Abstract: Endoscopic mucosal resection is performed by the steps of injecting a local injection preparation containing a biocompatible mucoploysaccharide having no anticoagulant activity, preferably sodium hyaluronate, into the submucosal layer of an affected mucosal tissue to create mucosal elevation, and then, trapping the thus-elevated mucosal tissue with a snare to perform resection. Preferably the local injection preparation further contains a hemostat or angiotonic, and a pharmaceutically acceptable dyestuff.

Abstract: A system for severing lesions within a living body includes a housing defining an interior tissue receiving chamber is coupled to the distal end of an endoscope. At least one snare extends around the ligating band supporting surface so that, when at least one ligating band is received around the ligating band supporting surface, drawing the at least one snare off the ligating band supporting surface releases a corresponding ligating band from the ligating band supporting surface. In addition, a method for severing tissue comprises the steps of introducing into the body an endoscope to which a housing defining an interior tissue receiving chamber is coupled, wherein at least one snare and at least one ligating band extend around the ligating band supporting surface and advancing the distal end of the endoscope into the body until the housing is located adjacent to a first portion of tissue to be severed.

Abstract: A wire loop type instrument for an endoscope has a control wire axially movably inserted in a flexible sheath, and a wire loop connected to the distal end of the control wire. The wire loop is formed by an elastic wire. When the control wire is advanced, the wire loop projects from the distal end of the flexible sheath and expands in a loop shape by its own elasticity. When the control wire is retracted, the wire loop is pulled into the distal end of the flexible sheath and folded. The elastic wire is a stranded wire formed by twisting together a plurality of thin metal wires. The control wire is formed by twisting together a pair of elastic wires extending from the rear end of the wire loop in the opposite direction to the direction of twist of each elastic wire.

Abstract: A medical retrieval device includes a basket formed of two or more loops. The basket may be used to retrieve material (e.g., a urinary stone) from a body. The basket opens and closes for end-encapsulation of a stone and is strengthened by support members that interconnect the basket loops. A captured stone may be released from the basket with the basket still in the body by opening the loops.

Abstract: A catheter with at least one integrated lumen and methods of its manufacture and use are provided. A method of manufacture includes: (1) covering a primary mandrel with a first layer, (2) disposing a second layer on the first layer, wherein the second layer has at least one removable secondary mandrel substantially embedded therein, (3) fusing the first layer to the second layer, (4) removing the secondary mandrel from the second layer to form a secondary lumen, and (5) removing the primary mandrel from the first layer to form a primary lumen. The method may further include forming an inflatable balloon at the surface of the second layer where the secondary lumen forms an opening. Also, auxiliary apparatus, such as snare instruments and bundles of optical fibers, may be inserted through the secondary lumen before or during use of the catheter.

Abstract: The present invention is directed to a surgical instrument used in minimally invasive procedures performed under either direct, endoscopic, fluoroscopic, or other visualization. The surgical instrument includes a frame which can be retracted into and extended from a sheath to form a loop and a sack having a mouth that is attached to the loop. The sack is used to encircle and capture foreign objects in body canals, cavities or organs. The wire frame is formed of a shape-memory-effect alloy wire in a super elastic state and previously trained to form the loop, the loop forming when the said wire frame is extended beyond the sheath. An invertor is connected to a closed end of the sack for urging the closed end of the sack toward the mouth of the sack.

Abstract: A surgical instrument for the deployment of medical devices such as wires and snares wherein one hand manipulates a device including advancing, opening, rotating, closing and retracting.

Abstract: A snare for an endoscope has a snare wire formed from an elastic wire that is connected to the distal end of a control wire axially movably inserted in a flexible sheath. When the control wire is advanced axially, the snare wire projects from the distal end of the flexible sheath and expands in a loop shape by its own elasticity. When the control wire is retracted axially, the snare wire is pulled into the distal end of the flexible sheath and thus contracted. The distal end surface of the flexible sheath is provided with a plurality of claw-shaped projections projecting forward in parallel to each other.

Abstract: A surgical snare instrument according to several embodiments includes a first handle capable of controlling the rotational position of the snare, and a second handle adapted to control the opening and closing of the snare and cauterization. The first handle serves as a grippable element on the sheath and contains a system which rotates the shaft, and consequently the snare, so that when the physician grips the first handle, the physician is capable of steering the snare by operating the first handle. In addition, the physician is also capable of positioning the entire sheath relative to the endoscope by sliding the sheath into and out of the working channel of the endoscope. The proximal handle is operable by an assistant and permits longitudinal movement of the shaft and cautery application. According to other embodiments, the snare instrument is provided with a mount which enables the snare instrument to be adjustably fixed relative to an endoscope handle.

Abstract: A surgical instrument for excising includes an endoscopic portion with an ultrasonically vibratable loop. The loop is positioned around the tissue and closed, whereupon ultrasonic energy is transmitted to the loop to cut and cauterize the body tissue. The apparatus and method described herein are particularly suitable for colonoscopic polypectomy procedures.

Abstract: A snare for an endoscope includes a control wire axially movably inserted in a flexible sheath. A snare loop formed by an elastic wire is connected to the distal end of the control wire. When the control wire is advanced, the snare loop projects from the distal end of the sheath and expands in a loop shape by its own elasticity. When the control wire is retracted, the snare loop is pulled into the sheath and folded. The snare loop is formed by two elastic wires between two mutually secured portions of the elastic wires, which are laid in parallel and in close contact with each other and secured together directly at two longitudinally spaced positions. The control wire is formed by an extending portion of at least one of the elastic wires that extends rearward from the mutually secured portion at the rear end of the snare loop.

Abstract: A method and apparatus for managing polyps by which an elongated tubular member generally positionable within the working channel of an endoscopic device. The tubular member carries a selectively extendable severing device and capturing device at its distal end. Control apparatus at the proximal end of the tubular member enables a physician to extend and retract the severing and capturing devices. The physician retracts the capturing device to grasp the portion of the polyp to be severed and retracts the severing device to sever the polyp. The capturing device retains the severed portion of the polyp for removal with the tubular member. In one embodiment the capturing device includes an injection needle.

Abstract: The treatment tool for an endoscope has an operation portion including an operation portion body and a slider. The operation portion body has a proximal end portion provided with a ring-like finger engaging portion, and a grip portion is formed to be adjacent to the finger engaging portion. The slider has a pair of flanges for engaging a finger and a finger rest extending from the flange adjacent the rear end portion. An operator can insert his or her thumb of one hand into the ring-like finger engaging portion, and engages another finger of the same hand between the pair of flanges of the slider. The operation portion body and the slider can be relatively moved thereby. Otherwise, the operator can also relatively move the operation portion body and the slider by gripping the grip portion of the operation portion body on his or her palm of one hand and by engaging the thumb of the same hand on the finger rest of the slider shaped like a hood.

Abstract: A device for treating a lesion comprises a sheath extending from a proximal end which, in an operative position, is located outside the body, to a distal end which, in the operative position is located within the body. A needle extending through the sheath has a tissue piercing distal tip and a central lumen extending through the needle from a proximal port to a distal opening formed in the distal tip and a needle actuator is provided for moving the needle between a retracted position in which the distal tip is received within the sheath to an injection position in which the distal tip extends distally beyond a distal end of the sheath. A snare extends within the lumen to a loop formed in a distal end of the snare and a snare actuator is provided for moving the snare between a covered position in which the loop is received within the lumen and an extended position in which the loop extends distally from the lumen beyond the distal tip.

Abstract: A hand held dental instrument for curing light-curable compounds comprises a housing and an array of solid state, light emitting junctions or dies for generating light having wavelengths within a narrow band of wavelengths (e.g. 400-500 nm). Preferably, a peak wavelength of 470 nm is generated. The device further comprises an optical fiber light pipe for capturing the light and transmitting a beam of the light to a work surface containing a light-curable compound. An optical lens or lenses may be used for focusing the light into the light pipe.

Abstract: A surgical apparatus is provided having a first instrument and a second instrument which are independently operable, but may be used in tandem. The first instrument may comprise a needle and the second instrument may comprise a snare for cutting, excising, or trapping tissue. An actuator extends the needle a fixed first length relative to a distal end of the catheter for independently extending or retracting the second instrument a variable second length relative to the catheter distal end. The needle may be biased to retract relative to the distal end of the catheter. The actuator has a support and a slider. The slider is connected to the support for movement in opposite directions relative the support to allow freedom of action. The first instrument is secured to the support and rail, and the second instrument is secured to the slider.

Abstract: A medical retrieval device, and related method, uses a basket formed by one or more legs to retrieve material such as calculi. At least one of the legs has at least an inner and a outer surface. The outer surface is an atraumatic surface such as a curved surface. The atraumatic surface can include one or more radii. The inner surface can be flat such that the leg has a D-shaped cross section. Other shapes are possible for the inner surface including a pointed shape that enhances the basket's stone crushing or breaking ability. The inner surfaces, whatever its shape, can have a rough surface (e.g., serrated, etched, toothed, etc.) for further enhancing the basket's ability to capture stones and other calculi.

Abstract: An electrosurgical cutting apparatus for performing laparoscopic section of an organ makes use of an electrical current transporter. The transporter includes a conducting wire, electrical insulation portions around the conducting wire at the first end and at the second end, forming respectively a first and a second insulated end and defining a non-insulated cutting portion between said first insulated end and said second insulated end, and a first fastening device located at the first end of the conducting wire and a second fastening device located at the second end of said conducting wire. The second fastening device is in electrical contact with the conducting wire.

Abstract: A medical retrieval device includes a basket with three or more legs. The device can be used to retrieve material from a body such as stones. At least one of the legs of the basket is moveable independently from at least one of the other legs. This independent movability allows material to be captured more readily and easily. A distal end of the basket can be non-perforated.

Abstract: A method and apparatus for managing polyps by which an elongated tubular member generally positionable within the working channel of an endoscopic device. The tubular member carries a selectively extendable severing device and capturing device at its distal end. Control apparatus at the proximal end of the tubular member enables a physician to extend and retract the severing and capturing devices. The physician retracts the capturing device to grasp the portion of the polyp to be severed and retracts the severing device to sever the polyp. The capturing device retains the severed portion of the polyp for removal with the tubular member. In one embodiment the capturing device includes an injection needle.

Abstract: A vascular filter for capturing and removing emboli includes a sack having a mouth and a closed bottom opposite the mouth. A guide wire is received through the mouth of the sack and projected through the closed bottom of the sack. The closed bottom of the sack is connected to the projection of the guide wire therethrough. A collapsible frame is connected between the guide wire and the mouth of the sack. The collapsible frame biases the mouth of the sack open around the guide wire. A tube slidably receives the guide wire coaxially therein. The collapsible frame is moveable via the guide wire between outside the tube where the mouth of the sack is biased open by the collapsible frame and inside the tube where the mouth of the sack is closed, and vice versa.

Abstract: A tool actuating assembly for a multi-function surgical instrument is disclosed. The tool actuating assembly of the present invention can be utilized in a variety of differently configured multi-function surgical instruments and can be embodied in various physical configurations. The tool actuating assembly of the present invention provides for more efficient use of the tools of the instrument by the surgeon who is utilizing the instrument.

Abstract: A device for laproscopic surgery with an expandable basket for entrapping cutting and removing target tissue. The basket consists of a plurality of elongate flexible elements with cutting edges facing the central longitudinal axis of the device.

Abstract: In a surgical instrument for endoscopes, one end of an resecting section of a wire to be used for resecting a lesion is fixedly connected to a fluid injection needle, and the other end of the same is fixedly connected to a surgical instrument operation section. As a result, the retraction of the fluid injection needle and the resection of the lesion can be carried out by means of a single operation for sliding the treatment instrument operation section.

Abstract: A medical retrieval device includes a basket formed of two or more loops. The basket may be used to retrieve material (e.g., a urinary stone) from a body. The basket opens and closes for end-encapsulation of a stone and is strengthened by support members that interconnect the basket loops. A captured stone may be released from the basket with the basket still in the body by opening the loops.

Abstract: An endoscopic treatment tool including a flexible sheath (1) that is to be passed into or out of a treatment tool insertion channel in an endoscope and which has openings (4A, 4B) formed at and near the distal end to communicate with the interior of the flexible sheath (1). A plurality of manipulating wires (3A, 3B) that have treating members (5A, 5B) are coupled to the distal ends and are passed through the flexible sheath (1) such that they can be moved back and forth independently of each other along the longitudinal axis. The treating member (5a) is provided to have access to the flexible sheath (1) via the opening (4A) at its distal end and the other treating member (5B) is provided to have access to the flexible sheath (1) via the opening (4b) near its distal end.

Abstract: This application is directed to a stent delivery system for introducing a flexible, generally cylindrical, self-expandable stent.

Abstract: A treatment unit for an endoscope, for example, a grasping unit is connected at a distal end of a manipulation wire that is connected to a first manipulation member. An inner tube slidably surrounds the manipulation wire. A proximal end of the inner tube is connected to a proximal end of a second manipulation member. Further, an outer tube is provided to surround the inner tube and the manipulation wire. A proximal end of the outer tube is connected to the first manipulation member so that the positional relationship between the manipulation wire and the outer tube along the axis is fixed. By moving the first and second manipulation members towards each other, the grasping unit is closed as the inner tube slides to cover a part of the grasping unit, while when the first and second manipulation members are spaced from each other, the grasping unit opens by resilience.

Abstract: A basket-type grasping tool, adapted for use in combination with an endoscope, for capturing a foreign material or the like into a basket section. Axially corresponding portions of elastic wires are each twisted in the same direction about a center axis of a basket section. Guide paths, through which the elastic wires respectively pass, are formed on an inner face of a tip-end mouth of a sheath.

Abstract: The present invention provides an endoscope having an opening of a channel tube retracted from a distal end face having an observation window of the insert therein toward a proximal end side. When a plurality of polyps are removed, a picked-up polyp is moved back from the distal end face of the insert toward the proximal side of the insert in order for the picked-up polyp not to interfere with observation by the endoscope and operation by a cutting tool extending through the endoscope channel.

Abstract: A flat section is provided at a distal end of a snare pipe located in a sheath. When a snare is pushed, the snare is moved in the snare pipe with a looped expansible section of the snare kept in contact with both opposite sides of the flat section. As a result, the expansion direction of the looped section is regulated.

Abstract: A surgical snare instrument includes a tubular sheath having proximal and distal ends, a flexible shaft having proximal and distal ends extending through and axially movable relative to the sheath, a snare loop at the distal end of the shaft, and a handle assembly coupled to the proximal ends of the sheath and shaft for moving the shaft axially relative to the sheath. The handle assembly is provided with cautery capability to provide a cautery current to the snare loop. The snare loop is trained to have a proximal portion which extends along an angle or curve relative to the tubular member and a distal portion which is substantially parallel to the tubular member. As such, when the snare loop is axially moved beyond the distal end of the sheath, the distal portion of the snare loop; i.e., that portion which is adapted to engage a polyp, is oriented substantially parallel, yet non-axial, with the tubular member.

Abstract: A wire loop type instrument for an endoscope having a plurality of elastic wires bundled together at distal and proximal ends thereof and adapted to form a loop shape as a whole. When withdrawn into the distal end of a sheath, the elastic wires are folded. When projecting from the distal end of the sheath, the elastic wires expand in the loop shape by their own elasticity. The elastic wires are inserted in a bundle into a pipe-shaped member at at least one of the distal and proximal ends thereof. The elastic wires are fixed to the pipe-shaped member by a fixing material such that portions of the elastic wires which are in the vicinity of the entrance of the pipe-shaped member are not fixed, but the elastic wires are fixed to the pipe-shaped member at portions thereof which are on the inner side of the vicinity of the entrance.

Abstract: A method and apparatus for managing polyps by which an elongated tubular member generally positionable within the working channel of an endoscopic device. The tubular member carries a selectively extendable severing device and capturing device at its distal end. Control apparatus at the proximal end of the tubular member enables a physician to extend and retract the severing and capturing devices. The physician retracts the capturing device to grasp the portion of the polyp to be severed and retracts the severing device to sever the polyp. The capturing device retains the severed portion of the polyp for removal with the tubular member. In one embodiment the capturing device includes an injection needle.

Abstract: An injection snare is disclosed. One embodiment of the present invention includes an instrument body, an actuator slidably attached to the body, a catheter attached to and extending through the body at a proximal end of the catheter, an injection needle, and a snare. The injection needle is disposed within the catheter and has a proximal end connected to the actuator. A distal end of the injection needle contains a piercing tip. The injection needle is movable within the catheter between a first position wherein the distal end of the needle extends beyond the distal end of the catheter and a second position wherein the distal end of the needle is retracted within said catheter. The snare is attached to the distal end of the injection needle.

Abstract: A surgical instrument assembly for a snare cauterization operation comprises a tubular member having a diameter sufficiently small so that the tubular member can be inserted through a biopsy channel of a flexible endoscope. Multiple endoscopic instrument including a cauterization loop, a flexible web member connected to the cauterization loop or to an auxiliary loop so as to form a capture pocket, and an elongate flexible fluid feed tube provided at a distal end with a needle point and an aperture, are slidably disposed in the tubular member. The fluid feed instrument is used to expand a flat or nonprojecting polyp prior to severing thereof with the cauterization loop and capture of the severed polyp with the web member or pocket.

Abstract: A treatment unit for an endoscope, for example, a grasping unit is connected at a distal end of a manipulation wire that is connected to a first manipulation member. An inner tube slidably surrounds the manipulation wire. A proximal end of the inner tube is connected to a distal end of a second manipulation member. Further, an outer tube is provided to surround the inner tube and the manipulation wire. A proximal end of the outer tube is connected to a main body connected to the first manipulation a member by a connecting rod that the positional relationship between the manipulation wire and the outer tube along the axis is fixed. By moving the first and second manipulation members towards each other, the grasping unit is opened as the inner tube slides to uncover a part of the grasping unit which opens by resilience, while when the first and second manipulation members are spaced from each other, the inner tube slides to cover a part of the grasping unit forcing it closed.

Abstract: In one embodiment the present invention comprises an ultrasonic polyp snare adapted to grasp, cut and coagulate polyps and other tissue masses in internal body lumens, specifically in the colon. An ultrasonic polyp snare according to the present invention includes an ultrasonic signal generator attached to the proximal end of a flexible ultrasonic waveguide. An ultrasonic vibration amplifier is coupled to the distal end of the flexible ultrasonic waveguide. An ultrasonic blade is coupled to the ultrasonic amplifier. An ultrasonic attenuator is coupled to the distal end of the ultrasonic blade. And, a snare wire is positioned adjacent at least a portion of the ultrasonic blade.

Abstract: An insertion tube has a suction opening and a view window provided to an end surface of a tip thereof. The hood includes an outer wall and a partition wall mounted to the tip of the insertion tube. The outer wall projects from the tip so as to surround the end surface of the tip. The partition wall is provided to divide a cavity surrounded by the outer wall into two cavities, in such a manner that the suction opening and the view window are separately located in the cavities.

Abstract: The invention relates to a high frequency surgical instrument comprising a handling part (11) which has a guide channel (12) which is open at at least one end and a holding element (13) which is axially displaceably guided therein and on which a high frequency voltage acts. The holding element (13) is axially displaceable by means of an actuating part (14) axially displaceable relative to the handling part (11) and is electrically conductively connected at its free end to a preferably elastic cutting loop (15) in such a way that, through axial adjustment of the actuating part (14), the cutting loop (15) can be drawn to a greater or lesser degree into the guide channel (12), or into a tube (16) which continues it outwardly, or can be pushed out of the guide channel (12), or out of the tube (16) continuing it outwardly, whereby the loop size can be changed.

Abstract: A device for treating a lesion comprises a sheath extending from a proximal end which, in an operative position, is located outside the body, to a distal end which, in the operative position is located within the body. A needle extending through the sheath has a tissue piercing distal tip and a central lumen extending through the needle from a proximal port to a distal opening formed in the distal tip and a needle actuator is provided for moving the needle between a retracted position in which the distal tip is received within the sheath to an injection position in which the distal tip extends distally beyond a distal end of the sheath. A snare extends within the lumen to a loop formed in a distal end of the snare and a snare actuator is provided for moving the snare between a covered position in which the loop is received within the lumen and an extended position in which the loop extends distally from the lumen beyond the distal tip.

Abstract: Grasping an object, e.g., a calculus in the biliary tract, using a grasper, such as a basket, that can be opened and closed without mechanical advantage and also rotated about the device axis to make it easier to capture the object. The basket can then be closed further with mechanical advantage to crush the object.

Abstract: Apparatus for cleaning a vessel having a stenosis therein comprising first and second balloon catheters. Balloons are disposed on opposite sides of the stenosis in the vessel and form a closed chamber in the vessel. A therapeutic catheter having a distal extremity is disposed in the chamber. Irrigation liquid is supplied to the chamber and liquid is aspirated from the chamber to form an aspirate. The distal extremity of the therapeutic catheter is moved to cause the material forming the stenosis to be removed from the wall of the vessel and to be broken into particles which are removed with the aspirate.

Abstract: A surgical combination apparatus includes a first instrument (e.g., an injection needle), a second instrument (e.g., a snare) and a catheter for sheathing the first and second instruments. An actuator is included for extending the first instrument and the second instrument independent of each other. A biasing mechanism is also provided to bias the first instrument into a retracted position. A locking mechanism is also preferably provided to hold the first instrument in either the extended or retracted position.

Abstract: A wire loop type instrument for an endoscope that uses an elastic wire formed from a stranded wire bent into a U-shape and looped at the rear of the U-shaped bent portion. Each strand of the stranded wire has a non-circular cross-sectional configuration in which the strand is more resistant to bending in other directions than in a direction toward the center of the elastic wire. The stranded wire is formed by twisting together a plurality of strands each having a circular cross-section. The stranded wire is passed through a die with a hole having a smaller diameter than that of the stranded wire, thereby compression-deforming each strand into a non-circular cross-sectional configuration. A composite stranded wire may be used as the elastic wire, which is formed by twisting together a plurality of stranded wires each formed from a plurality of strands twisted together.

Abstract: A medical extractor comprising a cannula assembly having an annularly expanding and retracting gripping and releasing mechanism on the distal end thereof and a moving assembly on the proximal end thereof. The arrangement is such that a manual movement of the moving assembly in one direction effects a longitudinally outward movement of an annular array of longitudinally movable wire flexure elements within an annular array of longitudinally fixed tubular flexure elements to cause the fixed flexure elements to flex transversely outwardly and create an annularly expanded condition defined by an annular series of transversely outwardly flexed fixed flexure elements interconnected at their ends by an annular series of arcuately outwardly flexed portions of the movable flexure elements.

Abstract: An endoscopic surgical device for severing tissue within a subject and for retrieving severed tissue from within the subject is disclosed. The device has a support unit, a tissue severing snare system, and a tissue retrieving net system. The snare and net systems are carried by the support unit and may be inserted into the subject through an orifice or small incision and individually operated to sever and retrieve tissue. The snare system includes a snare, a snare actuator, and a snare deployment and retrieval assembly for transmitting motion between the actuator and the snare. The net system includes a net, a net actuator, a net deployment and retrieval assembly for transmitting motion between the net and its actuator and a net controller for assuring the net is fully opened when deployed.

Abstract: A surgical instrument assembly for use in snare cauterization operations includes a first tubular sheath member containing a metallic electrical snare cauterization loop. A second tubular sheath member is disposed inside of the first tubular sheath member. A flexible suture member is releasably connected to the cauterization loop, and is provided with a one-way slip knot at its distal end thereby forming a loop of a size corresponding to that of the cauterization loop. The proximal end of the suture member is disposed in the distal end of the second tubular sheath member and is releasably joined to a manually-controlled flexible tensioning device. During use of the instrument, the cauterization loop and connected suture member is expanded from a collapsed configuration and passed over a polyp or other body tissue that is to be removed.

Abstract: The present invention provides a device or apparatus for manipulating matter in a confined or inaccessible space, comprising manipulator means at least partly constructed of one or more bent or twisted elongate metallic members having pseudoelasticity at the intended manipulation temperature, and a hollow housing (preferably of elongate tubular form) or cannula capable of holding at least the metallic member(s) in a relatively straightened state, and actuating means for extending the metallic member(s) from the housing to manipulate matter within the said space and for withdrawing the metallic member(s) into the housing, the arrangement being such that the metallic member(s) bend(s) or twist(s) pseudoelastically in a lateral or helical sense to manipulate the matter on extending from the housing at the said manipulation temperature, and become(s) relatively straightened on withdrawal into the housing at the said temperature.

Abstract: A surgical instrument for removing the cataractous nucleus from the eye. The instrument consists of a proximal handle and plunger. The plunger also acts as a screw-drive for an auger located at the distal end of the instrument. The screw-drive plunger is advanced exposing a nucleus encasing basket at the distal end of the instrument. The nucleus is completely encased in the distal basket and slowly ground up by the auger, removing the nucleus from the eye in its entirety. The use of unique internal gearing between the auger and encasing element results in a safe, efficient, controllable evacuation of the nucleus from the eye.