System for monitoring temperature during intracorporeal laser lithotripsy procedures

Abstract

To provide a system for monitoring temperature during laser beam-based lithotripsy.SOLUTION: A system includes a module part 9. The module part includes: a flow rate sensor 10 which is attachable side by side with an irrigation fluid channel and determines an irrigation fluid quantity without contacting the irrigation fluid; input means 13 which is connected to a processing part 12 and is capable of transmitting to the processing part an operation parameter of laser to become a basis for determining laser output that can be irradiated to a position of a light emission port 4; a temperature sensor 11 which is attachable side by side with the irrigation fluid channel and determines temperature of the irrigation fluid without contacting the irrigation fluid; an analysis part 14 which is fitted to the processing part and numerically determines temperature T generated in the body during laser lithotripsy at a position of the light emission port on the basis of at least the irrigation fluid quantity, temperature (TS) of the irrigation fluid, and the determined irradiation laser output; and a comparison part 15 which compares the determined temperature T with threshold and generates a signal when the temperature is over the threshold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for monitoring temperature during laser light-based intracorporeal lithotripsy procedures that employs an endoscopic assembly that includes a working channel for a fiber optic cable optically connected proximally to a laser and having a light exit distally, and an irrigation fluid channel that opens distally into the region of the light exit and is in fluid communication proximally with an irrigation fluid reservoir. [Background technology]

[0002] Intracellular lithotripsy is a minimally invasive procedure for breaking up stones, such as gallstones, urinary stones, or kidney stones, which primarily accumulate in the excretory ducts of affected organs and can cause severe pain as well as other medical problems. Among the many known intracellular lithotripsy procedures, laser-induced lithotripsy has become an established treatment method, in which a high-energy laser beam is directed via a fiber optic cable in the form of laser pulses at the location of the stone to be fragmented. When the laser pulses interact with the body's internal media, they form vapor bubbles. These pulsed expansions generate pressure waves, which cause the stone to fragment. Depending on their size, stone fragments created by laser-induced lithotripsy can be naturally excreted or extracted with an appropriately configured endoscopic grasper.

[0003] Endoscopes are used to perform laser-based lithotripsy. They are optically connected to a laser at a proximal end and have at least one working channel for a fiber optic cable with a distal optical exit. To allow the endoscope to follow the underlying access path to the stone and to minimize patient discomfort during the procedure, these endoscopes may be soft and flexible. Additionally, irrigation fluid can often be applied through these endoscopes via a working channel that opens distally into the area of ​​the optical exit and is in fluid communication proximally with an irrigation fluid supply and reservoir, preferably in the form of an irrigation syringe and / or a controllable or adjustable supply pump.

[0004] Using this type of endoscope assembly, which includes an endoscope and the aforementioned peripheral devices connected to it, the laser power emitted inside the body at the location of the stone to be fragmented and the amount of irrigation fluid released into the distal irrigation channel must be coordinated to ensure effective stone fragmentation on the one hand, and to avoid local overheating of the surrounding tissue area by the laser light, which could cause irreversible tissue damage on the other hand. In most cases, this type of endoscope is equipped with additional glass fiber optics or an image sensor at the tip of the endoscope for the operator. The tip of the endoscope must be kept optically clear using a metered delivery of irrigation fluid to guarantee the operator a clear view for monitoring the fragmentation process.

[0005] US Patent No. 5,949,999 describes an endoscope assembly of this type for performing laser light-based lithotripsy, having an associated irrigation fluid supply that can be adjusted depending on at least one parameter influencing the lithotripsy process, i.e., the irrigation flow rate is influenced depending on the lithotripsy process. In addition to optical monitoring of the lithotripsy process, known endoscope assemblies are provided with a temperature sensor attached to the tip of the endoscope that can detect the distal temperature of the surrounding fluid, and the irrigation fluid supply is limited accordingly in order to adjust the irrigation fluid flow rate.

[0006] Even in the case of the known medical endoscope according to US Pat. No. 5,629,999, which is suitable for performing laser light-based lithotripsy, an ambient temperature sensor is provided in the distal region of the endoscope for temperature measurement purposes. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2018 / 0055568 [Patent Document 2] German Utility Model No. 202017102316 Summary of the Invention [Problem to be solved by the invention]

[0008] An endoscope assembly equipped with such sensors constitutes a highly complex medical device that must undergo extensive medical-technical approval and testing over a long period of time. [Means for solving the problem]

[0009] The object of the present invention is to further develop a system for monitoring temperatures during the performance of laser-based lithotripsy employing an endoscope assembly comprising a working channel for a fiber optic cable optically connected to a laser at its proximal end and having a light outlet at its distal end, and an irrigation fluid channel opening distally into the region of the light outlet and fluidly connected proximally to an irrigation fluid reservoir, so as to enable such monitored intracorporeal lithotripsy to be performed without the need for excessive costs and time for medico-technical testing or approval. There is a need for means by which appropriately selected components can be retrofitted into other medico-technical devices already in use, such as endoscopes, laser systems and irrigation fluid devices for passive and active irrigation, which are generally suitable for laser-based lithotripsy, in order to be able to exclude any thermally induced tissue deterioration that may occur in the area immediately surrounding the stone fragmentation site.

[0010] The solution to the basic object of the present invention is defined in claim 1. Features which further develop the inventive concept in an advantageous manner are formed by the subject matter of the dependent claims and the further description, in particular by reference to the exemplary embodiments.

[0011] Generally, intracorporeal laser applications without irrigation, i.e., without the supply of irrigation fluid in the area of ​​the distal optical exit of the fiber optic cable, are possible only for short periods of time, i.e., less than a few seconds, and in the absence of any additional cooling provided by irrigation, a critical temperature of approximately 42°C would be reached and exceeded, beyond which the surrounding tissue would be irreversibly thermally damaged. Consequently, irrigation during laser-based lithotripsy is essential to ensure sufficient cooling.

[0012] A reliable mathematical or theoretical relationship between the laser power delivered to the body, the irrigation fluid flow rate, the irrigation fluid temperature, and the internal body temperature generated during application of the laser pulses is known from numerous experiments with laser light-based lithotripsy that have been performed to date.

[0013] Based on this discovery, it is possible to combine a known endoscope having at least one working channel for a fiber optic cable optically connected to a laser at its proximal side and having an optical output at its distal side, and an irrigation fluid channel, which may be separate from or integral with the working channel and which opens distally into the region of the optical output and is fluidly connected proximally to an optional irrigation fluid supply and an irrigation fluid reservoir, with a modular section comprising at least one flow sensor and at least one temperature sensor, each detachably and fixedly mountable alongside the irrigation fluid channel and / or a supply line fluidly connected to the irrigation fluid channel, which are aligned with an extracorporeal region of the endoscope assembly. In this way, the flow sensor is configured and arranged so that the irrigation flow rate can be determined without contacting the irrigation fluid. At the same time, the temperature sensor is configured and mounted alongside the irrigation fluid channel and / or a supply line fluidly connected to the irrigation fluid channel so that the temperature of the irrigation fluid can be determined without contacting the irrigation fluid.

[0014] Furthermore, the module part comprises either an input means via which the operating parameters for the laser can be input and which can transmit the operating parameters for the laser to a processing part connected to the input means, or an interface via which the operating parameters for the laser can be directly transferred. The operating parameters for the laser preferably include the laser power, whereby the calculation of the laser power irradiated at the position of the light exit aperture can be calculated via the laser pulse frequency and the individual pulse energy.

[0015] Additionally, an analyzer is attached to the processor for numerically determining the temperature generated within the body during laser-based lithotripsy at the light outlet based on the irrigation flow rate obtained by the irrigation fluid sensor, the temperature obtained by the sensor, and the determined laser power applied within the body. A comparator, separate or integrated with the processor, compares the determined temperature with an adjustable threshold, e.g., 42°C, and generates a signal if the temperature exceeds the threshold.

[0016] Additionally, in a preferred embodiment, a signaling unit is provided that is wirelessly or hardwired connected to the comparison unit, so that the signal generated by the comparison unit can be tactile, audible and / or visually perceptible, allowing the physician performing the lithotripsy to be aware of potential internal overheating effects and to interrupt the lithotripsy procedure or take other measures.

[0017] The modular part according to the invention, which is preferably configured as a retrofit set or retrofit kit, exclusively comprises components that can be modularly attached to an endoscope assembly already in use, without impairing the general functionality of the endoscope assembly. The system according to the invention thus constitutes a safety system that assists the physician during the performance of laser-based lithotripsy, by which the physician receives reliable and trustworthy information that enables the lithotripsy treatment to be performed in an effective and patient-friendly manner.

[0018] The only information required in this regard is the current temperature of the irrigation fluid introduced into the body through the endoscope assembly by the working channel or irrigation channel, the laser power applied at the location of the stone to be fragmented, and the irrigation flow rate of the irrigation fluid introduced into the body through the working channel or irrigation channel at the location where the laser light is applied.

[0019] The sensors required for the irrigation fluid temperature and irrigation flow rate constitute structural elements detachably and fixedly attached to the irrigation fluid channels and / or supply lines fluidly connected to the irrigation fluid channels applied to the regions of the endoscope assembly not introduced into the body. Thus, preferably, the sensor for determining the irrigation flow rate is a flow sensor in the form of an ultrasonic sensor. A temperature sensor in the form of an infrared sensor appears suitable for obtaining the temperature of the irrigation fluid.

[0020] The operating parameters that can be specified for the laser required to determine the temperature generated at the optical exit of the fiber optic cable are the laser pulse frequency and the individual pulse energy, which can be provided by a suitably configured input means such as a keyboard or voice-operated input means or by a direct interface of the processor with the laser device.

[0021] The analysis unit attached to the computer unit determines the temperature T occurring at the position of the light exit port based on the following formula:

number

[0022] The mathematical relationship between the temperature generated in the body during laser-based lithotripsy at the laser application site, the applied laser power, the irrigation flow rate, and the temperature of the irrigation fluid has been established in numerous in vitro and ex vivo experiments.

[0023] Although the above algorithm shows a simple and formulaic relationship, the expected final internal temperature at the site of stone fragmentation during laser light-based lithotripsy can be predicted accurately enough by the above algorithm to eliminate localized overheating that could lead to irreversible tissue damage in the immediate vicinity of the laser light-based lithotripsy site.

[0024] If the laser unit does not have an interface for indicating laser operation, the module unit further comprises a microphone unit for detecting an acoustic signal indicative of laser operation, which is transmitted to the analysis unit for the purpose of signal analysis synchronized with the actual laser operation. In this way, during laser operation, the laser produces a clearly detectable acoustic signal which can be detected by the microphone unit in a time-resolved manner.

[0025] While the physician responsible for performing the lithotripsy procedure is the sole decision maker during laser light-based lithotripsy, in a further embodiment the modular part according to the invention comprises an additional emergency stop switch, i.e. in addition to the audible, visual and / or tactile signal emitting signal part, which signal can also cause a power cut-off of at least the laser source.

[0026] In a further preferred embodiment, the modular unit compatible with the endoscope assembly further comprises a unit for detecting the fill level of the irrigation fluid contained in the irrigation fluid reservoir. The unit may be configured as a sensor in the irrigation fluid reservoir and / or in the form of a software-based analytical algorithm implemented in the processing unit, which determines the current fill level based on the irrigation flow rate detected by the sensor and the measured duration between irrigation fluid release events. The sensor signal representing the fill level or a numerically determined fill level value representing the fill level serves at least to monitor the actual condition, to predict the time required to completely empty the irrigation fluid reservoir, or to warn when a minimum remaining amount is reached. The information thus obtained is made visible or audible to the physician by a suitable display. The display may be provided by a signal unit, via which the physician performing the lithotripsy procedure is warned of the effects of possible internal overheating, or by an additional display.

[0027] A further embodiment allows for additional monitoring of the temperature of the irrigation fluid being delivered. To this end, the temperature of the irrigation fluid (T S ) is preferably displayed as an alphanumeric value on the visual display. Furthermore, the measured temperature is preferably provided to a comparison unit or further comparison unit, where the temperature of the irrigation fluid (T S ) rises above or falls below a critical temperature value, a signal is generated that serves to alert the treating physician. As an example, if the irrigation fluid becomes too cold, a warning is issued to avoid the risk of the patient becoming hypothermic.

[0028] In a further possible embodiment, the irrigation fluid supply is provided with means capable of adjusting the flow rate of the irrigation fluid as a function of the temperature T occurring at the light exit and / or as a function of at least one operating parameter of the laser. This makes it possible to actively adjust the amount of irrigation fluid to the irrigation fluid supply in the form of a pump as a function of the applied laser light power and / or the calculated temperature in the intervention area.

[0029] The system for monitoring temperature during laser-based lithotripsy procedures according to the present invention can be used in various anatomical regions, such as the bladder, ureter, or renal pelvis region. Depending on the area of ​​application, different modes suitable for the intervention may be selected. In this regard, the system offers the choice of prostate, bladder, ureter, or renal pelvis modes, each distinguished by definable warning limits and stored characteristics. In this way, the individual risk spectrum for various procedures can be addressed.

[0030] Thus, the system can be used in any laser light-based procedure in the urological field, in particular laser lithotripsy, prostate removal (HoLEP, ThuLEP), laser vaporization (PVP) and interstitial laser coagulation (ILC). [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a diagram showing an endoscope 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] One drawing shows an endoscope 1 having a working channel for a fiber optic cable 2 that is optically connected to a laser 3 at its proximal side and has a light exit 4 at its distal side. Furthermore, the endoscope 1 has an irrigation fluid channel 5 that opens distally into the region of the light exit 4 and is fluidly connected proximally with a fluid supply 6 and a fluid reservoir 7. Obviously, endoscopes are also known that combine the irrigation fluid channel 5 with the working channel for the fiber optic cable 2 in one channel. Known endoscope assemblies of this kind serve to fragment intracorporeal stones 8 during the process of laser light-based lithotripsy.

[0033] The system according to the invention for monitoring temperature relates to a modular part 9 that can be combined with the extracorporeal region of an endoscope assembly comprising an endoscope 1, a laser 3, a fluid supply 6 and a fluid reservoir 7. In a preferred embodiment, it comprises the following components:

[0034] A flow sensor 10, preferably in the form of an ultrasonic sensor, is removably fixed alongside the irrigation fluid supply line 5. Similarly, a temperature sensor 11, preferably in the form of an infrared sensor, is removably fixed alongside the irrigation fluid channel 5 or a supply line in fluid communication therewith for detecting the temperature of the irrigation fluid. The sensor signals S, T generated by the sensors 10, 11 S is transmitted to the processing unit 12 wirelessly or via a hardwired connection.

[0035] Furthermore, input means 13 are provided, preferably in the form of an interface to the laser section for automatic operating parameter transmission or alternatively in the form of a manually operable keyboard by means of which operating parameters for the laser 3 can be entered. Operation of the laser 3 involves the laser pulse frequency f L and individual pulse energy E P These operating parameters can also be supplied to the processing unit 12 via the input means 13, and the laser output that can be applied to the position of the light exit port 4 can be calculated based on these parameters.

[0036] The analysis unit 14 is installed in the processing unit 12 and detects the operating parameters of the laser, the irrigation flow rate S of the irrigation liquid detected by the sensor, and the temperature T S Based on this, the current temperature occurring at the position of the light exit port 4 is determined based on the following algorithm:

number

[0037] The determined core temperature T is then preferably calculated as T K The comparator 15 compares the temperature with an adjustable threshold T K If the difference is greater than 1, the comparator 15 outputs the signal S K which is then tactilely, audibly and / or visually perceptible by the physician performing the lithotripsy.

[0038] Additionally, a microphone unit 17 is connected to the processing unit 12, which detects the activation of the laser 3. This generates data and a signal S based thereon that are processed by the processing unit 12 and the analysis unit 14 implemented therein. K By generating the signal, synchronization with the actual operation of the laser 3 is achieved. [Explanation of symbols]

[0039] 1. Endoscope 2 fiber optic cables 3 Laser 4 Light exit port 5 Irrigation fluid 6 Irrigation fluid supply 7 Irrigation fluid reservoir 8 stones 9 Module section 10 Flow Sensor 11 Temperature Sensor 12 Processing section 13 Input Methods 14 Analysis Department 15 Comparison section 16 Signal Section 17 Microphone section

Claims

[Claim 1] 1. A system for monitoring temperature during a laser light-based lithotripsy procedure employing an endoscope assembly including: a working channel for a fiber optic cable optically connected to a laser at a proximal end and having an optical exit at a distal end; and an irrigation fluid channel opening at the distal end into the region of the optical exit and in fluid communication with an irrigation fluid reservoir at the proximal end, a modular unit that can be combined with the endoscope assembly; The module section includes: a flow sensor mountable alongside the irrigation fluid channel and / or a supply line in fluid communication with the irrigation fluid channel to determine an irrigation flow rate without contacting the irrigation fluid; an input means connected to a processing unit and capable of transmitting to said processing unit operating parameters for said laser that are the basis for determining a laser output that can be irradiated at the position of said light exit opening; a temperature sensor mountable alongside the irrigation fluid channel and / or a supply line in fluid communication with the irrigation fluid channel, the temperature sensor being non-contact with the irrigation fluid to determine the temperature of the irrigation fluid; A device is attached to the processing unit, and controls at least the irrigation flow rate and the temperature (T Ｓ an analysis unit that numerically determines a temperature T generated in the body during the laser light-based lithotripsy at the position of the light exit port based on the determined irradiation laser power; a comparator for comparing the determined temperature T with a threshold and generating a signal if the determined temperature T exceeds the threshold; A system comprising:

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