Surgical instrument for minimally invasive aspiration of tissue

Abstract

The present invention relates to a surgical instrument for minimally invasive aspiration of tissue. A device for destroying cataracts in lens tissue. The device includes a housing; a pulsed laser radiation source and an optical waveguide. The optical waveguide is configured to conduct pulsed laser radiation from the pulsed laser radiation source and can be coupled to the pulsed laser radiation source at the proximal end of the optical waveguide to receive pulsed laser radiation from the pulsed laser radiation source. The device further includes a drive mechanism that is coupled to the optical waveguide to controllably change the relative position of the optical waveguide and the distal end of the housing.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of September 21, 2018, an application number of 201880055421.0, and an invention title of "Surgical Instrument for Minimally Invasive Aspiration of Tissue".

[0002] Cross - Reference to Related Applications

[0003] This application claims the priority of U.S. Provisional Patent Application No. 62 / 564,019, filed on September 27, 2017, entitled "Surgical Instrument for Minimally Invasive Aspiration of Tissue", which is incorporated herein by reference in its entirety. Technical Field

[0004] The present invention generally relates to devices and methods used in cataract surgery. In particular, the present invention relates to surgical laser ablation devices and methods for disrupting and aspirating cataract lens tissue. Background Art

[0005] Cataract surgery has been developed to treat blindness caused by the turbidity of the lens tissue in the human eye. Although most cases of cataracts are related to the aging process, occasionally a child may be born with this condition, or cataracts may develop after eye injuries, inflammation, and other eye diseases. The treatment of cataract lens tissue is one of the most commonly performed surgeries.

[0006] In modern small-incision cataract surgery, an eye surgeon uses a handheld metal or diamond blade to form an incision at the junction of the sclera and the cornea. The next step in cataract surgery is to remove the front part of the capsule to access the cataract. Once the capsule is incised, instruments can be inserted to separate and disrupt the cataract before removal. Tools for separating the lens include mechanical tools such as a 'chopper' or forceps for separating tissue, and more recently, tools incorporating ultrasonic transducers have been adopted to emulsify the tissue prior to aspiration. For example, US8454551B2 has proposed a variety of single-use ultrasonic aspiration needles.

[0007] A device has been proposed that uses laser radiation to disrupt tissue through a heating effect or photoacoustically generated ultrasonic energy (e.g., U.S. Patent 6083192A). Others have also adopted a technique in which radiation from a very short-pulse laser that is not sufficiently absorbed in the eye tissue is focused within the volume of the cataract lens to achieve photo-disruption of the tissue prior to aspiration. The latter technique is affected by the need for a projection system and has not been implemented in a handheld instrument due to the lack of an effective optical waveguide bundle transmission for such short pulses.

[0008] Mid-infrared lasers with microsecond and longer pulses have been used to ablate lens tissue. U.S. Patent 8,029,501 (the entire content of which is incorporated into the present application) describes a laser ablation mechanism (pulse thermal deposition), in which rapid heating caused by exciting the vibrational modes inside the tissue causes vaporization of the exposed tissue. The laser source required for this new mechanism can be compatible with a specific fiber bundle transmission system.

[0009] WO2016041086A1 (the full text of which is incorporated into the present application) presents a surgical device and method, in which the above laser mechanism can be used to destroy and remove lens tissue through a handheld instrument, and the handheld instrument includes a fiber bundle transmission system for contact tissue destruction. In an embodiment of the invention, the distal end of the optical fiber is transmitted to the tissue inside a suction needle with a larger diameter. Summary of the Invention

[0010] In some examples, the present invention describes a device for destroying cataracts in lens tissue. The device includes a housing; a pulsed laser radiation source and an optical waveguide. The optical waveguide is at least partially accommodated in the housing and includes a flexible optical fiber. The optical waveguide is configured to transmit pulsed laser radiation to cause damage to the cataract, and the optical waveguide can be coupled to the pulsed laser radiation source at the proximal end of the optical waveguide to receive pulsed laser radiation from the pulsed laser radiation source. The device further includes a drive mechanism that is coupled to the optical waveguide to controllably change the relative position of the optical waveguide and the distal end of the housing. Brief Description of the Drawings

[0011] Now, by way of example, reference will be made to the drawings showing embodiments of the present application, in which:

[0012] Figure 1 is a partial perspective view of an embodiment of laser destruction of cataract lens tissue;

[0013] Figure 2 is a partial perspective view of an embodiment of a handheld laser instrument for transmitting a laser pulse source;

[0014] Figure 3 is Figure 2 a cross-sectional view of an example of the distal tip of the handheld laser instrument, in which the suction needle and the optical fiber are collinear, and the entrance of the suction channel is unobstructed;

[0015] Figure 4 is Figure 2 a cross-sectional view of an example of the distal tip of the handheld laser instrument, in which tissue debris is drawn towards the suction channel under negative pressure, and the tissue debris is too large to be suctioned and completely blocks the entrance of the suction channel;

[0016] Figure 5 is Figure 4Cross-sectional view of an example of the same tissue fragment being disrupted and aspirated, with the blockage partially or completely removed;

[0017] Figure 6 is Figure 2 Cross-sectional view of an example of the distal tip of a hand-held laser instrument that has created a persistent blockage, where the laser fiber disrupts all tissue within its range but cannot clear the blockage;

[0018] Figure 7 Is a cross-sectional view of an example hand-held laser instrument where the distal end of the optical fiber can be positioned within the aspiration needle such that aspirating fluid can be contained within a sterilizable or disposable tool assembly without contaminating some of the reusable parts that the fiber bundle transmits, while allowing the non-elastic optical fiber to move within the aspiration channel;

[0019] Figure 8 is Figure 2 An embodiment of a laser instrument where the instrument is in three separable parts; including a reusable laser transmission assembly with an optical fiber connector for the optical fiber, a detachable tip hand-held assembly including a distal instrument tip with an output channel for irrigation, an aspiration needle, and an extended optical fiber tip that also includes a location for connecting a disposable tube to a disposable aspiration and irrigation device; and

[0020] Figure 9 Is an example of an exploded view of a replaceable hand-held assembly where a small optical fiber is attached to an optical fiber connector that connects to a corresponding connector in the reusable laser transmission assembly.

[0021] In different figures, similar element symbols may be used to represent similar elements. Detailed Description

[0022] In some examples, the present invention provides a hand-held laser phacoemulsification device for disrupting and removing cataract lens tissue.

[0023] In some examples, the present invention provides a device that, by utilizing laser energy to disrupt tissue in contact with the optical fiber tip 16, helps to provide an improved aspiration rate for the surgical instrument 54 compared to conventional instruments. The optical fiber tip 16 is collinearly located within the small diameter of the aspiration channel, which is adapted for manual positioning within the anterior capsule of the human eye. The optical fiber 16 can be advanced or retracted within the aspiration channel to enhance the aspiration rate of the tissue and also minimize the risk of disrupting non-intended aspirated tissue.

[0024] In some examples, the present invention integrates control of fluid (aspiration and irrigation devices) and laser disruption through an algorithm that adjusts laser parameters, such as pulse frequency, envelope, and the positioning of the laser tip, based on user input and sensor output (e.g., measuring pressure and flow rates within aspiration and irrigation channels) to achieve faster and more precise aspiration with minimal jets (flow and vacuum) and minimal disruption of surrounding tissue.

[0025] In some examples, the present invention provides a surgical instrument 54 that enhances user control of the aspiration rate by additionally integrating a movable optical fiber 16 into the irrigation / aspiration tip and a control system algorithm that automatically optimizes the fiber position and laser pulse frequency in response to various user inputs and sensed fluid condition feedback to minimize invasive damage to surrounding tissue structures, limit pressure variations in the anterior capsule, and minimize the flow of aspiration and irrigation during tissue removal.

[0026] The present invention describes an apparatus including a laser probe that contacts and enters the body and is capable of effectively driving rapid decomposition of tissue by optical excitation of selected vibrational modes within tissue molecules in a time sequence earlier than heat diffuses to the surroundings. The laser probe uses a laser mechanism similar to that disclosed previously in WO2016041086A1, which is incorporated herein by reference in its entirety.

[0027] The present invention is directed to an exemplary method for effectively disrupting hard cataract tissue while avoiding energy transmission to other tissues of the eye.

[0028] Reference Figure 1 , discloses an exemplary laser ablation method. Figure 1Illustrates an explanation of laser disruption of cataract lens tissue 1. Laser disruption is generated when a laser pulse having a selected duration, wavelength, and pulse energy (e.g., the laser pulse disclosed in WO2016041086A1) is coupled to an optical waveguide 12 and exits from the distal end 16 of the optical waveguide 12. The optical waveguide 12 has passed through the incision point 7 and is inserted into the anterior chamber of the eye through an opening within the capsule 9 and is directed towards the interior of the cataract lens tissue 1. The light is strongly absorbed by the lens cells 3 or the intercellular regions 8 in contact with the exit of the optical waveguide 16, or irradiates a volume of tissue 5 within a distance approaching the laser optical absorption depth 40 within the tissue, causing disruption to the lens cells and / or the lens cell structure 4 and effectively decomposing and aspirating the disrupted fragments of the cataract tissue 6 with minimal interference to the distal portion of the eye (e.g., the cornea 2 or the lens capsule 9). When connected to a vacuum pressure device, a vacuum tube or a needle 13 serves as a device for removing the disrupted tissue. The inner tip of the aspiration channel 52 contains the distal end 16 of an optical fiber from which the laser pulse is emitted. The laser pulse disrupts the tissue in contact therewith, and thus the generated substances can be aspirated out of the eye.

[0029] This collinear transmission of laser energy is advantageous in small optical fibers and in the precise laser disruption process because the tissue is actively pulled towards the laser energy by the aspiration pressure. The contact tissue disruption of the present invention is not limited to lens tissue but can be applied to all tissue types.

[0030] It is noted that in an embodiment, a device for moving or repositioning the position of the optical fiber tip 16 during a surgical procedure and a device for controlling this position based on user input and the fluid conditions within the irrigation channel and the aspiration channel are provided, see Figure 2 .

[0031] Figure 2 An embodiment of the present invention is disclosed, in which a handheld instrument 54 is coupled to a laser pulse source 10. The laser pulse source 10 is controlled by a signal 22 from a control circuit 21, which also controls an aspiration tool 18 and an irrigation tool 17. The laser pulse source 10 also receives inputs from one or more sensors, such as a flow sensor 38 and a pressure sensor 48 within the fluid channels. By using a user input device 11 (e.g., a multifunctional foot pedal) and preset parameters stored in the control circuit 21, the actions of irrigation, aspiration pressure, aspiration flow rate, laser power, pulse frequency, and the position of the optical fiber can be further controlled. Other control devices can be provided. The preset parameters can include maximum flow rate and pressure limits, laser power limits, and other operating modes. The irrigation and aspiration channels 52 can be coupled to a flexible tube 100 (see Figure 8), which is further coupled to the component 19, which may be detachable, reusable or disposable. The flexible tube 100 allows the insertion and control of the distal tip 20 of the tool component 19 within the eye lens 1 to obtain a controllable micro-destruction of the cataract tissue at the tip, see Figure 1 . In one example, a tool 24 (e.g., a drive mechanism such as a linear motor, a linear translation mechanism driven by a rotary motor, a voice coil actuator, etc.) for moving the optical fiber 12 is provided to control the relative distance between the distal optical fiber tip 16 and the distal end of the suction channel 52. A sensor or encoder 53 (e.g., a photoacoustic sensor) may also be provided to track the position of the optical fiber tip. Another sensor may also be provided to detect when physical contact occurs between the optical fiber 12 and the tissue.

[0032] The optical fiber 12 may be made of any suitable material in some examples, such as sapphire, diamond, chloride glass (ZBLAN) or yttrium aluminum garnet (YAG). The optical fiber tip 16 may be straight or have any other suitable configuration, such as curved, tapered or angled as described in WO2016041086A1.

[0033] The user can control the position of the optical fiber tip 16 in a variety of different ways. In one embodiment, an additional user input device is provided that is configured to move the optical fiber position back and forth. In another embodiment, a proportional pedal commonly used in traditional procedures to increase flow / suction pressure is used to advance the optical fiber. Actuation of the pedal results in a higher degree of suction and at the same time the proximity of the laser destruction mechanism to the suction tip is also reduced.

[0034] In some examples, the position of the optical fiber tip 16 may be automatically adjusted based on the response of the pressure and flow rate in the suction channel 52 to the user's demand for a higher degree of suction, for example by sensing the degree of blockage at the tip. In this embodiment, the position of the optical fiber tip 16 may be directly determined by the surgeon or in combination with a control algorithm that can sense the fluid conditions within the suction channel 52 and identify a variety of situations including blockage and unobstructed flow. In some examples, the automatic adjustment may be used in combination with direct user input to control the position of the optical fiber head 16.

[0035] In traditional cataract surgical systems, the user is able to control aspiration (e.g., via a foot pedal). Some simple automatic controls may be included in traditional systems to limit flow when pressure is too high. In the present invention, more comprehensive control of the system is provided, where laser parameters are controlled while taking into account the detected pressure and flow and also while controlling the positioning of the optical fiber. For example, flow may be restricted due to excessive pressure, and further, the system may control the laser to turn on and control the optical fiber to move distally towards the tip as a way to reduce pressure. Further details of such comprehensive control are described below.

[0036] Referring Figure 3 , in the unobstructed case, the relationship between flow and pressure within the aspiration channel 52 can be estimated by considering laminar flow and Newtonian fluid within a circular cross-section tube, where laminar flow can be considered according to Poiseuille's law.

[0037]

[0038] where, is the volumetric flow rate (volume / time), Δp is the pressure change across the two ends of the tube, R is the radius of the tube, η is the viscosity of the fluid, and L is the length of the tube. As disclosed by the Poiseuille equation, in order to increase the viscosity, a larger pressure difference is required to maintain a constant flow rate. To prevent catastrophic pressure changes from damaging the eye, most ophthalmic aspiration devices have a settable pressure limit, Δp max is typically set to about 350 to 600 millimeters of mercury. Above this pressure, the pump is prevented from operating more forcefully and thus preventing an increase in flow rate. Similarly, there is usually also a flow rate limit, for the purpose of aspirating tissue Q max is set at about 20 to 50 milliliters per minute.

[0039] Given a user control signal for a desired aspiration flow rate, which can vary between 0 and 100%, the user may expect the flow to follow the control signal up to the maximum pressure.

[0040] Q∝A(Δp)forΔp<Δp max or Q∝A(Δp max )

[0041] At limited pressures, it is important to consider methods to prevent high viscosity tissue from clogging the aspiration channel 52. For example, to minimize downstream clogging, the tip 51 of the aspiration channel 52 can be tapered such that the inlet diameter is less than the diameter of the aspiration channel 52. Laser energy transmitted within the inlet of the aspiration channel 52 can thus be used to prevent unwanted clogging in the aspiration channel 52. It is also advantageous to directly push the optical fiber out of the channel unobstructed, where a small diameter optical fiber can be used as a sculpting or high-precision disruption tool, with the pressure or flow in the aspiration channel 52 being nearly zero. However, in high flow aspiration modes, laser disruption of tissue unobstructed is not required and Poiseuille's law will hold. By monitoring pressure, flow parameters, and their rates of change, it can be confirmed whether a blockage has occurred, as detailed below.

[0042] Further reference is made to Figure 3 , which discloses the insertion of an exemplary device. Figure 3 The distal tip of an exemplary instrument 54 is shown, where the aspiration needle 13 and the optical fiber 12 are collinear and the inlet of the aspiration channel 52 is unobstructed. The pressure within the aspiration channel 52 is low and the flow is not pressure limited. In this example, the position of the optical fiber tip 16 is not critical and it can be retracted several millimeters within the aspiration needle. In some examples, the optical fiber tip 16 can be retracted distally up to and including a range of about 5 millimeters or more; and proximally up to and including a range of about 10 millimeters. Other distances are also possible depending on the size of the human eye and the particular application. The laser energy used in the retracted position helps to further disrupt tissue debris aspirated into the aspiration channel 52 by negative pressure. In this mode, the instrument 54 operates in a manner similar to the tip of a conventional aspiration / irrigation instrument. Aspiration of the lens capsule is unlikely to contact the optical fiber and can be maintained in the event of accidental aspiration.

[0043] During a surgical procedure, it is desirable to use the aspiration needle to hold a piece of tissue until the piece of tissue is properly positioned within the anterior chamber for energy disruption. Once a piece of tissue is held by the aspiration pressure, it fills the inlet of the aspiration channel 52 and blocks further removal without additional pressure.

[0044] Figure 4 An example of a blockage when the optical fiber is retracted is shown. Tissue debris 81 is pulled towards the aspiration channel 52 by negative pressure and is too large to be aspirated in, completely blocking the inlet of the aspiration channel 52. In this example case, the pressure within the aspiration channel 52 increases as a function of the flow, and it is advantageous to advance the laser optical fiber towards the inlet of the aspiration channel 52 to disrupt the obstructing tissue rather than attempting to aspirate at a higher pressure.

[0045] In addition, in this embodiment, if the optical fiber does not protrude, the aspiration needle can better hold the blockage. Otherwise, the optical fiber itself either gets buried in the blockage tissue debris or prevents any blockage from occurring. The tissue debris is held at the tip of the aspiration needle by the force caused by the pressure difference between the surroundings of the tissue debris and the inside of the aspiration channel 52. In this case, assuming that R and L in Poiseuille's law are fixed values, since no volume can flow through the blockage, Q approaches 0, and thus the relationship between pressure and flow deviates significantly from Poiseuille's law.

[0046]

[0047] The solution of Q = 0 only occurs when Δp = 0 (the pump is off and the tissue mass is not held) or when the viscosity actually becomes infinitely large η → ∞. Despite the blockage, the pump will continue to attempt and aspirate, and the pressure becomes proportional to the control signal and rapidly increases to its limit value.

[0048] Δp ∝ A for Δp < Δp max or Δp = Δp max

[0049] The time required to reach the pressure limit value is usually referred to as the 'rise time' τ of the aspiration fluid system.

[0050] By monitoring the pressure and flow over time, if the flow rate decreases when the pressure rises, the algorithm can predict the blockage. In other words, when unobstructed and below the pressure and flow limits, the control signal and aspiration rate are clearly defined.

[0051] Q ∝ A(Δp) and thus the rate of change of the flow rate under the control signal is clearly defined The pressure can be described by Equation 1.

[0052] However, when blocked, an additional demand for flow, i.e., increasing A, does not result in additional flow: Q = 0 and is negligible. Subsequently, the rate of change of the pressure corresponding to the control signal is now clearly defined In this way, the degree of blockage can be sampled by observing how the flow rate and pressure respond to changes in the control signal.

[0053] Assume that the control signal does not change while the blockage occurs Before the blockage occurs, the tip is unobstructed and the flow rate is fixed by the control signal and by Equation 1 Δp ∝ Qη ∝ A or (Equation 2),

[0054] However, once the blockage occurs, since the initial flow rate Q0 starts to drop to 0, becomes negative, and Δp increases to Δp with the 'rise time'max , the viscosity actually becomes infinitely large. In other words, within this time, changes sign and becomes negative. At the same time, the pressure begins to rise at the following rate: After the rise time, the pressure is at its maximum value and neither the flow nor the pressure changes. In this case, However, now Q = 0 and Δp = Δp max , so the tube must be completely blocked. In other words, when completely blocked, becomes undefined; but it swings from positive to negative during the rise time when not blocked.

[0055] In this embodiment, an operator of a conventional ultrasound machine would start using a higher vacuum pressure or ultrasound to break the blockage.

[0056] Figure 5 A device is disclosed by which a laser fiber facilitates the transition from blocked to unblocked. In other words, Figure 5 It is disclosed that tissue debris is disrupted and aspirated and the blockage is locally or completely removed, and the laser fiber can start to retract until another blockage occurs. Once the blockage starts to clear and the pressure no longer increases significantly with the flow rate, the laser power can be reduced or the laser tip can be retracted to avoid residual tissue debris being pushed away from the tip. The larger the blockage, the closer the fiber should be to the blockage inlet of the aspiration channel 52.

[0057] In some examples, a simple control algorithm can be defined to determine the position of the fiber tip based only on pressure as follows:

[0058]

[0059] D is the distance of the fiber tip from the inlet of the aspiration channel 52.

[0060] In some examples, the fiber position can be set by the flow rate.

[0061]

[0062] In some examples, the position of the fiber can be determined by the relative change in pressure and flow.

[0063]

[0064] In some examples, the fiber position can simply be linked to a user control signal that typically only controls the aspiration action assuming the user needs a higher degree of aspiration, and laser assistance will be required and thus a lower D value.

[0065] D(t) ∝ 1 - A(t).

[0066] The above example algorithms are not meant to be limiting. Other example control algorithms are possible.

[0067] Figure 6 A situation is disclosed where the blockage persists for a long time and cannot be cleared within a specific time t >> τ. In this case, the position of the optical fiber can oscillate longitudinally within the channel to increase the effective range of high-precision laser disruption and to provide mechanical reinforcement for this effect (similar to oscillating tissue). In this example case, the control algorithm can assume that if the foot pedal is fully depressed for a time longer than a set time, which is much greater than the rise time and the pressure remains at a maximum, the movement of the optical fiber becomes an oscillating mode. This is because an extended input for aspiration while the pressure has not decreased can indicate that the blockage has not been cleared and more mechanical assistance is needed.

[0068] In a further embodiment, the laser pulse frequency, envelope, and the position of the optical fiber are all used to minimize the total flow and pressure variations within the anterior capsule to achieve minimally invasive tissue removal, and most importantly to prevent unintentional disruption of the capsule or damage to the corneal endothelial cells by laser energy, mechanical force, or fluid. The average power of the laser pulse is a function of the pulse frequency and the energy per pulse. For a given specific laser intensity threshold for laser tissue disruption, it is useful in maintaining a constant pulse energy and attenuating the laser power by reducing the pulse frequency (non-decaying laser power). In the present invention, when the laser pulse frequency is not evenly divided, an enhancement of the operation of the instrument 54 occurs, but relatively there is a time segment during which the laser operation is modulated with a lower frequency envelope. It has been found that an envelope frequency of approximately 5 Hz is suitable for sclerotic eye tissue. The pulse frequency can be increased or decreased at the envelope frequency with a 0 - 100% pulse width modulation close to the laser pulse.

[0069] Assume that the laser pulse strongly heats a certain volume of tissue / liquid at the tip of the optical fiber. Since the tip is rigid and this area (about 200 microns) is much larger than the aspiration depth (about 1 micron), the irradiated material cannot expand backward into the solid optical fiber and there is a resultant force that pushes the tissue away from the fiber tip. This expansion force causes an increase in pressure, which cancels out the vacuum pressure of the aspiration pump. By pausing the laser for a period of time during the blockage, the aspiration pump can generate a higher pressure, and the pressure change caused by the laser pulse is less likely to accumulate to a sufficient extent to reverse the sign of the pressure in the aspiration channel (and cause tissue detachment).

[0070] Reference Figure 7, in some examples, the distal end 16 of the optical fiber can be disposed within the aspiration needle 13 such that the aspirated fluid 72 is contained within a disposable or single-use tool assembly 19 without contaminating some of the reusable portions of the optical fiber bundle transmission 12, while allowing the non-elastic optical fiber to move within the aspiration channel. In some examples, this can be achieved by means of a compression rubber seal 73 within which the optical fiber is fixed within a moving shaft assembly 74. The tool assembly 19 includes a flushing channel 70 and an aspiration channel 71, both of which are connected to the distal tip and a fitting, and the fitting is used to elastically connect to a fluid control device.

[0071] Reference Figure 8 , in some examples, the instrument 54 includes three separable parts: a reusable laser transmission assembly 75 (which includes the optical fiber 12 and has an optical fiber fitting 78); a detachable tip handle assembly 76 (which includes a distal instrument tip 20 having a flushing output channel 51, an aspiration needle 13, and an extended optical fiber tip 16 that is coupled to the optical fiber fitting 78 of the reusable transmission system at its sagittal end); and a disposable aspiration and flushing device 100. A connection point can be provided for connecting the disposable tube 100 to the tip handle assembly 76; or two disposable components can be pre-assembled.

[0072] Reference Figure 9 , which discloses an exploded view of the replaceable handle assembly 76. A small optical fiber 88 is attached to an optical fiber fitting 79 that is connected to a corresponding fitting 78 of the reusable laser transmission assembly. The shaft assembly 82 allows the optical fiber to be sealed by a washer 73 that is compressed by a nut 87 around the shaft assembly 82. The nut 87 is held by the shaft assembly and a spring 101 that acts to retract the optical fiber tip when not connected to the reusable component part. A manifold 92 (on which the aspiration needle 13 and the distal flushing sleeve 51 are disposed) is coupled to the flushing channel 70 and the aspiration channel 71 of the handle assembly 19 through a manifold extension 93 and a sealing washer 96 to keep the channels separate. The optical fiber shaft assembly is attached to the manifold extension 93 through a shaft seal nut 87.

[0073] As used herein, the terms "comprising" and "including" should be construed as inclusive and open-ended, rather than exclusive. Specifically, when used in this specification including the claims, the terms "comprising" and "including" and variants of those terms mean that a particular feature, step, or component is included. These terms should not be construed as excluding the presence of other features, steps, or components.

[0074] The foregoing description of the preferred embodiments of the present invention has been presented to illustrate the principles of the present invention, but is not intended to limit the present invention to the specific embodiments described. The scope of the present invention is intended to be defined by all embodiments encompassed by the appended claims and their equivalents.

Claims

1. An apparatus for disrupting cataract tissue, the apparatus comprising: a housing; a pulsed laser radiation source configured to provide pulsed laser radiation having a pulse duration in the range of 10 ps to 1 ns; an optical waveguide at least partially housed within the housing, the optical waveguide including a flexible optical fiber, the optical waveguide being capable of being coupled at a proximal end thereof to the pulsed laser radiation source to receive pulsed laser radiation from the pulsed laser radiation source, the optical waveguide being configured to conduct pulsed laser radiation having a wavelength in the range of 2700 nm to 3300 nm to match the absorption peak of water, the pulse duration and wavelength of the pulsed laser radiation being selected to cause pulsed thermal deposition in the cataract tissue; at least one flow sensor or pressure sensor located within at least one fluid passage of the apparatus, the flow sensor or the pressure sensor being coupled to a control system; and a drive mechanism coupled to the optical waveguide to controllably change a relative position of the optical waveguide with respect to a distal end of the housing, the drive mechanism being controlled by the control system to position the optical fiber in response to at least one of a vacuum pressure received by the control system from the pressure sensor or a flow rate received by the control system from the flow sensor.

2. The apparatus according to claim 1, wherein the drive mechanism is controlled by the control system to position the optical fiber in proportion to a degree of aspiration of a target tissue.

3. The apparatus according to claim 1, further comprising another sensor configured to sense contact between the optical fiber and the target tissue.

4. The apparatus according to claim 1, further comprising a photoacoustic sensor to sense a position of the optical fiber.

5. The apparatus according to claim 1, further comprising an encoder to sense a position of the optical fiber.

6. The apparatus according to claim 1, wherein the drive mechanism is controlled by the control system to longitudinally vibrate the optical fiber within the housing.

7. The apparatus according to claim 1, wherein the pulsed frequency of the pulsed laser radiation is modulated by a selected frequency, thereby achieving a balance between laser power and vacuum.

8. The apparatus according to claim 1, wherein the optical fiber is made of a material selected from: sapphire, diamond, fluoride glass (ZBLAN), or yttrium aluminum garnet (YAG).

9. The apparatus according to claim 1, wherein a distal end of the optical fiber is curved, tapered, or angled.

10. The apparatus according to claim 1, wherein the optical fiber is made of an infrared-transmitting optical material.

11. The apparatus according to claim 1, wherein the drive mechanism is a linear motor, a linear translation mechanism driven by a rotary motor, or a voice coil actuator.

12. The apparatus according to claim 1, wherein the housing includes a reusable laser transmission portion and a detachable tip handle, the optical fiber extends through the reusable laser transmission portion, an optical fiber tip extends from the detachable tip handle, and the detachable tip handle is capable of being releasably fixed to the reusable laser transmission portion.

13. The apparatus according to claim 12, wherein the optical fiber has a distal end with an optical fiber connector, and the optical fiber tip has a proximal end coupled to the optical fiber connector.

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