Laser fiber ranging based on coherence tomography

Abstract

Systems, devices, and methods are disclosed for providing adjustable laser therapy of a target using fiber-to-target distance measurements. An exemplary surgical laser system includes a laser system to generate laser pulses and deliver the laser pulses to an anatomical target via an optical fiber; a feedback analyzer circuit for receiving a return laser signal in response to the chirp laser irradiated at the target; and a controller circuit. The feedback analyzer circuit may generate an optical coherence metric using the chirp laser and the return laser signal and determine a fiber-to-target distance between the distal end of the optical fiber and the target. Based at least on the fiber-to-target distance, the controller circuit may adjust a position or orientation of the distal end of the fiber, or adjust a surgical laser output setting for generating and delivering a laser pulse to the target.

Description

[0001] Claiming priority

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 580,161, filed September 1, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates generally to endoscopic laser surgery systems, and more specifically to systems and methods for measuring the distance between a laser fiber and a treatment target and optimizing laser treatment based on the measured distance. Background Technology

[0004] Endoscopy has been used in a variety of clinical procedures, including, for example, illumination, imaging, detection and diagnosis of one or more disease states, delivery of fluids to anatomical regions (e.g., delivery of saline or other preparations via a fluid channel), providing access to one or more therapeutic devices or biological material collection devices (e.g., via a working channel) for sampling or treating anatomical regions, and providing aspiration access for collecting fluids (e.g., saline or other preparations), among other procedures. Examples of such anatomical regions may include the gastrointestinal tract (e.g., esophagus, stomach, duodenum, pancreaticobiliary ducts, intestines, colon, etc.), renal regions (e.g., kidneys, ureters, bladder, urethra), and other internal organs (e.g., reproductive system, sinuses, submucosal areas, respiratory tract), etc.

[0005] Some endoscopes include a working channel through which the operator can perform aspiration, place diagnostic or therapeutic devices (e.g., brushes, biopsy needles or forceps, stents, baskets, or balloons), or perform minimally invasive procedures such as tissue sampling or removal of unwanted tissue (e.g., benign or malignant strictures) or foreign bodies (e.g., stones). Some endoscopes can be used with laser or plasma systems to deliver energy to anatomical targets (e.g., soft or hard tissue or stones) to achieve the desired treatment. For example, lasers have been used in applications of tissue ablation, coagulation, vaporization, fragmentation, and lithotripsy to break down stones in the kidneys, gallbladder, ureters, and other areas where stones form, or to ablate large stones into smaller fragments. Summary of the Invention

[0006] When laser surgery systems are used to treat various diseases and conditions, the distance between the distal end of the laser fiber (or the distal end of a device such as an endoscope with integrated laser fibers) and the anatomical target to be treated (hereinafter referred to as the "fiber-to-target" distance) is a crucial factor in determining the success of the procedure. In the case of tissue ablation, if the laser fiber is too close to the target, flashes may occur, accompanied by fiber degradation and tissue adhesion. If the fiber is too far from the target, more energy will be required to achieve the desired tissue treatment effect.

[0007] Conventionally, the ideal or optimal fiber-to-target distance relies heavily on the operator's (e.g., an endoscopist's) experience. Based on this "best guess" of the ideal fiber-to-target distance, the operator manually positions the laser fiber relative to the treatment target to achieve the desired fiber-to-target distance. This method places high demands on the operator's experience and can therefore introduce inter-operator or inter-institutional variations, especially in challenging situations where the treatment target has a complex structure, composition, or shape, or is located in a difficult-to-access location. Manually positioning the laser fiber to meet the desired fiber-to-target distance is typically time-consuming and labor-intensive and can lead to operator fatigue, particularly when the fiber needs to be repositioned repeatedly throughout the procedure to treat complex targets. At least for these reasons, the inventors have recognized the continued need for equipment and techniques to automate the process of measuring the fiber-to-target distance and adjusting the position of the laser fiber during laser surgery.

[0008] This document describes systems, apparatus, and methods for measuring the fiber-to-target distance between a laser fiber and a treatment target during laser surgery and for optimizing laser treatment of the target using the fiber-to-target distance measurement. An exemplary surgical laser system includes: a laser system for generating laser pulses and delivering them via an optical fiber to a target in the anatomical environment of a patient; a feedback analyzer circuit for receiving a returned laser signal from the target in response to a chirped laser emitted from the laser system irradiating the target; and a controller circuit. The feedback analyzer circuit can use at least a portion of the returned laser signal and the chirped laser to generate an optical coherence metric relating to the round-trip laser travel time between the distal end of the optical fiber and the target, and determines the fiber-to-target distance between the distal end of the optical fiber and the target based on the optical coherence metric. Based at least on the fiber-to-target distance, the controller circuit can controllably adjust the position or orientation of the distal end of the optical fiber and adjust the surgical laser output settings for generating and delivering the laser pulses to the target.

[0009] Example 1 is a surgical laser system comprising: a laser system configured to generate laser pulses and deliver the laser pulses via an optical fiber to a target in the anatomical environment of a patient; and a controller circuit including a feedback analyzer circuit configured to: receive a laser signal returned from the target in response to a chirped laser emitted from the surgical laser system irradiating the target; generate an optical coherence metric using at least a portion of the returned laser signal and the chirped laser, the optical coherence metric relating to the round-trip laser travel time between the distal end of the optical fiber and the target; and determine an optical fiber-to-target distance between the distal end of the optical fiber and the target using the optical coherence metric, wherein the controller circuit is configured to generate a control signal to adjust the position or orientation of the distal end of the optical fiber relative to the target based at least in part on the determined optical fiber-to-target distance.

[0010] In Example 2, the subject of Example 1 may optionally include a feedback analyzer circuit, which can be configured to further determine the fiber-to-target distance based on the chirp rate of the chirped laser.

[0011] In Example 3, the subject matter of any one or more of Examples 1 to 2 optionally includes controller circuitry that can be configured to adjust the surgical laser output settings of the surgical laser system based at least in part on the determined fiber-to-target distance.

[0012] In Example 4, the subject matter of any one or more of Examples 1 to 3 may optionally include a light source configured to direct electromagnetic radiation to a target, wherein the feedback analyzer circuit is configured to: detect a reflected imaging signal from the target in response to electromagnetic radiation at the target; determine the spectral characteristics of the target based on the reflected imaging signal; and identify the target type or composition based at least in part on the determined spectral characteristics of the target.

[0013] In Example 5, the subject of Example 4 optionally includes controller circuitry that can be configured to further generate control signals based on the identified target type or composition to adjust the position or orientation of the distal end of the optical fiber relative to the target.

[0014] In Example 6, the subject matter of any one or more of Examples 4 to 5 optionally includes controller circuitry that can be configured to adjust the surgical laser output settings of the surgical laser system based at least in part on the identified target type or composition.

[0015] In Example 7, the subject matter of any one or more of Examples 4 to 6 may optionally include an optical fiber that can be configured to simultaneously guide laser pulses and reflected imaging signals.

[0016] In Example 8, the subject matter of any one or more of Examples 1 to 7 optionally includes controller circuitry that can be configured to provide control signals to a robotic device coupled to an optical fiber, thereby allowing the robot to adjust the position or orientation of the distal end of the optical fiber relative to a target.

[0017] In Example 9, the subject matter of any one or more of Examples 1 to 8 optionally includes a user interface configured to present the user with the determined fiber-to-target distance and suggestions for adjusting the position or orientation of the distal end of the fiber relative to the target.

[0018] In Example 10, the subject matter of any one or more of Examples 1 to 9 optionally includes a target that may be a tissue target, wherein the surgical laser system is configured to generate and deliver laser pulses to treat the tissue target.

[0019] In Example 11, the subject matter of any one or more of Examples 1 to 10 optionally includes a target that may be a stone target, wherein the surgical laser system is configured to generate and deliver laser pulses to ablate or fragment the stone target.

[0020] In Example 12, the subject matter of any one or more of Examples 1 to 11 optionally includes an endoscope that includes or is coupled to a surgical laser system, the endoscope including a longitudinal channel for allowing optical fibers to pass through.

[0021] In Example 13, the subject matter of any one or more of Examples 1 to 12 optionally includes a feedback analyzer circuit that may be further configured to: identify one or more anomalous measurements from a plurality of fiber-to-target distance measurements generated over time; filter the plurality of fiber-to-target distance measurements to exclude the identified one or more anomalous measurements; and use the filtered plurality of fiber-to-target distance measurements to determine the fiber-to-target distance.

[0022] In Example 14, the subject of Example 13 may optionally include a feedback analyzer circuit that can be configured to identify one or more anomalous measurements based on the average and variance of multiple fiber-to-target distance measurements.

[0023] Example 15 is a method for feedback control of a surgical laser system during laser surgery in a patient, the method comprising the steps of: guiding a chirped laser through an optical fiber of the surgical laser system to a target location in the patient's anatomical environment, and receiving a return laser signal from the target in response to the chirped laser irradiated at the target location; generating an optical coherence metric using at least a portion of the return laser signal and the chirped laser, the optical coherence metric being related to the round-trip laser travel time between the distal end of the optical fiber and the target; determining an optical fiber-to-target distance between the distal end of the optical fiber and the target using the optical coherence metric; and adjusting the position or orientation of the distal end of the optical fiber relative to the target based at least in part on the determined optical fiber-to-target distance.

[0024] In Example 16, the subject matter of Example 15 optionally includes: determining the fiber-to-target distance is further based on the chirp rate of the chirped laser.

[0025] In Example 17, the subject matter of any one or more of Examples 15 to 16 optionally includes adjusting the surgical laser output settings of the surgical laser system based at least in part on the determined fiber-to-target distance.

[0026] In Example 18, the subject matter of any one or more of Examples 15 to 17 may optionally include: directing electromagnetic radiation to a target; receiving a reflected imaging signal from the target in response to the electromagnetic radiation; determining the spectral characteristics of the target from the reflected imaging signal; and identifying the target type or composition based at least in part on the determined spectral characteristics of the target.

[0027] In Example 19, the subject matter of Example 18 may optionally include: adjusting the position or orientation of the far end of the optical fiber relative to a target, which may further be based on the identified target type or composition.

[0028] In Example 20, the subject matter of any one or more of Examples 18 to 19 optionally includes adjusting the surgical laser output settings of the surgical laser system based at least in part on the identified target type or composition.

[0029] In Example 21, the subject of any one or more of Examples 15 to 20 may optionally include a goal that can be an organizational goal or a stone goal.

[0030] In Example 22, the subject matter of any one or more of Examples 15 to 21 may optionally include: providing control signals to a robotic device coupled to an optical fiber to adjust the position or orientation of the distal end of the optical fiber relative to a target via the robot.

[0031] In Example 23, the subject matter of any one or more of Examples 15 to 22 may optionally include: presenting on the user interface the determined fiber-to-target distance and suggestions for adjusting the position or orientation of the distal end of the fiber relative to the target.

[0032] In Example 24, the subject matter of any one or more of Examples 15 to 23 may optionally include: identifying one or more anomalous measurements from a plurality of fiber-to-target distance measurements generated over time based on respective optical coherence metrics; filtering the plurality of fiber-to-target distance measurements to exclude the identified one or more anomalous measurements; and using the filtered plurality of fiber-to-target distance measurements to determine the fiber-to-target distance.

[0033] In Example 25, the subject of Example 24 may optionally include: identifying one or more anomalous measurements based on the average and variance of multiple fiber-to-target distance measurements.

[0034] The systems, apparatus, and methods described herein can be used in a variety of endoscopic laser surgical procedures to improve surgical success rates. Fiber-to-target distance measurement and automated fiber positioning, as described herein, can help reduce the inherent operator variability of the subjective “best guess” of fiber-to-target distance and produce more consistent and predictable surgical outcomes. Optical time-of-flight (ToF) methods applied to automated fiber-to-target distance measurement can produce more accurate and precise distance measurements. Compared to conventional methods that are limited by inaccuracies in small areas due to the short flight time of the pulses, ToF methods (such as optical coherence tomography (OCT) or frequency-modulated continuous wave (FMCW) methods) can eliminate or reduce timing jitter and provide higher accuracy, especially in small-range distance measurements. According to some embodiments described herein, fiber-to-target distance measurements can be filtered to exclude outlier measurements automatically identified using a statistical outlier detector, which can result in accurate fiber-to-target distances. Automated measurement of fiber-to-target distance and control of fiber position can lead to less user fatigue and faster procedures. Autonomous control of laser fiber advance or retraction provides more efficient use of the laser system. Precise fiber-to-target distance measurement and automatic control of the laser fiber position can also help prevent laser flash events, reduce the heating effect on fluids and tissues around the target, and achieve more efficient use of laser energy and overall cost savings.

[0035] The systems, apparatus, and techniques described according to the various embodiments herein can be used in a variety of endoscopic procedures involving laser treatment of tissues or other targets, including, for example, colonoscopy, anoscopy, arthroscopy, bronchoscopy, colonoscopy, cystoscopy, esophagoscopy, gastroscopy, laparoscopy, laryngoscopy, neuroendoscopy, thoracoscopy, sigmoidoscopy, thoracoscopy, etc.

[0036] This invention is an overview of some of the teachings of this application and is not intended to be an exclusive or exhaustive treatment of the subject matter. Further details regarding the subject matter can be found in the detailed description and the appended claims. Other aspects of this disclosure will be apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the accompanying drawings, each of which should not be considered limiting. The scope of this disclosure is defined by the appended claims and their legal equivalents. Attached Figure Description

[0037] Various embodiments are illustrated by way of example in the accompanying figures. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the subject matter.

[0038] Figure 1 This is a block diagram illustrating an example of a laser energy delivery system configured to provide laser therapy to an anatomical target.

[0039] Figure 2 This is a block diagram illustrating a laser surgery system that uses feedback information, including fiber-to-target distance measurements, to provide adjustable laser treatment of a target.

[0040] Figure 3 An example of an endoscopic laser surgery system with feedback control featuring automatic fiber-to-target distance measurement and fiber position control is shown.

[0041] Figures 4A to 4B This is a graph illustrating how the frequency modulated continuous wave (FMCW) method works to estimate the distance from an optical fiber to a target.

[0042] Figures 5A to 5B This is a graph illustrating an example of how bubbles can interfere with fiber-to-target distance measurements.

[0043] Figure 6 An example is shown where the distance from the fiber to the target is overestimated due to the presence of air bubbles in the optical path of the laser pulse.

[0044] Figure 7 This is a flowchart illustrating an example method of providing feedback control for a surgical laser system to provide adjustable laser treatment of a target using feedback including fiber-to-target distance measurements.

[0045] Figure 8 This is a block diagram illustrating that any one or more of the techniques (e.g., methods) discussed in this article are example machines on which they can be executed. Detailed Implementation

[0046] This document describes systems, apparatus, and methods for providing adjustable laser treatment to a target using feedback including fiber-to-target distance measurements. An exemplary surgical laser system includes: a laser system for generating laser pulses and delivering them via an optical fiber to a target in the anatomical environment of a patient; a feedback analyzer circuit for receiving a returned laser signal from the target in response to a chirped laser emitted from the laser system irradiating the target; and a controller circuit. The feedback analyzer circuit can use at least a portion of the returned laser signal and the chirped laser to generate an optical coherence metric relating to the round-trip laser travel time between the distal end of the optical fiber and the target, and determine the fiber-to-target distance between the distal end of the optical fiber and the target based on the optical coherence metric. The controller circuit can controllably adjust the position or orientation of the distal end of the optical fiber and adjust the surgical laser output settings for generating and delivering the laser pulses to the target, at least based on the fiber-to-target distance.

[0047] Figure 1This is a block diagram illustrating an example of a laser energy delivery system 100 configured to deliver laser treatment to a target structure 122 in the anatomical environment of a subject, such as an anatomical structure (e.g., soft tissue, hard tissue, or abnormalities such as cancerous tissue) or a stone structure (e.g., kidney, pancreas, or gallbladder stones). In some embodiments, the laser energy delivery system 100 may deliver precisely controlled treatments (e.g., tissue ablation, coagulation, evaporation, etc.) to tissues or other anatomical structures or to non-anatomical structures (e.g., ablation or dusting of stone structures).

[0048] The laser energy delivery system 100 may include a feedback control system 101 and at least one laser system in operational communication with the feedback control system 101. This is by way of example and not limitation. Figure 1 A laser feedback system is shown connected to a first laser system 102 and optionally (shown in dashed lines) to a second laser system 104. Additional laser systems are contemplated within the scope of this disclosure. The first laser system 102 may include a first laser source 106 and associated components such as a power supply, display, cooling system, etc. The first laser system 102 may also include a first optical path 108 operatively coupled to the first laser source 106. In an example, the first optical path 108 comprises an optical fiber. The first optical path 108 may be configured to emit a laser beam from the first laser source 106 to a target structure 122.

[0049] The feedback control system 101 can receive a feedback signal 130 from a target. In one example, the feedback signal 130 may include a signal indicating target characteristics or surgical site conditions. In another example, the feedback signal 130 may include an acoustic signal generated by a laser pulse propagating through a medium (e.g., liquids and vapors), projected onto the target, and causing the target to vibrate. In yet another example, the feedback signal 130 may include a reflected electromagnetic signal (e.g., reflected illumination light emitted from a light source). In yet another example, the feedback signal 130 may include an image or video frame of at least a portion of the surgical site, such as one generated by an imaging sensor during surgery. In yet another example, the feedback signal 130 may include a returned laser signal in response to a laser pulse illuminating the target. The laser pulse may be generated by a first laser system 102 or a second laser system 104 according to specific output settings (e.g., chirped laser). The returned laser signal can be used to determine whether the target is within the laser emission range, as will be referred to below. Figures 2 to 3 Further description.

[0050] Feedback signal 130 can be used to control laser delivery, laser energy output, and / or other system parameters to improve therapeutic efficacy and achieve or maintain a desired condition at the target site. In an example, feedback control system 101 can analyze feedback signal 130 to determine one or more target characteristics. Based on the determined target characteristics, feedback control system 101 can identify the target type or composition, adjust laser output settings (e.g., one or more laser irradiation parameters, such as power, duration, frequency, pulse shape, irradiation time, or emission angle) or other system parameters, and generate and deliver laser pulses to the target according to the laser output settings to achieve the desired therapeutic effect or maintain the desired condition. For example, feedback control system 101 can monitor the characteristics of the target structure during the treatment process (e.g., ablation of a kidney stone into smaller fragments) to determine whether the tissue has been properly ablated before another treatment process (e.g., coagulation of a blood vessel). In another embodiment, feedback control system 101 can analyze feedback signal 130 to automatically determine the distance between the distal end of the laser fiber and the target tissue to be treated, also referred to herein as the "fiber-to-target" distance. Fiber-to-the-distance can be used to guide the manual or autonomous positioning of the laser fiber (e.g., advancing or retracting or changing the orientation of the distal end of the laser fiber) to achieve more effective laser treatment of the target.

[0051] In the example, the first laser source 106 can be configured to provide a first output 110. The first output 110 may extend within a first wavelength range, for example, a wavelength range corresponding to a portion of the absorption spectrum of the target structure. The first output 110 can provide effective ablation and / or carbonization of the target structure because the first output 110 is within a wavelength range corresponding to the absorption spectrum of the tissue.

[0052] In the example, the first laser source 106 can be configured such that the first output 110 emitted in a first wavelength range corresponds to high absorption of the incident first output 110 by the tissue (e.g., exceeding approximately 250 cm⁻¹). -1 In an example, the first laser source 106 can emit a first output 110 between approximately 1900 nanometers (nm) and approximately 3000 nm (e.g., corresponding to high absorption in water) and / or between approximately 400 nm and approximately 520 nm (e.g., corresponding to high absorption in oxyhemoglobin and / or deoxyhemoglobin). Clearly, there are two main mechanisms by which light interacts with tissue: absorption and scattering. When tissue absorption is high (absorption coefficient exceeding 250 cm⁻¹), the light will scatter. -1 At this stage, the first absorption mechanism dominates, and when absorption is low (absorption coefficient less than 250 cm⁻¹), the absorption mechanism is dominant. -1 In the case of lasers, such as those in the 800-1100nm wavelength range, scattering mechanisms are dominant.

[0053] Various commercially available medical-grade laser systems are suitable for use with the first laser source 106. Examples of laser source 106 may include an emitting In... X Ga 1-X UV-VIS of N semiconductor lasers, such as GaN lasers with emission of 515-520 nm and InN lasers with emission of 370-493 nm. X Ga 1-X N-type lasers, with In-type lasers emitting at 750-850 nm. X Ga 1-X N-type lasers or In-type lasers with emission wavelengths of 904-1065 nm X Ga 1-X N-type lasers, etc. Alternatively, infrared (IR) lasers, such as those outlined in Table 1 below, can be used.

[0054] Table 1: List of Examples of Suitable IR Lasers

[0055] An optional second laser system 104 may include a second laser source 116 for providing a second output 120, and associated components such as a power supply, display, cooling system, etc. The second laser system 104 may be operably decoupled from the first laser source 106, or alternatively operably coupled to the first laser source 106. In some embodiments, the second laser system 104 may include a second optical path 118 (decoupled from the first optical path 108) operably coupled to the second laser source 116 for transmitting the second output 120. Alternatively, the first optical path 108 may be configured to transmit both the first output 110 and the second output 120.

[0056] In some aspects, the second output 120 may extend into a second wavelength range different from the first wavelength range. Therefore, there may be no overlap between the first and second wavelength ranges. Alternatively, the first and second wavelength ranges may at least partially overlap. In an advantageous aspect of this disclosure, the second wavelength range may not correspond to the portion of the absorption spectrum of the target structure in which the incident radiation is strongly absorbed by previously unablated or uncarbonized tissue. In some such aspects, the second output 120 may advantageously not ablate uncarbonized tissue. In another embodiment, the second output 120 may ablate previously ablated carbonized tissue. In yet another embodiment, the second output 120 may provide additional therapeutic effects. For example, the second output 120 may be more suitable for coagulated tissue or blood vessels.

[0057] Figure 2This is a block diagram illustrating a laser surgery system 200 that uses feedback information, including fiber-to-target distance measurements, to provide feedback-controlled laser treatment of the target. System 200 may be an embodiment of a laser energy delivery system 100 for treating various types of anatomical targets, or an embodiment of a lithotripsy system for breaking up hardened masses such as kidney stones, pisiform stones, gallstones, and other stone structures.

[0058] The laser surgical system 200 may include a feedback control system 210, one or more sensors 220, a laser system 230, a light source 240, a user interface 250, and actuators 260. The laser system 230 (which is...) Figure 1 The laser system 102 or laser system 104 shown herein may include a laser source 232 (which may be an example of a first laser source 106 or a second laser source 116) and an optical fiber 234 (which may be a first optical path 108 or a second optical path 118) for directing laser energy to a target structure 122. The laser source 232 can generate laser pulses according to output settings, which may include one or more laser irradiation parameters (e.g., intensity, power, duration, frequency or pulse shape, irradiation time, or emission angle). At least some of the laser irradiation parameters are programmable or automatically adjustable, such as by controller circuitry 218, or manually adjusted by a user via user interface 250. The laser pulses can be used for therapeutic purposes, such as for surgical removal or sampling of tissue or ablation of stone structures. In some examples, the laser source 232 may generate laser pulses for non-therapeutic purposes, such as for estimating the fiber-to-target distance, as described herein according to various embodiments. In some examples, the laser source 232 may include different laser sources, including a first laser source for generating therapeutic laser pulses (such as...). Figure 1 The first laser source 106 shown) and a second laser source (such as...) for generating non-therapeutic laser pulses that can be used to estimate the fiber-to-target distance. Figure 1 The second laser source 116 shown.

[0059] As Figure 1 The feedback control system 210 of the embodiment of the feedback control system 101 shown may include a feedback analyzer 212 and a controller circuit 218. According to the example embodiment, the feedback control system 210 or a portion thereof (such as the feedback analyzer 212 and / or the controller circuit 218) may include a processor, such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or any other equivalent integrated or discrete logic circuit, and any combination of such components for performing one or more functions undertaken by the feedback control system 210.

[0060] The feedback analyzer 212 can be communicatively coupled to one or more sensors 220, receiving feedback information from them, using the feedback information to determine target characteristics, and controlling the laser system 230 to provide appropriate laser treatment at least in part based on the target characteristics. This is by way of example and not limitation. Figure 2 As shown, one or more sensors 220 may include an imaging sensor 222 and a return laser detector 224. The imaging sensor 222 may be included in an imaging system that further includes a lens system. Examples of the imaging sensor 222 may include a CCD or CMOS camera sensitive to ultraviolet (UV), visible (VIS), or infrared (IR) wavelengths. The imaging sensor 222 may be located at the distal portion of an endoscope used during surgery, examples of which are shown in... Figure 3 As shown in the diagram. Imaging sensor 222 can acquire imaging signals of at least a portion of the target structure 122 during surgery. In an embodiment, light source 240 can generate and direct electromagnetic radiation at the target structure 122, and imaging sensor 222 can acquire imaging signals in response to the electromagnetic radiation incident on the target structure 122. Table 2 below shows examples of light source 240 suitable for the examples discussed herein.

[0061] Table 2: Light sources used in spectral systems

[0062] The return laser detector 224 can detect the return laser signal from the target structure 122 in response to an excitation laser pulse illuminating the target structure 122. The excitation laser pulse can be emitted from the laser system 230. The return laser detector 224 can be positioned at the distal end of the optical fiber 234, close to the end of the fiber from which the excitation laser pulse is emitted. In the example, the excitation laser can include a chirped laser with a time-varying instantaneous frequency, also known as a swept laser. The laser system 230 can include a beam splitter that splits the chirped laser into a first portion that is directed at and illuminates the target structure 122 and a second portion that remains local and does not extend to the target structure 122. In response to the first portion illuminating the target, the return laser signal from the target can be detected and interferometrically recombine with the second portion of the chirped laser. As will be further described below, a coherence metric can be determined and used to estimate the fiber-to-target distance.

[0063] The imaging signal acquired by imaging sensor 222 and the returned laser signal detected by returned laser detector 224 can be provided to feedback analyzer 212. Feedback analyzer 212 includes one or more of a spectrometer 213, a target recognition circuit 214, an optical coherence circuit 215, a fiber-to-target distance estimator 216, and a range filter 217. Spectrometer 213 can determine one or more spectral properties from the target's imaging signal, such as reflectance, absorption index, and other spectral characteristics. Examples of spectrometer 213 may include Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV-VIS reflectance spectroscopy, UV-VIS-IR spectroscopy, fluorescence spectroscopy, etc. FTIR is a method used for routine, easy, and rapid materials analysis. This technique has relatively good spatial resolution and provides information about the chemical composition of the material. Raman spectroscopy has good accuracy in identifying hard and soft tissue components. As a high spatial resolution technique, it is also useful for determining the component distribution within a target. UV-VIS reflectance spectroscopy is a method that collects information from light reflected from an object, similar to information generated by the eye or a color image produced by a high-resolution camera, but collected in a more quantitative and objective manner. Reflectance spectroscopy provides information about materials because light reflection and absorption depend on their chemical composition and surface properties. This technique can also be used to obtain unique information about the surface and overall properties of a sample. Reflectance spectroscopy can be a valuable technique for identifying the composition of hard or soft tissues. Fluorescence spectroscopy is an electromagnetic spectroscopic method for analyzing fluorescence from a sample. It involves using a beam of light, typically ultraviolet light, which excites the material compounds and causes them to emit light, typically in the visible or IR region. This method is suitable for the analysis of some organic components, such as those in hard and soft tissues.

[0064] Target identification circuitry 214 can identify the type or composition (or specific portions thereof) of target structure 122 in vivo during surgery using one or more spectral characteristics determined by spectrometer 213. In endoscopic laser therapy, it is desirable to identify the type and composition of the target, applying appropriate laser energy only to the treatment target (e.g., cancerous tissue or a specific type of stone), while avoiding or minimizing laser irradiation of non-treatment tissues (e.g., normal tissue). Conventional target identification typically requires collecting a sample of the target for in vitro analysis. Continuous monitoring at the endoscope tip and automated in vivo tissue identification can advantageously reduce surgical time and complexity, provide physicians with more information to better tailor treatment during surgery, and improve treatment efficacy. For example, in laser lithotripsy, where a laser is used to break or pulverize stones, automated and in vivo identification of a specific type of stone (e.g., the chemical composition of kidney, pancreatic, or gallbladder stones) and differentiation from surrounding tissues would allow physicians to adjust laser settings (e.g., power, irradiation time, or emission angle) to more effectively ablate the target stone while avoiding irradiation of adjacent non-treatment tissues. The commonly assigned U.S. Patent Application No. 16 / 947,488 entitled “Laser Fiber to Target Distance Control” describes an example method for identifying or classifying different target structures, such as the different compositions of kidney stones (e.g., calcium oxalate stones (monohydrate), calcium oxalate stones (dihydrate), calcium phosphate stones, struvite, and urate stones), the description of which is incorporated herein by reference in its entirety.

[0065] Optical coherence circuit 215 can use the returned laser signal from the target to interferometrically recombine with a second portion of the chirped laser separated from the chirped laser pulse to calculate a coherence metric. The optical coherence metric can involve the analysis of the interferogram and its frequency components. Fiber-to-target distance estimator 216 can estimate the distance between the distal end of fiber 234 and target structure 122 (“fiber-to-target distance”) based at least in part on the coherence metric. Optical coherence-based distance measurement methods, also known as frequency-modulated continuous wave (FMCW) methods, have been implemented in LiDAR (light detection and ranging) scanners and have found significant applications in object ranging in land management and planning, hazard assessment, forestry, agriculture, geological mapping, and watershed and river surveying. Figures 4A to 4B This is a graph illustrating the working principle of the FMCW method used to measure the distance from an optical fiber to a target. Figure 4AA time-frequency representation 412 of the second portion of the chirped laser (LO) separated from the chirped laser emitted from the laser system 230, and a time-frequency representation 414 of the returned laser signal (RX) in response to the first portion of the chirped laser irradiated at the target structure 122 are conceptually illustrated. As a non-limiting example and as shown, the chirped laser LO is linearly chirped, where the optical frequency (on the y-axis) is a linear ramp function of time (on the x-axis). The returned laser signal RX also has a linear ramp frequency over time, which is very similar to that of the chirped laser LO, and has a time delay following the chirped laser LO. D It was then detected. The time delay occurred when the returning laser detector 224 was positioned at the distal end of fiber 234, near the end of the fiber from which the excitation laser pulse was emitted. D This corresponds to the round-trip laser travel time between the target structure 122 and the detector 224. Specifically, D The relationship given by equation (1) relates to the distance (R) from the fiber to the target and the velocity (v) of the laser in the medium (e.g., fluid) along the laser path:

[0066] Time delay can be used D The heterodyne beat frequency f is determined by the chirp rate (k), which represents the rate of change of instantaneous frequency (in Hertz per second). beat It represents the frequency difference between the two optical fields corresponding to the chirped laser LO and the returned laser signal RX at any given time t, as follows:

[0067] Combining equations (1) and (2) above, the distance from the fiber to the target can be determined using equation (3) given below:

[0068] Figure 4B This demonstrates the use of heterodyne beat frequency f beat The Fourier transform of the full waveform distance distribution 420 is calculated. This distribution curve shows f at different frequencies. beat The amplitude (power) (dB, logarithmic scale on the y-axis) can be converted to distance on the x-axis. beat The peak power 422 corresponds to the fiber-to-target distance R. In the example, the fiber-to-target distance estimator 216 can measure the heterodyne beat frequency f over time. beat (i.e., the time-varying frequency difference between the chirped laser LO and the returned laser signal RX), calculate the heterodyne beat frequency f. beat The Fourier transform of f, and determine the corresponding fbeat The peak amplitude (power) of the fiber to the target distance is 424.

[0069] The fiber-to-target distance estimated using the FMCW method described above is sensitive to the laser velocity (v) in the medium (e.g., fluid) at the target site. During endoscopic laser surgery, bubbles can be generated from laser energy and fluid flushing and aspiration. Depending on the type of surgery and the target being treated, tissue debris or stone fragments may be generated. Bubbles, tissue debris, stone fragments, and other particles or objects can cause inhomogeneities in the fluid space along the laser path, affecting the laser transmission velocity (v) and thus interfering with the fiber-to-target distance measurement. Figure 5A and Figure 5B An example illustrating how bubbles can interfere with fiber-to-target distance measurements. Figure 5A The image shows a laser signal emitted from the distal end 510 of the laser fiber, which travels at a speed of v. fluid Traveling through a uniform fluid environment free of bubbles or other interfering objects (e.g., tissue debris, stone fragments), it reaches the target structure 122, which reflects at a velocity v. fluid At least a portion of the laser signal (return laser signal) that travels back to the end of the laser fiber through the same uniform fluid medium. Figure 5B The image shows a laser signal emitted from the distal end 510 of the same laser fiber, traveling through a non-uniform fluid environment filled with bubbles 520. Because water is denser than air, its refractive index is greater than that of air (1.3 in water and 1.0 in air). This is compared to approximately 3 in air. 10 8 Laser velocity c in meters per second (m / sec) air In comparison, the laser velocity v in the fluid fluid Approximately 2.25 10 8 The laser travel time is m / sec. Therefore, when bubbles are present in the optical path of a fluid medium, the laser travel time is longer than in a bubble-free fluid medium. When it is assumed that the entire optical path is a fluid without bubbles or other interfering objects, it will be calculated as a larger distance (greater than the actual distance). This is known as overestimation of the fiber-to-target distance. Figure 6 An example of overestimation of the fiber-to-target distance due to the presence of bubbles or other interfering objects in the fluid space of the optical path is illustrated. As shown, the fiber-to-target distance can be measured continuously or periodically over time using the optical coherence method described above. The time series of the obtained distance measurements shows an overestimation 610 of the fiber-to-target distance at those times when bubbles or other interfering objects are present in the optical path between the laser fiber tip and the target. The overestimation 610 is an “outlier” greater than other distance measurements 620 taken in a bubble-free fluid space.

[0070] Return to reference Figure 2 The distance filter 217 can filter a series of fiber-to-target distance measurements obtained over time, such as... Figure 6 As shown, this is to exclude outliers, such as overestimations caused by bubbles or other interfering objects along the light path in the fluid space. In the example, distance filter 217 can use statistical methods to identify outliers. Examples of statistical methods may include the Grubb test (when testing for a single outlier), the Tietjen-Moore test, or the generalized extreme research bias (ESD) test. In the example, the average (or other measure of central tendency) of multiple distance measurements within the moving window and the tolerance margin of the distance measurements within the moving window (such as the fraction k of variance or standard deviation (SD)) can be used to determine the distance threshold or acceptable range. Parameters such as window length and fraction k can be adjusted to ensure accurate distance measurements. In the non-limiting example, the moving window has a length of 50 consecutive distance measurements. In the non-limiting example, k takes a value between 0.25 and 0.5.

[0071] Each distance measurement generated by the fiber-to-target distance estimator 216 can be tested against a distance threshold or acceptable range, and if it exceeds the threshold (e.g., average + 0.25), it will be evaluated. SD) or outside the acceptable range (e.g., average). 0.25 If the variance (SD) is not found, it is identified as an outlier (e.g., overestimated); otherwise, it is identified as a valid measurement. To improve the signal-to-noise ratio (SNR), the optimized fiber-to-target distance can be calculated as the average (or other measure of central tendency) of a specified number (e.g., 30-50) of valid distance measurements. The mean and variance (or SD) of the distance measurements can be updated as new distance measurements become available and are identified as valid or outliers. By excluding outliers, only valid measurements are involved in the update process. This allows for continuous, more accurate, and robust fiber-to-target distance measurements.

[0072] Controller circuitry 218 can be coupled to feedback analyzer 212 via a wired or wireless connection. Controller circuitry 218 can control laser system 230 according to one or more control algorithms described herein to control the laser output of laser source 232. In some examples, feedback analyzer 212 can continuously monitor target structure 122 and continuously communicate with controller circuitry 218 to provide feedback control signals to adjust the laser output, such as by increasing or decreasing pulse amplitude, pulse rate, power intensity, duration, frequency, pulse shape, irradiation time, and other laser irradiation parameters. Controller circuitry 218 can continue to maintain laser system 230 in a specific state (with a specific output) until a change in feedback is detected. For example, when target recognition circuitry 214 detects different target types or compositions based on spectral characteristics from spectrometer 213, controller circuitry 218 can adjust the laser output of laser source 232. In one example, for a kidney stone having a hard surface with a first composition and a softer core with a second composition, the sequential tissue composition identified by the target allows for the use of a first, higher laser output to fragment the hard surface of the kidney stone, and automatically, or upon user confirmation, switches to a different, lower laser output to ablate the soft core of the stone. As an alternative to automatic adjustment of the laser output, in some examples, the controller circuitry 218 can adjust the laser output in a command mode, in which case the controller circuitry 218 can present the current laser output and information about the identified target type or composition to a user (e.g., a surgeon or endoscopist) via a user interface, and recommend that the user adjust the laser output to produce the desired therapeutic effect on the target structure 122.

[0073] In addition to target identification information (e.g., target type or composition), controller circuitry 218 can control laser system 230 to further deliver laser energy to target structure 122 based on an estimated fiber-to-target distance. For example, if target structure 122 is identified as the intended type of treatment structure (e.g., a specified soft tissue type or a specified stone type), and if the fiber-to-target distance (d) meets a condition (e.g., drops to a threshold d),... th If the target structure 122 is outside the laser emission range (e.g., d>d), then the laser pulse can be delivered to the target structure 122. However, if the target structure 122 is outside the laser emission range (e.g., d>d), then the laser pulse can be delivered to the target structure 122. th If the target structure 122 is outside the laser emission range, the controller circuit 218 can generate a control signal to temporarily "lock" the laser source 232, preventing laser pulses from being emitted towards the target until the target structure 122 is within the laser emission range. The estimated fiber-to-target distance and the fact that the target structure 122 is outside the laser emission range (d>d) can be displayed to the user on the user interface. th The user can adjust fiber 234, such as repositioning the far end of fiber 234 to move it closer to the target.

[0074] In some examples, controller circuitry 218 can generate control signals to a robotic device (such as actuator 260) to adjust the position or orientation of the distal end of optical fiber 234 relative to target structure 122 via the robot. For example, actuator 260 can automatically advance or retract the optical fiber or change the orientation (e.g., aiming angle) of the distal end of optical fiber 234 relative to target structure 122 in response to control signals from controller circuitry 218. In examples, controller circuitry 218 can adjust the position or orientation of the distal end of the optical fiber based on the identified target type or composition. The desired or optimal distance or range for emitting laser at the target can depend on multiple factors, including target type or composition, target location and surrounding anatomy, laser setup, type of surgery, or desired tissue effect. As mentioned above, laser output can be adjusted manually or automatically based on target type or composition, allowing different laser outputs to be used to treat different parts of the target (e.g., the surface and core of a stone structure with correspondingly different compositions). In addition to or as an alternative to adjusting laser output, in some examples, the position or orientation of the distal end of the optical fiber can be adjusted based on target type or composition. In the example of laser lithotripsy, as the target recognition circuit 214 continuously analyzes the target type and composition, the controller circuit 218 can control the actuator 260 to advance the distal end of the optical fiber 234 closer to the kidney stone target in response to the recognition of the hard surface of the target, so as to better fragment the stone surface. In response to the recognition of the soft core of the stone target, the actuator 260 controls the actuator 260 to retract the distal end of the optical fiber 234 further away from the kidney stone target.

[0075] User interface 250 can operatively communicate with feedback control system 210. User interface 250 may include a display unit to display information, including, for example, surgical site conditions such as images, pressure, or other information sensed by sensor 220, information generated by feedback analyzer 212 including target identification and estimated fiber-to-target distance, and current device settings such as laser output settings. The display unit may display UI elements including visual elements, alarms, tactile feedback, or any combination thereof. In some examples, user interface 250 may generate an alarm if the fiber-to-target distance exceeds a threshold or a specific range. Alarms may be presented in an auditory, visual, tactile, or other human-perceptible form. User interface 250 may include one or more input units to receive user programming of various components of laser surgery system 200, such as parameter values ​​for identifying target type or composition, estimating fiber-to-target distance, and laser output settings. In some instances, the display unit may generate suggestions for adjusting the position or orientation of the distal end of fiber 234 or for adjusting laser output or other system parameters. The user may use one or more input units to confirm, reject, or modify any recommended adjustments.

[0076] Figure 3 An example of an endoscopic laser surgery system 300 with feedback control featuring automatic fiber-to-target distance measurement and fiber position control is shown. System 300 may be an exemplary implementation of laser surgery system 200.

[0077] System 300 may include an endoscope 301 integrated with a feedback control system 310, a laser system including a laser source 332 and an optical fiber 334, and robotic devices such as actuators. Endoscope 301 has a proximal portion and an elongated distal portion configured for insertion into the patient's surgical site during endoscopic surgical procedures. Endoscope 301 can provide visual examination or manipulation of soft (e.g., non-calcified) or hard (e.g., calcified) targets, including but not limited to stone structures. Figure 3 As shown, endoscope 301 may include or provide visualization and illumination optics, such as visualization light path 360 and illumination light path 350, each of which may extend longitudinally along the elongated body of endoscope 301. An eyepiece or camera or imaging display may be positioned at or coupled to visualization light path 360 to allow a user or machine to visualize a target area at or near the distal end of endoscope 301. The target area may be illuminated by light 370, for example, provided by illumination source 324 at the proximal end of illumination light path 350 and emitted from the distal end of illumination light path 350. Light source 324 may include, for example, a xenon lamp, a light-emitting diode (LED), a laser diode, or any combination thereof. In an example, light source 324 may include two or more light sources emitting light with different illumination characteristics (referred to as illumination modes). In an example, illumination modes may include a white light illumination mode or a special light illumination mode, such as a narrow-band imaging mode, an autofluorescence imaging mode, or an infrared imaging mode. Special light illumination may focus and enhance light of a specific wavelength, for example, resulting in better visualization of tissue or other structures at the surgical site.

[0078] The endoscopic laser surgery system 300 may include or be coupled to a laser source 332, which may be Figure 1 The first laser source 106 or the second laser source 116 or Figure 2 An example of laser source 232. Laser source 332 can be mechanically and optically connected to optical fiber 334, which may include a single fiber or a bundle of fibers. Optical fiber 334 (which is...) Figure 1 The first optical path 108 or the second optical path 118 or Figure 2 (Example of fiber optic 234) may be introduced via the proximal access port of endoscope 301 and extend within the working channel or other longitudinal channel or lumen of endoscope 301 or similar instrument.

[0079] In some examples, laser source 332 may include a first laser source (such as...) Figure 1 The first laser source 106 shown) and the second laser source (such as Figure 1 The second laser source 116 shown is configured to generate therapeutic laser pulses (also known as therapeutic beams) for surgical removal or sampling of tissue or ablation of stone structures. The second laser source generates non-therapeutic laser pulses, such as excitation laser pulses, for estimating the distance from the fiber to the target. The therapeutic and non-therapeutic laser pulses can be guided to the target via the same or different optical paths.

[0080] The endoscopic laser surgery system 300 may include a camera or imaging device 325. The camera or imaging device 325 may include an imaging sensor (such as...) Figure 2 The imaging sensor 222 in the image can generate an imaging signal 365 of the target in response to electromagnetic radiation (e.g., illumination light 370) from the target at or near the surgical site. The camera or imaging device 325 can be a CCD or CMOS camera or a laser scanning device. Figure 3 As shown, the target structure 122 is within the field of view of the camera or imaging device 325, such that in response to electromagnetic radiation, the camera or imaging device 325 can collect signals reflected from the target structure 122 and generate an imaging signal 365 of the target structure 122. The imaging signal 365 can be transmitted to a feedback control system 310 (which is an example of a feedback control system 210) via an optical path 360 or alternatively via an optical fiber 334. In this example, the optical fiber 334 can simultaneously guide a laser pulse (including a chirped laser 383 and a returned laser signal 385) and the reflected imaging signal 365. The feedback control system 310 may include a feedback analyzer 312 and a controller circuit 318. In this example, the imaging signal can pass through a beam splitter before reaching the feedback analyzer 312. The feedback analyzer 312 (which is an example of a feedback control system 210) can be transmitted to a feedback control system 310 via an optical path 360 or alternatively via an optical fiber 334. Figure 2 An example of feedback analyzer 212 may include a spectrometer capable of generating one or more spectral characteristics from imaging data. Feedback analyzer 312 may use one or more spectral characteristics to identify a target as a type of tissue or a different composition of stones, as described above. Figure 2 As described.

[0081] Feedback analyzer 312 can calculate or estimate the fiber-to-target distance between the distal end 336 of fiber 334 and the target structure 122. In the example, the fiber-to-target distance can be estimated using the FMCW method, where a coherence metric is derived from the chirped laser 383 emitted from laser source 332 and the returned laser signal 385 in response to a portion of the chirped laser irradiating the target structure 122, as described above regarding... Figure 2 and Figures 4A to 4BAs described, controller circuitry 318 can generate control signals to laser source 332 to adjust the output settings of the therapeutic laser pulses. The adjustment of the therapeutic laser output settings can be based at least in part on the identified target type or composition. In some embodiments, the adjustment of the therapeutic laser output settings can be further based on a determined fiber-to-target distance. For example, if the estimated fiber-to-target distance exceeds a threshold range, controller circuitry 318 can temporarily “lock” laser source 332 to prevent it from emitting laser pulses.

[0082] Controller circuitry 318 may additionally or alternatively generate control signals to the robotic device to adjust the position or orientation of the distal end 336 of optical fiber 334. A robotic device (such as actuator 338) may be coupled to a portion of optical fiber 334 and may be in electrical communication with controller circuitry 318. In an example, actuator 338 may be located at or near the distal end of endoscope 301. Actuator 338 may include one or more of electromagnetic, electrostatic, piezoelectric, or other actuating elements to actuate or otherwise allow the distal end 336 of optical fiber 334 to be longitudinally or rotationally positioned relative to the working channel or other longitudinal channel of endoscope 301 or relative to another reference position that endoscope 301 can serve as a reference frame. Based at least in part on the identified target type or composition, controller circuitry 318 can activate actuator 338 to adjust the position or orientation of the distal end 336 of fiber optic cable 334, such as adjusting the longitudinal position by advancing or retracting the distal end 336 to increase or decrease the distance to target structure 122, or adjusting the rotational position by manipulating the distal end 336 to increase or decrease the aiming angle relative to target structure 122. This adjustment of the position or orientation of the distal end of the fiber optic cable can improve the effectiveness of laser therapy while maintaining laser energy.

[0083] Figure 7 This is a flowchart illustrating an example method 700 for providing feedback control of a surgical laser system to deliver adjustable laser treatment to a target using feedback including fiber-to-target distance measurement. Method 700 can be... Figure 2 The laser surgery system 200 shown Figure 3 The feedback-controlled endoscopic laser surgery system 300 shown is implemented and executed for laser lithotripsy of kidney stones, Bella, gallstones, and other stone structures, or for laser cutting or vaporization of soft tissues such as during endoscopic surgery. Although the procedures of method 800 are drawn as a flowchart, they do not need to be performed in a specific order. In various examples, some procedures may be performed in a different order than that shown herein.

[0084] At 710, the chirped laser can be pointed at the target structure, and a returned laser signal can be received in response to the chirped laser illuminating the target. The chirped laser can be emitted from a laser source via an optical fiber in a laser system (such as laser surgery system 200 or feedback-controlled endoscopic laser surgery system 300). The chirped laser (also called a swept-frequency laser) has a time-varying instantaneous frequency. The chirped laser can be divided into a first part that travels through the optical fiber to the target structure, and a second part that remains localized and does not travel to the target structure. The returned laser signal can be detected in response to the first part of the chirped laser illuminating the target. The first part of the chirped laser is also referred to as the chirped laser excitation. In the example, the chirped laser is linearly chirped, such that the optical frequency of the chirped laser is a linear ramp function of time. As mentioned above regarding Figure 4A As described in the example, the returned laser signal can have a similar time-frequency distribution (e.g., a linear ramp frequency over time) to the chirped laser that is guided to the target, the difference being that the returned laser is essentially a time-delayed version of the chirped laser, where the time delay is related to the round-trip travel time between the far end of the laser fiber and the target structure.

[0085] At 720, an optical coherence metric can be generated between the chirped laser excitation and return laser signals. This optical coherence metric is related to the round-trip time of the chirped laser between the far end of the fiber and the target structure. At 730, the coherence metric can be used to determine the distance between the far end of the fiber and the target structure (“fiber-to-target distance”). This optically coherent distance measurement is also known as the frequency-modulated continuous wave (FMCW) method. (See above regarding...) Figure 4B The FMCW method, as described, involves detecting the heterodyne beat frequency f. beat It represents the frequency difference between two optical fields corresponding to the chirped laser excitation and return laser signals at any given time, and identifies f in the frequency domain. beat Peak amplitude (power) (such as heterodyne beat frequency f) beat (Fourier transform of the fiber). The distance from the fiber to the target can be determined as corresponding to f. beat The frequency conversion distance of the peak amplitude (power).

[0086] At 740, the time series of fiber-to-target distance measurements obtained over continuous or periodic distances using the optical coherence described above can be filtered, such as by using... Figure 2 The distance filter 217 shown can identify one or more anomalous measurements from fiber-to-target distance measurements. (See above regarding...) Figure 5BOutliers can include overestimations caused by bubbles, tissue debris, stone fragments, and other particles or objects generated by laser energy and fluid flushing and aspiration. Bubbles and interfering objects can cause inhomogeneities in the fluid space and affect laser transmission speed, which can lead to an overestimation of the fiber-to-target distance. Statistical methods can be used to identify outlier measurements and filter them from the data when determining the fiber-to-target distance. Examples of statistical methods can include the Grubb test (when testing for a single outlier), the Tietjen-Moore test, or the generalized extreme research deviation (ESD) test. In the example, outlier measurements can be identified based on the mean and variance or standard deviation (SD) of multiple fiber-to-target distance measurements. In the example, the distance threshold or acceptance range can be determined based on the moving average (mean or other central tendency) of multiple distance measurements within a moving window and the tolerance margin (such as a fraction of SD) of the distance measurements within the moving window. Each new distance measurement can be tested against the distance threshold or acceptance range, and if it exceeds the threshold or is outside the acceptance range, it is identified as an outlier; otherwise, it is identified as a valid measurement. The optimized fiber-to-target distance can be calculated as the average of a specified number of qualified distance measurements.

[0087] At 750°, control signals can be generated to the surgical laser system to adjust the position or orientation of the distal end of the fiber relative to the target, at least in part, based on the determined fiber-to-target distance. Robotic devices (such as...) can be used. Figure 2 The actuator 260 shown is used to perform adjustments. The robotic device can advance or retract the optical fiber, or change the aiming angle of the distal end of the fiber relative to the target structure. For example, if the fiber-to-target measurement exceeds a distance threshold, the robot can manipulate the fiber to advance the distal end closer to the target. Alternatively, the position or orientation of the distal end of the optical fiber relative to the target can be adjusted based on the target type or composition, which can be identified at least in part based on the target's spectral characteristics, such as using the aforementioned relative... Figure 2 The target recognition circuit 214.

[0088] At 760, laser therapy can be delivered to the target structure according to laser output settings. Laser output settings include one or more laser output parameters, such as pulse amplitude, pulse rate, power intensity, duration, frequency, pulse shape, irradiation time, and other laser irradiation parameters. The laser output settings can be adjusted based on the target type or composition, which can be identified at least in part based on spectral characteristics, as described above regarding... Figure 2As described. Additionally or alternatively, laser output settings can be adjusted based on fiber-to-target distance measurements. For example, if the target structure is identified as the intended treatment target type (e.g., a specific soft tissue or stone structure), and if the fiber-to-target distance meets certain conditions (e.g., below a distance threshold or within a specified laser emission range), laser pulses can be delivered to the target structure. If the target structure is outside the laser's range, the laser source can be temporarily "locked" so that no laser pulses are emitted to the target until the target structure is within the laser's emission range. In some examples, the laser output settings, an identifier of the target type or composition, and the fiber-to-target distance measurement can be presented to the user on the user interface. Before the laser output settings are applied to the laser system to initiate or adjust laser treatment on the target, the user can, for example, accept, reject, or modify the laser output settings via the user interface.

[0089] Figure 8 A block diagram of an example machine 800 on which any one or more of the techniques (e.g., methods) discussed herein can be generally shown. Parts of this specification can be applied to the computational framework of various parts of the laser surgery system 200 or the endoscopic laser surgery system 300.

[0090] In alternative embodiments, machine 800 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, machine 800 may operate as a server machine, a client machine, or both in a server-client network environment. In the example, machine 800 may act as a peer-to-peer (P2P) (or other distributed) network environment. Machine 800 may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), mobile phone, network device, network router, switch, or bridge, or any machine capable of executing instructions (sequentially or otherwise) specifying actions to be taken by that machine. Furthermore, although only a single machine is shown, the term "machine" should also be considered to include any collection of machines that individually or jointly execute a set (or more) of instructions to perform any one or more methods discussed herein, such as cloud computing, Software as a Service (SaaS), and other computer cluster configurations.

[0091] As described herein, examples may include logic or multiple components or mechanisms, or may be operated by logic or multiple components or mechanisms. A circuit set is a collection of circuits implemented in a tangible entity including hardware (e.g., simple circuits, gates, logic, etc.). Circuit set membership can vary flexibly over time and with the variability of the underlying hardware. A circuit set includes members that can perform specified operations individually or in combination during operation. In the examples, the hardware of the circuit set can be variably designed to perform specific operations (e.g., hardwired). In the examples, the hardware of the circuit set may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) including computer-readable media that are physically modified (e.g., magnetically, electrically, or movableally placed invariant aggregate particles, etc.) to encode instructions for specific operations. When connecting physical components, the underlying electrical characteristics of the hardware components, for example, change from an insulator to a conductor, and vice versa. Instructions enable embedded hardware (e.g., execution units or loading mechanisms) to create members of the circuit set in the hardware via variable connections to perform portions of specific operations during operation. Thus, when the device operates, the computer-readable medium is communicatively connected to other components of the circuit set members. In the example, any physical component can be used in more than one member of more than one circuit set. For instance, under operation, an execution unit may be used in a first circuit of a first circuit set at one point in time, and may be reused at different times by a second circuit of the first circuit set or by a third circuit of the second circuit set.

[0092] Machine (e.g., computer system) 800 may include a hardware processor 802 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), main memory 804, and static memory 806, some or all of which may communicate with each other via interconnect (e.g., bus) 808. Machine 800 may also include a display unit 810 (e.g., a raster display, vector display, holographic display, etc.), an alphanumeric input device 812 (e.g., a keyboard), and a user interface (UI) navigation device 814 (e.g., a mouse). In this example, display unit 810, input device 812, and UI navigation device 814 may be a touchscreen display. Machine 800 may additionally include a storage device (e.g., a drive unit) 816, a signal generation device 818 (e.g., a speaker), a network interface device 820, and one or more sensors 821, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensors. Machine 800 may include an output controller 828, such as a serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection, to communicate with or control one or more peripheral devices (e.g., printers, card readers, etc.).

[0093] Storage device 816 may include machine-readable medium 822 thereon storing one or more sets of data structures or instructions 824 (e.g., software) embodying or utilized any or more of the techniques or functions described herein. Instructions 824 may also reside wholly or at least partially within main memory 804, static memory 806, or hardware processor 802 during execution by machine 800. In this example, one or any combination of hardware processor 802, main memory 804, static memory 806, or storage device 816 may constitute the machine-readable medium.

[0094] Although machine-readable medium 822 is shown as a single medium, the term “machine-readable medium” can include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions 824.

[0095] The term "machine-readable medium" can include any medium capable of storing, encoding, or carrying instructions for execution by machine 800 and causing machine 800 to perform any one or more of the techniques disclosed herein, or any medium capable of storing, encoding, or carrying data structures used by or associated with such instructions. Examples of non-limiting machine-readable media can include solid-state memory as well as optical and magnetic media. In examples, large-scale machine-readable media includes machine-readable media having multiple particles with invariant (e.g., rest) masses. Therefore, large-scale machine-readable media are not transient propagating signals. Specific examples of large-scale machine-readable media can include non-volatile memories such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EPSOM)) and flash memory devices; disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

[0096] Instruction 824 can also transmit or receive over communication network 826 using a transmission medium via network interface device 820 and utilizing any of a variety of transmission protocols, such as Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc. Example communication networks may include local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile phone networks (e.g., cellular networks), conventional telephone (POTS) networks, and wireless data networks (e.g., the IEEE 802.11 family of standards known as Wi-Fi®, the IEEE 802.16 family of standards known as WiMax®), the IEEE 802.15.4 family of standards, peer-to-peer (P2P) networks, etc. In one example, network interface device 820 may include one or more physical jacks (e.g., Ethernet, coaxial cable, or telephone jacks) or one or more antennas for connection to communication network 826. In one example, network interface device 820 may include multiple antennas to perform wireless communication using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) technologies. The term "transmission medium" should be considered to include any intangible medium capable of storing, encoding, or carrying instructions executed by machine 800, and includes digital or analog communication signals or other intangible media to facilitate communication of such software.

[0097] Additional notes

[0098] The above detailed description includes reference to the accompanying drawings, which form part of the detailed description. The drawings illustrate, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are generally also referred to as “examples.” These examples may include elements other than those shown or described. However, the inventors also contemplate examples in which only the shown or described elements are provided. Furthermore, the inventors contemplate examples of any combination or substitution of those elements (or one or more aspects thereof) shown or described, whether with respect to a particular example (or one or more aspects thereof) or to other examples (or one or more aspects thereof) shown or described herein.

[0099] In this document, the term "a," as commonly used in patent literature, is used to include one or more and is independent of any other instance or usage of "at least one" or "one or more." Unless otherwise stated, the term "or" is used herein to refer to non-exclusivity, such that "A or B" includes "A but not B," "B but not A," and "A and B." In this document, the terms "comprising" and "wherein" are used as their concise English equivalents. Furthermore, in the following claims, the terms "comprising" and "including" are open-ended, meaning that a system, device, article, composition, formulation, or method that includes other elements besides those listed after the term in the claim is still considered to be within the scope of that claim. Additionally, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose reference numeral requirements on their objects.

[0100] The foregoing description is intended to be illustrative and not restrictive. For example, the foregoing examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, for example, by those skilled in the art after reading the foregoing description. An abstract is provided to allow the reader to quickly determine the nature of the technical disclosure. It should be understood that it should not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, various features may be combined together to simplify this disclosure. This should not be construed as meaning that any unclaimed disclosed feature is essential to any claim. Rather, the subject matter of the invention may lie in fewer than all features of a particular disclosed embodiment. Therefore, the following claims are incorporated into the detailed description as examples or embodiments, wherein each claim exists independently as a separate embodiment, and it is conceivable that such embodiments may be combined with each other in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

Claims

1. A surgical laser system, the surgical laser system comprising: A laser system configured to generate laser pulses and deliver the laser pulses to a target in the anatomical environment of the patient via an optical fiber; as well as The controller circuit includes a feedback analyzer circuit, which is configured to: In response to the chirped laser emitted from the surgical laser system illuminating the target, a returned laser signal is received from the target; An optical coherence metric is generated using at least a portion of the returned laser signal and the chirped laser, the optical coherence metric being related to the round-trip laser travel time between the far end of the optical fiber and the target; as well as The optical coherence metric is used to determine the fiber-to-target distance between the distal end of the optical fiber and the target. The controller circuit is configured to generate control signals, at least in part, based on the determined fiber-to-target distance, to adjust the position or orientation of the distal end of the fiber relative to the target.

2. The surgical laser system according to claim 1, wherein, The feedback analyzer circuit is configured to further determine the distance from the optical fiber to the target based on the chirp rate of the chirped laser.

3. The surgical laser system according to any one of claims 1 to 2, wherein, The controller circuit is configured to adjust the surgical laser output settings of the surgical laser system based at least in part on the determined fiber-to-target distance.

4. The surgical laser system according to any one of claims 1 to 3, further comprising a light source configured to direct electromagnetic radiation to the target. in, The feedback analyzer circuit is configured as follows: Detect the reflected imaging signal from the target in response to the electromagnetic radiation at the target; Determine the spectral characteristics of the target from the reflected imaging signal; and The target type or composition is identified at least in part based on the spectral characteristics of the determined target.

5. The surgical laser system according to claim 4, wherein, The controller circuit is configured to generate the control signal to further adjust the position or orientation of the distal end of the optical fiber relative to the target based on the identified target type or composition.

6. The surgical laser system according to any one of claims 4 to 5, wherein, The controller circuit is configured to adjust the surgical laser output settings of the surgical laser system, at least in part, based on the identified target type or composition.

7. The surgical laser system according to any one of claims 4 to 6, wherein, The optical fiber is configured to simultaneously guide the laser pulse and the reflected imaging signal.

8. The surgical laser system according to any one of claims 1 to 7, wherein, The controller circuit is configured to provide the control signal to a robotic device coupled to the optical fiber, so as to adjust the position or orientation of the distal end of the optical fiber relative to the target by the robot.

9. The surgical laser system according to any one of claims 1 to 8, the surgical laser system comprising a user interface configured to present to a user a determined fiber-to-target distance and suggestions for adjusting the position or orientation of the distal end of the fiber relative to the target.

10. The surgical laser system according to any one of claims 1 to 9, wherein, The objectives include organizational objectives. The surgical laser system is configured to generate and deliver laser pulses to treat the tissue target.

11. The surgical laser system according to any one of claims 1 to 10, wherein, The targets include kidney stones. The surgical laser system is configured to generate and deliver laser pulses to ablate or fragment the target stone.

12. The surgical laser system according to any one of claims 1 to 11, the surgical laser system comprising an endoscope, the endoscope being included in or coupled to the surgical laser system, the endoscope including a longitudinal channel for allowing the optical fiber to pass through.

13. The surgical laser system according to any one of claims 1 to 12, wherein, The feedback analyzer circuit is also configured to: Identify one or more anomalous measurements from multiple fiber-to-target distance measurements generated over time; The plurality of fiber-to-target distance measurements are filtered to exclude one or more identified anomalous measurements; as well as The fiber-to-target distance is determined using multiple filtered fiber-to-target distance measurements.

14. The surgical laser system according to claim 13, wherein, The feedback analyzer circuit is configured to identify one or more anomalous measurements based on the average and variance of the plurality of fiber-to-target distance measurements.

15. A method for feedback control of a surgical laser system during laser surgery on a patient, the method comprising: The chirped laser is guided to a target location in the patient's anatomical environment via an optical fiber of the surgical laser system, and a return laser signal is received from the target location in response to the chirped laser illuminating the target location. An optical coherence metric is generated using at least a portion of the returned laser signal and the chirped laser, the optical coherence metric being related to the round-trip laser travel time between the far end of the optical fiber and the target; The optical coherence metric is used to determine the fiber-to-target distance between the distal end of the optical fiber and the target; as well as The position or orientation of the distal end of the optical fiber relative to the target is adjusted, at least in part, based on the determined fiber-to-target distance.

16. The method according to claim 15, wherein, The distance from the optical fiber to the target is further determined based on the chirp rate of the chirped laser.

17. The method according to any one of claims 15 to 16, the method further comprising adjusting the surgical laser output settings of the surgical laser system based at least in part on the determined fiber-to-target distance.

18. The method according to any one of claims 15 to 17, wherein the method further comprises: To direct electromagnetic radiation toward the target; In response to the electromagnetic radiation, a reflected imaging signal is received from the target; The spectral characteristics of the target are determined from the reflected imaging signal; as well as The target type or composition is identified at least in part based on the spectral characteristics of the determined target.

19. The method according to claim 18, wherein, Adjusting the position or orientation of the distal end of the optical fiber relative to the target is further based on the identified target type or composition.

20. The method according to any one of claims 18 to 19, the method further comprising adjusting the surgical laser output settings of the surgical laser system based at least in part on the identified target type or composition.

21. The method according to any one of claims 15 to 20, wherein, The objectives include organizational objectives or stone objectives.

22. The method according to any one of claims 15 to 21, the method comprising providing a control signal to a robotic device coupled to the optical fiber to adjust the position or orientation of the distal end of the optical fiber relative to the target by the robot.

23. The method according to any one of claims 15 to 23, the method comprising presenting on a user interface the determined fiber-to-target distance and a suggestion for adjusting the position or orientation of the distal end of the fiber relative to the target.

24. The method according to any one of claims 15 to 23, wherein the method comprises: Identify one or more anomalous measurements from multiple fiber-to-target distance measurements generated over time based on their respective optical coherence metrics; The plurality of fiber-to-target distance measurements are filtered to exclude one or more identified anomalous measurements; as well as The fiber-to-target distance is determined using the filtered fiber-to-target distance measurements.

25. The method according to claim 24, wherein, Identifying one or more anomalous measurements is based on the average and variance of the plurality of fiber-to-target distance measurements.

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