Devices and methods for efficient hard and soft tissue ablation

Abstract

Systems and methods for use in laser lithotripsy procedures. The system may include a laser source configured to generate pulsed laser energy, an optical fiber configured to direct the pulsed laser energy to a target, and a controller. The controller is configured to receive an input parameter, determine at least one process parameter, and calculate an N factor (Nf) corresponding to a number of laser pulses delivered to a treatment region on the target and having a diameter approximately equal to that of the laser pit produced by the pulsed laser energy. Nf is compared to a maximum N factor value (Nfmax), and in response to the comparison, the laser operating parameters are adjusted or used to control the laser source.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 462,588, filed April 28, 2023, entitled “DEVICE AND METHOD FOR HIGHLYEFFICIENT HARD AND SOFT TISSUE ABLATION,” the contents of which are incorporated herein by reference in their entirety. Background Technology Technical Field

[0003] This technical field generally relates to laser lithotripsy, and more specifically to a laser system configured to determine optimal laser pulse parameters for a laser lithotripsy procedure.

[0004] BACKGROUND

[0005] DISCUSSION

[0006] Laser lithotripsy is one of the most effective and less invasive urological procedures for treating stone-like diseases, including kidney, bladder, and ureteral stones. Laser energy is directed from a laser source to the stone-like object (e.g., uric acid stones, calcium oxalate monohydrate stones, cysteine ​​stones, etc.) via an optical fiber. Typically, the surgeon uses a flexible or rigid / semi-rigid endoscope (endoscope, ureteroscope, cystoscope, pyeloscope, nephroscope, etc.) with a built-in camera and illumination source to guide the distal end of the optical fiber to the target (stone, gallstone, etc.) inside the patient's body.

[0007] To treat natural stones, the laser energy power density should exceed the stone ablation threshold (i.e., the ablation threshold). The ablation threshold is inversely proportional to the stone's absorption coefficient. Therefore, Ho:YAG, Tm:YAG, and thulium pulsed fiber lasers are the most efficient in laser lithotripsy because the wavelengths of these lasers (2.1µm, 2.01µm, and 1.94µm, respectively) match the peaks of the absorption spectrum of water, which is the dominant chromophore in the near-IR wavelength range.

[0008] When a surgeon is certain that the distal end of the fiber is positioned at an effective distance in front of the target, for example, when the distance between the target and the fiber tip is less than 1 mm, he or she turns on or otherwise activates the laser to treat the stone stones.

[0009] Laser treatment remains a process with multiple complex factors. During treatment of a staghorn calculus several processes can occur simultaneously or one after the other: 1) the laser pulse over heats the water in front of the distal end of the fiber and vaporizes, a bubble of vapor appears on top of the fiber tip and starts to grow, the bubble reaches the surface of the staghorn calculus (so-called "Moses effect" or "Moses channel"), 2) the laser pulse over heats the surface of the staghorn calculus and ablates and creates a laser crater, 3) small staghorn calculus particles that form as part of the laser ablation products pass in all directions including the direction of the fiber tip and the laser beam is absorbed and scattered by these particles to create a so-called "debris shadow" from the bottom of the laser crater, 4) due to water pressure waves and jetting effect of the ablated particles (so-called "retrograde effect") the staghorn calculus moves away from the fiber tip, 5) as the staghorn calculus breaks up in larger particles and becomes finer particles or staghorn calculus dust, staghorn calculus cratering and fragmentation occurs, the fiber tip overheats and gets damaged, 6) if the laser pulse repetition rate falls below a threshold level, the bubble collapses and the gap between the fiber tip and the target is filled with water.

[0010] The staghorn calculus ablation process and its efficiency depend on factors (parameters) that are altered and changed such as (but not limited to): laser wavelength, pulse energy, peak power, pulse shape, pulse width, pulse frequency (repetition rate), average power, fiber diameter, gap between fiber tip and target surface, target type (staghorn calculus type / chemical composition and structure / shape of the staghorn calculus), condition of the fiber tip, type of surgical instrument (rigid, semi-rigid, flexible endoscope) and speed of instrument manipulation (movement) or scan speed in the body (depending on the surgeon and his skills and style) and so on.

[0011] Performing the procedure in the body (and at a location in the body) also has an impact on the process efficiency: in order not to overheat and damage the internals (e.g. tissue and organs) the average laser power inside the ureter should be much smaller from a safety point of view than the average laser power inside e.g. the bladder or the kidney due to the volume of free space inside each organ. If the endoscope supports a water flow, the flow rate is also a factor of influence.

[0012] Typically, the surgeon sets the laser parameters (pulse energy, pulse width, pulse frequency etc.) manually by trial and error based on his or her clinical experience and the capabilities of the chosen laser system and based on literature data and recommendations of colleagues. Typically, the chosen parameters are suboptimal and far from achieving high ablation efficiency. There is typically no clear and obvious visible relationship between the laser settings and the impact on the ablated staghorn calculus.

[0013] LITERATURE DATA

[0014] Many literature sources present exact (predetermined) optimal laser parameters for different types of ablation modes (fragmentation, comminution, disintegration) and their dependency on laser type (Ho:YAG, Thulium Fiber Laser (TFL)), stone type (artificial Bego stone, COM, uric acid, etc.), organ type (environment), and fiber diameter. FIG. 1A , FIG. 1B and FIG. 1C An overview of various examples of these sources is presented, and Table 1 below lists the bibliographic references of each example.

[0015] Table 1 - FIG. 1A , FIG. 1B and FIG. 1C Bibliography of documents cited in the references

[0016] NUMERATION BIBLIOGRAPHY 1 Klaver, P. et al., "In Vitro Comparison of Renal Stone Laser Treatment Using Fragmentation and Popcorn Technique”, Lasers in Surgery and Medicine, September 2017, Vol. 49(7): 698-704 2 Elhilali, M. et al., "Use of the Moses Technology to Improve Holmium Laser Lithotripsy Outcomes: A Preclinical Study, Journal of Endourology, June 2017, Vol. 31(6): 598-604 3 Aldoukhi, A.H. et al., "Watch Your Distance: The Role of Laser Fiber Working Distance on Fragmentation When Altering Pulse Width or Modulation”, Journal of Endourology, February 2019, Vol. 33(2): 120-126 4 Winship, B. et al., "Dusting Efficiency of the Moses Holmium Laser: An Automated In Vitro Assessment”, Journal of Endourology, December 2018, Vol. 32(12): 1131-1135 5 Vassar, G.J. et al., "Holmium:Yag Lithotripsy Efficiency Varies with Energy Density”, The Journal of Urology, August 1998, Vol. 160: 471-476 6 Sea, J. et al., "Optimal Power Settings for Holmium:YAG Lithotripsy, The Journal of Urology, March 2012, Vol. 187: 914-919 7 Mues, A.C. et al., "Quantification of Holmium:Yttrium Aluminum Garnet Optical Tip Degradation", Journal of Endourology, September 2009, vol. 23(9): 1425-1428 8 Aldoukhi, A.H. et al., "Calyceal Fluid Temperature During High-Power Holmium Laser Lithotripsy in an In Vivo Porcine Model, Journal of Endourology, August 2018, vol. 32(8): 724-729 9 Black, K.M. et al., "Pulse modulation with Moses technology improves popcorn laser lithotripsy", World Journal of Urology, June 2021, vol. 39(6): 1699-1705 10 Aldoukhi, A.H. et al., "Understanding the Popcorn Effect During Holmium Laser Lithotripsy for Dusting", Urology, December 2018, vol. 122: 52-57 11 Panthier, F. et al., "Laser Fiber Displacement Velocity during Tm-Fiber and Ho:YAG Laser Lithotripsy: Introducing the Concept of Optimal Displacement Velocity", J Clin Med, December 2021, 11(1): 181

[0017] For example, for comminution ablation mode of operation, the presented laser parameters are in the following parameter ranges: average power of 10-28 W, pulse energy of 0.05-0.5 J, and pulse frequency of 10-80 Hz. However, few sources explain why these ranges of presented laser parameters are actually optimal. In general, the explanation is based on holding ablation experiments, without any connection to the nature and / or cause of stone ablation. Currently, no explicit method for determining optimal laser parameters has been presented, whether for real-time process (during surgical procedure) or before the process, the optimal laser parameters depend on different varying factors (cases).

[0018] The applicant believes that the published recommended data contradict themselves and are difficult to use for the purpose of providing optimal laser treatment.

[0019] Some efforts have been made to increase the overall efficiency of laser lithotripsy, particularly stone ablation efficiency. Non-limiting examples of these efforts include: using real-time sensory feedback (e.g., sensors for determining distance to target, tissue type sensors, stone type and size sensors, etc.), improving fiber scanning by automatic periodic movement, applying special shaped laser pulses or modulated periodic pulse groups, using presets for each specific stone and operating area / organ, etc. For example, some laser systems can support certain parameter presets.

[0020] Some laser systems for lithotripsy can utilize so-called intelligent real-time feedback systems in order to increase lithotripsy efficiency. For example, in Chinese patent CN110811826 entitled “Intelligent Lithotripsy System,” an intelligent system implements a distance sensor (based on an ultrasonic distance sensor or a laser distance measuring device or a structured light distance measuring device), a temperature sensor, and a pressure sensor. Additionally, stone composition, structure, color, hardness, stone fragmentation level, and the environment of the lesion are automatically determined by image recognition technology via negative feedback and automatically matched with a large database, thereby providing the surgeon with appropriate laser pulse energy, laser pulse time, and other parameters for the surgeon’s reference. This configuration utilizes a big data platform and an artificial intelligence deep learning system that proposes efficient laser parameters for laser lithotripsy.

[0021] In PCT publication WO2013154708 entitled “Surgical Laser Systems and Laser Lithotripsy Techniques,” a stone analyzer includes an imager and a laser Doppler vibrometer (LDV) or a laser-induced breakdown spectrometer (LIBS) to determine characteristics of a target stone (such as the size and geometry of the stone, the composition of the target stone). The received feedback is mapped to laser energy settings (e.g., pulse repetition rate, pulse width, etc.) for generating laser energy that is tuned to break up the target stone. In some embodiments, a laser controller determines a laser treatment to perform to break up the stone based on the identified stone type.

[0022] In PCT publication WO2021026161 entitled “Laser Control Using a Spectrometer,” a spectrometer-based surgical feedback control system includes a feedback analyzer configured to receive a reflected signal from a target in response to electromagnetic radiation directed at the target, and a controller that can perform predetermined operations based on the received reflected signal, including determining a composition of the target, or programming laser settings to direct laser energy to the target. The system continuously identifies the composition of the target through an endoscope and updates laser settings throughout the procedure. The spectral system gathers information about the target material that can be used for diagnostic purposes and to confirm that the laser parameters are optimal for the target. The feedback analyzer can automatically optimize the operating mode of the laser system (using a library of optimal settings database) and reduce the risk of human error.

[0023] The controller of the laser system in PCT publication WO2021026164 entitled“Endoscopic Laser Energy Delivery System and Methods of Use” can automatically program the laser treatment with the appropriate laser parameter settings based on the target composition using a machine learning algorithm trained with spectral data.

[0024] In PCT publication WO2016201092 entitled“Bodily Substance Detection by Evaluating Photoluminescent Response to Excitation Radiation”, smart feedback is used to detect a human’s stone-like calculus and distance to the stone-like calculus by evaluating the photoluminescent radiation level response (fluorescent radiation) emitted by the stone-like calculus excited by a low-power probe laser in order to not perforate the urinary system wall. The method also includes adjusting one or more parameters of the delivery of ablation energy based on the received parameters of the detected photoluminescent radiation.

[0025] In PCT publication WO2019157406 entitled“System, Method and Computer-Readable Storage Device for Controlling Laser Light Source of Lithotripsy Device”, a laser controller system picks and changes one variable operating parameter of the laser source of a lithotripsy device (energy, peak power, pulse width, average power and frequency of the laser output from the laser source) during a stone-like calculus ablation process and then determines which of a plurality of base settings is more suitable for breaking or fragmenting another layer of the stone-like calculus. User assistance is still required in each particular case in reaching the conclusion of increased ablation efficiency.

[0026] In PCT publication WO2015175151 entitled "Computer Aided Image-Based Enhanced Intracorporeal Lithotripsy", a processor of a laser system is programmed to execute an image processing routine and use an analysis program to determine the properties of a stone-like calculus. The system utilizes time-varying properties of the current stone-like calculus accumulated from the start of ablation. Using these properties, the processor calculates optimal power parameters and communicates them to a controller that adjusts the power settings in response to one or more energy generation parameters.

[0027] In US patent US11160573 entitled "Scanning Ureteroscope for Maximizing Efficiency in Laser Lithotripsy", the periodic movement (scanning) of the mirror's swing arm is coordinated by a computer with the laser pulses so that laser energy from each pulse is irradiated to two different regions of the stone-like calculus instead of one, thereby drilling a continuous hole. This method results in more laser energy being spent on fragmenting the stone-like calculus instead of heating water.

[0028] There are laser systems that use predetermined amplitude periodic pulse groups for "shaped pulse laser lithotripsy" to provide high ablation rates while also minimizing the recoil of the ablation products, such as described in Applicant's PCT publication WO2020033121 entitled "Method and Apparatus for Laser Lithotripsy". Depending on the treatment target stone-like calculus size, the proposed presets are divided into different stone-like calculus pulverization stages: fragmentation, pulverization, and burst. To achieve minimal recoil effects combined with high ablation efficiency, the use of extended pulse width or the use of a double pulse mechanism (modulation or periodic variation of pulse energy, peak power, and pulse frequency, and formation of optimal pulse shape) is proposed. The pulse energy is split so that water is evaporated to form a bubble (Moses channel) and the pulse energy is also used to ablate the stone-like calculus. High power in the first pulse is not needed, high power would overheat the water and create force wave pressure that causes recoil of the ablation products. Once the Moses channel is overcome, the pulse power can be increased to increase ablation.

[0029] There are methods for analyzing large arrays of data received during laser lithotripsy and implementing analytical approximation formulas based on the received data to calculate different process parameters. For example, to increase the efficiency of lithotripsy of stony calculi located in the upper third of the ureter, the risk factor of "proximal migration" (retreat of the stony calculus or its fragments due to the expansion of the ureter near the stony calculus, the pressure of the irrigation fluid and the effect of the laser on the ureteral mucosa) can be calculated to select the optimal treatment method by using the proposed empirical formula, such as the one disclosed in the Russian patent RU2725961 entitled "Method of Choosing Therapeutic Approach in Laser Contact Ureterolithotripsy of Stones of Upper Third of Ureter", which is expressed as:

[0030] Y = exp(b0+b1*X1+b2*X2-b3*X3+b4*X4+b5*X5) / [1+exp(b0+b1*X1+b2*X2-b3*X3+b4*X4+b5*X5)],

[0031] where

[0032] Y = risk factor of proximal migration,

[0033] b0-b5 = determined regression coefficients,

[0034] X1 = distance to the stony calculus,

[0035] X2 = maximum size of the stony calculus,

[0036] X3 = minimum size of the stony calculus,

[0037] X4 = presence of hydronephrosis (static pressure expansion of the renal pelvis and calyces due to obstruction of downstream urine flow) (0 if not present, -1 if present),

[0038] X5 = duration of the presence of the stony calculus (0 if not more than 30 days, -1 if more than 30 days).

[0039] If the value of the risk factor Y is 30% or less, it is recommended to perform lithotripsy using a rigid ureteroscope, and if the value of the risk factor Y exceeds 30%, it is recommended to perform lithotripsy with the use of a flexible ureteroscope.

[0040] Proper selection of laser lithotripsy parameters allows to provide the ability to safely and quickly remove stony calculi, which at the same time requires:

[0041] 1. Preventing thermal injury to the kidney, ureter, or bladder due to over-heating of water, which depends on the average laser power as well as the irrigation and outflow of water.

[0042] 2. Preventing perforation of the kidney, ureter, or bladder wall due to soft tissue ablation. The chance of perforation increases with laser pulse energy and repetition rate.

[0043] 3. Minimizing the laser treatment time, which depends on the ablation efficiency and the amount of time the laser is on during the treatment. This is especially important for large staghorn stones due to the limited time of anesthesia. SUMMARY

[0044] Aspects and embodiments relate to a method and system for use in a laser lithotripsy procedure.

[0045] According to one example embodiment, a system for use in a laser lithotripsy procedure is provided, the system comprising: a laser source configured to generate pulsed laser energy; an optical fiber configured to direct the pulsed laser energy at a target; and a controller coupled to the laser source and configured to: receive one or more input parameters; determine at least one procedure parameter, wherein the at least one procedure parameter comprises one or more laser operating parameters; calculate an N-factor (Nf) based at least in part on the one or more procedure parameters and the at least one input parameter, wherein the Nf corresponds to a number of laser pulses delivered to a treatment region having a diameter approximately equal to a diameter (Dc) of a laser crater produced by the pulsed laser energy at the treatment region directed onto the target; compare the Nf to a maximum Nf (Nfmax); and in response to determining that the Nf is greater than the Nfmax, adjust at least one of the one or more laser operating parameters, or in response to determining that the Nf is less than or equal to the Nfmax, control the laser source using the one or more laser operating parameters.

[0046] According to another example embodiment, a method for performing a lithotripsy procedure is provided, the method comprising: providing a controller configured to: receive one or more input parameters; determine at least one procedure parameter, wherein the at least one procedure parameter comprises one or more laser operating parameters; calculate an N-factor (Nf) based at least in part on the one or more procedure parameters and the at least one input parameter, wherein the Nf corresponds to a number of laser pulses delivered to a treatment region having a diameter approximately equal to a diameter of a laser crater (Dc) produced by pulsed laser energy at the treatment region directed onto a target; compare the Nf to a maximum Nf (Nfmax); and in response to determining that the Nf is greater than the Nfmax, adjust the at least one laser operating parameter, or in response to determining that the Nf is less than or equal to the Nfmax, control a laser source using the one or more laser operating parameters.

[0047] In one example, the one or more laser operating parameters comprise pulse energy, pulse frequency, average power, peak power, and / or pulse width.

[0048] In one example, when the controller determines that the Nf is greater than the Nfmax, the controller is configured to adjust the at least one laser operating parameter such that the Nf is less than or equal to the Nfmax.

[0049] In one example, the controller is further configured to: display the Nf on a display device coupled to the controller; and in response to determining that the Nf is greater than the Nfmax, output a negative alert message on the display device, or in response to determining that the Nf is less than or equal to the Nfmax, output a positive alert message on the display device.

[0050] In one example, the one or more procedure parameters used to calculate the Nf comprise a laser pulse frequency, a laser crater diameter (Dc), and a fiber speed (υ). In another example, the Nf is calculated according to the following equation: Nf = (f*D c ) / υ, where f (Hz) is the laser pulse frequency, D c (mm) is the laser crater diameter, and υ is the fiber speed directing pulsed laser energy at the treatment region.

[0051] In one example, the laser crater diameter Dc is in a range according to the following expression: (2NAΔ + d)(0.12 ln (E1 / (0.25 F’(2NAΔ + d) 2 )) – / 250) + (1.82d) (0.21 – 0.025E1) ≤ Dc ≤ (2NAΔ + d)(1 / (1.61 + 10.23d 4+ (0.92 - 2.97d)Δ)) x (1 + ( / 12.85) ln((12.85 / )(1 / (6.4 - 6.75d))(E / (0.25 F'(2NAΔ + d) 2 -1) + 1)) where NA is the numerical aperture of the optical fiber, Δ (mm) is the gap between the distal tip of the optical fiber and the surface of the staghorn stone, d (mm) is the core diameter of the optical fiber, (W) is the peak power of the laser pulse, E1 (J) is the single pulse energy, and F'(J / cm 2 ) is the threshold for staghorn stone ablation.

[0052] In one example, the controller is configured to calculate Nfmax, where Nfmax corresponds to a number of laser pulses delivered to a treatment region having a diameter approximately equal to the laser crater diameter Dc that provides an average per pulse stone ablation efficiency greater than or equal to a predetermined K value for a maximum number of pulses, the predetermined K value corresponding to an ablation efficiency achieved after an impact from a single (first) pulse.

[0053] In one example, the K value is in a range of about 25% to 75%, inclusive. In another example, the K value is in a range of about 25% to 50%, inclusive.

[0054] In one example, the controller is configured to calculate Nfmax, where Nfmax is calculated according to the following equation: Nfmax = (12.4 - 3.4d) + (3.3d - 8.4) / (1 + 4.7x10 -5 exp(P peak / 0.0375)) - ((14.7d - 16) + (80 - 65d)P peak + (55d - 62)P peak 2 ) / (1 + 0.34 E 5.5-2.6 Ppeak ), where P peak is the peak power.

[0055] In one example, Nfmax is in a range of 1 to 12, inclusive. In another example, Nfmax is in a range of 1 to 7, inclusive. In another example, Nfmax is in a range of 1 to 5, inclusive. In another example, Nfmax is in a range of 1 to 3, inclusive.

[0056] In one example, the controller is configured to display at least one laser operating parameter on the display device based on the comparison.

[0057] In one example, the controller is configured to display at least one of Nf and Nfmax on the display device.

[0058] In one example, the system further includes at least one sensor coupled to the controller and configured to measure at least one input parameter and / or at least one process parameter. In another example, the at least one sensor includes a sensor configured to measure fiber speed.

[0059] In one example, when the controller determines that Nf is greater than Nfmax, the controller is configured to adjust the at least one laser operating parameter such that Nf is less than or equal to Nfmax.

[0060] In one example, the controller is further configured to output a negative alert message including at least one of an audio alert message, a visual alert message, and a haptic alert message in response to determining that Nf is greater than Nfmax, or a positive alert message including at least one of an audio alert message, a visual alert message, and a haptic alert message in response to determining that Nf is less than or equal to Nfmax.

[0061] In one example, the controller is configured to output an alert message including at least one of an audio alert message, a visual alert message, and a haptic alert message in response to the comparison. In another example, the system further includes a user input device coupled to the controller, where the user input device is configured to receive input from a user, the input including at least one value of a laser operating parameter used by the controller to control the laser source. In another example, the alert message includes information provided to the user regarding whether Nf is greater than Nfmax or whether Nf is less than or equal to Nfmax.

[0062] In one example, the input parameters include at least one of a target parameter, a system parameter, and a safety parameter. In one example, the input parameters include a target parameter, and the target parameter includes a target type, a target location, and one or more target characteristics. In one example, the target is a stone, and the one or more target characteristics include a size and / or a hardness of the stone. In one example, the input parameters include at least one system parameter, and the at least one system parameter includes a fiber diameter and / or a fiber numerical aperture. In one example, the input parameters include at least one safety parameter, and the at least one safety parameter includes a maximum average power, a maximum peak power, a maximum pulse energy, and / or a maximum pulse frequency.

[0063] In one example, the method further includes measuring, using the at least one sensor, at least one input parameter and / or at least one process parameter. In another example, the at least one input parameter includes fiber speed.

[0064] In one example, the controller is further configured to receive input from a user input device, the input including at least one value of a laser operating parameter used by the controller to control the laser source.

[0065] According to another example embodiment, a system for use in a laser lithotripsy procedure is provided, the system including: a laser source configured to generate pulsed laser energy; an optical fiber configured to direct the pulsed laser energy at a target; and a controller coupled to the laser source and configured to: receive one or more input parameters; determine at least one process parameter, wherein the at least one process parameter includes one or more laser operating parameters; calculate an N-factor (Nf) based at least in part on the one or more process parameters and the at least one input parameter, wherein the Nf corresponds to a number of laser pulses delivered to a treatment region having a diameter approximately equal to a diameter (Dc) of a laser crater produced by the pulsed laser energy directed at the treatment region on the target; display the Nf on a display device coupled to the controller; compare the laser operating parameter to a threshold value; and in response to determining that the laser operating parameter is greater than the threshold value, adjust at least one of the one or more laser operating parameters, or in response to determining that the laser operating parameter is less than the threshold value, use the one or more laser operating parameters to control the laser source.

[0066] In one example, the laser operating parameter compared to the threshold value is pulse energy. In one example, the controller is further configured to calculate the pulse energy based at least in part on a pulse frequency. In one example, the controller is further configured to calculate the pulse frequency based at least in part on a maximum N-factor (Nmax).

[0067] In one example, the controller is configured to adjust the at least one laser operating parameter such that the Nf is determined to be less than or equal to a maximum N-factor Nfmax.

[0068] In one example, in response to determining that the laser operating parameter is greater than the threshold value, the controller is configured to adjust the laser operating parameter value to a maximum safe value associated with the laser operating parameter.

[0069] In one example, the controller is configured to display the at least one laser operating parameter based on the comparison.

[0070] Other aspects, implementations, and advantages of these example aspects and implementations are discussed in detail below. Moreover, it should be understood that the foregoing information and the following detailed description are merely illustrative examples of various aspects and implementations, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and implementations. The implementations disclosed herein can be combined with other implementations and the reference to “implementation,” “example,” “some implementations,” “some examples,” “alternative implementation,” “various implementations,” “one implementation,” “at least one implementation,” “this implementation and other implementations,” “certain implementations,” etc. is not necessarily mutually exclusive, and is intended to indicate that a particular feature, structure, or characteristic described can be included in at least one implementation. The appearance of such phrases in various places in the specification are not necessarily all referring to the same implementation. BRIEF DESCRIPTION OF DRAWINGS

[0071] Various aspects of at least one implementation are discussed in the detailed description below in reference to the drawings, which are not intended to be drawn to scale. The drawings are included to provide an illustration and a further understanding of the various aspects and implementations and are incorporated in and constitute a part of this specification, but are not intended as limitations on the claims. The drawings along with the remainder of the specification serve to explain principles and operations of the aspects and implementations described and claimed. In the drawings:

[0072] Figure 1A , Figure 1B and Figure 1C are tables of laser settings for lithotripsy procedures according to various literature sources;

[0073] Figure 2 is a table showing typical fiber movement speeds for different mirror types and human organ types;

[0074] Figure 3 is a schematic representation of the N-factor as the number of pulses in one spot / point according to various aspects of the present invention;

[0075] Figure 4 is a table showing safe maximum values for various laser operating parameters for different body organs according to aspects of the present invention;

[0076] Figure 5 is a photo of a crater array on a Bego stone-like stone surface as a function of pulse energy and number of pulses for different peak powers according to aspects of the present invention;

[0077] Figure 6are photographs and plots of the surface of a Bego stone-like calculus and its measured cross-sectional profile according to aspects of the application;

[0078] Figure 7 are several plots of the depth profile of craters on the surface of a Bego stone-like calculus for various pulse energies (single pulse, 500 W peak power) according to aspects of the application;

[0079] Figure 8 is a table of measured crater diameters after impact from single pulses for different fiber sizes according to aspects of the application for various gaps (distance between fiber and stone-like calculus), pulse energies, and peak powers;

[0080] Figure 9 is a table of measured saturated crater diameters after impact from multiple pulses for different fiber sizes according to aspects of the application as a function of gap, pulse energy, and peak power;

[0081] Figure 10 are photographs of the groove array on the surface of a Bego stone-like calculus as a function of average power for different fiber scan speeds according to aspects of the application;

[0082] Figure 11 is a table of specific crater volume measured in scan mode as a function of peak power, pulse energy, and N (pulse sequence number) according to aspects of the application;

[0083] Figure 12 are a pair of tables showing comparisons between measured crater diameters and calculated crater diameters after impact from single pulses and multiple pulses according to aspects of the application;

[0084] Figure 13 are three separate plots showing comparisons between measured crater diameters and calculated crater diameters as a function of pulse energy for different gaps between a Bego stone-like calculus and a fiber tip according to aspects of the application;

[0085] Figure 14 are three separate plots showing comparisons between measured saturated crater diameters and calculated saturated crater diameters as a function of pulse energy for different gaps between a Bego stone-like calculus and a fiber tip according to aspects of the application;

[0086] Figure 15 are three plots of calculated crater volume for a 0.2 mm fiber for different (pulse sequence numbers) as a function of peak power and pulse energy according to aspects of the application;

[0087] Figure 16 is a table showing measured vs. calculated values of the highest number of efficient pulses in one spot for different fiber diameters as a function of peak power and pulse energy, in accordance with aspects of the present application;

[0088] Figure 17 are three graphs showing highest efficient N-factor as a function of pulse energy and peak power for different fiber diameters, in accordance with aspects of the present application;

[0089] Figure 18 is a flowchart showing steps in one example of a smart assistant operating mode (“first” method), in accordance with aspects of the present application;

[0090] Figure 19 is a flowchart showing steps in another example of a smart assistant operating mode (“second” method), in accordance with aspects of the present application;

[0091] Figure 20 is a flowchart showing steps in another example of a smart assistant operating mode (“third” method), in accordance with aspects of the present application;

[0092] Figure 21 includes two screenshots from a GUI showing examples of notifications about N-factor that can be displayed to a user on a laser system display device screen, in accordance with aspects of the present application;

[0093] Figure 22 is a block diagram of a lithotripsy system, in accordance with aspects of the present application; and

[0094] Figure 23 is a block diagram of a configuration for pulsed laser energy output, in accordance with aspects of the present application. DETAILED DESCRIPTION

[0095] Physics and properties of the ablation process

[0096] After a Moses channel is formed between the fiber tip and the target stone, the laser energy starts to impact the stone primarily, initiating the ablation process. The irradiated area on the surface of the stone depends on the fiber output aperture and the distance to the target surface. The farther the stone is and the larger the fiber output aperture is, the larger the irradiated area is and the lower the laser power density on the surface of the stone is. However, if the ablation process is only related to the dissociation of the material in the irradiated area when the laser power density exceeds the damage threshold of the stone, the craters or cavities produced on the surface of the stone should correspond to (match, fit) the irradiated area, which can be calculated according to the following equation:

[0097] D = 2*NA*L + d (1)

[0098] wherein

[0099] D is the diameter of the irradiated area on the surface of the stony concretion,

[0100] NA is the numerical aperture of the output of the optical fiber,

[0101] L is the distance to the surface of the stony concretion, and

[0102] d is the optical fiber core diameter (size of the emission source).

[0103] If the distribution of laser power density at the tip of the optical fiber is uniform and the laser power density remains uniform on the surface of the stony concretion (above the damage threshold of the stony concretion), it is reasonable to assume that the ablation crater produced on the stony concretion is the same as the irradiated area. If this distribution on the surface of the stony concretion is not uniform (e.g., Gaussian), then the ablation crater produced should be the same as the irradiated area where the laser power density is equal to or greater than the damage threshold of the stony concretion. Thus, the ablation crater can be the same as or smaller than the irradiated area. According to some conventional reasoning, in either case, there is no apparent reason why the ablation crater can be larger than the irradiated area. Furthermore, it is reasonable to assume that the ablation crater area has no correlation with the number of irradiation pulses. An increase in the number of pulses on a stony concretion spot can be associated with an increase in the depth of the crater and an increase in the distance between the tip of the optical fiber and the surface of the stony concretion. A recoil impact can also increase the distance of the tip of the optical fiber to the stony concretion. In both cases, the result is a decrease in the laser power density on the surface of the stony concretion.

[0104] However, as practice and experiments have shown, even for a single laser pulse, the ablation crater diameter is often larger than the irradiated area. For example, when using a pulsed thulium laser with a wavelength of 1940 nm and a peak power of 500 W, a 200 pm core optical fiber (distance to target shorter than 100 pm) in contact with the stony concretion and surrounded by water produced an ablation crater of about 1 mm in diameter on the surface of the stony concretion after a single 6 J pulse impact, which is five times the diameter of the optical fiber. This indicates that the nature of the ablation process is more complex than just the dissociation of the material in the laser irradiated area.

[0105] The physics / properties of the ablation process depend on many factors: laser parameters, such as irradiation wavelength, average and peak power, pulse width, energy and frequency, shape of the laser pulse, etc., also referred to herein as laser operating parameters; the instrumentation used (scope type, fiber diameter, fiber tip condition, fiber movement speed, etc.); the properties of the stone (chemical composition, structure, size, absorption, etc.); environmental features (distance to the target, substances in the interlayer between the fiber tip and the surface of the stone, organ type, amount of stone, etc.); and so on. These varying parameters affect various physical processes and ablation mechanisms, including one or more of the following: photomechanical mechanisms, photothermal mechanisms, and photochemical or photothermal-chemical mechanisms, as described in Applicant’s PCT publication WO2020033121.

[0106] The photothermal mechanism is by absorption of the radiant energy by the target material, which is converted into heat energy, which then generates thermo-mechanically induced stresses in the stone within the irradiation area, and possibly around it by conduction: the local increase in temperature causes thermal expansion of the stone material or vaporization of the trapped water in the stone, which leads to high pressures and mechanical stresses that can exceed the tensile stone strength. Note that there can be different degrees of tensile strength in any given stone (for crystal associations or cross-linking of large domains with small domains). The thermo-mechanical mechanism also comes into play when cavitation bubbles collapse near the surface of the stone, resulting in the formation of microscopic fractures and other defects in the stone. The induced stresses propagate as stress waves within and outside the irradiation area. Such cavitation bubbles can be induced by the shock wave, which in turn is generated by the violent collapse of large laser-induced bubbles generated via the photothermal process. The photothermal-chemical mechanism involves dissociation of molecular bonds inside the stone mass based on the absorption of high-energy photons or thermally induced changes in the chemical composition, which can induce changes in the stone absorption of laser radiation and changes in one or more mechanical properties, such as mechanical strength. For example, if organic materials are involved, the thermal effect can lead to chemical reactions in or on the mineral matrix of the stone, such as pyrolysis. The former process leads to direct mechanical damage to the stone, while the latter generates cavitation bubbles that can mechanically damage the stone in the vicinity.

[0107] These ablation mechanisms, together with the understanding of the structure and chemical composition of the stone, indicate that the ablation crater can be larger than the irradiation area, i.e. via stress wave propagation, thermal diffusion, and / or stress propagation, depending on the structure and chemical composition of the stone.

[0108] Three surgical techniques have been developed through experiments involving the described mechanisms: the fragmentation mode technique utilizes lower frequency of pulses at higher peak laser power applied to a small area of the stone-like calculus over a longer period of time. This technique causes a relatively deep and large area of holes by macroscopic fragmentation produced by photo-thermal stress and subsequent thermo-mechanical stress. The pulverization (scanning, dancing) mode technique utilizes a fiber continuously moved across the surface of the stone-like calculus during delivery of higher frequency laser pulses. This technique ablates a thin layer of stone-like calculus along the path traversed by the laser. Finally, the so-called burst mode technique utilizes a stationary fiber directed into the stone-like calculus and debris cloud produced by repeated laser firing. Each pulse of the laser induces bubble expansion and collapse in the surrounding water, which in turn creates water flow in a confined volume, such as can be seen in the renal calyx or bladder. Each particular surgical technique can be efficient for one type of stone-like calculus and less efficient for another. In other words, there is no universal multi-purpose laser mode for all types and environments of stone-like calculus.

[0109] For a given type of fiber, it can be inferred that the larger the laser impact (power density) applied to the stone-like calculus, the larger the size of the ablation crater. However, this is not entirely true because it neglects other consequences of the ablation process. According to one publication, [Boris Majaron et al., “Debris screening and heat diffusion in Er:YAG drilling of hard dental tissues” Proc. SPIE 2973, Lasers in Dentistry III, (15 May 1997)], the dependence of the depth and volume of the ablation crater on the applied laser fluence exhibits a non-linear, quasi-logarithmic dependence during exposure of human dentin and enamel to Er:YAG laser pulses. The stone-like calculus laser drilling process in lithotripsy can be similar to the laser drilling process in human dentin and should therefore also exhibit such non-linearities. The debris screening nonlinearity has multiple causes and is extremely complex: if the current laser pulse is long enough, the debris ejection and ablation effects on the stone-like calculus can interfere with the current laser pulse, but if the pulse frequency is low enough, they can not interfere with the next laser pulse. On the other hand, the adhesion of debris to the fiber tip can be permanent and persist throughout the process unless the fiber is cut.

[0110] When the incident laser flux of a single pulse at a given location exceeds a threshold for stone destruction, the depth and volume of the ablation pit initially increase with increasing laser flux (energy density). However, further increases in laser flux beyond a certain level do not lead to further pit growth, thus wasting additional laser energy. This flux level can be determined and occurs due to so-called "fragmentation shielding," which is the shielding (covering) of the fiber tip by the ejected fragments (small particles of stone). These (very hot) fragments are ejected in all possible directions, and portions directed to the tip may adhere to the tip, or at least remain in the laser's path during firing, partially hindering energy delivery to the stone surface by scattering or absorbing radiation. The fragmentation process is nonlinear and disproportionately exacerbates with increasing laser energy. Therefore, it is expected that the ablation rate will decrease disproportionately with increasing laser power density (or flux).

[0111] Furthermore, if debris adheres to the fiber tip, it will continue to absorb laser energy and transfer heat to the fiber. The fiber tip may suffer thermal damage and may then directly absorb laser energy, resulting in additional fiber tip damage. In this case, most of the applied laser energy is blocked and cannot impact the stone-like stone, and the clinician must remove the fiber from the endoscope and move it outside the body to cut and activate the fiber tip.

[0112] In summary, while backsliding has adverse effects, higher pulse energies can be ineffective or even detrimental. On the other hand, too low a pulse energy can reduce the size of the ablation pit, thus prolonging the process, or, in the worst case, falling below the ablation threshold. Therefore, the most efficient pulse energy for a given peak power lies somewhere between these two limits. Thus, it is important to better understand and quantify the ablation process so that the optimal range of laser parameters can be found to optimize ablation efficiency and, consequently, increase the safety and effectiveness of lithotripsy procedures.

[0113] Ablation rate and ablation efficiency

[0114] It has been shown that the efficiency of the ablation process for stone-like stones can vary under factors related to changes in laser parameters, environmental characteristics, and target type. The potential effectiveness of the ablation process can be characterized by ablation rate and ablation efficiency.

[0115] ablation rate (A) R mm 3 ( / s) is the rate at which the target volume is removed or separated. The ablation rate quantifies the speed at which the target can be ablated and removed. In other words, A R Average quantification of how much volume (mm) is eliminated / removed per unit of exposure time (e.g., one second).3 ). The ablation rate can be expressed as:

[0116] A R = V / t(2)

[0117] where V (mm 3 ) is the target volume and t (s) is the time of full target laser irradiation for destruction / dissolution / removal. In other words, the ablation rate indicates the speed at which a current target with a certain volume can be destroyed, which impacts the shot time and the operation (process) time. As described above, the ablation rate is expected to vary with the laser parameter settings, and the goal is to minimize this metric for a given process.

[0118] The ablation threshold, the ablation process, and the competing detrimental effects of shadowing, retreat, and tip damage all depend on the power density, which is proportional to the ratio of energy to time for a given fiber type and environment. This means that additional metrics need to be introduced to properly characterize the ablation process in lithotripsy. While the ablation rate is an important metric to determine the time of the process for a given stone size, it is even more important to minimize the total laser energy required for a given process and stone. For example, there are cases where applying additional pulse energy does not result in an increase in the ablation rate. For example, 3 J can have the same ablation rate as 6 J at the same power density. At a lower power density, a 3 J energy pulse will provide a higher ablation rate than the 6 J case. This can happen due to the competing effects discussed above and possibly other effects. If the same ablation rate can be achieved with lower pulse energy (energy efficiency), there is no rational reason to apply additional energy.

[0119] The ablation efficiency (A E , mm 3 / J) is the amount of stone volume (mm 3 ) that is eliminated / removal by applying laser energy to the target. It reflects the efficiency of the applied laser pulse energy. For example, the ablation efficiency of a single laser pulse is the volume of the resulting crater / cavity divided by the pulse energy. For multiple pulses applied to one target point, the ablation efficiency is the final crater volume divided by the total applied energy, which is the sum of the energy of each applied pulse. The average ablation efficiency can be expressed as:

[0120] A E = V / Σ(E)(3)

[0121] where Σ(E) (J) is the total applied laser energy: Σ(E) = E1 + E2 + … + En n (n = pulse sequence number or number of pulses). If the energy of each pulse is the same, E j = E, then Σ(E) = nE.j ) = N*E, where N is the number of pulses.

[0122] In other words, the ablation efficiency indicates the target volume that can be removed by applying a certain unit of laser energy (e.g., one Joule).

[0123] When applied to a lithotripsy procedure in which the optical fiber can move relative to the stony calculus, the ablation efficiency can be expressed as:

[0124] A E = (S*υ) / (4)

[0125] where S (mm 2 ) is the vertical cross-sectional area of the crater produced by the laser after scanning, υ (mm / s) is the relative speed of the optical fiber and the stony calculus, and (W) is the average laser power. Note that in some cases, the inverse of the ablation efficiency (1 / A E , J / mm 3 ) can also be referred to as the ablation efficiency. In this case, the inverse indicates how much energy should be spent to ablate a unit target volume (e.g., one cubic millimeter).

[0126] The ablation efficiency is important to evaluate during the procedure. If the ablation efficiency is known, then given the stony calculus volume V, the shot time T of the procedure can be evaluated with the following expression:

[0127] T = V / (A E * )(5)

[0128] Given expression (3), the shot time can also be expressed as:

[0129] T = Σ(E) / (6)

[0130] Expression (5) indicates that increasing the ablation efficiency shortens the shot time, and thus the procedure time, which is crucial for treating large stony calculi and completing the procedure within the anesthesia time. In order to achieve this, it is necessary to first understand what the ablation efficiency depends on, e.g., what is the material of the target, and what can be done to increase the ablation efficiency.

[0131] Ablation efficiency depends on many factors, including laser wavelength, pulse energy, pulse frequency, pulse width, pulse shape, average and peak power, laser power density, fiber diameter, energy distribution inside the fiber, numerical aperture of the fiber, condition and shape of the fiber tip, distance to the target, target type (stone type / chemical composition and structure / shape of the stone), target absorption, surgical instrument type (rigid, semi-rigid, flexible endoscope) and speed of instrument manipulation (movement), clinician skill, and other factors.

[0132] To illustrate, the ablation efficiency of a fiber in contact with a stone will be higher than that of a fiber 1-2 mm away from the stone, all other factors being the same, because less laser light is absorbed in the medium (water) in the gap between the fiber tip and the stone, and possibly because the power density is higher on the surface of the ablated stone (smaller laser spot size due to laser beam divergence can increase the ablation rate). In addition, a fiber with a larger diameter and aperture, located at the same distance from the stone (all other factors being the same), delivers lower power density to the surface of the stone, and therefore can have lower ablation efficiency, depending on the level of power density relative to the ablation threshold. Therefore, it is important to properly select the appropriate power, energy, and fiber type, and to control the distance to the target, in order to perform lithotripsy more efficiently.

[0133] As discussed above with reference to the drilling of human dentin, a similar ablation efficiency nonlinearity is expected to apply to multiple pulses delivered to the same point on a stony calculus. The ablation efficiency of multiple successive pulses to a single point or site of a target stony calculus is less than the ablation efficiency of a first pulse to that point or site. The crater created by the first (or previous) pulse increases the distance of the fiber to the surface of the stony calculus (the bottom of the crater), thus reducing the incident power density and fluence of subsequent (subsequent) pulses. The laser radiation of subsequent pulses will be attenuated due to many of the factors described above, including but not limited to, the longer distance between the distal end of the fiber tip and the laser target, the opportunity for greater attenuation due to scattering and absorption by the ablation products, attenuation due to ablation of the crater filled with deeper water, and other factors. Thus, the number of pulses that hit one target site of a stony calculus and the effect on ablation efficiency depend on both the pulse frequency and the fiber movement speed. The greater the fiber speed, the fewer the number of pulses that hit a given target point. In a conventional procedure, the urologist selects only three laser parameters for treatment, namely the laser energy, the repetition rate, and the pulse width (or peak power). Their selection controls / determines the average laser power, which is important to prevent overheating and damage to surrounding soft tissue. The conventional understanding is that the energy should be selected in a range that provides acceptable levels of ablation efficiency per pulse, retreatment level, and visibility. The frequency (repetition rate) f is selected as high as possible (with a maximum of fmax) while keeping the average power P = E*f at a safe level Pmax to prevent thermal damage to soft tissue from overheated water. However, due to the mechanisms mentioned above that reduce the ablation efficiency during multiple pulses to the same point on the target, this approach of increasing the repetition rate is ineffective to maximize the ablation efficiency and / or minimize the treatment time. For this reason, the Applicant proposes a new parameter, the N-factor, to account for laser lithotripsy.

[0134] N-factor

[0135] During a laser lithotripsy procedure, the clinician directs laser pulses to the stony calculus and moves the scope, with the fiber positioned in front of the stony calculus (pulverization mode). The speed of the fiber movement depends on the clinician, the type of scope, and the body organ being treated. For example, Figure 2 A table is shown that illustrates typical fiber movement speeds for different scopes and organ types.

[0136] The speed of the fiber and the pulse frequency are parameters that determine the number of pulses to a site on the target, which in turn determines the D c (i.e., the crater diameter). Thus, the fiber speed and the pulse frequency determine the ablation efficiency. For the purposes of this disclosure, the number of pulses that hit one target point or site is referred to as the “N-factor” (= N f ). The N f can be expressed as:

[0137] Nf = (f*D c ) / υ(7)

[0138] where

[0139] f (Hz) is the laser pulse frequency (repetition rate),

[0140] D c (mm) is the laser crater diameter, and

[0141] υ (mm / s) is the speed of the optical fiber relative to the point on the stony calculus (i.e., the relative speed of the distal tip of the optical fiber in a direction parallel to the surface of the stony calculus).

[0142] Increasing the pulse frequency directly leads to an increase in the N-factor. Increasing the pulse energy (applied to one target point) at the current peak power can lead to an increase in the crater diameter, and thus can increase the N-factor, as long as the non-linearity of the ablation efficiency mentioned previously does not exist. As another example, the crater diameter also depends on the distance to the target surface, so the closer the optical fiber is to the target stony calculus, the smaller the crater diameter will be, and thus a smaller N-factor will result. Furthermore, increasing the fiber speed υ leads to a lower N-factor.

[0143] A visualization of the N-factor can be represented as in the schematic shown in Figure 3 . As shown in Figure 3 , according to certain aspects, Nf can be considered to correspond to the number of laser pulses delivered to a treatment area having a diameter approximately equal to the diameter of a laser crater (Dc) produced by the pulsed laser energy directed onto the treatment area on a target (e.g., calculus). For example, as indicated in Figure 3 , Nf = 2 means that the optical fiber scans the target surface (e.g., during pulverization) such that any point within the scan is exposed to two consecutive laser pulses. In other words, the area scanned receives a total of two laser pulses at each point along the scan. Likewise, N f = 4 means that the optical fiber scans the target surface such that each point within the scan is exposed to four consecutive laser pulses.

[0144] Considering expressions (4) and (7), the ablation efficiency can be expressed in terms of Nf as:

[0145] A E = (S*f*D c ) / ( *Nf)(8)

[0146] Note that S*D c is proportional to the crater volume after the cumulative effect of N f pulses, so S = S(N f ), and Dc = D c (N f ). As will be appreciated, the maximum ablation efficiency corresponds to the first pulse delivered to the treatment site, N f = 1, because although the multi-shot crater volume increases with increasing N f , the crater size does not increase proportionally. For example, the crater size after two pulses is less than twice the single pulse crater size. Thus, the ablation efficiency decreases with each subsequent laser pulse. However, the powder ablation technique assumes that the fiber is scanned through successive grooves rather than through the manufacture of individual drill holes / holes / craters.

[0147] As shown below, in practice, as N f increases, the ablation crater diameter will "saturation" or asymptotically reach a constant value. This means that at some point, additional pulses (increases in the N factor) will not provide increased crater diameter and depth, and thus, increased volume. The ablation efficiency of each pulse after saturation begins is zero, and thus, the overall ablation efficiency begins to decrease rapidly.

[0148] There is a point at which the N factor value provides both continuous target scanning / grooving on the one hand, and sufficient ablation efficiency of each subsequent laser pulse on the other hand. In practice, one might ask, "What is the purpose of an additional pulse serving to expose the current target site to additional exposure if it does not result in any visible / valuable ablation?" This point is underscored by the basic principle that it is desirable to minimize the energy deposited into the body as much as possible. According to certain aspects, it is better to target / move the fiber to a new site / location so that energy and time are not wasted heating water in the surrounding area. Thus, a simple increase in pulse energy and / or pulse frequency is not the best way to increase ablation efficiency (and sometimes even harmful), which is the conventional approach taken by many physicians.

[0149] Another aspect of implementing the N factor is to employ the most efficient laser parameter or set of laser parameters (which provide the greatest ablation efficiency with the least energy) according to the typical movement speed of the physician. While the speed of the fiber is a difficult parameter to control depending entirely on the clinician's technique, the N f factor will also be a continuously varying factor. Nonetheless, a laser configured with an intelligent assistant mode (implemented by the controller) can use feedback to control (in real-time or through presets) the laser parameters (e.g., pulse energy, pulse frequency, average power, pulse width, peak power, etc.) to maintain an efficient process.

[0150] Generally, the greater the pulse energy, the larger the crater size and the higher the fiber speed that the physician can use to provide efficient ablation. Alternatively, the physician can use a lower pulse frequency, which has a similar effect on the N-factor and ablation efficiency as an increase in fiber speed (N f = f D c / v). On the other hand, if the physician tends to use low fiber speed, the pulse energy and / or pulse frequency should also be limited in order to effectively adapt to the physician's ablation procedure style (A E = S v / (E p f)).

[0151] There is also an important aspect of the N-factor limitation related to the basic safety of the procedure. In order to avoid overheating and damaging the organ, there are basic upper limits (or ranges) based on safety considerations for applicable laser operating parameters such as pulse energy and average power, which are referred to herein as safety parameters. These safety parameter limits (or ranges) depend on the organ type. Figure 4 is a table showing the limits on various safety parameters for different organs. Using expression (7), the N-factor can be considered to depend at least in part on both the pulse energy and the pulse frequency, which in turn depend on the above-mentioned safety considerations that must first be reviewed and authorized before any laser operating parameter presets can be implemented.

[0152] While laser lithotripsy has many advantages over other alternative methods for removing stone-like concretions (e.g., mechanical, acoustic / ultrasonic, etc.), there are still various problems and challenges that need to be addressed, including increasing procedure safety, shortening procedure time, maximizing procedure efficiency, etc. Many of the factors described above directly affect these challenges and need to be considered together.

[0153] It would therefore be of great value to have an intelligent laser system (a so-called smart assistant mode) that can automatically calculate, determine, and suggest in real-time the optimal laser parameter set or optimal parameter range (such as pulse energy, frequency, peak power, pulse width, etc.) for laser lithotripsy. Such an algorithm depends on at least some of the physical / properties of the ablation procedure and related varying factors (fiber diameter, average power, organ type, endoscope type, physician's typical fiber speed, etc.) in order to increase the efficiency of the procedure and shorten the procedure time. The specific goal in this case is an algorithm that adjusts the laser parameters in order to continuously optimize the N-factor (e.g., to ensure that Nf is less than or equal to Nfmax), as described in more detail below.

[0154] Experiments, methods and measurements

[0155] According to various embodiments, an implemented intelligent assistant mode is provided to help a physician select the exact laser mode (i.e., laser parameter set) that is most efficient for ablating the current target (e.g., a stone-like calculus or soft tissue). As used herein, such treatment is a calculus or stone-like calculus (hard tissue) treatment, and as used herein, the term "calculus" refers to a calculus (stone-like calculus) present in an anatomical location, such as a ureter, kidney, or bladder. Calculi include all types of stone-like calculi in a human or animal body. However, it should be appreciated that similar methods can also be applied to soft tissue ablation, cutting, incision, and resection. Which laser mode to select should be done in real-time before or during the procedure. To achieve this, the calculus and the ablation efficiency of the procedure need to be characterized, and it needs to be understood what the ablation efficiency depends on, and thus what factors are most important for increasing the ablation efficiency.

[0156] As mentioned above, the ablation efficiency depends on many dynamic and static variables / parameters / factors. While some of these variables are static or not precisely controlled (e.g., fiber movement speed, fiber size), other available parameters can be precisely controlled in real-time during the procedure (e.g., laser settings such as pulse energy, pulse frequency, peak and average power, etc.).

[0157] It is key to understand the relationships between these different categories of factors and how they affect the ablation efficiency. This understanding is key to the best intelligent assistant mode implementation.

[0158] There are several ways to determine these relationships. A first method is to study theoretical models (scientific theories) of the processes that occur during laser ablation of stone-like calculi / tissue, and based on this theoretical model, identify and define the variables. However, it is often found that the predictions of the theoretical model can differ from actual measurements, because there are important factors / variables that are not included in the theoretical model. However, even when the exact representation is known and the theoretical model is incomplete, an analytical approximation can still provide a sufficiently accurate solution to the problem while significantly reducing its complexity.

[0159] A second method is to perform a heuristic analytical approximation, which includes the following: conduct a comprehensive experimental program that includes controllable and uncontrollable factors during the procedure, provide appropriate measurements, analyze the results, and develop an analytical approximation model of the ongoing ablation procedure that predicts experimental results with a certain level of accuracy. This model can be used to calculate and predict the ongoing ablation procedure, and thus select the appropriate settings of the laser parameters that provide the maximum ablation efficiency in a clinical situation.

[0160] As an example of this approach, the Applicant has identified and characterized parameters relevant to the goal of improving the safety and efficiency of surgical procedures for lithotripsy and soft tissue manipulation, and has introduced analytical models and derived expressions (5) and (8) (above, for lasing time and process length dependent on ablation efficiency, which in turn depends on laser parameters and N-factor). As a next step in this program, the Applicant has performed a wide, comprehensive series of in vitro laser ablation experiments in a scanning mode on the surface of a stone-like calculus, to be discussed below, which data will provide determination of the optimal N-factor, which in turn defines the most efficient use of the laser for a given clinical procedure.

[0161] In these experiments, Bego stone-like calculi were used as target stone-like calculi. The stone-like calculi are composed of a special heavy-duty plaster and are generally considered in the industry as a good model of a uric acid prosthetic stone-like calculus. The Bego stone-like calculi are about 60 mm x 40 mm x 5 mm in size and have a flat and even surface, and were placed in water within a cuvette. The stone-like calculus surface level was controlled by a horizontal tool. A surgical fiber optic tip with a factory cut was directed at the stone-like calculus surface at a right angle and at a predetermined precisely controlled distance (gap). A thulium fiber laser was used to generate the directed pulsed energy. After each impact (drilling or scanning) of the laser pulse, the fiber was moved to a new position using a motorized precision linear 2-axis stage to form an array of laser treatment sites. Scanning of the fiber parallel to the stone-like calculus surface at an adjustable constant speed was controlled by a motorized X-Y linear stage. The first goal of the experimental procedure was to identify and quantify laser-generated craters as a function of laser parameters in the stone-like calculus model.

[0162] A matrix / array of craters was formed on the stone-like calculus surface, where each crater was generated by a specific laser parameter, which range was defined as follows:

[0163] 1. The surgical fiber used had a core diameter in the range of 0.2 mm to 0.94 mm.

[0164] 2. The distance between the fiber tip and the stone-like calculus surface had a range of 0.1 mm (quasi-contact) to 1 mm.

[0165] 3. The pulse energy was in the range of 0.1 J to 6 J.

[0166] 4. The peak power was in the range of 250 W to 2000 W.

[0167] 5. The number of pulses in a spot (N-factor) was in the range of 1 to 20 / crater (pc).

[0168] Figure 5The peak power (P) values ​​for 500W, 750W, and 1000W are shown. peak An example photograph of an array of pits on the surface of a Bego stone after being subjected to a laser pulse, showing how the pulse energy (E) and N factor (Nf) vary (all using 200 μm optical fiber with a 0.1 mm gap between the fiber and the surface of the Bego stone).

[0169] After drying the Bego stone-like stones (waiting 24 hours at 25°C before measurement), the optical profilometer (Zygo NewView) was used. ™ 8300) Measure the diameter and cross-section of all pits, such as Figure 6 As illustrated in the diagram, each pit has a U-shaped cross-section, as shown in the diagram. Figure 7 The graphical results shown in the figure (and also as shown in the figure) are as follows: Figure 6 As can be seen, it shows the “U-shaped” depth profile of different pits that vary with pulse energy (single pulse, 500W peak power). The pit diameter was determined from the digital image using sampling of 886 points / pit (pc). The size and shape of the pits (diameter, depth, cross-section, volume) are related to or vary with laser pulse parameters (pulse energy, N-factor, peak power) and other conditions (such as fiber diameter and gap).

[0170] Figure 8 This table shows the diameter of the pits formed by a single laser pulse. The results indicate that the pit diameter increases with increasing pulse energy or peak power, respectively, as the total laser fluence or laser fluence rate (power density) increases. Similarly, for higher power, the pit diameter increases with increasing fiber diameter, but not for lower power, because lower power pulses are closer to the threshold power density, and beam profile becomes important. With increasing gap, the trend is complicated by the interaction between the laser, the stone-like structure, and the water due to the Moses channel dynamics.

[0171] Depending on other pulse parameters, the pit diameter exhibits a saturation point when the N-factor value is in the range of 10 to 20. This means that the rate of increase in pit diameter under additional laser pulses decreases significantly. Figure 9 This shows the number of pulses (N) from 10 to 20. f = 10-20) The results show that, for a given fiber diameter and gap, the "saturation" (maximum) pit diameter exhibits a similar trend to that shown by the diameter of a single-pulse pit with different pulse energies and peak powers. However, the value of the saturation pit diameter is not even twice the value of the single-pulse pit diameter.

[0172] The scanning / groove matrix / array depends on varying / altering parameters. The experiment utilized factors ranging from the following (note that for all data points, the distance between the distal tip of the fiber and the surface of the stony nodule remained constant at 0.5 mm):

[0173] 1. Surgical optical fibers have core diameters ranging from 0.2 mm to 0.94 mm.

[0174] 2. The pulse energy is in the range of 0.2J to 6J.

[0175] 3. Peak power ranges from 250W to 1000W.

[0176] 4. Average power is in the range of 10W to 40W.

[0177] 5. The pulse frequency is in the range of 5Hz to 55Hz.

[0178] 6. The fiber optic scanning speed is constant for each scan and ranges from 0.5 mm / s to 10 mm / s.

[0179] 7. The N factor Nf is in the range of 1 to 20.

[0180] Each scan is unique to itself. As an example, Figure 10 The average power (A / S) is shown for fiber scanning speeds of 0.5 mm / s, 1.25 mm / s, and 2 mm / s. The image shows an array of grooves on the surface of a Bego stone-like nodule after being subjected to a scanning laser pulse (200 μm fiber, 500 W peak power, 0.8 J pulse energy, 0.5 mm gap between the fiber and the Bego stone-like nodule surface). Therefore, in this figure, the number of pulses per click N across the grooves is... f The range is 4 to 64 shots per point.

[0181] A total of 88 data points were collected (per pit) for measuring scan depth and cross-section. The depth and cross-section of each scan were measured using the same optical profilometer.

[0182] Following the scanning experiment, different laser parameters (pulse energy E, J) and average power were considered. The area (S, mm²) of the cross-section of the ablation pit in the vertical plane is measured for each laser parameter (W), pulse frequency (f, Hz), and fiber scanning speed (υ, mm / s). 2 ).

[0183] Figure 11is a table showing the results of the recess measurement after the impact from a scanning pulse, and indicates the calculated specific pit (recess) volume (volume contribution of a single pulse) in scanning mode for a 0.2 mm fiber core diameter as a function of peak power, pulse energy, and N (pulse sequence number). The specific pit (recess) volume (in mm 3 as a unit) is calculated according to the following expression:

[0184] V = (S*υ) / f (9)

[0185] where

[0186] S (mm 2 ) = area of the pit (recess) cross section,

[0187] υ (mm / s) = fiber scanning speed (constant during each scan), and

[0188] f (1 / s) = pulse frequency.

[0189] Calculations, approximations, and discussion

[0190] An analytical expression with adjustable coefficients was fitted to the experimental data to describe the relationship between the pit diameter at a single point after the first laser pulse (FP). The result is the following formula:

[0191] D c FP = (2NAΔ + d)(0.12 ln (E1 / (0.25 F’(2NAΔ + d) 2 )) – / 250) +

[0192] + (1.82d) (0.21 – 0.025 E1)(10)

[0193] where

[0194] NA = fiber numerical aperture,

[0195] Δ (mm) = gap between the fiber tip and the stone surface,

[0196] d (mm) = fiber core diameter,

[0197] (W) = peak power of the laser pulse,

[0198] E1 (J) = single pulse energy,

[0199] F’ (J / cm 2) = target stone damage threshold, for Bego stone model at 1.94 pm wavelength, this threshold is 20 J / cm 2 (threshold ablation).

[0200] Equation (10) is an analytical approximation that depends on physical factors. For example, the factor (2NAΔ + d) is the diameter of the irradiation spot on the target, which varies with the distance to the target, Δ, the fiber diameter (core), d, and the numerical aperture, NA. The factor E1 / (0.25 (2NAΔ + d) 2 ) can be described in units of J / cm 2 and reflects the fluence (energy density) on the target surface. Dividing this factor by F’ gives the fractional excess of energy / fluence over the ablation threshold. The rest of the expression / values are overall correction factors with secondary physical meaning.

[0201] Equation (10) is not the only possible expression that approximates and describes the crater diameter behavior as a function of the variables of interest. Based on experimental data, many other analytical approximations can be found, but regardless of which equation is used, the solutions for the crater diameter should be equal to each other, as they must all fit / predict the same experimental data.

[0202] Figure 12 is a pair of tables showing the comparison of experimental data and data calculated using the proposed crater diameter equation (10) as a function of pulse energy and peak power for a 200 pm fiber and 0.5 mm gap after impact from a single pulse and multiple pulses. Figure 13 shows an example of the application of equation (10) (solid line in the graph of Figure 13 ) and reflects a graph showing the comparison between measured experimental data and calculated data (via the proposed equation 10) for a 0.2 mm fiber and 500 W peak power for 0.1 mm, 0.5 mm, and 1 mm gaps. The shape of the curves indicates that the crater diameter and the pulse energy are logarithmically related. The error of the proposed equation (10) (i.e., the difference between the measured data and the calculated data divided by the average of the measured data and the calculated data) is within 30% for all energies.

[0203] Another analytical approximation equation was found to describe the existing relationship between the saturated crater diameter after multiple laser pulses (Nf = 10-20):

[0204] D c SAT = (2NAΔ + d)(1 / (1.61 + 10.23d 4 + (0.92 - 2.97d)Δ)) x (1 + ( / 12.85) ln((12.85 / )(1 / (6.4 - 6.75d))(E / (0.25 F'(2NAΔ + d) 2 - 1) + 1))(11)

[0205] Likewise, equation (11) is also not the only possible expression that can predict the saturation crater diameter as a function of the dependent variable. Many other analytical approximations can be found and fitted to experimental data, but all approximations should yield the experimental crater diameter.

[0206] According to at least one embodiment, the crater diameter D c In the range of the expression in equation (10) and the expression in equation (11):

[0207] D c FP < D c < D c SAT

[0208] or

[0209] (2NAΔ + d)(0.12 ln (E1 / (0.25 F'(2NAΔ + d) 2 )) - / 250) + (1.82d) (0.21 - 0.025 E1) ≤ D c ≤ (2NAΔ + d)(1 / (1.61 + 10.23d 4 + (0.92 - 2.97d)Δ)) x (1 + / 12.85) ln((12.85 / )(1 / (6.4 - 6.75d))(E / (0.25 F'(2NAΔ + d) 2 - 1) + 1)),

[0210] where the variables are defined as above for those equations.

[0211] Figure 14Three graphs showing the application of equation (11) from which the saturated crater diameter is obtained are shown and reflect the comparison between measured experimental data and calculated data (equation (11)) for 0.2 mm fiber and 500 W peak power for 0.1 mm, 0.5 mm, and 1 mm gap. As with Figure 13 equation (10), the shape of the curves indicates that the crater diameter and pulse energy are also logarithmically related. The error (i.e., the difference between the measured data and the calculated data divided by the average of the measured data and the calculated data) of the proposed equation (11) is within 30% for all pulse energies.

[0212] Figure 15 Three graphs showing the calculated specific crater volume for a 0.2 mm fiber for different N f (pulse sequence number) values as a function of peak power and pulse energy are shown. The gap between the fiber tip and the stone-like calculus is 0.5 mm. The dots (data points) reflect the experimental data points, and the lines reflect the curve of the calculated data approximation. The error is less than 30%.

[0213] Figure 16 is a table showing the comparison between the measured and calculated most efficient values for the number of pulses in one spot site as a function of peak power and pulse energy for different fiber diameters. The error is less than 30%.

[0214] As stated previously, increasing the pulse frequency while using the same pulse energy and increasing Nf (the number of pulses into one spot site) does not necessarily result in an increase in the ablation efficiency or the overall efficiency of the procedure. Clearly, from a certain point in time, each additional irradiation pulse on the same target spot site does not necessarily result in any efficient ablation of the target volume. According to various aspects, a new parameter can be named and utilized, namely the most efficient number of pulses in one spot site, or Nf max that satisfies the following equation

[0215] A E (Nf max ) / A E (Nf = 1) = K (12)

[0216] where A E (Nf max ) is the average ablation efficiency per pulse after Nfmax pulses in a single spot site, and A E(Nf = 1) is the ablation efficiency of the first pulse into the point, which is the maximum possible ablation efficiency per pulse (or ablation efficiency of a single pulse). The value of K is a predetermined value, and according to some embodiments, can be selected to be in the range of about 0.25 to 0.75 (25% to 75%) (including the end values), more preferably in the range of about 0.50 to 0.75 (50% to 75%) (including the end values). In some embodiments, the value of K is in the range of about 25% to 75% (including the end values), and in some embodiments, the value of K is in the range of about 25% to 50% (including the end values). A higher value of K provides a higher ablation efficiency and shorter procedure time. According to at least one embodiment, Nfmax is in the range of 1 value 12 (including the end values). In another embodiment, Nfmax is in the range of 1 to 7 (including the end values). In yet another embodiment, Nfmax is in the range of 1 to 5 (including the end values), and in yet another embodiment, Nfmax is in the range of 1 to 3 (including the end values).

[0217] Expression (12) implies that Nf max is determined such that the exact number of pulses in one point provides an ablation efficiency no less than the value of K, which corresponds to the maximum possible ablation efficiency or ablation efficiency of a single pulse. In some embodiments, Nfmax corresponds to the number of laser pulses delivered to a treatment area having a diameter approximately equal to the laser crater diameter Dc, which provides an average per pulse stone ablation efficiency greater than or equal to a predetermined value of K, which corresponds to the ablation efficiency achieved following the impact from a single (first) pulse, for the maximum number of pulses. In other words, each current point of the target is irradiated by the minimum number of the most efficient pulses. In one embodiment, when the ablation efficiency of additional pulses decreases to a value of K lower than the maximum possible ablation efficiency or from the ablation efficiency of a single pulse to K, it is not meaningful to irradiate the current point by additional laser pulses, and it is more efficient to move the fiber into a new target point during the target scan (pulverization technique). In other embodiments, the same applies for K no less than 0.25 of the maximum value, no less than 0.50 of the maximum value, or no less than 0.75 of the maximum value.

[0218] Since the ablation efficiency and the ablation volume are tied together by expression (3), Nf max can also be found by using the crater volume:

[0219] V (Nf max ) / [Nf max *V (Nf = 1)] = K (13)

[0220] Expression (13) means that Nfmax The exact number of pulses that can be determined to be in a point location that provides a K fraction of the maximum possible ablation volume per pulse of stone volume ablation that is produced under the impact of the first pulse. In other words, each point location of the target is irradiated by a minimum number of the most efficient pulses. While the example in expression (13) provides a K fraction of the maximum possible (first pulse) ablation volume per pulse of stone ablation volume that is not less than the maximum possible first pulse ablation volume, other percentage values are within the scope of the present disclosure, including K = 0.25 of the maximum possible first pulse ablation volume, K = 0.50 of the maximum possible first pulse ablation volume, and up to K = 0.75 of the maximum possible first pulse ablation volume that is not less than the maximum possible first pulse ablation volume. When the ablation volume of additional pulses is reduced to 25%, 50%, 70%, or 75% of the maximum possible first pulse ablation volume, there is no reason to irradiate the current point location by additional laser pulses, and it is more efficient to move the optical fiber into a new target point location during the target scan.

[0221] According to at least one embodiment, Nf is compared to Nfmax. This can be done by the controller, as discussed in further detail below. In response to determining that Nf is less than or equal to Nfmax, one or more laser operating parameters are used to control the laser source that were used to calculate Nf to control the laser source during the lithotripsy procedure. In response to determining that Nf is greater than Nfmax, the controller (or user) can adjust at least one laser operating parameter used to control the laser during the lithotripsy procedure. In this example, the goal is to adjust the laser operating parameters such that the Nf value is equal to or less than Nfmax. This method is discussed in further detail below. Additionally, the controller can be configured to display at least one laser operating parameter on a display device based on the comparison, and in some examples, at least one of Nf and Nfmax can be displayed on the display device.

[0222] According to at least one embodiment, Nf is selected or otherwise adjusted to be less than or equal to Nfmax. In some embodiments, this is accomplished by adjusting one or more laser operating parameters such as pulse energy, pulse frequency, average power, peak power, and / or pulse width. As described above, Nfmax corresponds to the number of laser pulses delivered to the tissue surface at a particular point site in the treatment region, and each pulse at that point site ablates a volume of stone (increasing the diameter / depth / volume of the crater formed by the previous pulse) to provide an average per pulse stone ablation efficiency that in some embodiments is not less than 25% of the ablation efficiency achieved with the first (single) pulse, in some embodiments is not less than 50% of the ablation efficiency achieved with the first (single) pulse, and in yet other embodiments is not less than 75% of the ablation efficiency achieved with the first (single) pulse. In one embodiment, the 75% criterion is calculated according to equation (14) described below.

[0223] The method is illustrated in the three graphs of Figure 17 , where it can be seen that Nfmax (solid line) is determined for each fiber diameter (0.2 mm, 0.55 mm, and 0.94 mm) for 0.5 kW peak power. The graphs show the highest efficient N-factor as a function of pulse energy and peak power for different fiber diameters using a 0.5 mm gap between the fiber and the Bego stone surface. The data points reflect measured experimental data, and the solid line curve indicates data calculated using the analytical approximation formula. For example, for a 0.2 mm fiber diameter with 0.5 kW peak power and 6 J pulse energy, the maximum ablation volume (ablation volume for a single pulse) is V(Nf = 1) = 0.37 mm 3 . Using expression (13), the calculated (V (Nf max ) / (Nfmax*V (Nf = 1)) = 0.7 = 0.7 * 0.37 mm 3 = 0.26 mm 3 . By interpolating the volumes between Nfmax = 10 and 12 in the table of Figure 11 , the corresponding pulse number corresponding to the calculated ablation efficiency value is found: Nfmax = 12. This value represents the maximum number of pulses in one point site with an acceptably high per pulse ablation efficiency.

[0224] Figure 16It is also shown that the method has the highest number of efficient pulses in one spot as a function of peak power (0.25 kW to 1 kW) and pulse energy (0.2 J to 6 J) for different fiber diameters (0.2 mm, 0.55 mm, and 0.94 mm).

[0225] Using the measured data of Nfmax from the table in Figure 11 , another approximate formula was determined that describes the dependence of the highest efficiency N-factor on other factors (i.e., fiber-stone gap d, peak power, and pulse energy E) and K = 0.75:

[0226] Nfmax = (12.4 - 3.4d) + (3.3d - 8.4) / (1 + 4.7x10 -5 exp(P peak / 0.0375))-

[0227] ((14.7d - 16) + (80 - 65d)P peak + (55d - 62)P peak 2 ) / (1 + 0.34 E 5.5 - 2.6(Ppeak) ) (14)

[0228] Since the number of pulses is a natural number, the result of expression (14) must be rounded to the nearest integer. Formula (14) is also not the only possible expression that describes the behavior of the highest efficiency N-factor as a function of the variables. It is only one of several possible approximate formulas that describe this relationship. Thus, based on the experimental data obtained, many other possible analytical approximations can be found, but the solution of the highest efficiency N-factor equation must be predicted from Figure 11 experimental data.

[0229] According to various embodiments, Nfmax is determined based on a database of stored Nf data (e.g., from Figure 11 later data) obtained from experiments. Preclinical and clinical trial data from laser lithotripsy procedures are analyzed, and Nfmax values are calculated for different combinations of input and process parameters to determine the highest number of efficient pulses in one spot, and that pulse number also meets safety parameter thresholds so that no tissue damage or other harmful effects are encountered.

[0230] Returning to Figure 17, 3 graphs showing examples of the application of equation (14), and comparison between experimental data and data calculated via the proposed equation for 0.2 mm, 0.55 mm, and 0.94 mm optical fibers for 250 W, 500 W, and 1000 W peak power using a 0.5 mm gap. Data calculated using the proposed equation are also shown in Table Figure 16 . For all pulse energies, the accuracy of the proposed equation (14) (i.e., the difference between the measured data and the calculated data divided by the average of the measured data and the calculated data) is within 30%.

[0231] Based on the data in equation 14, Table 16, and Figure 17 , Nfmaxmay be in the range of 3 to 12. Nfmaxincreases with energy and peak power. This limits the optimal value of Nfmaxto be less than or equal to 12, preferably less than or equal to 7, more preferably less than or equal to 5, and most preferably less than or equal to 3. According to various aspects, Nfmay be less than the values in the above ranges during treatment.

[0232] It is apparent that the most efficient number of pulses Nf max increases with increasing peak power. For a given power, Nf max starts to grow and eventually also saturates with increasing pulse energy. For example, for a 0.55 pm fiber and a 1 kW peak power, increasing the pulse energy from 0.2 J to 3 J causes Nf max to increase from 4 to 10, but further increasing the pulse energy to 6 J does not result in an additional increase of Nf max The proposed equations (10), (11), and (14) are sufficient for an algorithm that provides the optimal treatment for stone stone removal (maximum efficiency with a minimum amount of energy) while taking into account the described variation factors (e.g., fiber diameter, gap, peak power).

[0233] Proposed intelligent assistant mode method

[0234] According to various embodiments, there are several ways to implement the intelligent assistant mode and possibly integrate it into the laser system. For the purposes of this disclosure, three non-limiting examples are discussed, the first example is process 1800 in Figure 18 , the second example is process 1900 in Figure 19 , and the third example is process 2000 in Figure 20of the process 2000 in FIG. 20. However, it should be understood that other variations of these methods are within the scope of the present disclosure. Moreover, equations (10), (11), and (14) can be used for other non-limiting methods and applications of the intelligent assistant mode during lithotripsy. One or more steps included in these processes can be performed by the controller 150 or components of the controller, which will be discussed in further detail below with respect to FIGS. 21-23. Figure 22 The system 100 of FIG. 20 is discussed in further detail below.

[0235] At the beginning of all of the proposed methods, the first step (1802, 1902, 2002) includes receiving or otherwise obtaining one or more input parameters. According to various embodiments, the one or more input parameters include at least one of a target parameter, a system parameter, and a safety parameter. The controller 150 can be configured to receive the one or more input parameters.

[0236] In some embodiments, the one or more input parameters include a target parameter, such as information about the target and the target location. The target parameter can include a target type (e.g., stone), a target location (e.g., kidney, bladder, ureter), and / or one or more target characteristics. For example, according to an embodiment in which the target is a stone, the one or more target characteristics can include a size and a hardness of the stone. Additionally, according to another embodiment in which the target is a stone, the one or more target parameters can include a proposed ablation technique, such as fragmentation, pulverization, or burst. These latter parameters can be based in part on the one or more target characteristics, such as the size and hardness of the stone.

[0237] According to at least one embodiment, the one or more input parameters include a system parameter, such as a laser type, laser characteristics, and other information about the system in which the process will be performed. Non-limiting examples of system parameters include a laser type, such as a thulium fiber laser (TFL), Ho:YAG, Tm:YAG solid state laser, and / or a laser wavelength, a fiber diameter (i.e., a diameter of a fiber (e.g., the surgical fiber 110 in FIG. 20, also referred to herein as a surgical fiber) that directs the laser energy to the target), and an instrument type (such as a flexible, rigid, and / or semi-rigid scope). Figure 22 According to at least one embodiment, the one or more input parameters include a safety parameter, including maximum laser operating parameters so that a patient undergoing the process is not exposed to unnecessary harm. In some embodiments, the safety parameter includes at least one of a maximum average power, a maximum peak power, a maximum pulse energy, and / or a maximum pulse frequency. In some embodiments, the safety parameter further includes a minimum pulse energy.

[0238] According to at least one embodiment, the one or more input parameters include a safety parameter, including maximum laser operating parameters so that a patient undergoing the process is not exposed to unnecessary harm. In some embodiments, the safety parameter includes at least one of a maximum average power, a maximum peak power, a maximum pulse energy, and / or a maximum pulse frequency. In some embodiments, the safety parameter further includes a minimum pulse energy.

[0239] The input parameters can be received or otherwise determined by the controller 150 in a variety of different ways. For example, the user 120 (e.g., a physician) can input one or more input parameters to the system 100 via the user input device 135 (e.g., a touch screen). In one embodiment, the physician 120 inputs at least one target parameter (e.g., target location, and if the target is a stone, the size and hardness of the target). In some instances, the target size and hardness can be determined by pre-observation of the target using an imaging device. In another embodiment, the user 120 (physician) inputs to the system (e.g., via the user input device 135, such as a touch screen) input parameters that include one or more system parameters, such as fiber diameter and / or fiber numerical aperture. In another embodiment, the user 120 (physician) inputs input parameters that include one or more safety parameters, such as: maximum average power, maximum pulse energy, and / or maximum peak power. In some embodiments, the user 120 can input one or more safety parameters, such as maximum average power and maximum pulse energy, using (e.g.) Figure 4 tables in FIGS. 1-3, for example). In other embodiments, the controller 150 itself can be configured to determine one or more safety parameters based at least in part on one or more other input parameters (e.g., target type, target characteristics, target location, fiber size, and / or instrument type). For example, information stored by the controller 150 (e.g., a table including information from FIGS. 1-3, for example) can be used at least in part by the controller 150 to determine one or more safety parameters based on one or more other input parameters. Figure 4

[0240] According to another embodiment, the controller 150 calculates and / or uses stored input parameters. For example, in one embodiment, the user 120 selects (e.g., using the user input device 135, such as a GUI touch screen) one or more proposed (pre-determined) input parameter values, and the controller 150 automatically determines input parameters (such as maximum average power and safe energy range (E min -E max )) based on other input parameters such as the organ being treated (e.g., kidney, ureter, bladder), instrument type (rigid, semi-rigid, flexible), fiber diameter, and the desired ablation technique (fragmentation, pulverization, burst).

[0241] In some embodiments, the fiber diameter can also be automatically determined by the controller 150, for example, by using a built-in NFC chip or RFID chip (e.g., a sensor such as sensor 125 in FIG. 1) associated with the surgical fiber instrument (e.g., an endoscope). Figure 22

[0242] ​​In some implementations, one or more process parameters (also referred to herein as treatment parameters), such as laser operating parameters, may be automatically determined (calculated) by controller 150. For example, peak power may be automatically determined by controller 150 based on the potential / capacity / characteristics of laser source 105 and safety parameters to be used in the process.

[0243] Based on various aspects, three examples of laser systems utilizing the N-factor as a treatment parameter are described below. Furthermore, other treatment parameters, such as pulse energy, frequency, pulse width (or peak power), and average power, are used to provide maximum ablation efficiency and minimum process time. For example, one or two users (a urologist or their assistant) select treatment parameters to maintain the N-factor at a specific level. <N fmax Within the optimal range. Example 3 of the laser system includes real-time measurement of fiber velocity and automatic adjustment of laser parameters to keep the N-factor ≤ N. fmax Within the optimal range.

[0244] First example of a laser system with intelligent assistant mode

[0245] A flowchart illustrating an example of the steps used in the first method or process 1800 of using the intelligent assistant mode. Figure 18 As shown in the diagram. As previously described, one or more steps included in process 1800 may be performed by a controller (e.g., controller 150 discussed below). The initial step at 1802 includes receiving (e.g., by the controller) one or more input parameters, as described above. According to at least one embodiment, the input parameters include target parameters. In one embodiment, the target parameters include target type, target location, and one or more target characteristics. In some embodiments, the target type is a stone, and the target location is a kidney, bladder, or ureter. In some embodiments, the target type is a stone, and one or more target characteristics include the size and / or hardness of the stone. In some embodiments, the input parameters include at least one system parameter, and in one embodiment, at least one system parameter includes at least one of fiber diameter, fiber numerical aperture, and instrument type. For example, as... Figure 22 As shown, fiber 110 is used to guide pulsed laser energy, and the fiber diameter and numerical aperture are related to the distal end of fiber 110 (the end from which pulsed laser energy is emitted). In some embodiments, the instrument type is a flexible or rigid mirror type. In another embodiment, the input parameters include at least one safety parameter, and in one embodiment, at least one safety parameter includes maximum average power, maximum peak power, maximum pulse energy, and / or maximum pulse frequency.

[0246] According to another embodiment, at least one procedure parameter (also referred to herein as a procedure parameter) is determined. The procedure parameter can include one or more parameters used or otherwise implemented by the physician and / or system in performing the lithotripsy procedure. Non-limiting examples of procedure parameters include pulse frequency, peak power, pulse energy, laser crater diameter, fiber speed, gap between fiber tip and target, and target ablation threshold. According to certain aspects, the N factor Nf or the maximum N factor Nfmax can also be considered a procedure parameter and / or a laser operating parameter.

[0247] In some embodiments, the determined at least one procedure parameter includes fiber speed (υ). This can be done automatically by the controller 150 using a table in Figure 2 based on one or more previously received parameters (e.g., input parameters such as organ type, instrument type, fiber diameter, etc.). Alternatively, the physician can input the fiber speed he or she needs or intends to use. Another approach is for the physician to select the proposed relative fiber manipulation regime / style (e.g., slow, average, or fast) he or she needs or intends to use, and the laser system automatically determines the corresponding fiber speed (min, typical, max) using the proposed data shown in the table, for example. Figure 2 Figure 2 The fiber movement speeds in the table in were determined based on processing of endoscopic videos captured during stone lithotripsy treatments performed by several different urologists. The specific values in this table can be averaged across different urologists, or can be collected for a particular user and stored in the controller for Nfmax computation. In other embodiments, the physician can pre-define the fiber speed.

[0248] According to some embodiments, the average safe pulse energy is calculated or otherwise determined based on one or more safety parameters. For example, in step 1806, the average safe pulse energy is based on the maximum pulse energy Emax and the minimum pulse energy Emin (e.g., the minimum pulse energy required to perform ablation) and is calculated according to the following expression: = (E min +E max ) / 2). Emin can be determined according to stored data obtained from previous preclinical and / or clinical trial data, and corresponds to the minimum pulse energy that provides the lowest acceptable efficiency (i.e., acceptable amount of ablation on the target stone).

[0249] In some embodiments, the determined at least one procedure parameter is crater diameter Dc. For example, at step 1808, the controller 150 can be configured to calculate the crater diameter (D c). As the crater diameter varies with the gap (Δ), another process parameter that can be determined includes the gap between the fiber and the target. This can be determined by the controller 150 and, in some instances, can be considered to be a typical average gap for lithotripsy (e.g., 0.5 mm) and thus a value stored in memory (e.g., memory 140 in Figure 22 controller 150. Alternatively, the physician 120 can input (e.g., via the user interface device 135) the gap that he or she needs or intends to use. The crater diameter also varies with the target threshold (F’). This can be accepted or otherwise determined by the controller 150 as a typical average threshold for a target stone-like calculus during lithotripsy or a threshold for a Bego stone-like calculus (e.g., 20 J / cm 2 ). Alternatively, the physician 120 can input the target threshold that he or she needs or intends to use during treatment. Another approach can be for the physician to select the type of stone-like calculus (target and target properties) at the beginning of treatment (e.g., target properties such as uric acid, cysteine, calcium oxalate monohydrate (COM), struvite, xanthate, silicate, mixed / combination type of stone-like calculus, etc.) and input this information as an input parameter (via the user interface device 135) and the controller 150 uses preset / predetermined values (e.g., previously obtained / measured threshold data for each type of stone-like calculus stored in memory 140) to determine the stone-like calculus threshold.

[0250] According to another embodiment, a maximum N factor (Nfmax, also referred to herein as Nmax) is calculated or otherwise determined and Nfmax can be considered to be the most efficient number of pulses, as previously discussed. In the process 1800, Nfmax is determined (e.g., by the controller 150) at step 1810 using equation (14).

[0251] In some embodiments, a process parameter such as a pulse frequency is calculated, which can be based at least in part on Nfmax. For example, in the process 1800, the pulse frequency (f) is calculated at step 1812 using expression (7):

[0252] f = (Nf max *D c ) / υ(15)

[0253] According to another embodiment, a process parameter such as a pulse energy is calculated. In some embodiments, the pulse energy is calculated (e.g., by the controller 150) based at least in part on the pulse frequency. For example, at step 1816 of the process 1800, the pulse energy (E) is calculated using the following expression:

[0254] E = / f(16)

[0255] The next step at 1816 is to check the safety of the calculated parameters. For example, process parameters such as pulse energy E can be compared with thresholds (e.g., Emax) corresponding to safety parameter values ​​(e.g., by controller 150).

[0256] According to another embodiment, if the calculated pulse energy E is less than or equal to a threshold Emax, a second comparison calculation can be performed at step 1822 (e.g., by controller 150). For example, the calculated pulse energy E can be compared with a second threshold, such as the average safe pulse energy calculated at step 1806. If the calculated pulse energy E is higher than the second threshold ( Large pre-orders (e.g., 20%) -E) / > 0.2), then in some embodiments, the process returns to step 1808 to determine (e.g., by controller 150) the pit diameter Dc using the calculated pulse energy (calculated using expression (16) at step 1814) using the proposed formula (10) or (11), and the process continues from step 1808. If the calculated pulse energy E is equal to the second threshold ( If the value is less than or equal to the second threshold by a predetermined amount (e.g., 20%), the controller 150 displays one or more process parameters (whether already calculated or calculated at this step) on the display device 130, such as laser operating parameters (e.g., pulse energy, power, and frequency). This is shown at step 1824 in process 1800.

[0257] Returning to step 1816, if the calculated pulse energy is greater than or otherwise exceeds the threshold (E > E),... max If the pulse energy E is set to the maximum pulse energy (safe pulse energy value) Emax at step 1818, then at step 1820, the pulse frequency is recalculated (e.g., by the controller 150) using expression (16). Once the pulse frequency is recalculated, the controller 150 displays one or more process parameters (e.g., laser operating parameters, such as pulse energy, pulse frequency, average power, peak power) on the display device 130 (e.g., as discussed in step 1824 above).

[0258] In some implementations, when the pulse energy E is less than or equal to a threshold (e.g., Emax), the controller 150 outputs a positive alarm message on the display device 130. An example of such a positive alarm message 157 is... Figure 21on the left (i.e., "You are currently using the best parameters"). In alternative embodiments, when the pulse energy E is greater than the threshold (e.g., Emax), then the controller 150 outputs a negative alert message 159 on the display device 130. An example of such a negative alert message is shown on the right (i.e., "You are currently outside of the best parameters"). Figure 21

[0259] According to at least one embodiment, the last step of the process is the user 120 authorizing the displayed process parameters from step 1824. For example, at step 1826, the physician can authorize the calculated parameters (e.g., by interacting with the user input device 135 and / or by starting the process). These displayed process parameters will then be used to start the process.

[0260] Second example of a laser system with an intelligent assistant mode

[0261] A flowchart showing the steps of an example of a second method 1900 using the smart assistant mode is shown in Figure 19 . The first step at 1902 is similar to step 1802 discussed above with reference to the process 1800, and includes receiving (e.g., by the controller) one or more input parameters, as previously described. Figure 18 According to another embodiment, at least one process parameter is determined. For example, at the second step 1904 in the process 1900 includes determining at least one process parameter, such as determining the fiber velocity (υ) in a similar manner as described above with reference to step 1804 in the first method 1800.

[0262] The next step is divided into two parallel processes / actions.

[0263]

[0264] ​​A first parallel process / action begins at step 1906, where the physician enters (via user input device 135) a pulse energy E (E) that falls within a safety range he or she wants to use (e.g., the safety range is based on input safety parameters). In some examples, this step can be performed by controller 150 based on one or more input parameters. Another process parameter that can be calculated includes the crater diameter Dc, which is done at step 1908 using proposed equation (10) or (11). In some embodiments, the crater diameter Dc at step 1908 can be based at least in part on the input pulse energy E entered at step 1906. This step can also be performed by controller 150. At step 1908, the fiber gap (Δ) and the target threshold (F’) can be entered as constant values in a similar manner as described above. The next step 1910 is to calculate the pulse frequency (f) using expression (16), which is performed by controller 150. Then, the pulse number, i.e., the N factor (Nf) is calculated at step 1912 using expression (7) (this can also be done by controller 150).

[0265] A second parallel process / action begins at step 1914, where the average safe energy is calculated using the received safe energy range (E ) in a similar manner as described above with reference to step 1806 of process 1800. This can also be calculated or otherwise determined by controller 150. At step 1916, a process parameter such as the crater diameter Dc is calculated (e.g., by controller 150) using proposed equation (10) or (11) in a similar manner as described above with reference to step 1808 of process 1800. Here, the fiber gap (Δ) and the target threshold (F’) can be entered as constant values in a similar manner as described above.

[0266] The next step 1918 is to calculate (e.g., by controller 150) the maximum N factor Nfmax, i.e., the most efficient pulse number, using equation (14) in a similar manner as described above with reference to step 1810 of process 1800. At step 1920, a process parameter such as the pulse frequency (f) is calculated using expression (15) in a similar manner as described above with reference to step 1812 of process 1800. Then, at step 1922, another process parameter such as the pulse energy E is calculated using expression (16) in a similar manner as described above with reference to step 1814 of process 1800.

[0267] At step 1924, a safety check similar to step 1816 of process 1800 is performed for the computed parameters. For example, the process parameter such as pulse energy E is compared by controller 150 to a threshold value (Emax). If the computed pulse energy is greater than or otherwise exceeds the threshold value, then controller 150 sets (adjusts) the pulse energy E to the maximum pulse energy Emax (E = Emax) at step 1926, and re-computes the pulse frequency (e.g., using expression (16)) at step 1928 in a manner similar to that described above with reference to steps 1818 and 1820 of process 1800. In process 1900, after step 1928, the process returns to step 1918 to compute the maximum N factor using equation (14) due to the changed energy and frequency parameters (E = Emax at step 1926, which triggers the pulse frequency change at step 1928). If and when the computed pulse energy E does not exceed the upper limit of the safety range (E < E max ), then the second parallel process / action ends.

[0268] The next step 1930 in process 1900 is to compare Nf to Nfmax. For example, the Nf computation made at step 1912 is compared to the Nfmax value computed at step 1918. Recall that the crater diameter Dc value computed at step 1908 used to compute Nf at step 1912 can itself depend on the pulse energy value entered by the physician at step 1906. Although this Nf vs. Nfmax comparison is explicitly shown in Figure 19 , it should be understood that this step can be included in all of the methods discussed herein.

[0269] If Nf is greater than Nfmax, then at step 1934, controller 150 gives feedback and informs the physician that he or she is currently outside of the optimal laser parameters, for example, via a positive or negative alert message. This can be accomplished using any of a variety of different ways, such as (but not limited to) outputting a corresponding warning (notification) on the screen (visual notification) in combination with the current Nf value. Figure 21 Two different screens (GUI screen shots) are shown that are output to user 120 on display device 130. The right-hand screen shot is an example of a negative alert message 159 (i.e., You are currently outside of the optimal parameters) to user 120 indicating that Nf 155 (value 17) is greater than Nfmax and that the optimal process parameters (i.e., laser operating parameters) have not been computed. Sub-optimal process parameters can also be displayed to user 120 on display device 130. If Nf is less than or equal to Nfmax, then at step 1932, controller 150 gives positive feedback to user 120. For example, Figure 21The screenshot on the left is an example of a positive alarm message indicating to the user that the N-factor 155 (value 5) is less than Nfmax and that the optimal process parameters (including laser operating parameters) have been calculated (i.e., you are currently using the optimal parameters). The optimal process parameters can also be displayed to the user 120 on the display device 130.

[0270] According to some implementations, in response to determining that Nf is greater than Nfmax, at least one laser operating parameter can be adjusted, as illustrated in step 1924, where the pulse energy is set to a maximum safe value and then fed back into the process to calculate a new Nfmax value. In some implementations, in response to determining that Nf is less than or equal to Nfmax, the laser operating parameters can be used to control the laser source.

[0271] Although not explicitly shown in process 1900, controller 150 may display one or more process parameters (whether already calculated or calculated at that step) on display device 130 in a manner similar to that described above with reference to step 1824 of process 1800 prior to the physician authorization step at 1936, such as laser operating parameters (e.g., pulse energy, power, and frequency).

[0272] remove Figure 21 In addition to the positive alarm message 157 or negative alarm message 159 shown, it should be understood that other visual and / or voice signals (audio notifications) and / or tactile notifications may also be provided as possible feedback.

[0273] The final step 1936 is for the physician (or physician assistant) 120 to authorize the desired parameters in a manner similar to step 1826 of the referenced procedure 1800 described above. Here, the user 120 must make a choice: he or she may still want to use suboptimal laser parameters and perform the less efficient procedure, or he or she may choose to accept the proposed calculated (and most efficient) laser parameters. Alternatively, he or she may choose to keep the changes still falling within the range Nf ≤ Nf max Laser parameters (e.g., pulse energy and / or frequency) under certain conditions.

[0274] Third example of a laser system with an intelligent assistant mode

[0275] A flowchart illustrating the steps in the third example method 2000 using the intelligent assistant mode is shown in [the flowchart]. Figure 20 As shown in the diagram. According to some aspects, this method is considered more accurate and efficient because it assumes a real-time feedback system and one or more laser sensors 125 (e.g., fiber optic speed, current fiber optic distance to the target, current stone type, and / or structure identification, for example...). Figure 22 The specific implementation of sensor 125 in the process.

[0276] The first step at 2002 is similar to the reference above. Figure 18 The process 1800 discusses step 1802 and includes receiving (e.g., by a controller) one or more input parameters as previously described. Step 2004 includes calculating the average safe energy calculation based on the received safe energy range. (and similar to step 1806 of the previously described process 1800).

[0277] The next step is divided into three parallel processes / actions.

[0278] The first parallel process / action is to acquire the current fiber velocity data (υ) at step 2006. This can be achieved using various methods, such as (but not limited to) relative fiber velocity calculations based on so-called real-time visual image computer processing or similar processing (e.g., processing images including the treatment area and the fiber (distal tip), built-in fiber velocity sensors (such as accelerometers), or other technologies. For example, Figure 22 The sensor 125 may include a sensor configured as an optical fiber velocity sensor (i.e., a sensor configured to measure the velocity of an optical fiber). If the optical fiber velocity sensor is not present in the lithotripsy system, the current method can still be used by inputting the optical fiber velocity as a constant value in this step, in a manner similar to that described above with reference to steps 1804 of process 1800 and 1904 of process 1900.

[0279] The second parallel process / action at step 2008 includes measuring the current gap between the fiber tip and the target surface from a distance sensor (e.g., Figure 22 The sensor 125 may include a distance sensor to acquire data. This can be achieved in various possible ways, such as (but not limited to) relative target size calculation based on the relationship between target size and fiber diameter (as mentioned above in the so-called real-time visual image computer processing or similar processing), backscattering / reflection sensors, ultrasonic sensors, etc. If the fiber optic distance sensor is not present in the lithotripsy system, the current method can still be used by inputting a constant value for the fiber gap in this step, in a manner similar to that described above in processes 1800 and 1900.

[0280] The third parallel process / action at step 2010 involves acquiring data on the type and / or structure of the stony nodule currently located in front of the optical fiber. This can be achieved using various techniques, such as (but not limited to) sensors configured as backscattering / reflection sensors, fluorescence sensors, visual sensors, or other technologies / sensors (e.g., Figure 22 Sensor 125).

[0281] According to at least one embodiment, the data (process parameters) collected at steps 2006, 2008, and / or 2010 are received by the controller 150.

[0282] Then, a process parameter such as a stone or stone-like stone ablation threshold F' can be calculated (e.g., by the controller 150) at 2012. This can be achieved by the controller 150 using preset values (e.g., previously obtained / measured threshold data for each stone-like stone type) stored in the memory 140 and based on the target input parameters. In some embodiments, if a stone-like stone type and / or structure sensor is not present in the lithotripsy system, the current method can still be used by inputting the target threshold as a constant value at this step, in a manner similar to that described above with reference to processes 1800 and 1900.

[0283] This step (with three parallel processes) ends when data is acquired for all currently required sensors for process parameters and / or target parameters for the data acquisition.

[0284] The next step at 2014 is to check if the acquired sensor data is different from the previously collected data. One or more process parameters (e.g., fiber speed, distance between fiber tip and target, target properties) are compared by the controller 150 to the stored process parameters. Essentially, the system checks if any changes have occurred since the last automatic laser parameter setting calculation. According to some aspects, step 2014 can be optional, such as at the beginning of the process. In some embodiments, step 2014 can be important because the speed at which the fiber is moved and / or the properties as the gap between the fiber tip and the stone-like stone can change during the treatment and need to be rechecked.

[0285] If the fiber is moved at the same constant speed (v), the target is the same stone-like stone with the same threshold (F'), and it is located at the same distance (D), there is no need to change any of the laser parameter settings in the previous laser parameter settings (if any). Thus, at step 2014, if the acquired sensor data related to one or more process parameters is not different from the previously collected sensor data (or data has not been previously collected), the next step at 2016 is to calculate at least one process parameter such as the crater diameter (D c ) using the proposed formula (10) or (11). Otherwise, i.e., if the acquired data (fiber speed, distance between fiber tip and target) and / or target properties (ablation threshold) is different from the previously collected data, the process returns to the step of acquiring new real-time sensor data (2006, 2008, 2010).

[0286] The next step at 2018 is to calculate Nfmax using equation (14), followed by calculating the pulse frequency (f) at step 2020 using expression (15), and then calculating the pulse energy (E) at step 2030 using expression (16). Each of these steps is similar to steps 1810, 1812, and 1814, respectively, as previously described in process 1800, and can be performed by controller 150.

[0287] At step 2032, a check of the safety of the calculated parameters is performed in a similar manner as described above with reference to step 1816 of process 1800. Also as described above with reference to process 1800, a positive or negative alert message can be displayed on display device as a result of the comparison between the pulse energy (or Nf) and the threshold value (Emax or Nfmax).

[0288] If the calculated pulse energy is less than or equal to the threshold value (E ≤ E max ), a second comparison calculation is performed at step 2036 in a similar manner as described above with reference to step 1822 of process 1800. For example, if the calculated pulse E is greater than a second threshold value by a predetermined amount, then in some embodiments the process returns to step 2016 to determine (e.g., by controller 150) the crater diameter in a similar manner as returning to step 1808 of process 1800 described above. If the calculated pulse energy E is less than or equal to the second threshold value, then at step 2040 controller 150 displays one or more of the process parameters (whether already calculated or calculated at this step) on display device 130, such as the laser operating parameters (e.g., pulse energy, pulse frequency, average power). These laser operating parameters can be considered the proposed or “current” laser operating parameters, and according to at least one embodiment, controller 150 can then use these laser operating parameters to control laser source 105. Thus, process 2000 skips the “doctor authorization” step 1826 of process 1800 and the “doctor authorization” step 1936 of process 1900.

[0289] Returning to step 2032, if the calculated pulse energy E is greater than the threshold (Emax), i.e., E > Emax, then at step 2034, the controller 150 sets the pulse energy E to the maximum pulse energy (the safe pulse energy value) in a manner similar to that described above with reference to step 1818 of the process 1800, and then at step 2038, the pulse frequency is recalculated (e.g., by the controller 150) using expression (16) (similar to step 1820 of the process 1800). Once recalculated, the controller 150 displays one or more process parameters (e.g., laser operating parameters such as pulse energy, pulse frequency, average power, etc.) on the display device 130, and then uses these laser operating parameters to control the laser source 105 (e.g., as discussed above in step 2040).

[0290] The last step of the process is to return to the step of acquiring data from the sensors (steps 2006, 2008, 2010) until it is determined at step 2042 that the lithotripsy process is complete. According to certain aspects, the user 120 can determine that the process is complete when there are no more stones visible in the scope image sensor, and / or the controller 150 can determine that the process is complete when no more stone material is detected in the volume of interest (kidney, ureter, bladder). The entire process is cyclical and consists of acquisition of real-time sensor data and real-time calculations and setting of the most efficient current laser parameters based on the acquired data.

[0291] The faster the sensors 125 can work (measure and communicate), the faster the laser parameters can adapt to real-time changing process parameters (e.g., fiber speed, gap, stone-like stone type / structure), and the more efficient the lithotripsy process.

[0292] General system description

[0293] Figure 22 is a block diagram of one non-limiting example of a laser system (also referred to herein as a lithotripsy system) generally shown at 100 for use in a lithotripsy procedure provided by at least one embodiment. According to various aspects, the system 100 can operate in an intelligent assistant mode of operation according to the flowcharts described in Figure 18 、 Figure 19 and Figure 20 . The system 100 includes a controller 150 coupled to a display device 130 and a user input device 135.

[0294] The display device 130 is configured to display information (output) to the user 120 (e.g., a physician), and the user input device 135 is configured to receive information (input) from the user 120 (e.g., one or more input parameters). In some embodiments, the display device 130 and the user input device 135 can be integrated into one device. For example, a graphical user interface (GUI) can be displayed to the user 120 on a touchscreen, and display information to the user (e.g., N factor) and receive information from the user 120 (via the touchscreen). The controller 150 is coupled to the display device 130 and is configured to display information such as process parameters, laser operating parameters, Nf, and / or Nfmax on the display device 130.

[0295] The user input device 135 is configured to receive input from the user 120, such as a physician, and can take any of a variety of different forms, including a touchscreen. In addition to touch-sensitive screens, other non-limiting examples of user input devices include a cursor control device (CCD), such as a mouse, trackball, or joystick; a keyboard; one or more buttons, switches, or knobs; and a voice input system. In some embodiments, input from the user constitutes user input data, which can be used (at least in part) by the controller 150 to control one or more components of the system 100, such as the laser source 105.

[0296] The user input data can include initial user input data received from the user 120 at the start of a procedure. In some embodiments, the initial user input data includes input parameters including at least one of: (1) one or more properties of the laser lithotripsy system, and (2) one or more properties of the target, and (3) one or more safety parameters.

[0297] According to at least one embodiment, the system 100 further includes a laser source 105 configured to generate pulsed laser energy. Non-limiting examples of the laser source 105 include a thulium-doped fiber laser (TFL), an erbium-doped fiber laser, a ytterbium-doped fiber laser, a Ho:YAG solid-state laser, a Tm:YAG solid-state laser, or a Nd:YAG solid-state laser. Although not explicitly shown in Figure 22 The controller 150 or the processing laser 110 itself includes a driver for the laser source, although not explicitly shown in FIG. 1. According to one embodiment, the energy storage device 109 is used to generate pulsed laser energy, as described in Figure 23The configuration shown in FIG. 1. In this configuration, a power supply 103, a laser driver 107, a pump 111, and an energy storage device 109 (e.g., a capacitor and / or an inductor) are included in the system 100. The pump 111 is configured with one or more diode lasers that provide laser radiation to the laser source 105. The power supply 103 supplies power to the system, and the energy storage device 109 is configured to store a sufficient amount of energy needed to form a laser pulse. The laser driver 107 of the pump 111 forms an electrical pulse with specified characteristics in response to a control signal from the controller 150. The electrical pulse is received by the one or more diodes of the pump 111, forming an optical pulse needed by the laser medium of the pump laser source 105.

[0298] In alternative embodiments, the pulsed laser energy can be generated via any of several techniques, including laser modulators (e.g., AOM, EOM, EAM), Q-switching, mode-locking, cavity dumping, and / or gain-switching.

[0299] Now returning to Figure 22 According to at least one embodiment, the system 100 further includes an optical fiber 110 configured to direct the pulsed laser energy at the target 115. The pulsed laser energy can be output as a laser beam 112 and used to treat any of a variety of urological conditions at the target. According to some embodiments, the optical fiber 110 can be configured as a component of a lithotripsy device. The lithotripsy device (e.g., a cystoscope, a flexible endoscope with / without a sheath, a percutaneous nephrolithotomy (PCNL) / rigid endoscope, a micro / ultra-micro PCNL endoscope) can include other associated support components such as fluid flow devices (e.g., irrigation and aspiration functionality), one or more optical devices, reflective devices, articulating arms, and / or mechanical or robotic devices configured to assist in performing the lithotripsy procedure.

[0300] The controller 150 is coupled to the laser source 105, the user input device 135, and the display device 130, and (optionally) one or more sensors 125 (as discussed above with reference to the processes 1800, 1900, and 2000). Although only one sensor 125 is shown in Figure 22 It should be understood that more than one sensor can be used in a lithotripsy system. According to at least one embodiment, the sensor 125 is configured to measure at least one input parameter and / or at least one process parameter. It should also be understood that the sensor 125 can be a video sensor of the treatment region, for example as part of an endoscope, and the processed endoscope video can be used to calculate fiber tip speed and / or fiber gap distance, as well as to calculate the N-factor in real-time, and / or to adjust laser parameters (as referenced in the processes 1800, 1900, and 2000). Figure 20Described, it is an automated algorithm). It should be understood that the endoscope can include a processor configured to determine these values, but for simplicity, this functionality is described herein using Figure 22 Other various methods and devices can be used to measure fiber speed, such as a speed sensor integrated in the distal tip of the endoscope.

[0301] Controller 150 includes circuitry, which can be separate or integrated components. Those skilled in the art will appreciate that operations performed by controller 150 can be performed by one or more controllers, processors, and / or other electronic components, including software and / or hardware components. For example, controller 150 includes a processor 145 (which can include more than one processor (also referred to as central processing units, CPUs), as will be appreciated by those skilled in the art) and a computer readable storage device (also referred to as a storage device or storage memory), and a memory 140 (also referred to as a storage device or storage memory), as well as other hardware and software components, as will be appreciated by those skilled in the art. Figure 22 (not explicitly shown in FIG. 1), and a memory 140 (also referred to as a storage device or storage memory), as well as other hardware and software components, as will be appreciated by those skilled in the art.

[0302] Processor 145 can be a single- or multi-core processor, or multiple processors for parallel processing, and can execute a series of machine-readable instructions, which can be embodied in a program or software. The instructions can be stored in a memory location, such as memory 140. The instructions can be directed to processor 145, which can subsequently program or otherwise configure processor 145 to implement the methods and / or steps of the present disclosure.

[0303] Storage memory 140 includes one or more computer-readable and / or writable media, and can include, for example, a magnetic disk (e.g., a hard disk drive, HDD), an optical disk (e.g., a DVD, a Blu- ® ray disk, etc.), a magneto-optical disk, a semiconductor memory (e.g., a nonvolatile memory card, a flash memory ® , a solid state drive, SRAM, DRAM), an EPROM, an EEPROM, etc. Storage memory 140 can store computer-readable data and / or computer-executable instructions, including an operating system (OS) program, as well as control and processing programs.

[0304] The electronically stored information is stored in memory 140 of controller 150. According to at least one embodiment, the electronically stored information can include look-up tables, empirical functions, and / or analytical models. In some embodiments, this information is generated by inputting results from preclinical and clinical tests, trials, and studies.

[0305] The controller 150 can display data (e.g., one or more process parameters Nf, Nfmax, etc.) on the display device 130. The display device can provide three-dimensional or two-dimensional images, and non-limiting examples include touch screen displays and / or flat panel displays or any other suitable visual output device capable of displaying graphical data and / or text to a user. In some embodiments, a touch screen can serve as both the display device 130 and the user input device 135. According to at least one embodiment, the controller 150 is configured to generate a graphical user interface (GUI) on the display device 130 that receives user input in conjunction with the user input device 135.

[0306] The systems and user interfaces disclosed herein can enable physicians and technicians to make more intelligent and faster decisions to enhance the outcome of a lithotripsy procedure (e.g., optimize stone-like calculus removal), reduce procedure time, and reduce the cognitive load required during the procedure. This is especially true when the system is more fully automated using a computer that controls / monitors as described in the algorithm above in Figure 20

[0307] Robotic system

[0308] In some embodiments, joystick control of the robotic arm that controls the positioning and movement of the optical fiber is contemplated. The clinician controls the insertion and positioning of the device via joystick control that more precisely moves and positions the optical fiber, and possibly the endoscope together with the optical fiber. The speed and positioning of the optical fiber can now be directly measured via sensors that monitor the electronic / pneumatic signals to / from the robotic arm / joystick control system. This information can be used in the laser control portion of the algorithm discussed above in this disclosure. In addition, the images from the endoscope camera can be processed by an image processing algorithm that can, for example, assess stone-like calculus type, verify optical fiber speed and positioning (used in conjunction with the electronic sensing signals mentioned above), and detect unsafe conditions in the treatment area such as the optical fiber being directed to an unsafe target. The laser control module will receive the data to adjust the laser parameters discussed above in this disclosure. As mentioned previously, and with reference to Figure 22 , the display device 130 and the user input device 135 can be combined into a single subsystem, such as a computer suitable for this monitoring and control system. The computer algorithm can perform calculations in real-time to update the laser parameters, assess unsafe conditions, and provide corrective feedback in the event that a false optical fiber movement is detected, much faster than a human would be able to.

[0309] ​The aspects of the invention disclosed herein are not limited in their application to the construction details and component arrangements set forth in the following description or illustrated in the drawings. These aspects are capable of presenting other embodiments and can be practiced or performed in various ways. The examples of specific embodiments provided herein are for illustrative purposes only and are not intended to be limiting. In particular, actions, components, elements, and features discussed in connection with any one or more embodiments are not intended to exclude similar effects in any other embodiments.

[0310] Furthermore, the wording and terminology used herein are for descriptive purposes and should not be considered restrictive. Any reference to examples, embodiments, components, elements, or actions of systems and methods mentioned herein in the singular may also include plural embodiments, and any reference herein in the plural to any embodiment, component, element, or action may also include only the singular embodiments. References in singular or plural form are not intended to limit the systems or methods, components, actions, or elements disclosed in this invention. The terms “comprising,” “including,” “having,” “containing,” “involving,” and variations thereof, as used herein, are intended to cover the items listed thereafter and their equivalents, as well as additional items. References to “or” are to be interpreted as inclusive, such that any term described using “or” may indicate any of the terms “single,” “more than one,” and “all” among the described terms. Furthermore, in the event of any inconsistency between the terminology used in this document and in documents incorporated herein by reference, the terminology used in the incorporated references shall supplement the terminology used in this document; in the case of irreconcilable inconsistencies, the terminology used in this document shall prevail. Furthermore, for the convenience of the reader, headings or subheadings may be used in the specification, which should not affect the scope of the invention.

[0311] Therefore, several aspects of at least one example have been described, and it should be understood that various changes, modifications, and improvements will readily occur to those skilled in the art. For example, the examples disclosed herein may also be used in other contexts. Such changes, modifications, and improvements are intended to be part of this disclosure and are intended to fall within the scope of the examples discussed herein. Therefore, the foregoing description and figures are by way of example only.

Claims

1. A system for use during laser lithotripsy, the system comprising: a laser source configured to generate pulsed laser energy; an optical fiber configured to direct the pulsed laser energy at a target; and a controller coupled to the laser source and configured to: receive one or more input parameters; determine at least one process parameter, wherein the at least one process parameter comprises one or more laser operating parameters; calculate an N-factor (Nf) based at least in part on one or more process parameters and at least one input parameter, wherein Nf corresponds to a number of laser pulses delivered to a treatment region having a diameter approximately equal to a diameter of a laser crater (Dc) produced by the pulsed laser energy directed at the treatment region on the target; compare Nf to a maximum Nf (Nfmax); and in response to determining that Nf is greater than Nfmax, adjust at least one of the one or more laser operating parameters, or in response to determining that Nf is less than or equal to Nfmax, control the laser source using the one or more laser operating parameters.

2. The system of claim 1, wherein the one or more laser operating parameters comprise pulse energy, pulse frequency, average power, peak power, and / or pulse width.

3. The system of claim 1, wherein when the controller determines that Nf is greater than Nfmax, the controller is configured to adjust the at least one laser operating parameter such that Nf is less than or equal to Nfmax.

4. The system of claim 1, wherein the controller is further configured to: display Nf on a display device coupled to the controller; and in response to determining that Nf is greater than Nfmax, output a negative alert message on the display device, or in response to determining that Nf is less than or equal to Nfmax, output a positive alert message on the display device.

5. The system of claim 1, wherein the one or more process parameters used to calculate Nf comprise a laser pulse frequency, a laser crater diameter (Dc), and an optical fiber speed (v).

6. The system of claim 5, wherein Nf is calculated according to the following equation:

7. The system of claim 6, wherein the laser crater diameter Dc is in a range according to the following expression:

8. The system of claim 1, wherein the controller is configured to calculate Nfmax, wherein Nfmax corresponds to a number of laser pulses delivered to the treatment region having a diameter approximately equal to the laser crater diameter Dc that provides an average stone ablation efficiency per pulse greater than or equal to a predetermined K-value for a maximum number of pulses, the predetermined K-value corresponding to an ablation efficiency achieved after an impact from a single (first) pulse. Nf = (f*D c ) / υ, where f (Hz) is the laser pulse frequency, D c (mm) is the laser pit diameter, and υ is the fiber speed at which the pulsed laser energy is directed at the treatment area.

9. The system of claim 8, wherein the K-value is in a range of about 25% to 75%, inclusive. (2NAΔ + d)(0.12 ln (E1 / (0.25 F’(2NAΔ + d) 2 )) – / 250) +(1.82d) (0.21 – 0.025 E1) ≤ Dc ≤ (2NAΔ + d)(1 / (1.61 + 10.23d 4 + (0.92 –2.97d)Δ)) × (1 + ( / 12.85) ln((12.85 / )(1 / (6.4 – 6.75d))(E / (0.25 F’(2NAΔ + d) 2 – 1) + 1)), where NA is the optical fiber numerical aperture, Δ (mm) is the gap between the distal tip of the optical fiber and the surface of the staghorn, d (mm) is the core diameter of the optical fiber, (W) is the peak power of the laser pulse, E1 (J) is the single pulse energy, and F' (J / cm 2 ) is the staghorn ablation threshold.

10. The system of claim 9, wherein the K-value is in a range of about 25% to 50%, inclusive. ​ ​ 11. The system of claim 1, wherein the controller is configured to calculate Nfmax, wherein Nfmax is calculated according to the following equation: Nfmax = (12.4 - 3.4d) + (3.3d - 8.4) / (1 + 4.7x10 -5 exp(P peak / 0.0375)) - ((14.7d - 16) + (80 - 65d)P peak + (55d - 62)P peak 2 ) / (1 + 0.34 E 5.5-2.6 Ppeak ), where P peak is the peak power.

12. The system of claim 1, wherein Nfmax is in a range of 1 to 12, inclusive.

13. The system of claim 12, wherein Nfmax is in a range of 1 to 7, inclusive.

14. The system of claim 13, wherein Nfmax is in a range of 1 to 5, inclusive.

15. The system of claim 14, wherein Nfmax is in a range of 1 to 3, inclusive.

16. The system of claim 1, wherein the controller is configured to display at least one laser operating parameter on a display device based on the comparison.

17. The system of claim 1, wherein the controller is configured to display at least one of Nf and Nfmax on a display device.

18. The system of claim 1, further comprising at least one sensor coupled to the controller and configured to measure at least one input parameter and / or at least one process parameter.

19. The system of claim 18, wherein the at least one sensor comprises a sensor configured to measure a fiber speed.

20. The system of claim 19, wherein when the controller determines that Nf is greater than Nfmax, the controller is configured to adjust the at least one laser operating parameter such that Nf is less than or equal to Nfmax.

21. The system of claim 1, wherein the controller is further configured to: output a negative alert message comprising at least one of an audio alert message, a visual alert message, and a haptic alert message in response to determining that Nf is greater than Nfmax, or output a positive alert message comprising at least one of an audio alert message, a visual alert message, and a haptic alert message in response to determining that Nf is less than or equal to Nfmax.

22. The system of claim 1, wherein the controller is configured to output an alert message comprising at least one of an audio alert message, a visual alert message, and a haptic alert message in response to the comparison.

23. The system of claim 22, further comprising a user input device coupled to the controller, wherein the user input device is configured to receive input from a user, the input comprising at least one value of a laser operating parameter used by the controller to control the laser source.

24. The system of claim 23, wherein the alert message comprises information provided to the user regarding whether Nf is greater than Nfmax or whether Nf is less than or equal to Nfmax.

25. The system of claim 1, wherein the input parameters comprise at least one of a target parameter, a system parameter, and a safety parameter.

26. The system of claim 25, wherein the input parameters comprise a target parameter, and the target parameter comprises a target type, a target location, and one or more target characteristics.

27. The system of claim 26, wherein the target is a stone, and the one or more target properties include a size and / or hardness of the stone.

28. The system of claim 27, wherein the input parameters include at least one system parameter, and the at least one system parameter includes a fiber diameter and / or a fiber numerical aperture.

29. The system of claim 23, wherein the input parameters include at least one safety parameter, and the at least one safety parameter includes a maximum average power, a maximum peak power, a maximum pulse energy, and / or a maximum pulse frequency.

30. A method for performing a lithotripsy procedure, the method comprising: providing a controller configured to: receive one or more input parameters; determine at least one procedure parameter, wherein the at least one procedure parameter includes one or more laser operating parameters; calculate an N-factor (Nf) based at least in part on the one or more procedure parameters and the at least one input parameter, wherein Nf corresponds to a number of laser pulses delivered to a treatment region having a diameter approximately equal to a diameter of a laser crater (Dc) produced by the pulsed laser energy at the treatment region directed onto the target; compare Nf to a maximum Nf (Nfmax); and in response to determining that Nf is greater than Nfmax, adjust the at least one laser operating parameter, or in response to determining that Nf is less than or equal to Nfmax, control a laser source using the one or more laser operating parameters.

31. The method of claim 30, wherein when the controller determines that Nf is greater than Nfmax, the controller is configured to adjust the at least one laser operating parameter such that Nf is less than or equal to Nfmax.

32. The method of claim 30, wherein the controller is further configured to: display Nf on a display device coupled to the controller; and in response to determining that Nf is greater than Nfmax, output a negative alert message on the display device, or in response to determining that Nf is less than or equal to Nfmax, output a positive alert message on the display device.

33. The method of claim 32, wherein Nf is calculated according to the following equation: Nf = (f*D c ) / υ, where f (Hz) is the laser pulse frequency, D c (mm) is the laser pit diameter, and υ is the fiber speed at which the pulsed laser energy is directed at the treatment area.

34. The method of claim 33, wherein the laser crater diameter Dc is in a range according to the following expression: (2NAΔ + d)(0.12 ln (E1 / (0.25 F’(2NAΔ + d) 2 )) – / 250) +(1.82d) (0.21 – 0.025 E1) ≤ Dc ≤ (2NAΔ + d)(1 / (1.61 + 10.23d 4 + (0.92 –2.97d)Δ)) × (1 + ( / 12.85) ln((12.85 / )(1 / (6.4 – 6.75d))(E / (0.25 F’(2NAΔ + d) 2 – 1) + 1)), where NA is the optical fiber numerical aperture, Δ (mm) is the gap between the distal tip of the optical fiber and the surface of the staghorn, d (mm) is the core diameter of the optical fiber, (W) is the peak power of the laser pulse, E1 (J) is the single pulse energy, and F' (J / cm 2 ) is the staghorn ablation threshold.

35. The method of claim 30, wherein the controller is configured to calculate Nfmax, wherein Nfmax corresponds to a number of laser pulses delivered to the treatment region having a diameter approximately equal to the laser crater diameter Dc that provides an average stone ablation efficiency per pulse greater than or equal to a predetermined K-value for a maximum number of pulses, the predetermined K-value corresponding to an ablation efficiency achieved after an impact from a single (first) pulse.

36. The method of claim 35, wherein the K-value is in a range of about 25% to 75%, inclusive.

37. The method of claim 30, wherein the controller is configured to calculate Nfmax, wherein Nfmax is calculated according to the following equation: Nfmax = (12.4 - 3.4d) + (3.3d - 8.4) / (1 + 4.7x10 -5 exp(P peak / 0.0375)) - ((14.7d - 16) + (80 - 65d)P peak + (55d - 62)P peak 2 ) / (1 + 0.34 E 5.5-2.6 Ppeak ), where P peak is the peak power.

38. The method of claim 30, wherein Nfmax is in a range of 1 to 12, inclusive.

39. The method of claim 30, further comprising measuring at least one input parameter and / or at least one process parameter using at least one sensor.

40. The method of claim 39, wherein the at least one input parameter comprises fiber speed.

41. The method of claim 40, wherein when the controller determines that Nf is greater than Nfmax, the controller is configured to adjust the at least one laser operating parameter such that Nf is less than or equal to Nfmax.

42. The method of claim 30, wherein the controller is configured to output an alert message comprising at least one of an audio alert message, a visual alert message, and a haptic alert message in response to the comparison.

43. The method of claim 42, wherein the controller is further configured to receive input from a user input device, the input comprising at least one value of a laser operating parameter used by the controller to control the laser source.

44. The method of claim 43, wherein the alert message comprises information regarding whether Nf is greater than Nfmax or whether Nf is less than or equal to Nfmax.

45. A system for use in a lithotripsy procedure, the system comprising: a laser source configured to generate pulsed laser energy; a fiber configured to direct the pulsed laser energy at a target; and a controller coupled to the laser source and configured to: receive one or more input parameters; determine at least one process parameter, wherein the at least one process parameter comprises one or more laser operating parameters; calculate a number factor (Nf) based at least in part on one or more process parameters and at least one input parameter, wherein Nf corresponds to a number of laser pulses delivered to a treatment region, a diameter of the treatment region approximately equal to a diameter of a laser crater (Dc) produced by the pulsed laser energy directed onto the treatment region on the target; display Nf on a display device coupled to the controller; compare a laser operating parameter to a threshold value; and in response to determining that the laser operating parameter is greater than the threshold value, adjust at least one of the one or more laser operating parameters, or in response to determining that the laser operating parameter is less than the threshold value, use the one or more laser operating parameters to control the laser source.

46. The system of claim 45, wherein the laser operating parameter compared to a threshold value is pulse energy.

47. The system of claim 46, wherein the controller is further configured to calculate the pulse energy based at least in part on a pulse frequency. ​ ​ 48. The system of claim 47, wherein the controller is further configured to calculate the pulse frequency based at least in part on a maximum N factor (Nmax).

49. The system of claim 45, wherein the controller is configured to adjust the at least one laser operating parameter such that Nf is determined to be less than or equal to a maximum N factor Nfmax.

50. The system of claim 45, wherein in response to determining that the laser operating parameter is greater than the threshold, the controller is configured to adjust the laser operating parameter value to a maximum safe value associated with the laser operating parameter.

51. The system of claim 45, wherein the controller is configured to display at least one laser operating parameter based on the comparison.

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