Suction cup design for capsulotomy device

Abstract

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

Description

[0001] This application is a divisional application of patent application with the application date of August 11, 2021, application number 202180071732.8, and the invention name of “Sucker Design for Capsulotomy Device”.

[0002] Cross Reference to Related Applications

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 078,128, filed September 14, 2020, and U.S. Patent Application No. 17 / 112,759, filed December 4, 2020, the entireties of which are hereby incorporated by reference for all purposes. BACKGROUND

[0004] This specification generally relates to medical devices, and particularly to microsurgical instruments for capsulotomy.

[0005] Current tissue cutting devices often create issues with uneven suction, which can result in inadequate cutting of the capsule. Uneven suction is particularly problematic for tissue cutting devices that deliver suction to the suction cup through a single orifice located at one circumferential location of the suction cup. In addition, current tissue cutting devices often create inconsistent edges in the cut tissue, which can not be adequate to withstand the remaining steps of a cataract procedure. Furthermore, using current tissue cutting devices, it is difficult to align the center of the device with a desired surgical landmark. Finally, using current tissue cutting devices, it is difficult to visually monitor the level of suction inside the device. SUMMARY

[0006] Embodiments relate to a microsurgical device for tissue cutting that creates consistent capsulotomies and improves upon current tissue cutting devices. The microsurgical device provides uniform suction across the circumference of the suction cup and creates a strong, tear-resistant roll. In addition, the microsurgical device consistently creates a complete capsulotomy without creating residual overhangs attached to the edge of the capsulotomy. Further, the device can include features that assist the surgeon during device placement, allow for visual monitoring of the amount of suction created in the suction cup, etc.

[0007] The design of the suction cup ensures that a uniform suction force is applied to the tissue to be resected. For example, the suction cup can form a tapered circumferential suction chamber that decreases in cross-sectional area from the proximal end of the device to the distal end of the device. Additionally, 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 the suction force is reduced, ensuring a more uniform suction force. Furthermore, in some embodiments, the suction cup can include one or more struts that create a channel for the flow of material. Due to the channel created, a uniform suction force is created throughout the suction cup.

[0008] In addition to the design of the suction cup, the configuration of the stem coupled to the suction cup ensures that a uniform suction force is applied to the tissue to be resected. The suction force is applied to the suction cup through the orifices of the stem that are coupled to the tapered sides of the suction cup. In some embodiments, the neck of the stem enables fluid to flow to and from the stem, and into the suction cup, in a direction that is substantially perpendicular to the direction of the suction force to be applied to the tissue. For example, the fluid flow through the neck can be substantially horizontal, and the suction force applied to the tissue can be substantially vertical. The different flow directions help to ensure that a uniform suction force is applied to the tissue.

[0009] Furthermore, the configuration of the suction cup helps to ensure that a consistent roll is formed. 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 distance far enough away from the tissue to affect the tissue remotely via a change in temperature. The change in temperature helps to form the roll.

[0010] Additionally, the manufacturing, shipping, and use of the device is made easier by the design of the suction cup. For example, the suction cup can include a containment pocket that is collapsible between a horizontal position and a vertical position. The containment pocket can be molded in the vertical position, and assembled and / or shipped in the horizontal position. Furthermore, different portions of the suction cup can have various thicknesses to reduce the amount of material used for the suction cup. By reducing the amount of material used for the suction cup, the force required to insert the suction cup through the incision is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1A A microsurgical device is shown coupled to its console according to one embodiment.

[0012] Figures 1B-1C A microsurgical device is shown according to one embodiment. Figure 1A A cross-sectional view of the microsurgical device is shown.

[0013] Figure 1D A microsurgical device is shown according to one embodiment. Figure 1AA bottom view of the microsurgical device is shown.

[0014] Figure 1E A microsurgical device according to one embodiment is shown. Figure 1A A bottom perspective view of the microsurgical device is shown.

[0015] Figure 1F A top perspective view of the microsurgical device is shown. Figure 1A A top perspective view of the microsurgical device is shown.

[0016] Figure 1A A flow of current through a cutting element of the microsurgical device is shown. Figure 2 A flow of current through a cutting element of the microsurgical device is shown.

[0017] Figure 1A A microsurgical device according to one embodiment is shown. Figures 3A-3F Steps of the device are shown.

[0018] The accompanying drawings, which are included to provide a further understanding only, depict various example embodiments of the technology. As will be readily appreciated by one skilled in the art, other embodiments DETAILED DESCRIPTION

[0019] Figure 1A Various views of a microsurgical device 100 for tissue cutting are shown. Figures 1A-1F An embodiment of a microsurgical device 100 is shown. Figure 1A A cross-sectional view of a microsurgical device 100 is shown. Figures 1B-1C A bottom view of a microsurgical device 100 is shown.

[0020] Figure 1D A bottom perspective view of a microsurgical device 100 is shown. Figure 1E A top perspective view of a microsurgical device 100 is shown.

[0021] Figure 1FThe illustrated device 100 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 stem 125. The suction cup 105 and the cutting element 110 are located at a distal end of the stem 125, which houses the one or more suction tubes 115 and the electrical leads 120A, 120B. The device 100 also includes a control 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 control console 130 via the one or more suction tubes 115 and a suction connector 135. The cutting element 110 is connected to the control 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.

[0022] The suction cup 105 is a collapsible structure that can provide a fluid-tight seal between the edges 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, a vacuum pressure can be applied to the suction cup 105 and the tissue such that the resulting pressure presses the cutting element 110 against the tissue. Pressing the cutting element 110 against the tissue facilitates a more precise, smoother cut. The collapsible structure of the suction cup 105 is reversibly collapsible such that the cross-section of the suction cup 105 can be reduced for insertion of the device 100 through an incision. As such, the suction cup 105 can comprise a compliant material, such as silicone, polyurethane, etc. In one embodiment, the material of the suction cup 105 is a medical grade silicone having a Shore A durometer of 60 (e.g., Nusil MED-4960). Additionally, the silicone can be transparent, which can facilitate placement of the suction cup 105.

[0023] The cutting element 110 is an element designed to be able to cut tissue by applying pressure and / or applying an electrical current via one or more electrical leads 120A, 120B coupled to the cutting element 110. The cutting element 110 can be made of various materials. In some embodiments, the metallic component of the cutting element 110 can be made of a suitable electroformed material, such as nickel, nitinol, gold, steel, copper, platinum, iridium, molybdenum, tantalum, etc. When the cutting element 110 is configured to electrically resect tissue, the material used for the cutting element 110 is electrically conductive. Additionally, the cutting element 110 is reversibly collapsible, such that the cross-section of the cutting element 110 can be reduced for insertion through the incision insertion device 100. Thus, the material of the cutting element 110 is typically elastic, such that it can return to its original shape after being passed through the incision insertion device 100. An example of a typical construction is a super-elastic nitinol ring with a 0.075 mm wall thickness, a 0.140 mm height, and a tab. Another strategy is to add a thin film (e.g., 0.0001 mm to 0.002 mm) of a material that is better conductive than the super-elastic body, which does not have to be super-elastic because it is very thin. Examples of materials include, but are not limited to, spring steel, stainless steel, nitinol, gold, silver, or any other material that allows the cutting element 110 to return to its previous shape.

[0024] The device 100 is capable of delivering a wide range of energy (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 on a specific tissue of interest. For example, in a capsulotomy of the anterior lens capsule of an adult human, it was found that about 1.2 Joules produced satisfactory results. Examples of some specific applications of capsulotomy include pediatrics as well as adult humans 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. Additionally, the temperature gradient in the cutting element 110 can be designed and / or modified for different tissues.

[0025] One or more suction tubes 115 are located within the shaft 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 tube 115 is a medical grade silicone with a Shore A hardness of 60 (e.g., Nusil MED-4960). In some embodiments, the electrical leads 120A, 120B, the anchor lines, and / or the rigid extensions pass through the one or more suction tubes 115 to the suction cup 105.

[0026] The one or more suction tubes 115 can also be configured to function as a fluid path. For example, the one or more suction tubes 115 can be primed with a solution, such as a balanced salt solution, prior to use. Priming the fluid path of the one or more suction tubes 115 can help ensure that there is little to no compressible air in the device 100. Additionally, after the resection of tissue is complete, a hydraulic release can be implemented on the one or more suction tubes 115 to release the suction cup 105 from the tissue. In some embodiments, the hydraulic release involves forcing 0.05 ml to 0.2 ml of balanced salt solution back into the suction cup 105 from the suction tube 115.

[0027] 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 the antipodal points of the suction cup 105. This configuration can ensure that the suction is equally distributed throughout the suction channel of the suction cup 105. In other embodiments, the suction tubes 115 can be positioned proximate to one another within a threshold angle, within a threshold distance, etc., relative to one another. Furthermore, 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, etc. 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, the proximal end of the suction cup 105, the distal end of the suction cup 105, etc.

[0028] The electrical leads 120A, 120B are configured to provide electrical energy to the cutting element 110. The electrical leads 120A, 120B are located within the shaft 125 of the device 100 and are coupled to the surface of the cutting element 110. In some embodiments, the electrical leads 120A, 120B are silver wire. In other embodiments, the electrical leads 120A, 120B are made of copper, aluminum, gold, etc. Additionally, the electrical leads 120A, 120B can be insulated.

[0029] The console 130 is configured to provide suction to the suction cup 105 and electrical energy to the cutting element 110. Additionally, an operator of the device 100 can control the depth of cut via the console 130 by modifying the suction and / or electrical parameters of the device 100.

[0030] Suction is provided to the suction cup 105 via one or more suction tubes 115 connected to the console 130 and a suction connector 135. Using the console 130, an operator of the device 100 can provide suction to the suction cup 105, reverse the suction during disengagement of the device 100, and / or flush the fluid path of the one or more suction tubes 115 with a solution. Additionally, an operator of the device 100 can modify the amount of suction applied to the suction cup 105 based on the operation being performed. In some embodiments, an 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 a vacuum gauge of the console 130. Alternatively or additionally, the console 130 can include predetermined suction parameters determined via experimentation, modeling, and / or a combination thereof, each associated with a procedure. Additionally, using the console 130, different amounts of suction can be provided to different suction tubes. For example, a suction pressure of 19 + / - 1 inch Hg vacuum has been successfully used. This suction pressure is a gauge pressure, not an absolute pressure, so the console 130 can establish the same pressure differential along the suction cup wall regardless of the height used.

[0031] 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 electrical connectors 145. The first set of electrical conductors 140A can be configured to provide electrical power to the cutting element 110. The second set of electrical conductors 140B can be used for resistance measurements and can be connected to a measurement device, such as a Kelvin probe (also known as 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 (respectively) 24 ga copper wire, 30 ga copper wire, and the like. In other embodiments, the first set of electrical conductors 140A and / or the second set of electrical conductors 140B are composed of aluminum, gold, silver, and the like. Electrical energy can be provided to the cutting element 110 as one or more electrical waveforms. The one or more electrical waveforms are discharged through the cutting element 110 to provide a short duration of heating to the cutting element 110, such as 0.0001 seconds to 0.05 seconds, depending on the voltage and current applied.

[0032] Using the console 130, the depth of cut can be controlled by controlling the amount of electrical discharge applied to the cutting element 110. For example, the depth of cut can be controlled by modifying one or more of the following: the energy of each pulse, the number of pulses in a pulse sequence, the inter-pulse interval, etc. As with suction, the operator of the device 100 can manually modify these parameters using control elements of the console 130. Alternatively or additionally, the console 130 can include predetermined sets of parameters that are each associated with a different depth of cut, a different patient type, etc. These sets of parameters can be determined through experimentation, modeling, and / or a combination thereof. The console 130 can be a controller, a microprocessor, programmable hardware logic, etc.

[0033] In some embodiments, the console 130 can automatically change the operating parameters of the device 100. For example, the console 130 can change the operating parameters according to a predetermined set of operating steps associated with a procedure. Alternatively or additionally, the console 130 can change the operating parameters of the device 100 based on feedback from the device 100 itself. For example, the console 130 can change the operating parameters of the device 100 during use in response to detection of a device resistance, a pressure, a pressure change, a temperature, a temperature change, a determined depth of cut, etc.

[0034] Figure 1A A cross-sectional view of the device 100 is shown. In the illustrated embodiment, 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 to ensure that a uniform suction force is applied, in part because the height of the chamber decreases as the volume to be evacuated decreases.

[0035] 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 antipode 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 force to be applied, the type of procedure to be performed, the type of tissue to be excised, the amount of electrical energy to be applied, features (e.g., struts and / or visual guides) included on the underside of the suction cup 105, etc. For example, the tapered circumferential suction chamber 150 can be inclined 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 a horizontal axis of the suction cup 105. Examples of the angle of inclination 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.

[0036] Additionally, the geometry and dimensions of the suction cup 105 can be modified to prevent the suction cup 105 from collapsing when suction is applied. For example, as shown, the top of the tapered circumferential suction chamber 150 can be arched to prevent collapse. The rise and span of the arched 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. Figure 1B

[0037] 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 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, and the like). In other embodiments, portions of the suction cup can have various thicknesses. For example, portions that should not create 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 portions with increased thickness can have a thickness of about 200 microns or greater. Other portions of the suction cup can have a thickness of about 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, and the like. By limiting the portions of the suction cup 105 with increased thickness, the overall amount of silicon required to manufacture the suction cup 105 is reduced, and collapse of the suction cup 105 is prevented. Moreover, by reducing the amount of silicon, the force required to insert the suction cup 105 through the incision is reduced.

[0038] The stem 125 is coupled to the proximal end of the suction cup 105 via an opening within the tapered side of the suction cup 105. The neck 155 of the stem 125 enables fluid to flow to the stem 125 along a direction that is substantially perpendicular to the direction of suction to be applied on the tissue, and out of the stem 125 into the suction cup 105. For example, the angle between the fluid flow into and out of the stem 125 and the direction of suction to be applied on the tissue can be between 85 degrees and 95 degrees, between 80 degrees and 100 degrees, and the like. The substantially perpendicular flow helps to ensure uniform distribution of suction. In alternative embodiments, the neck 155 of the stem 125 can be configured to provide substantially vertical flow. In these embodiments, additional mechanisms can be coupled to the neck 155 of the stem 125 to facilitate the flow of suction and / or fluid horizontally from the stem 125 to the suction cup 105.

[0039] ​As previously discussed, the device 100 can include a rigid extension (not shown) for extending the cutting element 110 out for insertion of the device 100 through an incision (e.g., a corneal incision). An 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 shipping. However, the length of the one or more prongs can need to prevent the one or more prongs from puncturing the containment pocket 160 of the suction cup 105.

[0040] A basic principle of injection molding in device manufacturing is that the intended molded part should not have features that create significant flash, prevent the two mold halves from separating, and restoration of the molded part. In some cases, the use of side pins can create the desired molding features, but can involve greater cost and can reduce precision. A horizontal containment pocket can have significant flash and cannot be manufactured using standard molding techniques with two mold halves that separate in a vertical direction.

[0041] To remove the flash created by a horizontal containment pocket, the containment pocket 160 can collapse between a vertical position and a horizontal position. In some embodiments, the containment pocket 160 can collapse between the horizontal and vertical positions due to the material of the containment pocket 160 being flexible. In alternative embodiments, the containment pocket 160 can be collapsible due to one or more joints or any other suitable collapsing mechanism. To facilitate manufacturing, the containment pocket 160 can be molded into the vertical position. The vertical position of the containment pocket 160 helps to ensure that the containment pocket is easily released when pulled away from the two mold halves along the vertical direction. When the containment pocket 160 collapses into the horizontal position, it can receive the end of the rigid extension. In some embodiments, the containment pocket 160 is constrained to be placed horizontally during shipping. When the suction cup 105 and the cutting element 110 are extended via the rigid extension, it can remain horizontal. When the rigid extension is retracted, the containment pocket 160 returns to its as-molded vertical state due to the elasticity of the silicone.

[0042] Figure 3A Another cross-sectional view of the device 100 is shown. As referenced above, the device 100 includes a rigid extension 120 that extends the cutting element 110 out for insertion of the device 100 through an incision (e.g., a corneal incision). An end of the rigid extension 120 can include one or more prongs 122 to which the cutting element 110 is coupled. The one or more prongs 122 can substantially prevent the rigid extension 120 and the cutting element 110 from separating during shipping. However, the length of the one or more prongs 122 can need to prevent the one or more prongs 122 from puncturing the containment pocket 160 of the suction cup 105. Figure 1CAs 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.

[0043] like Figure 1B 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.

[0044] 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. Figure 1CIn 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.

[0045] Figures 3A-3F Another view of the device 100 is shown. Figures 1D-1F 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.

[0046] 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.

[0047] 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.

[0048] In some embodiments, the struts include slots, such as slots 195. The slots face away from the direction of the stem 125 and / or the suction tube 115. In alternative embodiments, the slots can face toward the stem and / or the suction tube 115, each slot can face a different direction, etc. The slots can be modified to cause air to exit at different levels of suction.

[0049] Performing the capsulotomy at the precise location on the lens surface is critical, as an off-center capsulotomy can result in less IOL stability and poorer IOL optical performance. The surgeon can use a number of different surgical landmarks to center the capsulotomy. These include the location of certain Purkinje images or light reflections that can be used to indicate the patient's visual axis location. An automated capsulotomy device, such as device 100, should allow the cutting element 110 to be easily centered with such Purkinje images. In the illustrated device 100, the centering of the suction cup 105 with the desired surgical landmark, such as a Purkinje light reflection, is facilitated by placing an aiming guide, such as aiming guide 190, near the center of the suction cup 105. The aiming guide can have various geometries and facilitate the surgeon's visual recognition of the center location of the suction cup 105 and / or the cutting element 110. The aiming guide can be fabricated on the suction cup 105 using silicon micro-molding techniques well known in the art.

[0050] Once the suction cup 105 has been identified as desirably aligned, the activation of the suction should not cause substantial movement of the position of the cutting element 110, which can result in an off-center capsulotomy. If the cutting element 110 is merely inserted into the bore of the suction cup 105, but the suction cup 105 does not fully constrain the movement of the cutting element 110 as the internal volume of the suction cup 105 decreases under the action of the suction, then unwanted movement of the cutting element 110 can occur. To prevent unwanted movement, the cutting element 110 can be physically bonded to the suction cup 105, as shown. Figure 1D

[0051] ​The cutting element 110 is composed of an electrically conductive metal, and the suction cup 105 can be composed of silicone, so they are made as two separate parts. Hollow pockets, such as the pockets 197, are provided in the suction cup 105 to receive one or more tabs that protrude from the cutting element 110. During manufacturing, the tabs are positioned within the corresponding hollow pockets, and silicone is injected into the hollow pockets to secure the attachment tabs in place. In some embodiments, the silicone is potting from the top side of the suction cup 105. In alternative embodiments, the silicone is potting from the bottom side of the suction cup 105. For example, during bottom potting, liquid silicone can be dispensed in each pocket. The cutting element 110 is then placed on the suction cup 105, the electrical leads 120A, 120B are threaded through the inner cavity of the stem 125, and the attachment tabs are immersed in the liquid silicone in the potting pockets. The assembly can then be heated to cure the silicone. In some embodiments, the pockets include a membrane that prevents the liquid silicone from reaching the cutting element 110. When the attachment tabs are placed into the hollow pockets, the attachment tabs can pierce the membrane.

[0052] Figure 1E A path of the flow of electrical current within the cutting element 110 is shown. When entering the cutting element 110 through the electrical lead 120A, a portion of the electrical current (e.g., half of the electrical current (i 1 / 2 )) is transmitted along one half of the cutting element 110, while another portion of the electrical current (e.g., the other half of the electrical current (i 1 / 2 )) is transmitted along the other half of the cutting element 110. The electrical current then exits the cutting element 110 at the other electrical lead 120B. Due to the electrical resistance of the cutting element 110, the flow of electrical current causes the temperature of the cutting element 110 to rapidly increase. Due to the rapid increase in temperature, water molecules proximate or adjacent to the cutting element 110 and the tissue to be removed rapidly vaporize and mechanically break along the path defined by the tissue portion to be removed.

[0053] Figure 2 A step for using the apparatus 100 shown is shown, according to one embodiment. Figures 3A-3F A step for using the apparatus 100 shown is shown, according to one embodiment. Figure 1A is a cross-section of the apparatus 100 immediately proximate to the capsule membrane 305 that surrounds the lens capsule 310. In the cross-section shown, the suction cup 105 has a flow channel in which the silicone is dome-shaped and thick enough to prevent a constriction from occurring when suction is applied (e.g., along the tapered circumferential suction chamber 150 of the suction cup 105). The struts, such as the strut 185, keep the flow path open under the membrane center during suction. The body of the cutting element 110 shown has a rectangular cross-section. In alternative embodiments, the cutting element 110 can be any suitable shape, such as conical, elliptical, etc.

[0054] The sealing contact 170 of the skirt 180 of the suction cup 105 abuts against the lens capsule 305 that surrounds the lens 310. The operator of the device centers the device 100 on the visual axis of the patient. Once centered, the rigid extension has been retracted from its extended position so that the end of the rigid extension is in 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 large range of anterior chamber depths ACD (e.g., 1.9 mm to 4.0 mm ACD).

[0055] Figure 3A The deformation of the lens 310 and the suction cup 105 that occurs when suction is applied to the suction cup 105 is shown. The suction pulls the lens capsule 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. At the same time, 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 lens capsule and the outer bottom edge 183 of the cutting element 110 to limit the cut to the inner bottom edge 181 of the cutting element 110. In alternative embodiments, the cut 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.

[0056] A small volume 315 is formed so that the liquid here is trapped between the lens capsule 305, the cutting element 110, and the suction cup 105. The tensile forces caused by the suction create a significant tensile stress in the lens capsule 305. There is a concentration of tensile stress where the lens capsule 305 is in contact with the inner bottom edge 181 of the cutting element 110. Because this tensile stress is built up before the cutting discharge, it is already there to act upon at the instant the discharge occurs and adds a brief amount of heat. In some embodiments, the small volume 315 that separates the outer diameter of the cutting element 110 from the lens capsule 305 is small enough that it allows the cutting element 110 to cause a change in temperature in the lens capsule 305 from a distance, remotely, to help the lens capsule roll up after the cutting procedure is complete.

[0057] Figure 3B The situation is shown when a discharge is occurring through the cutting element 110. Within the first few microseconds of the cutting event, the cutting element 110 heats to a temperature hotter than the critical temperature of water. As a result, water molecules that are within a few microns of the cutting element 110 vaporize. The vapor that is trapped in the small volume 315 cannot escape in this short time, so the pressure in the trapped small volume 315 increases. The increase in pressure causes a change in curvature in the lens capsule 305. This can also cause a change in the volume of the small volume 315.

[0058] At the same time, heat flows from the cutting element 110 into the capsule membrane 305 at the point of contact (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 membrane 305 and the cutting element 110, the capsule membrane 305 becomes weak. Due to the symmetry of the device 100, equal forces and temperatures are applied circumferentially around the cutting element 110 in contact with the capsule membrane 305. When the strength of the capsule membrane 305 is less than the force to tear it, the capsule membrane 305 ruptures. The force to tear the capsule membrane 305 can be caused by 1) tensile stress from the suction force to be applied, and / or 2) increased pressure in the small volume 315 due to steam heating.

[0059] Because the cutting event occurs on the time scale of milliseconds (e.g., 1 to 10 milliseconds), the limiting factor is the inertia of the mass surrounding the material. A large force is required to accelerate the mass of material during this short time interval. During the time interval of milliseconds, the steam pressure builds up, the material will start to move, but at this point the capsulotomy is complete. For example, the discharge can be composed of 12 pulses of 66 microseconds on, 305 microseconds off, and a total time of 4 milliseconds. This can not be enough time to accelerate and move the mass of material. Note that different thicknesses of capsules or other tissue can be cut by varying the number of pulses, the duration of each pulse, the inter-pulse interval, and the energy of each pulse. Additionally, the bottom width of the cutting ring can be adjusted to vary the spatial extent of the remote temperature effect (e.g., rolling up).

[0060] Figure 3C A retraction area 325 is shown where the stretched capsule membrane 305 is retracted from the inner bottom edge 181 of the cutting element 110 after the discharge is complete. In some embodiments, the inertial mass involved in this motion is small.

[0061] Figure 3D The edge of the capsule membrane 305 is shown rolling up as the edge cools. Because the heating method employed by the device 100 creates a temperature gradient across the thickness of the capsule membrane 305, the edge of the capsule membrane 305 will roll up. As discussed with respect to Figure 3E The outer surface of the capsule membrane 305 will receive heat from the cutting element 110 through the steam (e.g., confined in the small volume 315) in contact with it. The heat causes the collagen to shrink. The collagen shrinks more at the outer surface 305A of the capsule membrane 305 than at the inner surface 305B of the capsule membrane 305 because the cutting event is too short for a significant amount of heat to pass through the steam layer and shrink the inner surface 305B of the capsule membrane 305 as much as the outer surface 305A. This creates a tensile stress gradient across the thickness of the capsule membrane 305 as it cools. The shrinkage of the collagen in the top layer pulls the edge inwards, causing it to roll up. The edge of the capsule bag can only roll up so far as it contacts the bottom of the cutting element 110 and / or the suction cup 105.

[0062] Figure 3B Figure 3F The flow direction 330 is shown that implements fluid release to relieve suction and lift the suction cup 105 off the lens 310. Because the edge of the capsular bag is rolled up against the bottom of the cutting element 110 and the suction cup 105, the flow at this location is directed between the capsular membrane 305 and the lens 310. This implements water separation to separate the capsular membrane 305 from the lens 310.

[0063] As the fluid release proceeds, the edge of the capsular bag remains rolled up against the bottom of the suction cup 105, so it still directs fluid between the capsular membrane 305 and the lens 310 to complete the water separation. In some embodiments, the fluid release proceeds quickly (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 for the released flow to follow the path of water separation, rather than simply float the suction cup 105 up. 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 stress created by the brief heat it reached during the cutting event.

[0064] Additional configuration information

[0065] The foregoing description of embodiments of the application has been presented for the purposes of illustration and description; it is not intended to be exhaustive or to limit the application to the precise form disclosed. Many modifications and variations are possible in light of the above teaching.

[0066] The language used in the specification is intended to be illustrative and is not intended to limit the subject matter of the present application. Therefore, it is contemplated that the claims will be drafted to include alternative language to express the subject matter of the application. It is further contemplated that the claims will be drafted to exclude any optional element of the application. Thus, the subject matter of the application is not intended to be limited to the particular embodiments disclosed in the specification. The scope of the application is defined by the claims appended hereto, which are intended to be construed in accordance with the principles of patent law. Accordingly, the disclosure of the embodiments is intended to be illustrative, but not limiting, of the scope of the disclosure, which is set forth in the following claims. As used herein, any reference to "one embodiment" or "the embodiment" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

Claims

1. A device for removing tissue, the device comprising: a suction cup forming a conical suction chamber, the conical suction chamber comprising a first conical portion that tapers from a periphery of the conical suction chamber at a first height to a center of the conical 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 conical 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 periphery of the suction chamber 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 rod coupled to a proximal end of the suction cup; and A cutting element is coupled to the suction cup and is configured to resect tissue.

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

3. 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.

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

5. 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.

6. The device according to claim 1, wherein The inner surface of the suction cup includes one or more aiming guides to provide an indication of the visual axis of the tissue to be resected.

7. The device according to claim 1, wherein The suction cup includes a transparent silicone material.

8. The device according to claim 1, wherein The suction cup is configured to form a watertight seal with tissue.

9. A device for removing tissue, the device comprising: a suction cup forming a conical suction chamber, the conical suction chamber comprising a first conical portion that tapers from a periphery of the conical suction chamber at a first height to a center of the conical 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 conical 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 periphery of the suction chamber 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 to the stem and from the stem into the suction cup; and A cutting element is coupled to the suction cup and is configured to resect the tissue.

10. The device according to claim 9, wherein The suction cup has a tapered edge.

11. The device of claim 9, 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.

12. The device according to claim 9, 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.

13. The device according to claim 9, 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.

14. The device according to claim 9, wherein The inner surface of the suction cup includes one or more aiming guides to provide an indication of the visual axis of the tissue to be resected.

15. The device according to claim 9, wherein The suction cup includes a transparent silicone material.

16. The device according to claim 9, wherein The suction cup is configured to form a watertight seal with tissue.

17. A device for removing tissue, the device comprising: a suction cup forming a conical suction chamber, the conical suction chamber comprising a first conical portion that tapers from a periphery of the conical suction chamber at a first height to a center of the conical 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 conical 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 periphery of the suction chamber 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; and A rod is coupled to the proximal end of the suction cup.

18. The device according to claim 17, 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.

19. The device according to claim 17, 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.

20. The apparatus according to claim 17, wherein The inner surface of the suction cup includes one or more aiming guides to provide an indication of the visual axis of the tissue to be resected.

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