CN219397564U - Femtosecond laser ablation system - Google Patents

Abstract

The utility model discloses a femtosecond laser ablation system, a femtosecond laser device, a beam expanding system, a first light path homogenizing system, an ablation catheter and an OCT imaging system, wherein the femtosecond laser device is used for generating an initial light beam; the beam expanding system is used for increasing the spot area of the initial beam and reducing the energy density; the optical path homogenizing system is used for homogenizing and shaping the initial light beam into a light beam with uniformly distributed energy; the beam combination focusing system is used for enabling the homogenized light beam of the light path homogenizing system to pass through the beam combination and is focused and coupled to the ablation catheter; the ablation catheter cooperates with an OCT imaging system to treat pathology; the femtosecond has the narrowest pulse width in all types of lasers, under the same single pulse energy, the peak power is the highest, the generated ultrashort pulse and the material action time are extremely short, the thermal influence on the periphery of the material is avoided, and the processing effect and the processing efficiency are better; the optical coherence tomography probe is added to monitor the laser ablation process in real time, and meanwhile, the lesion signal fed back in real time can also provide parameter setting basis for further treatment.

Description

Femtosecond laser ablation system

Technical Field

The utility model relates to a femtosecond laser ablation system, and belongs to the field of photoelectric medical treatment.

Background

With aging population and bad living habits such as obesity, hypertension/hyperlipidemia, smoke and wine and increasing diseases affecting health, the incidence rate and the influence range of intravascular diseases (PAD, CAD) are also increased, wherein diseases such as intravascular calcification, CTO, ISR and the like are still used as treatment difficulties, the deterioration of the diseases is hard, the traditional balloon expansion is limited, and the mechanical rotational abrasion operation has the risk of vascular perforation or interlayer. If the disease can not be timely interfered with the mismatching of the treatment or the treatment means, the disease is easy to cause the non-circulation of blood, and then causes life danger;

ultraviolet laser ablation is based on an intravascular laser plaque ablation technology, ultraviolet high-energy laser is transmitted to a lesion position in a blood vessel cavity by using an optical fiber bundle catheter, so that the ultraviolet high-energy laser acts on affected parts such as stenosis/blockage, plaque is ablated and crushed into micron-sized particles by using photochemical, photothermal and photo-mechanical effects, and the effects of reducing the volume and expanding the cavity are further realized;

for common ultraviolet band lasers, the wavelength is short, the single photon energy is high, the laser is commonly called cold laser in industrial application angle, namely, the thermal effect of the reaction with the material is not obvious, and the heat damage caused by the reaction is also low. The 308nm excimer laser has 4eV single photon energy, which can directly radiate to break down the plaque molecular bond of the patient and decompose the plaque molecular bond, the process is photochemical action, but the laser pulse width is generally of the order of hundred nanoseconds, and the thermal relaxation time is long, namely the thermal effect is increased;

355nmND: YAG third harmonic solid state lasers, with single photon energies of 3.5eV, lower single photon energies are generally considered unsuitable for use as bands for plaque ablation, but the solid state laser pulse width is narrower than that of excimer lasers, on the order of only 10ns, so the peak power is higher, and the thermal effect is also insignificant compared to that of 308 excimer lasers, but the forward burst bubble kinetic energy generated in the liquid is higher, i.e. the photomechanical action duty cycle is increased.

Intravascular OCT (optical coherence tomography) is a high resolution intravascular or luminal imaging modality with a resolution of about 10-20 microns and a penetration depth of about 1-2 mm. High resolution real-time imaging of blood vessels or lumens is possible.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model provides the femtosecond laser ablation system which has shorter pulse time, lower thermal influence and higher treatment effect and efficiency.

The utility model is realized by the following technical scheme:

a femtosecond laser ablation system comprises a femtosecond laser device, a beam expanding system, a first light path homogenizing system, a beam combining focusing system, an ablation catheter and an OCT imaging system, wherein the femtosecond laser device is used for generating an initial light beam; the beam expanding system is used for increasing the spot area of the initial beam and reducing the energy density; the optical path homogenizing system is used for homogenizing and shaping the initial light beam into a light beam with uniformly distributed energy; the beam combination focusing system is used for enabling the homogenized light beam of the light path homogenizing system to pass through the beam combination and is focused and coupled to the ablation catheter; the ablation catheter cooperates with an OCT imaging system to treat pathology.

Further, the femtosecond laser equipment has the wavelength of 1030nm, single pulse energy of not less than 300 mu J, pulse width of less than 600fs and repetition frequencyRate 100kHz (typicality), near field spot about 3mm, beam quality factor M ² Not higher than 1.5.

Further, the beam expanding system is arranged between the first light source and the light path homogenizing system; the light path homogenizing system comprises a flat-top beam shaper, wherein the diffraction efficiency of the flat-top beam shaper is more than 90%, and an antireflection film is plated for 1030nm and a nearby wave band.

Further, a 45-degree reflecting mirror is arranged between the first light source and the light path homogenizing system, and the 45-degree reflecting mirror is made of ultraviolet fused quartz.

Further, the beam expanding system comprises a first lens and a second lens, wherein the first lens is a convex lens or a concave lens, and the second lens is a convex lens; the first beam combining lens has the coating parameters of S1, wherein T is more than 99 percent@1030nm, and AOI is 45 degrees; s2, T is more than 99 percent@1030nm, R is more than 99 percent@1310nm, and AOI is at 45 degrees.

Further, the ablation catheter comprises a proximal incidence end and a distal treatment end, wherein the distal end is sleeved with a developing ring; the ablation catheter comprises an outer tube and an inner tube, and an optical fiber bundle cavity is arranged between the outer tube and the inner tube; the inner tube includes a suction lumen, a guidewire lumen, and an OCT probe lumen.

Further, the device also comprises a second light source, a second light path homogenizing system and a second beam combining lens, and the light beam is transmitted to the first beam combining lens through the second beam combining lens.

Further, the second light source is a 355nm laser device.

The utility model has the beneficial effects that:

ultrafast lasers (in the order of picoseconds/femtoseconds) have a narrower pulse width than the above-mentioned lasers, i.e. picoseconds (ps) of 10 ^{- 12} s, femtosecond (fs) of 10 ^-15 s, compared with the two, the nanoseconds (ns) are only 10 ^-9 s, the femtosecond has the narrowest pulse width in all types of lasers, under the same single pulse energy, the peak power is the highest (single pulse energy=peak power is the pulse width), and the generated ultrashort pulse and the material action time are extremely short, so that the thermal influence on the periphery of the material is avoided; in the field of industrial precision, ultra-fast laser has better processing effect and processing efficiency than the traditional laser;

the proposal of the utility model makes up for the blank of the femtosecond laser pulse for cardiovascular diseases;

the femtosecond laser equipment can be used together with ultraviolet laser equipment, and the optimal combination of photochemical action and optical mechanical action is realized by combining higher single photon energy of ultraviolet band and higher peak power of ultrafast laser, so that ablation treatment is facilitated; an Optical Coherence Tomography (OCT) probe is added to monitor the laser ablation process in real time, so that laser is prevented from being beaten at a non-pathological change position, and simultaneously, a pathological change position signal fed back in real time can also provide parameter setting basis for further treatment;

the two are used together, and the outgoing laser is homogenized/shaped into the homogenized light with uniform spatial intensity distribution through the homogenizing coupling optical path, and the homogenized light can allow higher energy to pass through the ablation catheter without damaging the fiber bundle end face of the catheter compared with the original laser.

Drawings

FIG. 1 is a schematic diagram of a femtosecond laser ablation system in embodiment 1 of the utility model;

FIG. 2 is a schematic plan view of an ablation catheter of the utility model;

FIG. 3 is a schematic view of the distal end cross-sectional structure of an ablation catheter of the utility model;

FIG. 4 is a schematic view of the cross-sectional working state structure of an ablation catheter of the utility model;

FIG. 5 is a schematic illustration of the detailed structure of the ablation catheter of FIG. 2 of the present utility model;

FIG. 6 is a schematic diagram of an ultraviolet laser and femtosecond laser two-in-one ablation system according to the utility model;

FIG. 7 is a schematic diagram showing the principle and effect of homogenizing the light beam in embodiment 1 of the present utility model;

wherein: 1, a femtosecond laser device; 2, a beam expanding system; 3, a first light path homogenizing system; 4, a first beam combining lens; 5, a first focusing lens; 6, ablating the catheter; 7, OCT imaging system; 8, 45 ° mirror; 9, a conduit connector; 10, luer connector; 11, developing ring; 12, an outer tube; 13, a guidewire lumen; 14, a suction chamber; 15, oct probe lumen; 16, a multi-lumen tube; a fiber optic bundle cavity; 18,355nm laser device; 19 A 45 ° mirror; 20, a second optical path homogenization system; 21, a second beam combiner; 22, a second focusing lens; 23, fixing the base; 24, fiber bundle end face; 25, rectangular grooves.

Detailed Description

In order to more clearly illustrate the technical scheme of the present application, the technical scheme of the present utility model is further described in detail below through examples.

The femtosecond laser ablation system comprises a light source, a light path homogenizing system, an ablation catheter and an OCT imaging system; the light source may be a single light source, or two different light sources may form a two-in-one light beam, and examples of different schemes are described below.

As shown in fig. 1, the femto-second laser ablation system in this embodiment includes a first light source, a beam expanding system 2, a first optical path homogenizing system 3, a first beam combining lens 4, a first focusing lens 5, an ablation catheter 6, and an OCT imaging system 7; wherein the first light source is a femtosecond laser device 1, parameters of the device are wavelength 1030nm, single pulse energy not less than 300 μJ, repetition frequency 100kHz (typing), near field light spot about 3mm, and beam quality factor M ² Not higher than 1.5;

the double 45 ° mirror 8 is used for laser leveling output, and it is not necessary to pursue simplification of the coupling light path, and if this part is omitted, it is required that the positions of the light spots in the laser leveling stage are kept consistent at the light outlet and at a distance of at least 1.5 meters from the light outlet. Further, the 45 ° reflecting mirror is made of ultraviolet fused quartz, and in order to reduce transmission loss, the lens should be coated with an antireflection film on both sides: HR > 99.5% @1030nm,45℃AOI;

the beam expanding system 2 has smaller femto-second laser light spots and higher energy density, the light spot area is required to be expanded, the energy density is reduced, the damage to optical elements caused by the excessively high energy density is avoided, the beam expanding system is divided into a kepler type beam expanding system and a Galileo type beam expanding system, the lenses 1 and 2 are both convex lenses, the focal length of the lens 2 is larger than that of the lens 1, if the Galileo type beam expanding system is used, the lens 1 is a concave lens, the lens 2 is a convex lens, the laser can be expanded in any scheme, and the two lenses can plate an antireflection film for a wave band containing 1030nm for increasing the light beam transmittance;

a first optical path homogenizing system 3, which is a flat-top beam shaper in a Diffractive Optical Element (DOE), for homogenizing and shaping the gaussian spatial light into rectangular spots with flat-top distribution, but is more suitable for the single-mode laser type of the scene than the conventional microlens array, requiring that the diffraction efficiency of the device is > 90%, and an antireflection film is coated for 1030nm and nearby bands to improve the transmission efficiency thereof; as shown in fig. 7, the principle of beam homogenization and the effect are schematically illustrated.

The first beam combining lens comprises the following coating parameters: s1, T is more than 99 percent@1030nm, and AOI is 45 degrees; s2, T is more than 99 percent@1030nm, R is more than 99 percent@1310nm, and AOI is at 45 degrees;

the first focusing lens is a plano-convex lens or an achromatic aspheric lens, and an antireflection film can be plated for OCT light source wave bands comprising 1030nm wave bands and 1310nm in order to improve transmission efficiency;

the ablation catheter 6, as shown in fig. 2, is divided into a proximal end (coupling end) and a distal end (treatment end), the proximal end is an incidence end of homogenized laser light, the distal end is a treatment end for performing ablation operation in blood vessels, the arrangement of optical fiber bundles at the incidence end is determined according to the homogenized spot shape, the optical fibers of the optical fiber bundles are high-hydroxyl optical fibers with the core diameter of 100 μm or less, and polyimide coatings are provided. The whole catheter and the near-far end are schematically shown in fig. 3, a developing ring 11 is sleeved on an outer tube 12 through forging and pressing, the developing ring is made of platinum iridium alloy or tantalum metal, the developing ring is made of an X-ray impermeable material, the position of the tip of the catheter in a human blood vessel can be displayed in real time in operation, and the outer tube is an annular hollow thin-wall tube;

as shown in fig. 3 and 4, the multi-cavity tube 16 is used as an inner tube, and has four cavity channels, namely a suction cavity 14, a guide wire cavity 13 and two OCT probe cavities 15, respectively, wherein the inner wall of each cavity channel of the multi-cavity tube can be coated with a fluorine coating to enhance the lubricity of the tube wall and enhance the trafficability of interventional instruments such as guide wires; the annular region between the outer tube 12 and the multi-cavity tube 16 is filled with optical fiber bundles, wherein a single optical fiber is an ultraviolet high-hydroxyl optical fiber with the core diameter of 100 mu m or less and is provided with polyimide coating, so that the tensile and bending resistance of the optical fiber bundles are enhanced, the total number of the optical fibers is determined according to the reserved cavity areas of the catheters with different specifications, and the optical fiber bundles are not particularly limited;

as shown in fig. 5, the fixing base 23 of the catheter connector 9 includes a rectangular groove 25, where the optical fiber bundle and the OCT probe optical fiber can be shaped into a rectangular end face, and in fig. 5, the black color is that the OCT probe is connected to the optical fiber, and the position is as close to the center of the end face as possible during the installation process, and the optical fiber bundle needs to be fixed in the groove by using glue or using a physical spring sheet;

FIG. 4 is a schematic view showing the working state of an ablation catheter, wherein the number of OCT probe channels is two, and the OCT probe channels are matched with each other to image plaque outside the distal end, and only one of the channels is shown in the figure due to the cross-section projection relationship; the connecting optical fiber and the optical fiber bundle of the OCT probe are fixed together at the catheter connector; the two Luer connectors 10 are arranged, the guide wire cavity is communicated with the outside through a first Luer connector, and the first Luer connector can be connected with a physiological saline injection device, so that the real-time cooling of the ablation process is facilitated; the suction cavity is centered and connected with the outside through a second luer connector, and is externally connected with a peristaltic pump, so that lesion scraps generated in the ablation process can be sucked outside the body, and the distal embolism caused by falling plaque particles is prevented;

the OCT imaging light source is a time domain OCT, frequency domain OCT or full-field OCT imaging light source, infrared laser is emitted and enters the optical fiber bundle catheter through the semi-transparent semi-reflecting mirror, the optical fiber bundle catheter is transmitted to a lesion from a far end, lesions such as thrombus and the like outside the far end reflect the optical fiber bundle catheter and are acquired and transmitted through the OCT probe, a real-time image of the lesion position can be displayed after image processing, and is used for medical staff to refer to and adjust parameters of laser ablation and the position of the far end of the catheter according to the parameters, so that more accurate treatment is realized, and medical accidents such as perforation interlayer and the like caused by the fact that the real-time image of the lesion cannot be observed in traditional treatment are prevented.

Example 2

The two-in-one scheme of 355nm laser equipment and femtosecond laser equipment is shown in fig. 6, and specifically comprises a first light source, a beam expanding system 2, a first light path homogenizing system 3, a first beam combining lens 4, a first focusing lens 5 and an ablation catheter 6; and a second light source, a second light path homogenization system 20, a second beam combiner 21, an ablation catheter 6 and an OCT imaging system 7;

femtosecond ultrafast laser 1 with wavelength of 1030nm, single pulse energy not less than 300 μJ, pulse width less than 600fs, repetition frequency of 100kHz (typicality), near field light spot about 3mm, and beam quality factor M ² Not higher than 1.5;

the first beam combining lens 4 has the following coating parameters: s1, T is more than 99 percent@1030nm, and AOI is 45 degrees; s2, T is more than 99 percent@1030nm, R is more than 99 percent@1310nm and 355nm, and AOI is 45 degrees;

the second beam combining lens 21 has the following coating parameters: s1, R is more than 99 percent and is at 355nm, and the AOI is 45 degrees; s2, R is more than 99 percent@355 nm, T is more than 99 percent@1310 nm, and AOI is 45 degrees;

the first focusing lens is a plano-convex lens or an achromatic aspherical lens, and an antireflection film may be plated for three wavelength bands including 355nm, 1030nm, and 1310nm in order to improve transmission efficiency.

The second beam combining lens is used for transmitting ultraviolet laser and reflecting OCT laser (1310 nm), so that the two light paths are combined to the S2 surface of the femtosecond beam combining lens, 355nm antireflection films are plated on the two surfaces of the S1 and S2 surfaces of the laser beam combining lens, and a 45-degree high reflection film for an OCT light source wave band is plated on the S2 surface; as shown in the figure, the two laser paths have independent homogenizing and shaping external light paths, and the homogenized light spots have more uniform spatial distribution, so that the light spots can allow higher-energy incidence in the subsequent spatial light coupling process and are less prone to damage to the end face of the optical fiber bundle of the guide tube compared with the original untreated Gaussian distribution light spots.

The laser ablation treatment method combines the photochemical effect of ultraviolet laser and the optical mechanical effect of femtosecond ultrafast laser in two schemes, and the scheme combines the optical paths of 355nm ultraviolet laser and the femtosecond ultrafast laser through a beam combining lens and then couples the laser to a treatment catheter, so that the two lasers can be used for ablation treatment simultaneously.

The specific workflow and principle of the utility model are as follows: the homogenized light of a single light source or two homogenized light beams of double light sources are focused and coupled to the near end of the front part of an ablation catheter through a focusing lens, the treatment end of the catheter is inserted into a vascular lesion through a guide wire (the specific position of the catheter is confirmed to be inserted into a blood vessel through a developing ring), at the moment, laser is emitted for treatment, plaque is eroded into 10 mu m-level particles which can be absorbed by a human body, however, larger damaged plaque still cannot be normally discharged, the treatment process of the head end of the catheter is tightly attached to the plaque, a suction cavity can pump the larger plaque outside the body, and a suction cavity channel is connected with a peristaltic pump for negative pressure suction of the ablated plaque;

at the same time of treatment, the OCT imaging light source emits near infrared laser, the near infrared laser enters an optical fiber bundle in the catheter through a laser beam combiner and is transmitted to a plaque position, the plaque reflects the imaging light beam, and the imaging light beam is collected by an ablation catheter and is transmitted back to the system to be imaged by interference with reference light in the system. Real-time ablation effect evaluation can be realized, so that a doctor can control the propulsion speed and adjust the propulsion direction, and laser ablation operation can be finished with high quality. Because OCT can penetrate plaque of 1 ~ 2mm and image to can effectively discern the blood vessel media, can also with early warning blood vessel perforation's risk in advance, remind the doctor to adjust the direction of ablation pipe, avoid blood vessel perforation.

Claims (8)

1. A femtosecond laser ablation system is characterized by comprising a femtosecond laser device, a beam expanding system, a first light path homogenizing system, a beam combining focusing system, an ablation catheter and an OCT imaging system, wherein the femtosecond laser device is used for generating an initial light beam; the beam expanding system is used for increasing the spot area of the initial beam and reducing the energy density; the optical path homogenizing system is used for homogenizing and shaping the initial light beam into a light beam with uniformly distributed energy; the beam combination focusing system is used for enabling the homogenized light beam of the light path homogenizing system to pass through the beam combination and is focused and coupled to the ablation catheter; the ablation catheter cooperates with an OCT imaging system to treat pathology.

2. The femtosecond laser ablation system according to claim 1, wherein the femtosecond laser device is a laser device with a wavelength of 1030nm, single pulse energy of not less than 300 μj, pulse width < 600fs, repetition frequency of 100kHz (typicai), near field spot of about 3mm, beam quality factor M ² Not higher than 1.5.

3. The femtosecond laser ablation system according to claim 2, wherein the beam expanding system is disposed between a first light source and an optical path homogenizing system; the light path homogenizing system comprises a flat-top beam shaper, wherein the diffraction efficiency of the flat-top beam shaper is more than 90%, and an antireflection film is plated for 1030nm and a nearby wave band.

4. The femtosecond laser ablation system according to claim 3, wherein a 45-degree reflecting mirror is arranged between the first light source and the optical path homogenizing system, and the 45-degree reflecting mirror is made of ultraviolet fused quartz.

5. The femtosecond laser ablation system according to claim 4, wherein the beam expanding system includes a first lens and a second lens, the first lens being a convex lens or a concave lens, the second lens being a convex lens; the beam combination focusing system comprises a first beam combination lens, wherein the coating parameters are S1, T is more than 99 percent@1030nm, and AOI is 45 degrees; s2, T is more than 99 percent@1030nm, R is more than 99 percent@1310nm, and AOI is at 45 degrees.

6. The femtosecond laser ablation system as recited in claim 5 wherein the ablation catheter comprises a proximal incident end and a distal treatment end, the distal end being sleeved with a developing ring; the ablation catheter comprises an outer tube and an inner tube, and an optical fiber bundle cavity is arranged between the outer tube and the inner tube; the inner tube includes a suction lumen, a guidewire lumen, and an OCT probe lumen.

7. The femtosecond laser ablation system according to any one of claims 1 to 4, further comprising a second light source, a second optical path homogenizing system, a second beam combiner, and a beam transmitted to the first beam combiner via the second beam combiner.

8. The femtosecond laser ablation system as recited in claim 7 wherein the second light source is a 355nm laser device.