US20040253129A1 - Liquid venting surgical cassette - Google Patents

Abstract

A surgical system having a cassette with an aspirant vent line that permits a fluidic connection between the inlet to a aspirant pump and the outlet of the aspirant pump through a vent valve. When the aspiration vent valve is open, fluid flows from the pump outlet into the pump inlet, thereby releasing any pressure within the pump inlet. Such a system does not require a second source of irrigation fluid, minimizes pressure surges into the irrigation fluid line and does not affect the fluidic performance of the aspiration system.

Description

• This application is a continuation-in-part of U.S. patent application Ser. No. 10/430,974, filed May 7, 2003, currently co-pending which is a continuation-in-part of U.S. patent application Ser. No. 10/407,388, filed Apr. 4, 2003, which is a continuation-in-part application of U.S. patent application Ser. No. 09/846,724, filed May 1, 2001, now U.S. Pat. No. 6,572,349 B2, which is a continuation of U.S. patent application Ser. No. 09/437,392, filed Nov. 10, 1999, now U.S. Pat. No. 6,293,926 B1, and a continuation-in-part of U.S. patent application Ser. No. 10/153,371, filed May 28, 2002, and is a continuation-in-part application of U.S. patent application Ser. No. 09/925,989, filed Aug. 9, 2001, now U.S. Pat. No. 6,740,074 B1, which is a continuation-in-part of U.S. patent application Ser. No. 09/771,945, filed Jan. 29, 2001, now U.S. Pat. No. 6,632,214 B1, which is a divisional of U.S. patent application No. 09/387,357, filed Aug. 31, 1999, now U.S. Pat. No. 6,261,283 B1.[0001]
BACKGROUND OF THE INVENTION
• This invention relates generally to the field of cataract surgery and more particularly to an aspiration system for a handpiece for practicing the phacoemulsification technique of cataract removal.[0002]
• The human eye in its simplest terms functions to provide vision by transmitting light through a clear outer portion called the cornea, and focusing the image by way of the lens onto the retina. The quality of the focused image depends on many factors including the size and shape of the eye, and the transparency of the cornea and lens.[0003]
• When age or disease causes the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. An accepted treatment for this condition is surgical removal of the lens and replacement of the lens function by an artificial intraocular lens (IOL).[0004]
• In the United States, the majority of cataractous lenses are removed by a surgical technique called phacoemulsification. During this procedure, a thin phacoemulsification cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquifies or emulsifies the lens so that the lens may be aspirated out of the eye. The diseased lens, once removed, is replaced by an artificial lens.[0005]
• A typical ultrasonic surgical device suitable for ophthalmic procedures consists of an ultrasonically driven handpiece, an attached cutting tip, and irrigating sleeve and an electronic control console. The handpiece assembly is attached to the control console by an electric cable and flexible tubings. Through the electric cable, the console varies the power level transmitted by the handpiece to the attached cutting tip and the flexible tubings supply irrigation fluid to and draw aspiration fluid from the eye through the handpiece assembly.[0006]
• The operative part of the handpiece is a centrally located, hollow resonating bar or horn directly attached to a set of piezoelectric crystals. The crystals supply the required ultrasonic vibration needed to drive both the horn and the attached cutting tip during phacoemulsification and are controlled by the console. The crystal/horn assembly is suspended within the hollow body or shell of the handpiece by flexible mountings. The handpiece body terminates in a reduced diameter portion or nosecone at the body's distal end. The nosecone is externally threaded to accept the irrigation sleeve. Likewise, the horn bore is internally threaded at its distal end to receive the external threads of the cutting tip. The irrigation sleeve also has an internally threaded bore that is screwed onto the external threads of the nosecone. The cutting tip is adjusted so that the tip projects only a predetermined amount past the open end of the irrigating sleeve. Ultrasonic handpieces and cutting tips are more fully described in U.S. Pat. Nos. 3,589,363; 4,223,676; 4,246,902; 4,493,694; 4,515,583; 4,589,415; 4,609,368; 4,869,715; 4,922,902; 4,989,583; 5,154,694 and 5,359,996, the entire contents of which are incorporated herein by reference.[0007]
• In use, the ends of the cutting tip and irrigating sleeve are inserted into a small incision of predetermined width in the cornea, sclera, or other location. The cutting tip is ultrasonically vibrated along its longitudinal axis within the irrigating sleeve by the crystal-driven ultrasonic horn, thereby emulsifying the selected tissue in situ. The hollow bore of the cutting tip communicates with the bore in the horn that in turn communicates with the aspiration line from the handpiece to the console. A reduced pressure or vacuum source in the console draws or aspirates the emulsified tissue from the eye through the open end of the cutting tip, the cutting tip and horn bores and the aspiration line and into a collection device. The aspiration of emulsified tissue is aided by a saline flushing solution or irrigant that is injected into the surgical site through the small annular gap between the inside surface of the irrigating sleeve and the cutting tip.[0008]
• During surgery, the hollow, resonating tip can become occluded. During occlusion, vacuum can build in the aspiration line downstream of the occlusion. When the occlusion eventually breaks apart, this pent up vacuum is released into the eye which can, depending upon the amount of vacuum, draw a significant amount of fluid from the eye, thereby increasing the risk of anterior chamber collapse. To address this concern, modem surgical console can detect increases in aspiration line vacuum beyond normal operating parameters and therefore predict occlusions. These consoles can then either stop or slow the aspiration pump, or sound an alarm so that the surgeon can take appropriate precautions.[0009]
• The cassettes used in modem consoles also allow the aspiration line to be vented, either to atmosphere or to a liquid so as to reduce or eliminate vacuum surge upon occlusion break. Prior art air vented cassettes allow ambient air to enter the aspiration line, however, venting air into the aspiration line changes the fluidic performance of the aspiration system. Liquid venting systems allow irrigation fluid to bleed into the aspiration line, thereby reducing any impact on the fluidic performance of the aspiration system. Liquid venting cassettes are more fully described in U.S. Pat. Nos. 4,832,685 and 4,935,005 (Haines) and U.S. Pat. No. 4,713,051 (Steppe, et al.), the entire contents of which being incorporated herein by reference. When higher aspiration vacuums are used, cassettes that vent the aspiration line to the irrigation line can cause high pressure surges in the irrigation line. Other systems provide a separate source of irrigation fluid to vent the aspiration line, requiring the use of two irrigation fluid sources and increasing the cost and complexity of the system.[0010]
• Therefore, a need continues to exist for a simple surgical system that allows rapid venting of excess aspiration vacuum without introducing pressure variations in the irrigation line or the downstream aspiration line.[0011]
BRIEF SUMMARY OF THE INVENTION
• The present invention improves upon the prior art by providing a surgical system having a cassette with an aspirant vent line that permits a fluidic connection between the inlet to a aspirant pump and the outlet of the aspirant pump through a vent valve. When the aspiration vent valve is open, fluid flows from the pump outlet into the pump inlet, thereby releasing any pressure within the pump inlet. Such a system does not require a second source of irrigation fluid, minimizes pressure surges into the irrigation fluid line and does not affect the fluidic performance of the aspiration system.[0012]
• Accordingly, one objective of the present invention is to provide a surgical system having a aspiration line vent.[0013]
• Another objective of the present invention is to provide a surgical system having a cassette that allows the aspiration line to be vented of excess vacuum.[0014]
• Another objective of the present invention is to provide a surgical system having a cassette that vents the aspiration line to an aspirant collection chamber.[0015]
• Another objective of the present invention is to provide a surgical system that vents the aspiration line without introducing pressure surges in the irrigation line.[0016]
• Another objective of the present invention is to provide a surgical system that vents the aspiration line without affecting the fluidic performance of the aspiration system.[0017]
• These and other advantages and objectives of the present invention will become apparent from the detailed description and claims that follow.[0018]
BRIEF DESCRIPTION OF THE DRAWING
• FIG. 1 is a schematic illustration of a first embodiment of the system and cassette of the present invention.[0019]
• FIG. 2 is a schematic illustration of a second embodiment of the system and cassette of the present invention.[0020]
DETAILED DESCRIPTION OF THE INVENTION
• As best seen in FIG. 1, first embodiment of[0021]system10 of the present invention generally includessurgical console12 andcassette14.Console12 may be any suitably modified commercially available surgical console, such as the SERIES TWENTY THOUSAND® LEGACY®V, INFINITI® or ACCURUS® surgical systems available from Alcon Laboratories, Fort Worth, Tex.Cassette14 may be any suitably modified commercially available surgical cassettes, such as those described in U.S. Pat. Nos. 5,267,956, 5,364,342 and 5,499,969 (Beuchat, et al.) and U.S. Pat. No. 5,899,674 (Jung, et al.), the entire contents of which being incorporated herein by reference.Cassette14 is held in operative association withconsole12 by means well-known in art.
• As seen in the FIG. 1,[0022]console12 generally containsaspiration pump mechanism16, which may be any suitable flow or vacuum based pump, such pumps being widely known in the art. For example,pump mechanism16 may be a peristaltic pump roller head that interacts with a peristaltic pump tube formed byaspiration line20 andaspiration exhaust line34.Aspiration line20 is connected tosurgical handpiece22 on one end and end18 ofaspiration line20opposite handpiece22 interacts withpump mechanism16 so as to draw fluid throughhandpiece22.Aspiration line20 is intersected betweenhandpiece22 and18 byaspiration vent line24. In fluid communication withaspiration vent line24 ispressure sensor26, which may be one of a variety of invasive or non-invasive pressure sensors well-known in the art.
• [0023]Cassette14 generally containsfluid reservoir28. Extending fromreservoir28 at or near bottom29 isaspiration vent line32, which fluidly connects toaspiration vent line24 throughvent valve30. Aspirant or exhaust frompump mechanism16 is directed intoreservoir28 throughaspiration exhaust line34.Reservoir28 may also vent to ambient throughfluid line41,waste bag40 and ventline36, which may containantimicrobial filter38.
• As discussed above, while it is preferred that[0024]pump mechanism16 be a peristaltic roller head andaspiration line20 andaspiration exhaust line34 be formed in one continuous length so as to form a peristaltic pump tube that interacts withpump mechanism16, one skilled in the art will recognize thataspiration line20 and aspiration exhaust line may be formed as a separate piece or pieces or may be formed integrally withcassette14 and thatpump mechanisms16 other that peristaltic pump roller heads may be used, such as linear peristaltic pumps.
• In addition,[0025]pressure sensor26 is depicted as being contained withinconsole12. One skilled in the art will recognize that portions ofpressure sensor26, such as a pressure diaphragm (not shown) may be contained in or oncassette14 and interact with a force transducer or other means (not shown) contained withinconsole12.
• In use,[0026]cassette14 is installed on or withinconsole12 and held in operative association withconsole12 by means well-known in the art.System10 is primed initially with clean surgical fluid so that a small amount of fluid fillsreservoir28. During surgery,pump mechanism16 draws aspirant throughhandpiece22 and intoreservoir28. If the vacuum withinaspiration line20 is too high and needs to be vented, ventvalve30 is opened allowing aspirant to be drawn off ofbottom29 of reservoir28 (reservoir28 being at or near ambient) and into aspiration line20 (which contains a vacuum) throughaspiration vent line24. One skilled in the art will recognize that by varying the vertical position ofreservoir28 relative toaspiration line20, various vent head pressures may be achieved.Reservoir28 may be relatively small, and not capable of holding all of the aspirant collected during surgery.Waste bag40 may be used to drain and hold excess fluid fromreservoir28, throughfluid line41 abovebottom29 ofreservoir28.Waste bag40 may be integrally formed withincassette14 or may be formed as a separate collapsible bag attached tocassette14, as is well-known in the art.
• As best seen in FIG. 2, second embodiment of system[0027]100 of the present invention generally includessurgical console112 andcassette114.Console112 may be any suitably modified commercially available surgical console, such as the SERIES TWENTY THOUSAND® LEGACY® or ACCURUS® surgical systems available from Alcon Laboratories, Fort Worth, Tex.Cassette114 may be any suitably modified commercially available surgical cassettes, such as those described in U.S. Pat. Nos. 5,267,956, 5,364,342 and 5,499,969 (Beuchat, et al.) and U.S. Pat. No. 5,899,674 (Jung, et al.), the entire contents of which being incorporated herein by reference.Cassette114 is held in operative association withconsole112 by means well-known in art.
• As seen in FIG. 2,[0028]console112 generally containsaspiration pump mechanism116, which may be any suitable flow or vacuum based pump, such pumps being widely known in the art. For example,pump mechanism116 may be a peristaltic pump roller head that interacts with a peristaltic pump tube formed by aspiration line120 and aspiration exhaust line134. Aspiration line120 is connected tosurgical handpiece122 on one end and end118 of aspiration line120opposite handpiece122 interacts withpump mechanism116 so as to draw fluid throughhandpiece122. Aspiration line120 is intersected betweenhandpiece122 and118 byaspiration vent line124. In fluid communication withaspiration vent line124 is pressure sensor126, which may be one of a variety of invasive or non-invasive pressure sensors well-known in the art.
• Extending from vent line[0029]134 is aspiration vent line132, which fluidly connects toaspiration vent line124 through vent valve130. Aspirant or exhaust frompump mechanism116 is directed into vent line132 through aspiration exhaust line134 but is prevented from enteringline124 by valve130. Exhaust line134 empties intowaste bag40, which may ventwaste bag140 to atmosphere throughvent line136, which may containantimicrobial filter38.
• As discussed above, while it is preferred that[0030]pump mechanism116 be a peristaltic roller head and aspiration line120 and aspiration exhaust line134 be formed in one continuous length so as to form a peristaltic pump tube that interacts withpump mechanism116, one skilled in the art will recognize that aspiration line120 and aspiration exhaust line134 may be formed as a separate piece or pieces or may be formed integrally withcassette114 and that pumpmechanisms116 other that peristaltic pump roller heads may be used, such as linear peristaltic pumps.
• In addition, pressure sensor[0031]126 is depicted as being contained withinconsole112. One skilled in the art will recognize that portions of pressure sensor126, such as a pressure diaphragm (not shown) may be contained in or oncassette114 and interact with a force transducer or other means (not shown) contained withinconsole112.
• In use,[0032]cassette114 is installed on or withinconsole112 and held in operative association withconsole112 by means well-known in the art. System100 is primed initially with clean surgical fluid so that a small amount of fluid fills exhaust line134 andwaste bag140. During surgery,pump mechanism116 draws aspirant throughhandpiece122 and into exhaust line134. If the vacuum within aspiration line120 is too high and needs to be vented, vent valve130 is opened allowing aspirant to be drawn out of exhaust line134 and into aspiration line120 (which contains a vacuum) throughaspiration vent line124, effectively shunting positively pressurized fluid from exhaust line134 into negatively pressurized aspiration line120.
• This description is given for purposes of illustration and explanation. It will be apparent to those skilled in the relevant art that changes and modifications may be made to the invention described above without departing from its scope or spirit. For example, one skilled in the art will recognize that by varying the vertical position of the distal end of exhaust line[0033]134 relative to aspiration line120, various vent head pressures can be achieved.

Claims (1)

We claim:

1. A cassette, comprising:

a) a body;

b) an aspiration line extending through the body;

c) an aspiration exhaust line extending through the body and connected to a waste bag;

d) an aspiration vent line extending through the body, the aspiration vent line connected on one end to the aspiration exhaust line and to the aspiration line on the other end; and

e) a vent valve located in the body in the aspiration vent line.

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