Femtosecond laser device for minimally invasive surgery

Abstract

The device delivers and controls femtosecond pulses of light with extremely high peak intensity. The device transmits pulses from a femtosecond laser via a suitable optical fiber to a location within the vessel and controls the light intensity distribution at the surgical site. The extremely high intensity allows for instantaneous ablation of material within the vessel (e.g., calcified plaque) with minimal damage to surrounding tissue.

Description

[Technical field]

[0001] This application relates to laser surgery devices. [Background technology]

[0002] Existing atherectomy devices generally remove plaque in two ways: (i) removing material by mechanical action, and (ii) removing material by severing molecular bonds with high-energy ultraviolet light from a laser source. Because removing unwanted material by forceful mechanical action in close proximity to healthy tissue carries significant risks, e.g., perforation of blood vessels, laser removal-based approaches are preferred.

[0003] Current state-of-the-art excimer laser-based devices use nanosecond pulses to perform material ablation in the linear absorption regime. However, sufficient ablation in the linear absorption regime is sensitive to the absorption properties of the material and is not very useful for treating emboli with high inorganic mass. To address this issue, hybrid systems that use both laser and mechanical ablation of material have been introduced in recent years.

[0004] In contrast, femtosecond lasers deliver light energy in ultrashort pulses (approximately 10 -12 seconds~10 -15 sec) to produce peak power densities sufficient to ionize atoms resulting in optical destruction (further termed ablation) of the material.

[0005] The timescale is too short for heat transport to eliminate localized heat accumulation and corresponding thermal damage to nearby tissues and blood vessels. Furthermore, the ablation process is largely independent of tissue absorption properties. Thus, the device can use near-infrared light for ablation, a wavelength range that is inherently less harmful and therefore minimizes peripheral damage to biological tissues due to stray light exposure. In contrast, ultraviolet light, used in nanosecond-pulsed excimer lasers currently used for atherectomy, can cause damage at the cellular level. Finally, femtosecond pulsed light allows operation in a nonlinear high peak power density regime, improving cutting precision and eliminating ruptures.

[0006] Endoscopic surgical devices for superficial microsurgery using ultrashort pulses (~1 ps) have been attempted by several research groups with some success. One approach uses a piezoelectric cantilever resonator to precisely guide a focused laser spot on the target. Another approach uses a conventional multicore fiber bundle to deliver optical energy in chirped pulses, followed by wavefront shaping to refocus the pulses to achieve ablation. Both approaches, while useful for superficial microsurgery, only accommodate a small field of view compared to the device dimensions and are therefore not compatible with atherectomy. Summary of the Invention [Problem to be solved by the invention]

[0007] Despite the advantages of ultrashort pulse ablation, femtosecond-based atherectomy is precluded by the lack of a means to deliver and control high-energy femtosecond pulses inside the body. [Means for solving the problem]

[0008] A femtosecond laser device for minimally invasive surgery includes an ultrafast (femtosecond or less than 100 picosecond) pulsed light source coupled to a flexible optical fiber capable of delivering femtosecond or picosecond pulses. The optical fiber carries the light to a surgical site inside the body. One embodiment includes an end cap for the fiber that delivers the femtosecond light from the laser to the surgical site (Figure 1). The fiber optic components and end cap are designed to deliver 1.5 TW / cm over the area of ​​the focal spot to ensure ablation of both organic and inorganic materials. 2 It is possible to handle the pulse energies and durations required to achieve target peak power densities of 10 ... The actuators move one or more optical elements relative to the output beam by translation or rotation of the optical components, independent of the external shell, or by rotation of the entire device. This allows high intensity focused femtosecond pulses to be delivered to the surgical site and controlled to achieve ablation intensity. This design also prevents damage to the optics and maintains isolation between the internal components and the external environment (Figure 2). [Brief description of the drawings]

[0009] [Figure 1] A system is presented that utilizes a femtosecond device to deliver and control femtosecond pulses for atherectomy and other intra-surgical applications. [Diagram 2] 1 illustrates the general operating principle of a femtosecond device for delivering and controlling femtosecond pulses. [Diagram 3] 1A-1D show schematic diagrams of components and designs of devices and support elements for atherectomy and other endo-surgical applications. [Figure 4] 1 shows components of a first embodiment for atherectomy and other endo-surgical applications to generate a forward light sheet for ablation. [Diagram 5] 1 shows light propagation and control of the front light sheet in a first embodiment. [Figure 6] 13A-13C show components of a second embodiment for atherectomy and other endo-surgical applications with lateral light sheet generation. [Figure 7] 13 shows light propagation and control of the lateral light sheet in a second embodiment. [Figure 8] 1 illustrates the applicability of the first, second and fourth embodiments in atherectomy and related surgical procedures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In one embodiment, the system includes an ultrafast laser configured to generate light pulses of less than 100 picoseconds, an optical fiber configured to transmit the light pulses from the ultrafast laser, and a fiber optic end cap device including one or more optical elements configured to ramp down and then ramp up the intensity of the light pulses from the optical fiber to create any optical pattern from the light pulses in the optical fiber. 12 W / cm 2 The optical fiber 100 is configured to focus light to a peak power density greater than 100 .mu.m.

[0011] In one embodiment, a method for performing a laser ablation procedure using a femtosecond laser ablation device includes inserting a fiber optic ablation device into a blood vessel and ablating the blood vessel with a femtosecond laser for 10 minutes. -7 J~10 -2 generating a plurality of optical pulses of less than 100 picoseconds with a pulse energy of 10 J; 12 W / cm 2 and focusing the output of the laser ablation device to an ablation site in the blood vessel.

[0012] In another embodiment, a method for performing a laser ablation procedure using a femtosecond laser ablation device includes the steps of inserting a fiber optic ablation device into a human body, and applying a femtosecond laser to the human body for 10 minutes. -7 J~10 -2 and generating a plurality of optical pulses of less than 100 picoseconds with a pulse energy of 10 J. 12 W / cm 2 and a focusing optics assembly configured to focus the output of the ablation device to an ablation site within the body for ablation of body tissue or foreign material. Example applications include, but are not limited to, removal of tissue or foreign material within the gastrointestinal tract, removal of cartilage, bone, ligament, or foreign material within a joint or intervertebral space within the body, removal of thrombotic material within the venous system, heart, or pulmonary artery, removal of an atrial septum to allow passage of an instrument from the right heart to the left heart, removal of enlarged cardiac tissue in a heart with hypertrophic cardiomyopathy, removal of tissue or foreign material within the peritoneal or retroperitoneal cavity, or removal of tissue or foreign material within the urethra, bladder, ureter, or renal calyx by navigating the device via cystoscopy or direct puncture of the renal calyx and positioning the device adjacent to the material to be ablated using fluoroscopy, fiber optics, or ultrasound guidance.

[0013] The described embodiments allow for the use of femtosecond pulses for bulk removal (surgery) of tissue or other material (e.g., calcified plaque) within the body, particularly within blood vessels such as arteries. One target application is atherectomy to treat narrowing of blood vessels caused by accumulation of organic / inorganic emboli. These embodiments can also be used for other outpatient applications that benefit from the removal of bulk material within the body, such as kidney stone removal, removal of tumor or cancer cells, removal of blood clots (blood clots) from the venous system, removal of foreign bodies within the vascular system or other parts of the body (laser lead removal), removal of bone or cartilage within joint cavities within the body, etc.

[0014] Femtosecond Laser Device In one embodiment, referring to FIG. 3, the apparatus comprises a femtosecond laser source (1), a hardware controller and power supply (2) that interfaces with the femtosecond laser device (1) via a control cable (3). These components may be mounted on a vibration isolation system (4) to protect them from external vibrations and may be enclosed in an optical enclosure (5) to prevent light leakage. The laser light enters the optical fiber (6) through a fiber coupler (7). The optical fiber (6) may be a single fiber or a fiber bundle. Additionally, control and power supply wiring (8) may interface with the optical fiber (6) via the fiber coupler (7). The apparatus terminates with a femtosecond ablation device (9).

[0015] The first embodiment creates a light sheet focal point in front of the device. The second embodiment creates a light sheet focal point in a perpendicular orientation to the device. The third embodiment combines aspects of the first and second embodiments to provide a forward light sheet and a perpendicular light sheet simultaneously or by switching between the two modes on demand. The fourth embodiment is an extension of the first embodiment.

[0016] 4-7 show an exemplary ablation device according to one or more embodiments. The ablation device (9) includes a flexible, protective, biocompatible shell (10) made of a biocompatible material that covers a flexible, protective internal structure (11) for a fiber core and cladding (12), such as a flexible monocoil. The flexible portion of the fiber made of (10), (11), (12) is connected to the ablation device (9) via a hermetic connector (13) that is sealed by adhesive or other means. Control / power circuitry (14) is embedded in (10), (11), or (12) and threaded through the hermetic connection (13) or provided separately as an external wire. Circuitry is provided for powering and / or controlling one or more actuators (15) for changing the position, bending angle, and rotation angle of the internal rotor (16). The actuator (15) here may be implemented using an ultrasonic piezo actuator due to the miniaturization requirement, but can also be implemented by motors based on piezoelectric, electrostatic, electromagnetic, electromagnetic conjugate fluid, thermal operating mode, bimetallic plate, inductive actuators, or any other suitable sized actuator components. The rotor (16) movement is stabilized by suitable bearings (18), such as those based on ball bearings or self-lubricating plastics. A counterweight (19) may be included at the distal end of the rotor (16) to stabilize the rotation and minimize vibrations. A focusing optics assembly (20) is attached to the rotor (16). This design can be enclosed in a rigid airtight shell (21) containing a transparent exit window (22) to prevent the movement of the internal components from interfering with the external environment (Figure 4).

[0017] FIG. 4 shows the components of a first embodiment for atherectomy and other endoscopic surgical applications that generate a front light sheet for ablation. The front light sheet design houses two focusing elements to steer the diverging beam propagating through the spacer (23). A cylindrical lens focuses the incident laser beam into a line (24) in one direction, and a second cylindrical lens expands the beam in the perpendicular direction (25) (FIG. 4). This results in a front light sheet (26) that rotates under the action of an actuator about a central axis to scan the ablation plane (27) projecting a light sheet of high intensity light sufficient to achieve ablation. In this embodiment, the focusing optics are selected such that ablation occurs over the entire diameter of the device, allowing poration of the target material (FIG. 5).

[0018] FIG. 6 shows the components of a second embodiment for atherectomy and other endoscopic surgical applications that generate a lateral light sheet. In the second embodiment, the front light sheet design for generating a vertical light sheet has the same basic structure as described above, except for the focusing assembly and the exit window. In this embodiment, the optical assembly consists of a transparent optical cylinder (28) crossed at an angle by a mirror (29). An alternative to using a mirror (29) is to select the refractive index of the material of the transparent optical cylinder (28) so that total internal reflection occurs at the diagonal cut. The end of the device is capped with a transparent tube (30). The distal cap (31) can be made of a non-transparent material only for vertical line focus designs (FIG. 6). In this embodiment, the diverging beam from the optical fiber enters the cylindrical optic from above and is reflected in a vertical direction (32). The sides of this cylinder (33) act as cylindrical lenses that focus the light to a line parallel to the device (33), where the light becomes intense enough to achieve ablation. Rotation of the inner assembly about a central axis causes this line focus to move around the device, allowing ablation of material around the device (Figure 7).

[0019] A third embodiment combines the optical elements of the vertical focusing design and the front focusing design, allowing for simultaneous front and vertical ablation of the device. In this embodiment, the mirror (29) is replaced by a beam splitter for simultaneous ablation in both the front and side directions. Alternatively, the switching between the two modes can be achieved by replacing the mirror (29) with a device with controllable reflectivity, for example using an electrically switchable semi-transparent mirror based on a liquid crystal layer.

[0020] In the fourth embodiment, the forward focusing design of the first embodiment is embedded into the side of a flexible hollow shell. The shell has a central space for trapping foreign objects. The device gradually rotates around the object to remove obstacles around it.

[0021] The first embodiment is designed to address complete or partial blockages in blood vessels where the device diameter is too large to allow passage of the embolus. The second embodiment is designed to remove emboli where lateral accumulation of emboli causes narrowing of the vessel but not severe enough to prevent passage of the device (FIG. 8). A possible application would be to use the first and second embodiments sequentially to first introduce a channel into the blockage and then gradually widen it.

[0022] The third embodiment allows for both types of procedures without the need to replace the device. The fourth embodiment is useful for surgical lead removal after cardiac surgery. The device is intended for atherectomy applications, but can be used in other medical procedures, such as kidney stone removal, ablation of bone or cartilage within joint or intervertebral spaces, or other surgical interventions where mineral-rich or dense material is problematic. Another potential application is the removal of foreign material by capturing it and vaporizing it with ablation, eliminating the need for open surgical removal.

[0023] In one embodiment, the system comprises: -7 J~10 -2The device is equipped with a fiber coupling device capable of delivering sub-100 picosecond optical pulses in the infrared, near-infrared, visible, or ultraviolet spectrum with pulse energies of 1 J.

[0024] In one embodiment, the fiber coupling device is configured to be capable of maintaining an elevated internal gas pressure or capable of maintaining an internal vacuum.

[0025] In one embodiment, the system comprises: -7 J~10 -2 The optical fiber is capable of transmitting sub-100 picosecond optical pulses in the infrared, near-infrared, visible, or ultraviolet spectrum with a pulse energy of 1 J.

[0026] In one embodiment, the optical fiber has a bend radius of 30 cm or more and a length of 1 m or more.

[0027] In one embodiment, the system comprises an end cap enclosure that is sealed and capable of holding an elevated internal gas pressure or capable of holding an internal vacuum.

[0028] In one embodiment, the system is configured to divide the beam output by the fiber by 10 12 W / cm 2 The laser has an internal spacer that dissipates a peak power density below 100 .mu.m.

[0029] In one embodiment, the system includes a 10 12 W / cm 2 The present invention provides an optical device or assembly capable of focusing light to a peak power density greater than 1000 dpi.

[0030] In one embodiment, the optical device or assembly is configured to generate a focal spot of any shape (other than a point focus) to accelerate scanning.

[0031] In one embodiment, the system comprises an actuator implemented using an ultrasonic piezo actuator or a motor based on piezoelectric, electrostatic, electromagnetic, electromagnetic conjugate fluid, thermal mode of operation, bimetallic plate, or inductive actuator configured to move or rotate the optical assembly relative to the fiber to achieve scanning.

[0032] In one embodiment, the system utilizes a second lumen adjacent to and coupled to the fiber / endcap to pass a guidewire that guides the location and trajectory of the device. The guidewire configuration can be a rapid exchange or over-the-wire configuration.

[0033] In one embodiment, the device can be passed through an endoscope, colonoscope, or upper gastrointestinal endoscope to allow for ablation of biological material or foreign bodies within the gastrointestinal tract.

[0034] In one embodiment, the device can be passed through an arthroscope to allow ablation of biological material, bone, cartilage, or foreign bodies within a joint or intervertebral space.

[0035] In one embodiment, the device can be passed into the venous system, the right ventricle, or the pulmonary artery to ablate acute or chronic thrombus within the venous system (thrombectomy).

[0036] In one embodiment, the device can be guided into position and placed against the atrial septum of the heart to create a channel between the right and left atria (transseptal puncture).

[0037] In one embodiment, the device can be navigated to the enlarged septum of hearts with hypertrophic cardiomyopathy as a safe alternative to alcohol septal ablation.

[0038] In one embodiment, the housing of the device may also incorporate a second lumen through which an intravascular ultrasound probe passes to facilitate guidance and positioning of the ablation tip.

[0039] In one embodiment, the ablation tip can be positioned in the subintimal space of a chronic occlusion adjacent to the true lumen and the subintimal tissue can be ablated to create a channel to the distal true lumen of the occluded vessel.

[0040] In one embodiment, the device may incorporate a Nitinol intravascular snare for capturing foreign objects or biological material within the body.

[0041] In one embodiment, the device can be passed through a laparoscopic approach into the peritoneal or retroperitoneal cavity to allow for ablation of biological or foreign material within the peritoneal cavity.

[0042] In one embodiment, the device can be passed internally into the urethra, bladder, ureter, or renal calyx by navigating the device via cystoscopy or direct puncture of the renal calyx and used to ablate biological tissue or foreign bodies within any of the above structures.

[0043] Any of the above embodiments may include a suction / negative pressure / vacuum system to capture and remove debris generated by the ablation process.

[0044] Usage example In one embodiment, a method for performing atherectomy / thrombectomy / foreign body ablation using a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into a blood vessel. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused to an ablation site in a blood vessel.

[0045] In one embodiment, a method for ablating tissue or foreign material in the gastrointestinal tract using a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into the gastrointestinal tract through an upper gastrointestinal endoscope or colonoscope and the fiber is positioned adjacent to the tissue or foreign material to be ablated. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused to an ablation site in the gastrointestinal tract.

[0046] In one embodiment, a method for ablating cartilage, bone, ligament, or foreign material in a joint or intervertebral space within a body using a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into the joint space under direct vision or fiber optic visualization (arthroscope) and the fiber is positioned adjacent to the material to be ablated. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused to an ablation site in the joint cavity.

[0047] In one embodiment, a method for ablating thrombotic material in the venous system, heart, or pulmonary artery using a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into a vein in the body, and optionally into the right atrium, right ventricle, or pulmonary artery, to ablate thrombotic material in these structures. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused onto thrombus material within the structure.

[0048] In one embodiment, a method for ablating the atrial septum using a femtosecond laser ablation device and passing the device from the right heart to the left heart includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into a vein in the body and the ablation tip is positioned adjacent to the atrial septum using fluoroscopy and / or intracardiac echo guidance. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused at the interatrial septum to form a channel between the right and left ventricles.

[0049] In one embodiment, a method for ablating enlarged cardiac tissue in a heart with hypertrophic cardiomyopathy using a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into an artery in the body and the ablation tip is positioned adjacent to the interatrial septum using fluoroscopy and / or intracardiac echo guidance. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused onto hypertrophied cardiac tissue to ablate the tissue.

[0050] In one embodiment, a method for ablating biological tissue or foreign material in the peritoneal or retroperitoneal cavity with a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, a fiber optic ablation device is inserted into the peritoneal or retroperitoneal cavity via laparoscopic techniques and positioned adjacent to the material to be ablated using fluoroscopic, fiber optic, or ultrasound guidance. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused onto the target tissue or foreign body.

[0051] In one embodiment, a method for ablating biological tissue or foreign material in the urethra, bladder, ureter, or renal calyx using a femtosecond laser ablation device includes inserting, generating, and focusing steps. In one embodiment, the fiber optic ablation device is inserted and guided by cystoscopy or direct puncture of the renal calyx, and fluoroscopy, fiber optic, or ultrasound guidance is used to position the device adjacent to the material to be ablated. In one embodiment, the light pulse is less than 100 picoseconds. In one embodiment, the light pulse is less than 10 picoseconds. -7 J~10 -2 In one embodiment, the ablation device has an incident beam energy of 10 12 W / cm 2 In one embodiment, the output of the ablation device is focused onto the target tissue or foreign body.

[0052] In any of the above use cases, the housing of the device may also incorporate a second lumen through which an intravascular ultrasound probe may be passed to facilitate guidance and positioning of the ablation tip.

[0053] In one embodiment, the femtosecond laser ablation device incorporates an additional lumen for passing a guidewire along the length of the device in an over-the-wire configuration to facilitate navigation and advancement of the ablation device through the vasculature.

[0054] In one embodiment, the femtosecond laser ablation device incorporates an additional lumen in the distal portion of the end cap / fiber to pass a guidewire in a rapid exchange configuration to facilitate navigation and advancement of the ablation device through the vasculature.

[0055] In one embodiment, the ablation tip can be positioned in the subintimal space of a chronic occlusion adjacent to the true lumen and the subintimal tissue can be ablated to create a channel to the distal true lumen of the occluded vessel.

Claims

1. an optical fiber configured to transmit optical pulses from a laser configured to generate optical pulses of less than 100 ps; an optical fiber end cap device including one or more optical elements configured to ramp down and then ramp up the intensity of the light pulses from the optical fiber to create an optical pattern from the light pulses from the optical fiber; Equipped with The one or more optical elements divide the light pulse by 10 １２ W / cm ２ configured to focus to a peak power density greater than system.

2. 10. The system of claim 1, wherein the fiber optic end cap device is less than 7 mm in diameter.

3. The system of claim 1 , wherein the optical pattern is a line, a spiral, or a cloud of points.

4. 10. The system of claim 1, wherein the one or more optical elements include a spacer configured to diverge a beam output by the optical fiber to a peak power density below an optical damage threshold prior to focusing by the one or more optical elements.

5. 10. The system of claim 1, wherein the fiber optic end cap device further comprises an actuator configured to rotate the one or more optical elements or the fiber optic end cap device about a central axis, thereby rotating or translating a final ablation pattern.

6. 10. The system of claim 1, wherein the one or more optical elements are: a first lens configured to focus an incident beam into a line in a first direction; a second lens configured to expand the incident beam focused by the first lens in a second direction perpendicular to the first direction; A system including:

7. 10. The system of claim 1, wherein the one or more optical elements are: A transparent optical tube; a mirror configured to diagonally cross the transparent optical barrel and to reflect an incident beam vertically through the transparent optical barrel; A system including:

8. 10. The system of claim 1, wherein the one or more optical elements are: A transparent optical tube; a beam splitter configured to reflect a portion of an incident beam through the transparent optical barrel; one or more lenses configured to focus and expand a non-reflected portion of the incident beam into a forward light sheet; A system including:

9. 10. The system of claim 1, wherein the one or more optical elements are: A transparent optical tube; an electrically switchable semi-transmissive mirror configured to switch between reflecting the incident beam through the transparent optical barrel and focusing the incident beam through one or more lenses configured to focus the incident beam into a forward light sheet; The system further comprises:

10. 10. The system of claim 1, wherein the one or more optical elements are embedded into a side of a flexible hollow shell that includes a central cavity configured to trap foreign objects.

11. An optical fiber end cap device comprising: a spacer configured to diverge an incident femtosecond laser beam received through an optical fiber; The incident femtosecond laser beam output from the spacer is １２ W / cm ２ a focusing optics assembly configured to focus to a peak power density greater than An ablation device comprising:

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