the tapered side of the suction cup such that a neck of the stem enables fluid to flow toward the stem and from the stem into the suction cup in a second direction substantially perpendicular to the first direction.

17. The device according to claim 16, wherein The first portion of the rod has a first diameter and the second portion of the rod has a second diameter, and wherein the second diameter is greater than the first diameter.

18. The device according to claim 16, wherein The surface of the suction cup includes one or more aiming guides to provide an indication of the approximate center of the suction cup.

19. The device of claim 16, further comprising a receiving bag located at a distal end of the suction cup, the receiving bag being collapsible between a horizontal position and a vertical position.

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