Laser treatment using acoustic feedback

Abstract

To provide a system, a device, and a method for automatically controlling laser treatment based on acoustic feedback responding to the delivery of laser energy to a target.SOLUTION: There are provided a system, a device, and a method for automatically controlling laser treatment of a target structure in the body of a subject based on acoustic feedback responding to the delivery of laser energy to a target. An exemplary laser energy delivery system includes a laser system to direct laser energy to a target in the body, and a controller circuit for receiving an acoustic signal in response to the delivery of laser energy to the target. To achieve a desired treatment effect, a control circuit can generate a control signal for controlling the laser system to adjust laser energy output, or a control signal for controlling an actuator to adjust the position of a laser fiber distal end with respect to the target.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 054,334, filed July 21, 2020, the contents of which are incorporated by reference herein in their entirety. [Background technology]

[0002] This document relates generally to laser surgical systems, and more particularly to a laser endoscopic system for controllably applying a surgical laser to a target using acoustic feedback.

[0003] Endoscopes are typically used to provide access to internal locations of a patient so that a physician is provided with visual access. Some endoscopes are used in minimally invasive surgical procedures to remove unwanted tissue or foreign bodies from a patient's body. For example, a nephroscope is used by a clinician to examine the renal system and perform various procedures under direct visual control. In a percutaneous nephrolithotomy (PCNL) procedure, a nephroscope is placed into the renal pelvis through the patient's flank. For example, stones or masses may be visualized and extracted from various areas of the body including the urinary system, gallbladder, nasal cavity, digestive tract, stomach, or tonsils. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 01-308544 [Patent Document 2] Special Publication No. 2011-507651 [Patent Document 3] US Patent Application Publication No. 2016 / 0206373 Summary of the Invention [Problem to be solved by the invention]

[0005] Lasers or plasma systems have been used to deliver surgical laser energy to various target treatment areas, such as soft or hard tissues. Examples of laser treatments include ablation, coagulation, vaporization, fragmentation, and the like. In lithotripsy applications, lasers have been used to destroy stone structures in the kidney, gallbladder, ureter, and the like, among other stone-forming areas, or to ablate large stones into smaller fragments. In endoscopic laser treatment, it is desirable to recognize the target treatment structure (e.g., stone or cancerous tissue) in vivo so that the laser can be applied only to the target treatment structure and non-treatment tissues can be spared unintentional laser irradiation. [Means for solving the problem]

[0006] This document describes systems, devices, and methods for automatic control of laser therapy based on acoustic feedback responsive to delivery of laser energy to a target. An exemplary endoscopic laser energy delivery system includes a laser system that directs laser energy to a target within a subject's body, and an acoustic feedback controller circuit that receives an acoustic signal in response to delivery of the laser energy to the target, measures one or more acoustic characteristics from the received acoustic signal, and generates a first control signal for controlling the laser system to generate laser energy for delivery to the target, such as by adjusting a laser firing parameter setting, based on the one or more acoustic characteristics. The control circuit can generate a second control signal to an actuator that adjusts a position of a laser fiber distal end relative to the target to achieve a desired therapeutic effect.

[0007] Example 1 is an endoscopic laser energy delivery system comprising a laser system configured to direct laser energy to a target within a subject's body, and an acoustic feedback controller circuit configured to receive an acoustic signal in response to delivery of the laser energy to the target, measure one or more acoustic characteristics from the received acoustic signal, and generate a first control signal based on the one or more acoustic characteristics for controlling the laser system to generate laser energy for delivery to the target.

[0008] In Example 2, the subject matter of Example 1 optionally includes an acoustic feedback controller circuit that can be configured to generate a first control signal to the laser system to adjust a laser firing parameter setting based on the one or more acoustic characteristics, and the laser system that can be configured to generate laser energy in accordance with the adjusted laser firing parameter setting.

[0009] In Example 3, the subject matter of any one or more of Examples 1-2 optionally includes an acoustic sensor configured to sense an acoustic signal, the acoustic sensor communicatively coupled to the acoustic feedback controller circuit.

[0010] In Example 4, the subject matter of Example 3 optionally includes an acoustic sensor that can be configured to be attached to a distal portion of the endoscope.

[0011] In Example 5, the subject matter of any one or more of Examples 3-4 optionally includes an acoustic sensor, which may include a piezoelectric sensor.

[0012] In Example 6, the subject matter of any one or more of Examples 3-5 optionally includes an acoustic sensor, which may include a microphone.

[0013] In Example 7, the subject matter of any one or more of Examples 1-6 optionally includes one or more acoustic characteristics, which may include acoustic signal strength.

[0014] In Example 8, the subject matter of any one or more of Examples 1-7 optionally includes one or more acoustic characteristics that may include an acoustic signal shape characteristic.

[0015] In Example 9, the subject matter of any one or more of Examples 1-8 optionally includes one or more acoustic characteristics that may include frequency or spectral content of the received acoustic signal.

[0016] In Example 10, the subject matter of any one or more of Examples 1-9 optionally includes an acoustic feedback controller circuit that can be configured to identify the target as one of a plurality of structure types using the measured one or more acoustic properties or one or more spectroscopic properties.

[0017] In Example 11, the subject matter of Example 10 optionally includes an acoustic feedback controller circuit that can be configured to identify the target as one of a stone structure or an anatomical structure using the measured one or more acoustic properties or one or more spectroscopic properties.

[0018] In Example 12, the subject matter of Example 11 optionally includes an acoustic feedback controller circuit that can be configured to use the measured one or more acoustic properties or one or more spectroscopic properties to classify the target as one of a plurality of stone types, each having a distinct composition, adjust laser illumination parameter settings based on the classification of the target, and generate a first control signal to the laser system to deliver laser energy to the target of the classified stone type in accordance with the adjusted laser illumination parameter settings.

[0019] In Example 13, the subject matter of any one or more of Examples 11-12 optionally includes an acoustic feedback controller circuit that can be configured to use the measured one or more acoustic properties or one or more spectroscopic properties to classify the target as one of a plurality of tissue types and generate a first control signal to the laser system to deliver laser energy or withhold delivery of laser energy according to the classified tissue type.

[0020] In Example 14, the subject matter of Example 13 optionally includes an acoustic feedback controller circuit that can be configured to classify the target as a treatment area or a non-treatment area and generate a first control signal to the laser system to deliver laser energy to the treatment area and withhold delivery of laser energy to the non-treatment area.

[0021] In Example 15, the subject matter of any one or more of Examples 13-14 optionally includes an acoustic feedback controller circuit that can be configured to generate a first control signal to the laser system to classify a target as normal tissue or cancerous tissue, deliver laser energy to a target of classified cancerous tissue, and withhold delivery of laser energy if the target is classified as normal tissue.

[0022] In Example 16, the subject matter of any one or more of Examples 1-15 optionally includes an optical pathway having a distal portion configured to be inserted into a subject via a longitudinal passage of an endoscope.

[0023] In Example 17, the subject matter of Example 16 optionally includes an optical path coupled to the laser system and which may include a laser fiber configured to transmit laser energy to the target.

[0024] In Example 18, the subject matter of Example 17 optionally includes an optical path that can be configured to transmit an acoustic signal to the acoustic feedback controller circuit.

[0025] In Example 19, the subject matter of any one or more of Examples 16-18 optionally includes an actuator configured to actuate longitudinal translation of the optical pathway relative to the longitudinal passage of the endoscope in accordance with a second control signal generated by the acoustic feedback controller circuit based on the one or more acoustic characteristics or the one or more spectroscopic characteristics, wherein the longitudinal translation causes a change in a position of a distal end of the optical pathway relative to the target.

[0026] In Example 20, the subject matter of Example 19 optionally includes an acoustic feedback controller circuit that can be configured to use the received acoustic signal to calculate a distance between a distal end of the optical path and a target, and to generate a second control signal for actuating longitudinal translation of the optical path based on the calculated distance between the distal end of the optical path and the target.

[0027] In Example 21, the subject matter of any one or more of Examples 19-20 optionally includes an acoustic feedback controller circuit that can be configured to measure a laser spot size on the target from an image of the target in response to delivery of laser energy to the target and generate a second control signal for actuating longitudinal translation of the optical path to achieve a desired laser spot size on the target.

[0028] Example 22 is a method for controlling a laser system to deliver laser energy to a target within a subject's body. The method includes directing laser energy generated by the laser system to the target via an optical path, receiving an acoustic signal via an acoustic sensor in response to delivering the laser to the target, measuring one or more acoustic characteristics from the received acoustic signal via an acoustic feedback controller circuit, and generating, via the acoustic feedback controller circuit, a first control signal for controlling the laser system to generate laser energy for delivery to the target based on the one or more acoustic characteristics.

[0029] In Example 23, the subject matter of Example 22 optionally includes generating a first control signal to adjust a laser firing parameter setting based on the one or more acoustic characteristics, and generating laser energy in accordance with the adjusted laser firing parameter setting.

[0030] In Example 24, the subject matter of any one or more of Examples 22-23 optionally includes one or more acoustic characteristics, which may include one or more of an acoustic signal strength, an acoustic signal shape characteristic, or a frequency or spectral content of the received acoustic signal.

[0031] In Example 25, the subject matter of any one or more of Examples 22-24 optionally includes a step of identifying the target as one of a plurality of structure types using the measured one or more acoustic properties or one or more spectroscopic properties, the plurality of structure types including one of a stone structure or an anatomical structure.

[0032] In Example 26, the subject matter of Example 25 optionally includes classifying the target as one of a plurality of stone types, each having a distinct composition, using the measured one or more acoustic characteristics or one or more spectroscopic characteristics, adjusting laser delivery parameter settings for the laser system based on the classification of the target, and generating a first control signal to the laser system to deliver laser energy to the target in accordance with the adjusted laser parameter settings.

[0033] In Example 27, the subject matter of any one or more of Examples 25-26 optionally includes a step of classifying the target as one of a plurality of tissue types using the measured one or more acoustic properties or one or more spectroscopic properties, and generating a first control signal to the laser system to deliver laser energy or withhold delivery of laser energy according to the classified tissue type.

[0034] In Example 28, the subject matter of any one or more of Examples 22-27 optionally includes adjusting, via the actuator, a position of a distal end of the optical path relative to the target based on the one or more acoustic properties or the one or more spectroscopic properties.

[0035] In Example 29, the subject matter of Example 28 optionally includes adjusting a distal tip position, which can include generating, via the acoustic feedback controller circuit, a second control signal to an actuator to actuate longitudinal translation of the optical path relative to a longitudinal passageway of the endoscope.

[0036] In Example 30, the subject matter of any one or more of Examples 28-29 optionally includes, in response to delivery of laser energy to the target, measuring a laser spot size on the target from an image of the target, and adjusting, via the actuator, a position of a distal end of the optical path to achieve a desired laser spot size on the target.

[0037] Example 31 is at least one non-transitory machine-readable storage medium including instructions that, when executed by one or more processors of the machine, cause the machine to perform operations including: directing laser energy generated by a laser system to a target via an optical path; receiving an acoustic signal via an acoustic sensor in response to delivering the laser to the target; measuring one or more acoustic characteristics from the received acoustic signal via an acoustic feedback controller circuit; and generating, via the acoustic feedback controller circuit, a first control signal for controlling the laser system to generate laser energy for delivery to the target based on the one or more acoustic characteristics.

[0038] In Example 32, the subject matter of Example 31 optionally includes instructions to cause the machine to perform operations further including generating a first control signal to adjust a laser firing parameter setting based on the one or more acoustic characteristics, and generating laser energy in accordance with the adjusted laser firing parameter setting.

[0039] In Example 33, the subject matter of any one or more of Examples 31-32 optionally includes instructions that cause the machine to perform operations of measuring one or more acoustic characteristics, including one or more of an acoustic signal strength, an acoustic signal shape characteristic, or a frequency or spectral content, of the received acoustic signal.

[0040] In Example 34, the subject matter of any one or more of Examples 31-33 optionally includes instructions that cause the machine to perform an operation of identifying the target as one of a plurality of structure types using the measured one or more acoustic properties or one or more spectroscopic properties, the plurality of structure types including one of a stone structure or an anatomical structure.

[0041] In Example 35, the subject matter of Example 34 optionally includes instructions to cause the machine to perform operations of classifying the target as one of a plurality of stone types, each having a distinct composition, using the measured acoustic characteristic or characteristics or spectroscopic characteristic, adjusting laser delivery parameter settings for the laser system based on the classification of the target, and generating a first control signal to the laser system to deliver laser energy to the target in accordance with the adjusted laser parameter settings.

[0042] In Example 36, the subject matter of any one or more of Examples 34-35 optionally includes instructions to cause the machine to perform operations including classifying the target as one of a plurality of tissue types using the measured one or more acoustic properties or one or more spectroscopic properties, and generating a first control signal to the laser system to deliver laser energy or withhold delivery of laser energy according to the classified tissue type.

[0043] In Example 37, the subject matter of any one or more of Examples 31-36 optionally includes instructions that cause the machine to perform an operation of adjusting, via the actuator, a position of a distal end of the optical pathway relative to the target based on the one or more acoustic properties or the one or more spectroscopic properties.

[0044] In Example 38, the subject matter of Example 37 optionally includes an operation of adjusting the distal tip position, including an operation of generating, via the acoustic feedback controller circuit, a second control signal to an actuator to actuate longitudinal translation of the optical path relative to the longitudinal passage of the endoscope.

[0045] In Example 39, the subject matter of any one or more of Examples 37-38 optionally includes instructions that cause the machine to perform operations including, in response to delivery of laser energy to the target, measuring a laser spot size on the target from an image of the target, and adjusting, via the actuator, a position of a distal end of the optical path to achieve a desired laser spot size on the target.

[0046] This Summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details regarding the present subject matter are found in the detailed description and the appended claims. Other aspects of the present disclosure will become apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the drawings, each of which forms a part of the detailed description and should not be taken in a limiting sense. The scope of the present disclosure is defined by the appended claims and their legal equivalents.

[0047] Various embodiments are illustrated by way of example in the accompanying drawing figures. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present subject matter. [Brief description of the drawings]

[0048] [Figure 1] FIG. 1 is a block diagram illustrating an example of a laser energy delivery system configured to provide laser treatment to a target structure within the body, such as an anatomical structure or a stone structure. [Diagram 2] FIG. 1 is a block diagram illustrating a laser feedback control system and a portion of the environment in which the system may be used. [Figure 3A] 1A-1C show examples of acoustic signals generated in response to delivery of laser energy and acoustic features extracted from the acoustic signals. [Figure 3B] 1A-1C show examples of acoustic signals generated in response to delivery of laser energy and acoustic features extracted from the acoustic signals. [Figure 4]FIG. 1 illustrates an example of an endoscopic laser lithotripsy system that can use an acoustic feedback signal to control and adjust the position of the optical path relative to the distal end of the endoscope. [Diagram 5] FIG. 13 shows an example of a calibration curve illustrating the relationship between the spectral reflected signal intensity and the distance between the distal end of the fiber and the target structure using a feedback signal reflected from the target structure. [Figure 6] 1 is a flow chart illustrating a method for controlling a laser system to deliver a laser beam to a target structure within a subject. [Figure 7] FIG. 1 is a block diagram illustrating an example machine upon which any one or more of the techniques (e.g., methodologies) discussed herein may be performed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Laser endoscopy is a medical procedure that observes and operates on internal organs and delivers a surgical laser to a targeted body area to achieve a specific diagnostic or therapeutic effect. Laser endoscopy has been used to treat soft and hard tissues (e.g., to damage or destroy cancer cells) or in lithotripsy applications. For example, in PCNL, a practitioner can insert a rigid scope into a patient's kidney through an incision in the patient's back. Through the scope, the practitioner can locate a specific stone within the kidney or upper ureter and break the stone into smaller fragments by irradiating the stone with a relatively high-powered infrared laser beam through the scope. The laser beam can ablate the stone into smaller fragments. The stone fragments can then be removed from the kidney. The scope can include an endoscope, a nephroscope, and / or a cystoscope.

[0050] In endoscopic laser treatment, it is desirable to detect targets in real time, recognize the target as a specific tissue or stone type, and apply laser energy only to the treatment structure (e.g., cancerous tissue, or specific stone type), avoiding or reducing laser irradiation to non-treatment tissue (e.g., normal tissue). Traditionally, recognition of the target treatment structure of interest is performed manually by an operator, such as by visualizing the target surgical site and its surrounding environment through an endoscope. Such manual techniques may be less accurate in certain environments where narrow access to the surgical site provides a limited surgical field of view. Biopsy techniques have been used to remove the target structure outside the body for ex vivo analysis of the composition. However, in many clinical applications, it is desirable to determine tissue composition in vivo to reduce surgical time and improve treatment efficacy. For example, in laser lithotripsy, automatic recognition of stone type in vivo, and distinguishing it from surrounding tissue, allows the physician to adjust irradiation parameter settings (e.g., laser power or irradiation time) to more effectively ablate the target stone while avoiding irradiation of non-treatment tissue adjacent to the target stone.

[0051] Conventional endoscopic laser therapy also has the limitation of not being able to continuously monitor tissue type (e.g., composition) during the procedure. There are many moving parts during an endoscopic procedure, and the tissue seen by the endoscope may change during the procedure. Conventional biopsy techniques cannot be used to monitor tissue type throughout the procedure because they require the removal of a tissue sample to identify its type. Continuous monitoring and recognition of the structure type (e.g., soft or hard tissue type, normal vs. cancerous tissue, or composition of the stone structure) at the tip of the endoscope may give the physician more information to better adapt the treatment during the procedure. For example, if a physician is pulverizing a kidney stone that has a hard surface but a soft core, continuous tissue composition information from the endoscope may allow the physician to adjust the irradiation parameter settings based on the continuously detected stone surface composition, such as from a first setting that performs better on the hard surface of the stone to a second different setting that performs better on the soft core of the stone.

[0052] For at least the above reasons, the inventors have recognized an unmet need for systems and methods that can distinguish between different structure types, each having a different composition, in vivo and tailor treatment according to the distinction between structure types.

[0053] Described herein are systems, devices, and methods for automatic control of laser treatment of a target structure within a subject's body based on acoustic feedback responsive to delivery of laser energy to the target. An exemplary endoscopic laser energy delivery system includes a laser system that directs laser energy to a target within the subject's body, and an acoustic feedback controller circuit that receives an acoustic signal in response to delivery of the laser energy to the target, measures one or more acoustic characteristics from the received acoustic signal, and generates a first control signal for controlling the laser system to generate laser energy for delivery to the target, such as by adjusting laser firing parameter settings, based on the one or more acoustic characteristics. The control circuit can generate a second control signal to an actuator that adjusts the position of the laser fiber distal end relative to the target to achieve a desired therapeutic effect.

[0054] The systems, devices, and methods according to various embodiments discussed herein improve target identification in vivo in real time during laser endoscopic procedures. The features described herein may also be used in conjunction with endoscopy, laser surgery, laser lithotripsy, irradiation parameter settings, and / or spectroscopy. Examples of targets and applications may include laser lithotripsy of kidney stones, and laser dissection or vaporization of soft tissue. In an example of an endoscopic system incorporating the features described herein, the type of tissue or stone may be identified and monitored in vivo and used to adjust the laser energy and delivery, such as irradiation parameter settings (e.g., intensity, power, duration, frequency, or pulse shape, irradiation time, or firing angle) for optimal laser treatment. The ability to continuously monitor and identify tissue type or stone type allows for instantaneous adjustment of the laser treatment. With improved recognition and classification of target structures, patients may be protected from accidental or misplaced laser firing, and improved treatment efficacy and tissue safety may be achieved.

[0055] According to some examples discussed herein, acoustic feedback during laser firing at the target may be used to identify tissue or stone type or composition, adjust irradiation parameter settings, and / or adjust the delivery of laser energy, such as by controllably adjusting the position or orientation of the laser fiber relative to the target to achieve a desired distance between the distal end of the laser fiber and the target (also referred to as the fiber-target distance). Acoustic feedback may include acoustic signals generated when the laser pulse propagates through a medium (e.g., liquid and vapor) along a path to the target, vibrating the liquid and vapor, and when the laser pulse projects onto the target, vibrating the target. According to various examples discussed herein, the fiber-target distance may be estimated using the acoustic feedback signal. An actuator may controllably adjust the position or orientation of a distal portion of the laser fiber relative to the target. In some examples, the laser may be locked (i.e., prevented from firing) if a suitable target element (e.g., a cancerous lesion or a stone) is not within the laser firing range. For example, during a laser lithotripsy procedure, the laser may be locked when no stone is within the laser firing range (e.g., only tissue is within the laser range). Automatic locking control or fiber-target distance adjustment may improve the performance of existing laser lithotripsy systems, conserve power, enhance patient safety, and ensure that the target is within optimal firing distance to improve stone ablation efficacy.

[0056] The acoustic feedback laser energy delivery systems discussed herein may be advantageous over conventional laser energy delivery systems that utilize other types of feedback. For example, visual feedback may be constrained by human reaction times, which may be long for fast laser-target interactions and processes (e.g., bubble formation at the fiber tip, time-nonlinear laser light absorption in the water / vapor medium and by the stone material, vibrations, and other instabilities). In addition, human reaction times may vary significantly between human operators. In contrast, acoustic waves have fast propagation speeds through tissue, stone, and surrounding liquid medium such that the latency from sound formation to getting feedback and adjusting the laser energy or laser delivery accordingly may be reduced.

[0057] The high-speed acoustic feedback system discussed herein allows for faster, real-time laser treatment control, including, for example, irradiation parameter settings and / or laser fiber position or orientation, with improved precision. Generally, for optical fibers ranging from about 150 μm to 1000 μm in diameter, there is a trade-off between fiber flexibility and ablation speed. Generally, larger diameter fibers provide faster ablation speeds, while smaller diameter fibers tend to be more flexible. Faster adjustment of fiber position can help achieve a desired laser spot size on the target, thereby improving laser ablation speed with smaller diameter fibers. Thus, the high-speed acoustic feedback system discussed herein allows an operator to use more flexible optical fibers with smaller diameters (e.g., about 150 μm to 365 μm) to achieve similar high ablation speeds as using larger diameter fibers (e.g., about 500 μm to 1000 μm). The high-speed acoustic feedback system may facilitate the creation of consistent air bubble tunnels in the medium between the laser fiber and the target to significantly reduce the loss of laser light due to water absorption.

[0058] Another advantage of the acoustic feedback laser energy delivery system discussed herein is that laser therapy can be optimized without detailed knowledge of the type of target and the condition of the medium between the laser fiber and the target. Such a therapy optimization approach can stabilize or maximize a preselected therapy goal with improved efficiency. For example, the laser ablation rate depends on the applied laser power density, and the strength of the acoustic signal (e.g., acoustic signal peak amplitude) generated in response to the laser firing at the target correlates to the laser power density. The laser energy delivery system discussed herein can automatically adjust the fiber position and laser power to maximize the acoustic signal peak amplitude. Compared to other in vivo feedback control laser therapies, the acoustic feedback system described herein can advantageously enable more accurate and faster therapy control, shortening the procedure time and improving the laser therapy efficiency.

[0059] FIG. 1 is a block diagram illustrating an example of a laser energy delivery system 100 configured to provide laser therapy to a target structure 122 within a subject's body, such as an anatomical structure (e.g., soft tissue, hard tissue, or abnormal tissue such as cancerous tissue) or a stone structure (e.g., kidney stones, pancreaticobiliary stones, or gallbladder stones). In one example, the system 100 is an endoscopic laser energy delivery system. The laser energy delivery system 100 includes a laser feedback control system 101 and at least one laser system 102. The laser feedback control system 101 may receive a feedback signal 130 from the target. Various feedback signals may be used to control the laser delivery. In one example, the feedback signal 130 may include an acoustic signal. The acoustic signal may be sensed when a laser pulse propagates through a medium (e.g., liquid and vapor) along a path to the target, vibrating the liquid and vapor, and when the laser pulse projects onto the target, vibrating the target. In 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 a reflected laser signal. The laser feedback control system 101 may analyze the feedback signal 130 and generate one or more signal characteristics, such as acoustic characteristics from an acoustic signal or spectroscopic characteristics from a reflected electromagnetic signal, to control the laser energy output and / or laser delivery. The laser feedback control system 101 may be used in various applications, such as industrial and / or medical applications for the treatment of soft (e.g., non-calcified) or hard (e.g., calcified) tissue, or stone structures, such as kidney stones, pancreaticobiliary stones, or gallbladder stones. In some examples, the laser energy delivery system 100 may deliver precisely controlled therapeutic treatments of tissue or other anatomical structures (e.g., tissue ablation, coagulation, vaporization, etc.), or treatment of non-anatomical structures (e.g., ablation or pulverization of stone structures).

[0060] The laser feedback control system 101 may be in operative communication with one or more laser systems. FIG. 1 shows a laser feedback system connected to a first laser system 102 and optionally connected to a second laser system 104 (shown in dotted lines). Additional laser systems are contemplated within the scope of the present disclosure. The first laser system 102 may include a first laser source 106 and associated components such as a power source, a display, a cooling system, etc. The first laser system 102 may also include a first optical path 108 operably coupled to the first laser source 106. In one example, the first optical path 108 includes an optical fiber. The first optical path 108 may be configured to transmit a laser beam from the first laser source 106 to the target tissue 122.

[0061] Based on analysis of the feedback signal 130, the laser feedback control system 101 may control the first laser system 102 and / or the second laser system 104 to generate an appropriate laser output to provide a desired therapeutic effect. For example, the laser feedback control system 101 may monitor characteristics of the target structure 122 during a therapeutic treatment (e.g., ablating a stone, such as a kidney stone, into smaller fragments) to determine if tissue has been properly ablated prior to another therapeutic treatment (e.g., coagulating a blood vessel).

[0062] In one example, the first laser source 106 can be configured to provide a first output 110. The first output 110 can span a first wavelength range, such as a wavelength range corresponding to a portion of the absorption spectrum of the target structure 122. Because the first output 110 spans a wavelength range corresponding to the absorption spectrum of tissue, the first output 110 can provide effective ablation and / or carbonization of the target structure 122.

[0063] In one example, the first laser source 106 is configured to emit a first output 110 in a first wavelength range such that the first output 110 is absorbed by tissue at a high wavelength (e.g., approximately 250 cm -1In an exemplary embodiment, the first laser source 106 may be configured to emit a first output 110 between about 1900 nanometers (nm) and about 3000 nm (e.g., corresponding to high absorption by water) and / or between about 40 nm and about 520 nm (e.g., corresponding to high absorption by oxyhemoglobin and / or deoxyhemoglobin). Clearly, there are two main mechanisms for the interaction of light with tissue: absorption and scattering. High tissue absorption (above 250 cm) -1 ), the first absorption mechanism dominates and absorption is low (absorption coefficient above 250 cm -1 For lasers with wavelengths in the range of 800 to 1100 nm (absorption coefficient less than 100 nm), for example, scattering mechanisms dominate.

[0064] A variety of commercially available medical grade laser systems may be suitable for the first laser source 106. For example, a semiconductor laser such as an InXGa1-XN semiconductor laser providing a first output 110 in a first wavelength range between about 515 nm and about 520 nm, or between about 370 nm and about 493 nm, may be used. Alternatively, an infrared (IR) laser such as those summarized in Table 1 below may be used.

[0065] [Table 1]

[0066] The 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 separate from the first laser source 106 or alternatively may be operably coupled to the first laser system 106. In some embodiments, the second laser system 104 may include a second optical path 118 (separate 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.

[0067] In certain aspects, the second output 120 may span a second wavelength range that is different from the first wavelength range. Thus, there may not be any overlap between the first and second wavelength ranges. Alternatively, the first and second wavelength ranges may have at least a partial overlap with each other. In advantageous aspects of the present disclosure, the second wavelength range may not correspond to a portion of the absorption spectrum of the target structure 122, where the incident radiation is strongly absorbed by tissue that has not previously been ablated or carbonized. In some such aspects, the second output 120 may advantageously not ablate non-carbonized tissue. In another embodiment, the second output 120 may ablate carbonized tissue that has not previously been ablated. In additional embodiments, the second output 120 may provide an additional therapeutic effect. For example, the second output 120 may be more suitable for coagulating tissue or blood vessels.

[0068] FIG. 2 is a block diagram illustrating a laser feedback control system 200 and at least a portion of an environment in which it may be used. The laser feedback control system 200, which is an example of the laser feedback control system 101, includes a feedback analyzer 240, a memory 250, and a controller circuit 260. The feedback analyzer 240 may include an acoustic sensor 241 configured to sense an acoustic signal in response to delivery of laser energy to a target, according to one embodiment of the subject matter described herein. The acoustic signal may be sensed when the laser pulse propagates through a medium (e.g., liquid and vapor) along a path to the target, vibrating the liquid and vapor, as well as when the laser pulse projects onto the target, vibrating the target. In some examples, the acoustic sensor 241 may sense a particular sound wave having a particular wavelength, such as audible range waves, ultrasound, or infrasound waves. Examples of the acoustic sensor 241 may include a microphone, a hydrophone, a capacitance sensor, a piezoelectric sensor, a piezoelectric ceramic sensor, a fiber optic sensor, or a solid-state acoustic detector, among others. The feedback analyzer 240 may analyze the acoustic signal to generate one or more acoustic characteristics. Examples of acoustic characteristics may include intensity, power, frequency or spectral content, or graphical features that represent the shape of the received acoustic signal (e.g., a shape characteristic of a time series of sound intensity). In some examples, the acoustic characteristics may include one or more statistical features of the received acoustic signal (e.g., the mean or variance of the signal).

[0069] The feedback analyzer 240 may optionally include a spectroscopic sensor 242 that may sense the spectroscopic signal reflected from the target structure 122 and generate one or more spectroscopic characteristics from the reflected signal. The spectroscopic characteristics may include characteristics such as reflectance, reflectance spectrum, absorption index, etc. Examples of the spectroscopic sensor 242 may include a Fourier transform infrared (FTIR) spectrometer, a Raman spectrometer, a UV-VIS spectrometer, a UV-VIS-IR spectrometer, or a fluorescence spectrometer, etc. Each spectroscopic sensor 242 corresponds to a spectroscopic technique. For example, UV-VIS reflectance spectroscopy may be used to gather information from light reflected from an object, similar to the information provided by the eye or from a color image created by a high-resolution camera, but more quantitatively and objectively. Reflectance spectroscopy may provide information about materials, since the reflection and absorption of light depends on the chemical composition and surface properties of the material. Using this technique, information about both surface and bulk properties of a sample may be obtained. Reflectance spectroscopy may be used to recognize the composition of hard or soft tissues. Fluorescence spectroscopy is a type of electromagnetic spectroscopy that analyzes fluorescence from a sample. Fluorescence spectroscopy involves using a beam of light, usually ultraviolet, to excite material compounds, causing them to emit light, typically in the visible or IR range. This method may be applied to the analysis of some organic components, such as hard and soft tissues. FTIR spectroscopy may be used for rapid material analysis, has relatively good spatial resolution, and gives information about the chemical composition of materials. Raman spectroscopy may be used to distinguish between hard and soft tissue components. As a high spatial resolution technique, Raman spectroscopy is also useful in determining the distribution of components within a target. The above-described spectroscopy techniques may be used alone or in combination to analyze the spectroscopic signal by the spectroscopic sensor 242 to generate one or more spectroscopic signatures indicative of structure types, each having different components.

[0070] The feedback analyzer 240, in one embodiment, may optionally include an imaging sensor 244, such as an imaging camera, such as a CCD or CMOS camera, sensitive to ultraviolet (UV), visible (VIS), or infrared (IR) wavelengths. In some embodiments, the spectroscopic sensor 242 may include two or more types of spectrometers or imaging cameras enumerated herein to enhance sensing and detection of various features (e.g., carbonized and non-carbonized tissue, vasculature, etc.).

[0071] The acoustic sensor 241, and optionally the spectroscopic sensor 242 and / or the imaging sensor 244, may be operably coupled to a signal transmission path 280. The signal transmission path 280 may include an optical path (e.g., an optical fiber) having optical properties suitable for transmitting a feedback signal (e.g., an acoustic signal or a spectroscopic signal reflected from the tissue). Alternatively, the acoustic sensor 241, and optionally the spectroscopic sensor 242 and / or the imaging sensor 244 may be operably coupled to the first optical path 108 and / or the second optical path 118 of the second laser system 104 to detect the respective feedback signals via the first optical path 108 and / or the second optical path 118.

[0072] The feedback analyzer 240 may include a target identifier that may detect and identify targets. In the example shown in FIG. 2, the target identifier may include one or more of the target detector 246 or the target classifier 248. For a tissue or stone target, its ability to absorb laser energy depends on its composition and liquid content. Different target types, such as different stone structures or soft or hard tissues, may have different compositions and / or liquid contents. If these targets absorb different amounts of laser energy, they may generate different vibration patterns that may be sensed as different acoustic characteristics. The target detector 246 may use one or more acoustic signal characteristics to identify the target structure 122 as one of a plurality of structure categories, such as a stone structure category or an anatomical structure category. Examples of stone structures may include stones or stone fragments in various stone formation areas, such as the urinary system, the gallbladder, the nasal cavity, the digestive tract, the stomach, or the tonsils. Examples of anatomical structures may include soft tissues (eg, muscles, tendons, ligaments, blood vessels, fascia, skin, fat, and fibrous tissue), hard tissues such as bone, connective tissues such as cartilage, among others.

[0073] The target classifier 248 may classify the target structure 122 as one of multiple structure types of the same category, such as a specific tissue type within an identified category of anatomical structures, or as a specific stone type within an identified category of stone structures. In one example, the target classifier 248 may classify the identified stone as one of stone types having different chemical compositions, such as CaP stones, MAP stones, COM stones, COD stones, cholesterol-based stones, or uric acid (UA) stones. The classification may be based on one or more acoustic characteristics, such as the intensity, power, frequency or spectral content, or graphical features or shapes of the received acoustic signal, or one or more statistical features generated from the received acoustic signal. In some examples, the target classifier 248 may classify the identified anatomical structure as one of multiple tissue types. The tissue types may include tissues in distinct anatomical locations, such as calyx tissue, skin tissue, medulla tissue, or ureteral tissue. In another example, the target classifier 248 may be configured to classify the identified anatomical structure as normal tissue or abnormal tissue (e.g., cancerous tissue). In another example, the classifier 248 may be configured to classify the identified anatomical structure as a treatment area (e.g., a tumor or polyp intended for removal) or a non-treatment area (e.g., a blood vessel, muscle, etc.). The classification may be based on one or more acoustic characteristics, such as the intensity, power, frequency or spectral content, or graphical features or shape of the received acoustic signal, or one or more statistical features generated from the received acoustic signal, as described above. Examples of acoustic signals generated in response to delivery of laser energy and various acoustic characteristics are discussed below, such as with reference to FIGS. 3A-3B.

[0074] In some examples, the target detector 246 or the target classifier 248 may use additional feedback to identify the target structure 122 as a stone structure or an anatomical structure or to classify the target structure 122 as a particular stone type or tissue type. Examples of such additional feedback may include, for example, one or more spectroscopic signal characteristics generated from the spectroscopic signal or one or more imaging characteristics generated from the imaging signal.

[0075] The controller circuit 260 may be in operative communication with the feedback analyzer 240 and the laser system 202. The laser system 202 may represent the first laser system 102, the optional second laser system 104, and / or any additional laser system. The controller circuit 260 may control the laser systems 202 operatively connected thereto according to one or more control algorithms described herein to control the laser output from the one or more laser systems to produce a desired therapeutic effect at the target structure 122. In one example, the controller circuit 260 may generate a first control signal to the laser system 202 to adjust the laser irradiation parameter settings based on at least acoustic feedback, such as one or more acoustic characteristics. Examples of laser irradiation parameters may include wavelength, power, power density, pulse parameters (e.g., pulse width, pulse rate, amplitude, duty cycle), irradiation time, total dose, or energy, among others. In one example, the controller circuit 260 may generate a second control signal to an actuator to automatically adjust a position or orientation of a distal portion of the optical fiber for delivering a laser pulse, such as to change the distance between the fiber distal end and the target structure 122 (the "fiber-target distance") based on at least the received acoustic signal. In one example, the feedback analyzer 240 may calculate or estimate the fiber-target distance using one or more acoustic properties derived from the acoustic signal, and the controller circuit 260 may adjust the position or orientation of the laser fiber such that the target is within the desired laser launch distance.

[0076] According to an exemplary embodiment, the controller circuit 260 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, as well as any combination of such components for performing one or more of the functions attributed to the controller circuit 260. Optionally, the controller circuit 260 may be coupled to the feedback analyzer 240 and the laser system 202 by a wired or wireless connection. The controller circuit 260 may communicate with the feedback analyzer 240 (e.g., via a wired or wireless connection) and determine an operating mode of the laser system 202 based on an identification of the target structure 122 (as determined by the target detector 246) or based on a classification of the target structure 122 (as determined by the target classifier 248).

[0077] In some examples, the laser system 202 may be associated with one of two distinct operating modes or states: a first state in which the laser system 202 generates a laser output, and a second state in which the laser system 202 does not generate a laser output. For example, the first laser system 102 may have a first state in which the first output 110 (e.g., over a first wavelength range) is generated, and a second state in which the first output 110 is not generated. Similarly, the second laser system 104 may have a second state in which the second output 120 (e.g., over a second wavelength range) is generated, and a second state in which the second output 120 is not generated. In such an embodiment, the controller circuit 260 may control the laser system 220 by sending a control signal that changes the operating state of the laser system from the first state to the second state, or from the second state to the first state. In some examples, the laser system 202 may have an additional state, e.g., a third state in which a laser output according to a different laser firing parameter setting is generated. Accordingly, additional control signals may be sent by the controller circuit 260 to the laser system to change the state of the laser system from a current state to one or more additional states (e.g., from the first state to a third state, from the second state to the third state, from the third state to the first state, or from the third state to the second state) to generate a laser output that provides a desired therapeutic effect.

[0078] In one example, the controller circuit 260 may generate control signals to operate the laser system 202 in a first operating mode if the target is identified as a stone structure, or in a second operating mode if the target is identified as an anatomical structure, or in a third mode if the target is identified as neither an anatomical structure nor a stone structure. In one example, the first operating mode may include activating the laser system 202 to deliver a laser beam programmed with a first irradiation parameter setting to ablate or pulverize the identified stone, such as a kidney stone. In one example, the second operating mode may include withholding laser delivery or delivering a laser beam programmed with a second irradiation parameter setting, different from the first irradiation parameter setting, to the identified tissue. In one example, the third operating mode may include deactivating the laser system 202 from delivering laser energy. The laser irradiation parameters may include, among others, wavelength, power, power density, pulse parameters (e.g., pulse width, pulse rate, amplitude, duty cycle), irradiation time, total dose, or energy.

[0079] In some examples, the controller circuit 260 may determine an operating mode of the laser system 202 based on a classification of the target structure 122 as one of a plurality of stone types, such as a CaP stone, a MAP stone, a COM stone, a COD stone, a cholesterol-based stone, or a uric acid (UA) stone, as determined by the target classifier 248. The controller circuit 260 may adjust irradiation parameter settings based on the stone type classification and generate control signals to control the laser system 202 to deliver laser energy to the target structure 122 in accordance with the adjusted irradiation parameter settings.

[0080] In some examples, the controller circuit 260 may determine an operating mode of the laser system 202 based on a classification of the target structure 122 as one of a plurality of tissue types, such as renal tissue (e.g., calyx tissue, skin tissue, medulla tissue, or ureter tissue), normal or abnormal tissue (e.g., cancerous tissue), treatment area (e.g., tumor or polyp intended for removal) or non-treatment area (e.g., blood vessel, muscle, etc.) in different anatomical locations. The controller circuit 260 may adjust the irradiation parameter settings based on the tissue type classification and generate control signals to the laser system 202 to deliver laser energy to the identified anatomical structure according to the adjusted irradiation parameter settings.

[0081] In some examples, irradiation parameter settings may be determined for multiple stone types and / or multiple tissue types, respectively. Stone type-irradiation parameter setting correspondences or tissue type-irradiation parameter setting correspondences may be created and stored in the memory 250 in a look-up table, an associative array, etc. The controller circuit 260 may use one of such stored correspondences to determine an irradiation parameter setting corresponding to a classified stone type or a classified tissue type.

[0082] In some examples, the controller circuit 260 may directly adjust the illumination parameter settings based on one or more acoustic characteristics generated by the feedback analyzer 240, without using information regarding the target type or target composition, as generated by the target detector 246 or the target classifier 248. For example, the intensity of the acoustic signal generated in response to the laser firing at the target stone structure is related to the laser power density. The controller circuit 260 may automatically adjust the illumination parameter settings (e.g., laser power) and the laser fiber position to achieve the desired acoustic signal amplitude.

[0083] In various examples, the feedback analyzer 240 may continuously monitor the target structure 122, collect and analyze the feedback signal, and continuously communicate with the controller circuit 260. Thus, the controller circuit 260 may continue to maintain the laser system in one or more states until a change in feedback is detected (e.g., a different category of the target structure 122, a different tissue type, or a different stone type). Once a change in feedback is detected, the controller circuit 260 may communicate with the one or more laser systems and change their state to deliver a desired therapeutic effect. Alternatively or additionally, the controller circuit 260 may communicate with an operator (e.g., a medical professional) and display one or more outputs indicative of the feedback signal via one or more output systems, and optionally instruct the operator to perform one or more therapeutic procedures with the first laser system and / or the second laser system to deliver a desired therapeutic effect.

[0084] In the illustrative examples described herein, the controller circuit 260 may control two or more laser systems by changing the operating state of each laser system. According to one embodiment, the controller circuit 260 may control each laser system independently. For example, the controller circuit 260 may send a separate control signal to each laser system to control each laser system independently from the other laser systems. Alternatively, the controller circuit 260 may send a common signal to control one or more laser systems.

[0085] The laser feedback control system 200 may be in operative communication with an output system 270. The output system 270 may communicate and / or transmit signals received and information generated by the feedback analyzer 240 to a user and / or to other systems, such as an irrigation aspiration / pumping system, or an optical display controller, or other systems used for a therapeutic treatment. Examples of transmitted signals and information may include one or more of the feedback signal 130 (e.g., acoustic signals, and optional spectroscopic and imaging signals), signal characteristics (e.g., generated acoustic characteristics, optional spectroscopic characteristics, and imaging characteristics), an identification of the target structure 122 generated by the target detector 246, or a classification of the target structure 122 generated by the target classifier 248. In one example, the output system 270 may include a display 272, such as a screen (e.g., a touch screen), or in the alternative, a visual indicator (e.g., LED lights of one or more colors). In one example, the output system 270 may include an audio output system 274 (e.g., a speaker, an alarm system, etc.) that can provide an audio signal. The output system 270 may provide one or more outputs (e.g., an LED light of a first color, a first message on the screen, an alarm sound of a first tone) to indicate that a desired therapeutic effect (e.g., ablation of a stone structure such as a kidney stone, or carbonization of abnormal tissue such as cancerous tissue) has been achieved. In some examples, the output system 270 may provide one or more different outputs when a desired therapeutic effect has not been achieved. For example, the output system 270 may provide one or more outputs (e.g., an LED light of a second color, a second message on the screen, an alarm sound of a second tone) to indicate that a desired therapeutic effect has not been achieved. In some examples, therapeutic effects on different identified structure categories (e.g., stone structure vs. anatomical structure) or different classified structure types may be indicated in the output system 270 using different outputs (e.g., LED lights of different colors, different messages on the screen, or different tones of an alarm), respectively.Such an output may prompt an operator (e.g., a medical professional) to take appropriate action, such as providing additional treatment using one or more laser systems.

[0086] 3A-3B show an example of an acoustic signal generated in response to delivery of laser energy and acoustic characteristics extracted from the acoustic signal. FIG. 3A shows an example of a portion of an endoscopic laser lithotripsy system including an endoscope 301 and an optical path 302 disposed at least partially within a longitudinal passageway of the endoscope 301. In the example shown in FIG. 3A, the optical path 302, which is an example of the first optical path 108 or the second optical path 118, has a distal end 304 extending from the distal end of the endoscope 301. In one example, the optical path 302 may include an optical fiber or laser fiber. Laser pulses, such as those generated from the first laser source 106 or the second laser source 116, may be transmitted through the optical path 302. The distal end 304 of the optical path 302 may direct the laser pulses to a stone target 322.

[0087] FIG. 3B begins at time t0 and continues at time t E3B shows an example of an acoustic signal 350 as sensed by the acoustic sensor 241 in response to a laser pulse 340 that terminates at t0. As the laser pulse propagates through the liquid medium 332 and the vapor bubble 334, the liquid and vapor absorb the laser energy and vibrate, generating a pressure wave that can be sensed by the acoustic sensor as an acoustic signal. As shown in FIG. 3B, the acoustic signal 350 has a time-varying signal intensity with a first peak 351 at t1 corresponding to maximum liquid vibration and a second peak 353 at t2 corresponding to maximum vapor vibration. When the laser pulse reaches the target, the stone target 322 absorbs the laser energy and vibrates, generating a pressure wave that can be sensed by the acoustic sensor as an acoustic signal peak 355 at t3. The time intervals from t0 to the acoustic signal peaks 351, 353, and 355 (i.e., t1-t0, t2-t0, and t3-t0) correlate to the distance traveled by the laser pulse along the propagation path from the optical path distal end 304. According to various examples described in this disclosure, such time intervals can be used to control the delivery of laser energy.

[0088] The acoustic signal 350 may be processed, such as by the feedback analyzer 240, to generate one or more acoustic characteristics, including, for example, the intensity, power, frequency or spectral content, or graphical features or shapes of the received acoustic signal. In some examples, the acoustic characteristics may include one or more statistical features of the acoustic signal (e.g., the signal mean or variance). The controller circuit 260 may adjust the irradiation parameter settings based on the one or more acoustic characteristics. For example, the intensity of the acoustic signal generated in response to the laser firing at the target stone structure (e.g., the amplitude of the acoustic signal peak 355) correlates to the laser power density. The controller circuit 260 may automatically adjust the irradiation parameter settings (e.g., power, power density, pulse parameters, irradiation time, total dose, or energy) and / or adjust the position or orientation of the laser fiber to achieve the desired acoustic signal intensity, such as to maximize the amplitude of the acoustic signal peak 355.

[0089] In some examples, the controller circuit 260 may adjust the irradiation parameter settings and / or the position or orientation of the laser fiber based on identification of the stone target 322 as one of multiple stone types having distinct compositions using one or more acoustic features generated from the acoustic signal, such as by using the target detector 246 and / or the target classifier 248.

[0090] In some examples, the controller circuit 260 may calculate or estimate the fiber-target distance using one or more acoustic characteristics derived from the acoustic signal, such as time information for an acoustic signal peak corresponding to a laser firing at the target. For example, the time interval between t0 and t3 (t3-t0) represents the laser pulse travel time from the laser fiber distal end 304 to the target 322, which correlates to the laser-target distance. The controller circuit 260 may estimate the fiber-target distance using the interval t3-t0. The controller circuit 260 may generate a control signal to an actuator to automatically adjust the laser fiber position relative to the target, such as to obtain or maintain a desired fiber-target distance.

[0091] 4 shows an example of an endoscopic laser lithotripsy system 400 that uses an acoustic feedback signal to control and adjust the position of an optical path 302 (such as a laser fiber) relative to the distal end of an endoscope 301. The endoscope 301 may include a proximal portion and an elongated distal portion that may be configured to be inserted into a patient, such as through an orifice or incision. The endoscope 301 may be useful for providing visual inspection or treatment of soft (e.g., non-calcified) or hard (e.g., calcified) tissue, as well as for visualizing or destroying or otherwise treating kidney stones or other stones or other targets.

[0092] The lithotripsy system 400 may include or be coupled to at least one laser source 430, which may be an example of the first laser source 106 or the second laser source 116. The laser source 430 may be mechanically or optically connected to an optical pathway 302, which may include a single optical fiber or a bundle of optical fibers. The optical pathway 302 may be introduced through a proximal access port to extend into a working channel or other longitudinal passageway or lumen of an endoscope 301 or similar instrument.

[0093] Endoscope 301 may include or provide visualization and illumination optics, such as visualization optical path 460 and illumination optical path 450, each of which may extend longitudinally along the elongated body of endoscope 301. An eyepiece or camera or imaging display may be provided in or coupled to visualization optical path 460 to enable user or machine visualization of a target area at or near the distal end of endoscope 301. The target area may be illuminated by light 470 provided by an illumination source at the proximal end of illumination optical path 450, emitted from the distal end of illumination optical path 450, or emitted from an LED or other illumination source that may be located at or near the distal end of the endoscope, such as having longitudinally extending electrical conductors for providing power.

[0094] The lithotripsy system 400 may include an actuator 485 that may actuate longitudinal translation of the distal end 304 of the optical path 302 within and relative to a longitudinal passage of the endoscope 301, such as according to control signals generated by the controller circuit 260. The controller circuit 260 may be in electrical communication with the actuator 485. The actuator 485 may be disposed at or near the distal end of the endoscope 301. In one example, the actuator 185 may include one or more of an electromagnetic element, an electrostatic element, a piezoelectric element, or other actuating element to actuate or otherwise enable longitudinal positioning of the distal end 304 of the optical path 302 relative to a working channel or other longitudinal passage of the endoscope 301, or relative to another reference position for which the endoscope 301 may serve as a reference frame.

[0095] The lithotripsy system 400 may include an acoustic sensor 241 configured to detect an acoustic signal in response to delivery of laser energy to the target. As discussed above with reference to FIG. 2, the acoustic signal may be sensed when the laser pulse propagates through a medium (e.g., liquid and vapor) along a path to the target, vibrating the liquid and vapor, as well as when the laser pulse impinges on the target, vibrating the target. The acoustic sensor 241 may be disposed within the endoscope 301 or otherwise associated with the endoscope 301. In an example such as shown in FIG. 4, the acoustic sensor 241 may be attached to a distal portion of the endoscope 301. In another example, the acoustic sensor 241 may be disposed at the distal end 304 of the optical path 302 (e.g., the laser fiber). The sensed acoustic signal may be transmitted to the feedback analyzer 240 via the optical path 302. In some examples, the sensed acoustic signal may additionally or alternatively be transmitted via another path different from the optical path 302, such as the illumination optical path 450, the visualization optical path 460, or a dedicated acoustic signal path.

[0096] The controller circuit 260 may use one or more acoustic characteristics to adjust the irradiation parameter settings (e.g., wavelength, power, power density, pulse parameters, irradiation time, total dose, or energy, among others). For example, the controller circuit 260 may automatically adjust the irradiation parameter settings and / or the position or orientation of the laser fiber to achieve a desired acoustic signal amplitude, such as to maximize the amplitude of the acoustic signal peak 355, as shown in FIG. 3B.

[0097] In some examples, the feedback analyzer 240 may generate one or more acoustic characteristics from the acoustic signal to recognize the target structure as a stone structure category or anatomy structure category (e.g., soft tissue or hard tissue), as discussed above with reference to Figure 2. The controller circuit 260 may adjust the irradiation parameter settings and / or the position or orientation of the laser fiber based on the identification of the stone target 322 as one of multiple stone types having distinct compositions using the one or more acoustic characteristics generated from the acoustic signal, such as by using the target detector 246 and / or the target classifier 248.

[0098] In some examples, the feedback analyzer 240 may calculate or estimate the distance between the distal end of the optical path 302 and the target (the "fiber-target distance") using one or more acoustic characteristics, such as time information for acoustic signal peaks corresponding to laser-target interactions, as discussed above with reference to FIGS. 3A-3B. The controller circuit 260 may control the actuator 485 to adjust the position or orientation of the fiber distal end 304 based on the calculated fiber-target distance. For example, if the calculated distance exceeds the desired laser launch range (within a specified margin), the controller circuit 260 may generate a control signal to the actuator 485 to move the optical path 302 longitudinally toward the target until the fiber distal end 304 arrives within the desired laser launch range relative to the target.

[0099] In some examples, the feedback analyzer 240 may receive additional feedback from the target and use such additional feedback together with the acoustic feedback to perform one or more of the following operations: identifying the target structure type, estimating the fiber-target distance, adjusting the illumination parameter settings, and controlling the laser source 430 to deliver laser energy according to the adjusted illumination parameter settings, or controlling the actuator 485 to longitudinally move the distal portion of the optical path 302 to achieve the desired fiber-target distance. In an example such as shown in FIG. 4, the lithotripsy system 400 may include an endoscopic camera or imaging device 425 that may collect an imaging signal reflected from the target in response to the electromagnetic radiation (e.g., the illumination light 470) of the target. The imaging signal may be transmitted to the feedback analyzer 240 through the optical path 460. Alternatively, the imaging signal reflected from the target may be transmitted through the optical path 302. An optical splitter may direct the reflected imaging signal to the feedback analyzer 240. The feedback analyzer 240 may include a spectrometer that may generate one or more spectroscopic signatures from the imaging data. The feedback analyzer 240 may use the spectroscopic signatures to recognize the target as a stone structure or an anatomical structure, or to classify the target as a type of tissue of distinct composition or a type of stone. The feedback analyzer 240 may use the spectroscopic signatures to calculate or estimate the fiber-to-target distance, an example of which is discussed below with reference to FIG. 5.

[0100] The controller circuit 260 may use the one or more spectral characteristics to adjust the illumination parameter settings. The controller circuit 260 may control the actuator 485 to adjust the position or orientation of the fiber distal end 304 based on the calculated distance.

[0101] In some examples, the feedback analyzer 240 may measure the laser spot size on the target from an image of the corresponding portion of the target as captured by the endoscopic camera or imaging device 425. The laser spot size, such as the diameter or area of ​​a circular laser spot, correlates to the fiber-to-target distance. A larger spot size corresponds to a longer fiber-to-target distance and a smaller spot size corresponds to a shorter fiber-to-target distance. Based on the laser spot size, the controller circuit 260 may generate a control signal to an actuator to actuate a longitudinal translation of the optical path 302, such as to adjust the position of the fiber distal end 304 relative to the target, such as to obtain or maintain a desired laser spot size.

[0102] FIG. 5 illustrates a calibration curve 500 that represents the relationship between the spectroscopic reflected signal intensity (e.g., the spectroscopic signal reflected from a target structure in response to electromagnetic radiation) and the distance between the distal end of the fiber and the target structure ("fiber-target distance") using a feedback signal reflected from the target structure. The calibration curve 500 can be generated by measuring the reflected light intensity at different distances between the tissue and the spectroscopic probe distal end when the target structure is projected by electromagnetic radiation at a particular wavelength (e.g., 450 nm or 730 nm). By reference to the calibration curve, analysis of the spectroscopic signal allows for a quick estimation of the distance.

[0103] An exemplary process for generating a calibration curve is as follows. First, a reference value for each distance may be calculated. Since the light reflection intensity depends on the reflectance of the sample, etc., the calibration curve itself may not be usable to identify the distance. An example of a reference value for canceling the effect of the reflectance of the sample is as follows: Reference value = dI / dx*1 / I (1)

[0104] During the in vivo surgical process, the operator may move the fiber or endoscope while continuously recording spectroscopic feedback until the reflectance spectrum of the target tissue composition can be detected.

[0105] Referring to FIG. 5, a first spectrum may be measured at a distance x1 where the reflected light intensity is I1. At this point, the actual value of x1 and the curve of the reflected signal intensity are unknown. Then, the distal end of the fiber or endoscope (the reflected light detector) may be moved continuously and the next reflected light intensity I2 corresponding to a distance x2 may be measured. x2 may be close to x1 such that the curve between x1 and x2 may be approximated as a straight line. At this point, x1, x2, and the curve of the reflected signal intensity are unknown. A comparison value may be calculated using I1, I2, and delta(x2-x1) as follows: Comparison value = delta(I2-I1) / delta(x2-x1)*1 / I1(2)

[0106] The reference value is then searched for one that is identical to the comparison value. The reference value (x r ), if there is exactly one x r can be determined as the distance between the two reference values ​​(x r1 , x r2 ), the distal end of the fiber or endoscope (the reflected light detector) can continue to be moved and the next reflected light intensity I3 corresponding to distance x3 can be measured. x3 may be close to x2 such that the curve between x2 and x3 can be approximated as a straight line. At this point, x1, x2, x3, and the curve of the reflected signal intensity are unknown. A new comparison value can be calculated using I1, I2, I3, delta(x2-x1), and delta(x3-x2) as follows: Comparison value = delta(I3-I2) / delta(x3-x2)*1 / I2(3)

[0107] Then, the reference value is x r1 +delta(x2-x1) and x r2 +delta(x2-x1). The reference value may be compared to the comparison value given in equation (3). The distance for which the reference value is closer to the comparison value is estimated as the actual distance.

[0108] During a surgical process in vivo, an exemplary method may include moving the fiber or endoscope while continuously recording the spectroscopic feedback until a reflected spectrum of the target composition is detected. In the main case when the distal end of the spectrometer is moving towards the target, the intensity of the detected reflected light is initially weak and increases as the distance between the target and the end of the fiber decreases. For example, a first spectrum was measured at a distance d1 where the reflected light intensity is I1. The distal end of the fiber or endoscope may continue to move slightly towards the target while continuously collecting the reflected data, and the method may measure the next reflected light intensity I2 corresponding to the distance d2. The method may then include the calculation of a value of the change in the reflected signal: slope=delta(I2-I1) / delta(d2-d1) [1]. To make the value of the calculated slope independent of the reflected light intensity, the calculated slope may be normalized. The final formula for calculating the slope of the reflected light at a measured distance is: Gradient(normalized)=[delta(I2-I1) / delta(d2-d1)] / I0(4) where I0 = average(I1,I2).

[0109] The method can then compare the calculated slope to that on a calibration curve in the library to allow the required distance to be estimated. All calculations can be done quickly using software.

[0110] FIG. 6 is a flow chart illustrating a method 600 for controlling a laser system to deliver a laser beam to a target structure within a subject's body, such as an anatomical structure (e.g., soft tissue, hard tissue, or abnormal tissue such as cancerous tissue) or a stone structure (e.g., a kidney stone, a pancreaticobiliary stone, or a gallbladder stone). The method 600 may be implemented and performed by a laser energy delivery system, such as the laser energy delivery system 100, or a variation thereof, such as the laser feedback control system 200 or the lithotripsy system 400. Although the processes of the method 600 are depicted in one flow chart, they need not be performed in a particular order. In various examples, some of the processes may be performed in a different order than that shown herein.

[0111] At 610, laser energy (e.g., a laser beam or pulse) is delivered to the target. The laser energy may be generated from a laser source, such as the first laser source 106 or the second laser source 116, and transmitted via an optical path, such as the first optical path 108 or the second optical path 118, or a variation thereof, such as the signal transmission path 280, as described above with reference to FIGs. 1 and 2.

[0112] At 620, an acoustic signal may be sensed in response to the delivery of the laser energy. As the laser pulse propagates through the medium (e.g., liquid and vapor) along the path to the target, the liquid and vapor absorb the laser energy and vibrate. When the laser pulse reaches the target, the target absorbs the laser energy and vibrates. The vibration of the liquid and vapor medium, as well as the vibration of the target structure, generate respective pressure waves that may be sensed as an acoustic signal. An example of an acoustic signal in response to the laser energy passing through the medium and interacting with the target is shown in FIGS. 3A-3B. As discussed above with reference to FIG. 2, the acoustic sensor may include, among others, a microphone, a hydrophone, a capacitance sensor, a piezoelectric sensor, a piezoelectric ceramic sensor, a fiber optic sensor, or a solid-state acoustic detector. The acoustic sensor may be disposed within or otherwise associated with the endoscope, such as in one example, a distal portion of the endoscope. The acoustic sensor may alternatively be disposed in a distal portion of the optical path (e.g., laser fiber), such as the distal end 304 of the optical path 302.

[0113] At 630, the acoustic signal may be analyzed to extract one or more acoustic characteristics. The acoustic signal may be transmitted through the same optical path for transmitting the laser pulses, as described above with reference to FIG. 4, or through a separate, different path, such as an illumination optical path or a visualization optical path. Examples of acoustic characteristics may include the intensity, power, frequency or spectral content, or graphical features or shapes of the received acoustic signal. In some examples, the acoustic characteristics may include one or more statistical characteristics of the acoustic signal (e.g., the mean or variance of the signal).

[0114] The one or more acoustic characteristics may be used to control laser energy delivery in several ways. At 640, the laser energy output may be adjusted, such as via the controller circuit 260, based on the one or more acoustic characteristics. For example, the acoustic signal strength (e.g., amplitude) correlates to the laser power density. The controller circuit 260 may automatically adjust the irradiation parameter settings (e.g., power, power density, pulse parameters, irradiation time, total dose, or energy) to achieve the desired acoustic signal strength, such as to maximize the amplitude of the acoustic signal peak 355, as shown in FIG. 3B.

[0115] In some examples, one or more acoustic characteristics may be used to identify a target type. As discussed above with reference to FIG. 2, for a tissue target or stone target, its ability to absorb laser energy depends on its composition and liquid content. Different target types, such as different stone structures or soft or hard tissues, may have different compositions and / or liquid contents. If these targets absorb different amounts of laser energy, they may generate different vibration patterns that may be sensed as different acoustic characteristics. One or more acoustic signal characteristics may be used to identify the target as one of a plurality of structure categories, such as a stone structure category or an anatomical structure category, such as by using the target detector 246. In addition, one or more acoustic signal characteristics may be used to classify the target as one of a plurality of structure types of the same category, such as a specific tissue type within an identified category of an anatomical structure or a specific stone type within an identified category of a stone structure, such as by using the target classifier 248. The laser illumination parameter settings may be adjusted based on the identified target type.

[0116] In addition to or instead of adjusting the laser energy output, at 650, one or more acoustic properties may be used to automatically adjust the position or orientation of a distal portion of an optical path (e.g., laser fiber) for delivering laser pulses, such as to change the distance between the distal end of the laser fiber and the target ("fiber-target distance"). The adjustment may be accomplished via an actuator, such as actuator 485 shown in FIG. 4, which may actuate longitudinal translation of the distal end of the optical path (e.g., laser fiber) within and relative to the longitudinal passage of the endoscope in accordance with control signals generated by the controller circuit 260. In one example, adjustment of the position or orientation of the distal portion of the optical path (e.g., distal end 304 of optical path 302) may be performed in conjunction with adjustment of the laser energy output (e.g., adjustment of the illumination parameter settings) to obtain or maintain a desired acoustic signal amplitude, such as to maximize the amplitude of acoustic signal peak 355.

[0117] In some examples, one or more acoustic characteristics may be used to calculate or estimate the fiber-target distance. Using the estimated fiber-target distance as a feedback signal, the laser fiber position may be adjusted such that the target is within the desired laser firing distance. One example of such an acoustic characteristic is a time interval (t3-t0) as shown in FIG. 3B, which represents the laser pulse travel time from the laser fiber distal end 304 to the target 322. Such a time interval may be correlated to the fiber-target distance and used to estimate the fiber-target distance. A control signal, such as generated by the controller circuit 260, may control an actuator to automatically adjust the laser fiber position, such as to obtain or maintain the desired time interval t3-t0.

[0118] In some examples, additional feedback (different from acoustic feedback) may be used to control an actuator to adjust the laser energy output at 540 and / or adjust the position or orientation of the distal end of the optical path. Examples of such additional feedback may include, for example, one or more spectroscopic signal characteristics generated from the spectroscopic signal or one or more imaging characteristics generated from the imaging signal. In some examples, such additional feedback may be used to distinguish different target types, such as according to various examples as discussed above with reference to FIG. 2. In some examples, such additional feedback may be used to calculate or estimate a fiber-target distance, such as according to various examples as discussed above with reference to FIG. 5. The distinction between different target types and the estimated fiber-target distance may be used by the controller circuit 260, etc., to controllably adjust the laser energy output at 650 and / or to controllably adjust the position of a distal portion of the optical path that directs the laser energy to the target.

[0119] 7 generally illustrates a block diagram of an example machine 700 on which any one or more of the techniques (e.g., methodologies) discussed herein may be executed. Portions of this description may apply to the computing framework of various parts of the laser energy delivery system 100 (e.g., the laser feedback control system 101) or the laser feedback control system 200.

[0120] In alternative embodiments, machine 700 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a network deployment, machine 700 may operate in the capacity of a server machine, a client machine, or both in a server-client network environment. In one example, machine 700 may function as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. Machine 700 may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), mobile phone, web appliance, network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by the machine. Furthermore, although only a single machine is shown, the term "machine" shall be construed to include any collection of machines that individually or jointly execute a set (or sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations, etc.

[0121] The examples described herein may include or operate by logic or some components or mechanisms. A circuit set is a collection of circuits implemented in a tangible entity that includes hardware (e.g., simple circuits, gates, logic, etc.). The membership of a circuit set may be flexible over time and variations in the underlying hardware. A circuit set includes members that may perform specified operations alone or in combination when in operation. In one example, the hardware of a circuit set may be universally designed (e.g., hardwired) to perform a particular operation. In one example, the hardware of a circuit set may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) that include computer-readable media that are physically modified (e.g., magnetic, electrical, movable arrangements of particles of invariable mass, etc.) to encode instructions for a particular operation. In connecting the physical components, the underlying electrical properties of the hardware components are changed, for example, from insulators to conductors or vice versa. The instructions enable the embedded hardware (e.g., execution units or loading mechanisms) to create the members of the circuit set in the hardware through the variable connections to perform some of the particular operations when in operation. Thus, the computer-readable medium is communicatively coupled to other components of the circuit set members when the device is operating. In one example, any of the physical components may be used in more than one member of more than one circuit set. For example, during operation, an execution unit may be used in a first circuit of a first circuit set at one time and reused by a second circuit in the first circuit set or by a third circuit in the second circuit set at a different time.

[0122] The machine (e.g., computer system) 700 may include a hardware processor 702 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 704, and a static memory 706, some or all of which may communicate with each other via an interlink (e.g., a bus) 708. The machine 700 may further include a display unit 710 (e.g., a raster display, a vector display, a holographic display, etc.), an alphanumeric input device 712 (e.g., a keyboard), and a user interface (UI) navigation device 714 (e.g., a mouse). In one example, the display unit 710, the input device 712, and the UI navigation device 714 may be touch screen displays. The machine 700 may additionally include a storage device (e.g., a drive unit) 716, a signal generation device 718 (e.g., a speaker), a network interface device 720, and one or more sensors 721, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensor. The machine 700 may include an output controller 728, 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, for communicating with or controlling one or more peripheral devices (e.g., a printer, card reader, etc.).

[0123] The storage device 716 may include a machine-readable medium 722 on which one or more sets of data structures or instructions 724 (e.g., software) are stored that embody or are utilized by any one or more of the techniques or functions described herein. The instructions 724 may also reside, completely or at least partially, within the main memory 704, within the static memory 706, or within the hardware processor 702 during its execution by the machine 700. In one example, one or any combination of the hardware processor 702, the main memory 704, the static memory 706, or the storage device 716 may constitute a machine-readable medium.

[0124] Although the machine-readable medium 722 is illustrated as a single medium, the term “machine-readable medium” may 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 724.

[0125] The term "machine-readable medium" may include any medium capable of storing, encoding, or carrying instructions for execution by the machine 700 and causing the machine 700 to perform any one or more of the techniques of this disclosure, or any medium capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memory, as well as optical and magnetic media. In one example, a massive machine-readable medium comprises a machine-readable medium having a plurality of particles having an unchanging (e.g., stationary) mass. Thus, a massive machine-readable medium is not a transitory propagating signal. Specific examples of massive machine-readable media may include non-volatile memory such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks.

[0126] The instructions 724 may further be transmitted or received over a communications network 726 using a transmission medium via the network interface device 720 utilizing any one of a number of transport protocols (e.g., Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.). Exemplary communications 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), plain old telephone (POTS) networks, and wireless data networks (e.g., the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, the IEEE 802.16 family of standards known as Wi-Max®), the IEEE 802.15.4 family of standards, peer-to-peer (P2P) networks, among others. In one example, the network interface device 720 may include one or more physical jacks (e.g., Ethernet jacks, coaxial jacks, or telephone jacks) or one or more antennas for connecting to a communications network 726. In one example, the network interface device 720 may include multiple antennas for wireless communication using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term "transmission medium" shall be taken to include any intangible medium, including digital or analog communications signals or other intangible media, capable of storing, encoding, or carrying instructions for execution by the machine 700 and facilitating communication of such software.

[0127] Additional Notes The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Furthermore, the inventors also contemplate examples that use any combination or permutation of those elements (or one or more aspects thereof) shown or described with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0128] In this document, the terms "a" or "an" are used to include one or more, as is common in patent documents, regardless of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a non-exclusive or, such as "A or B" including "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "comprising" and "comprising" are open-ended, i.e., a system, device, article, composition, formulation, or process that includes elements in addition to the elements listed after such terms in the claim will still be considered within the scope of that claim. Moreover, in the following claims, terms such as "first," "second," and "third" are used merely as labels and are not intended to impose numerical requirements on their objects.

[0129] The above description is intended to be illustrative and not limiting. For example, the examples described above (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used by those of ordinary skill in the art upon reviewing the above description. The Abstract is provided to enable the reader to quickly ascertain the nature of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Accordingly, the following claims are hereby incorporated into the Detailed Description as an example or embodiment, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. [Explanation of symbols]

[0130] 100 Laser Energy Delivery System 101 Laser Feedback Control System 102 Laser system, first laser system 104 Second Laser System 106 First Laser Source 108 First Optical Path 110 First Output 116 Second Laser Source 118 Second Optical Path 120 Second Output 122 Target structure 130 Feedback Signal 200 Laser Feedback Control System 202 Laser System 240 Feedback Analyzer 241 Acoustic Sensor 242 Spectroscopic Sensor 244 Image Sensor 246 Target Detector 248 Target classifier, classifier 250 Memory 260 Controller Circuit 270 Output System 272 Display 274 Auditory Output System 280 Signal Transmission Path 301 Endoscope 302 Optical Path 304 distal end, optical path distal end, fiber distal end 322 Stone target 332 Liquid medium 334 Steam Bubble 340 Laser Pulse 350 Acoustic Signals 351 First peak, acoustic signal peak 353 Second peak, acoustic signal peak 355 Acoustic Signal Peaks 400 Endoscopic Laser Lithotripsy System, Lithotripsy System 425 Endoscopic camera or imaging device 430 Laser Source 450 Illumination Optical Path 460 Visualization Optical Path 470 Light, Illumination 485 Actuator 500 Calibration Curves 700 Machines 702 Hardware Processor 704 Main Memory 706 Static Memory 708 Interlink 710 Display Unit 712 Alphanumeric input device, input device 714 User Interface (UI) Navigation Devices, UI Navigation Devices 716 Storage Devices 718 Signal Generating Devices 720 Network Interface Device 721 Sensors 722 Machine-Readable Media 724 Command 728 Output Controller

Claims

1. a laser system configured to direct laser energy to a target within the subject; receiving an acoustic signal resulting from delivery of laser energy to the target; measuring one or more acoustic characteristics from the received acoustic signal; identifying the target as one of a plurality of structure types based at least in part on the one or more measured acoustic characteristics; Generate a first control signal for controlling the laser system to generate laser energy for delivery to the target based on the identification of the target. A feedback controller circuit configured as follows:

1. An endoscopic laser energy delivery system comprising:

2. the feedback controller circuit is configured to generate the first control signal to the laser system to adjust laser firing parameter settings based on the one or more acoustic characteristics; the laser system is configured to generate laser energy in accordance with the adjusted laser irradiation parameter settings; 10. An endoscopic laser energy delivery system as defined in claim 1.

3. 3. An endoscopic laser energy delivery system as described in claim 1 or 2, comprising an acoustic sensor configured to sense the acoustic signal, the acoustic sensor communicatively coupled to the feedback controller circuit.

4. 4. The endoscopic laser energy delivery system of claim 3, wherein the acoustic sensor is configured to be mounted to a distal portion of an endoscope.

5. 5. An endoscopic laser energy delivery system as described in claim 3 or 4, wherein the acoustic sensor comprises a piezoelectric sensor.

6. 5. An endoscopic laser energy delivery system as described in claim 3 or 4, wherein the acoustic sensor includes a microphone.

7. 7. An endoscopic laser energy delivery system according to any one of claims 1 to 6, wherein the one or more acoustic characteristics include acoustic signal strength.

8. 8. An endoscopic laser energy delivery system as described in any one of claims 1 to 7, wherein the one or more acoustic characteristics include an acoustic signal shape characteristic.

9. 9. An endoscopic laser energy delivery system as described in any one of claims 1 to 8, wherein the one or more acoustic characteristics include a frequency or spectral content of the received acoustic signal.

10. 10. An endoscopic laser energy delivery system as described in any one of claims 1 to 9, wherein the feedback controller circuit is configured to measure one or more spectroscopic characteristics of the target and to identify the target as one of a plurality of structure types further based on the measured one or more spectroscopic characteristics.

11. The method of claim 1, wherein identifying the target comprises classifying the target as one of a plurality of stone types, each having a distinct composition, based at least in part on the measured one or more acoustic properties; the feedback controller circuit is configured to adjust laser delivery parameter settings based on the classification of the target and generate the first control signal to the laser system to deliver laser energy to the target of the classified stone type in accordance with the adjusted laser delivery parameter settings.

11. An endoscopic laser energy delivery system according to any one of claims 1 to 10.

12. The method of claim 1, wherein identifying the target includes classifying the target as one of a plurality of tissue types based at least in part on the measured one or more acoustic properties; the feedback controller circuit is configured to generate the first control signal to the laser system to deliver or withhold the laser energy according to the classified tissue type.

12. An endoscopic laser energy delivery system according to any one of claims 1 to 11.

13. 13. The endoscopic laser energy delivery system of claim 12, wherein the feedback controller circuit is configured to generate the first control signal to the laser system to classify the target as a treatment area or a non-treatment area and to deliver laser energy to the treatment area and to withhold delivery of laser energy to the non-treatment area.

14. 13. The endoscopic laser energy delivery system of claim 12, wherein the feedback controller circuit is configured to generate the first control signal to the laser system to classify the target as normal tissue or cancerous tissue, deliver laser energy to the target of the classified cancerous tissue, and withhold delivery of laser energy if the target is classified as normal tissue.

15. An endoscopic laser energy delivery system as described in any one of claims 1 to 14, comprising a laser fiber coupled to the laser system and configured to transmit laser energy to the target.

16. An endoscopic laser energy delivery system as described in any one of claims 1 to 15, comprising an optical path configured to transmit the acoustic signal to the feedback controller circuit.

17. The feedback controller circuit comprises: calculating a distance between a distal end of the optical path and the target using the received acoustic signal; generating a second control signal to actuate an actuator to longitudinally translate the optical path based on the calculated distance between the distal end of the optical path and the target; It was configured as follows:

17. An endoscopic laser energy delivery system as defined in claim 16.

18. The feedback controller circuit comprises: measuring a laser spot size on the target from an image of the target in response to the delivery of laser energy to the target; Generate a second control signal to actuate an actuator to longitudinally translate the optical path to achieve a desired laser spot size on the target. It was configured as follows:

17. An endoscopic laser energy delivery system as defined in claim 16.

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