SYSTEM FOR MONITORING TEMPERATURE WHILE INTRACORPORAL LASER LITHOTRIPSY IS BEING CARRIED OUT

Abstract

A system for monitoring temperature when carrying out laser light-based lithotripsy in which includes an endoscopic assembly comprising a working channel for a fiber optic cable which is optically coupled to a laser on a proximal side and include a light exit aperture on a distal side, and an irrigation fluid channel opening into a region of the light exit aperture on the distal side which is in fluid communication with an irrigation fluid reservoir on the proximal side. The system includes a modular unit including a flow sensor, which determines the irrigation flow rate without coming into contact with the irrigation fluid; input, via which operating parameters of the laser can be determined, can be transmitted to a processor connected to the input; a temperature sensor which determines the temperature of the irrigation fluid without coming into contact with the irrigation fluid; an analyzer, which numerically determines the temperature of the irrigation fluid and the determined applied laser power, and the temperature generated intracorporeally during the laser lithotripsy at the location of the light exit aperture, and a comparator, which produces a signal in the event that a threshold value is exceeded.

Claims

1-19. (canceled)

20. A system for monitoring temperature when carrying out laser light-based lithotripsy, in which an endoscopic assembly is employed which comprises a working channel for a fiber optic cable which is optically coupled to a laser on a proximal side and has a light exit aperture on a distal side, as well as an irrigation fluid channel which opens into a region of the light exit aperture on the distal side and is in fluid communication with an irrigation fluid reservoir on a proximal side, the system including a module which can be combined with the endoscopic assembly, the module comprising: a flow sensor, which can be attached alongside at least one of the irrigation fluid channel and a supply line, in fluid communication with an irrigation fluid channel and which determines an irrigation flow rate in a manner without contacting the irrigation fluid; an input means for determining operating parameters of the laser based on laser power applied at a location of the light exit aperture which are determined and transmitted to a processor connected to the input means; a temperature sensor, which is attachable to at least one of the irrigation fluid channel and a supply line, in fluid communication with the irrigation fluid channel and which determines irrigation fluid temperature without contact with the irrigation fluid; an analyzer, within the processor, which based on the irrigation flow rate, the temperature of the irrigation fluid and applied laser power, numerically determines a temperature generated intracorporeally during the laser-based lithotripsy at a location of the light exit aperture; and a comparator which compares the determined temperature T with a threshold value and produces a signal when the threshold value is exceeded.

21. The system as claimed in claim 20, wherein: the flow sensor is an ultrasound sensor.

22. The system as claimed in claim 20, wherein: the input includes a manually operable interface or a data interface.

23. The system as claimed in claim 20, wherein: the operating parameters of the laser are laser pulse frequency and individual pulse energy.

24. The system as claimed in claim 20, wherein: the analyzer determines the temperature T generated at a location of the light exit aperture based on a relationship of: $T=14.4K*\frac{\mathrm{laser}\mathrm{power}}{\mathrm{irrigation}\mathrm{flow}\mathrm{rate}}+\mathrm{irrigation}\mathrm{fluid}\mathrm{temperature}$

25. The system as claimed in claim 24, wherein: the temperature sensor is an infrared sensor.

26. The system as claimed in claim 24, wherein: a physiologically perceptible signal unit which provides a signal produced the comparator by one of haptical, acoustical and visual detection.

27. The system as claimed in claim 20, comprising: a cooler thermally coupled to at least one of the irrigation fluid channel and to the irrigation fluid reservoir, and wherein: the cooler is activated or controlled by the signal produced by the comparator.

28. The system as claimed in claim 20, comprising: an emergency stop switch which is activatable by the signal produced ley the comparator.

29. The system as claimed in claim 20, comprising: a microphone which provides a signal storing operation of the laser in which the microphone is connected to the analyzer.

30. The system as claimed in claim 20, wherein: the system is configured to be retrofitted by attachment to an endoscopic assembly for carrying out laser light-based lithotripsy.

31. The system as claimed in claim 20, wherein: the working channel and the irrigation fluid channel are a single channel in which the optic cable is positioned along a working channel which is irrigated by the irrigation fluid.

32. The system as claimed in claim 30, wherein: the endoscopic assembly includes an extracorporeal region outside a patient when the system carries out the lithotripsy; and the temperature sensor and the flow sensor are attached in the extracorporeal region of the endoscopic assembly alongside the irrigation fluid channel or along a supply line in fluid communication therewith.

33. The system as claimed in claim 20, comprising: means for computing or for providing direct detection by sensors of a level of filling of irrigation fluid in the irrigation fluid reservoir and which produces at least one signal dependent on the level of filling.

34. The system as claimed in claim 33, wherein: the means for computing comprises a sensor provided with the irrigation fluid reservoir and executes a software-based analysis algorithm implemented by the processor which determines the level of filling based on the irrigation flow rate detected by the sensors and a measured length of time during which the irrigation fluid is discharged.

35. The system as claimed in claim 33, wherein: the signal is producible by at least one of haptical, acoustical or visual detection by the signal unit or by means of a further signal means.

36. The system as claimed in claim 20, wherein: the temperature of the irrigation fluid is detected by the temperature sensor which is coupled to the comparator or to a further comparator unit which produces a signal when the temperature of the irrigation fluid falls below or exceeds a critical temperature value.

37. The system as claimed in claim 20, wherein: the irrigation fluid channel is connected on a proximal side to an electrically operable irrigation fluid delivery unit.

38. The system as claimed in claim 37, wherein: the irrigation fluid channel includes means for controlling irrigation fluid flow rate as a function of the temperature generated at the light exit aperture and at least one operating parameter of the laser.

Description

EXAMPLES OF THE INVENTION

[0030] The single FIGURE shows an endoscope 1 with a working channel for a fiber optic cable 2 which is optically coupled to a laser 3 on the proximal side and has a light exit aperture 4 on the distal side. Furthermore, the endoscope 1 has an irrigation fluid channel 5 which opens into the region of the light exit aperture 4 on the distal side and on the proximal side is in fluid communication with a fluid delivery unit 6 as well as a fluid reservoir 7. Endoscopes are also known which combine the irrigation fluid channel 5 with the working channel for the fiber optic cable 2 in one channel. Known endoscopic assemblies of this type serve to shatter intracorporeal stones 8 during the course of laser-based lithotripsy.

[0031] The system in accordance with the invention for monitoring temperature concerns a modular unit 9 which can be combined with the extracorporeal region of the endoscopic assembly comprising the endoscope 1, the laser 3, the fluid delivery unit 6 as well as the fluid reservoir 7, a preferred embodiment, the invention is composed of the following components:

[0032] Alongside the irrigation fluid supply line 5, a flow sensor 10, preferably an ultrasound sensor, is detachably secured. Similarly, alongside the irrigation fluid channel 5 or a supply line which is in fluid communication therewith, a temperature sensor 11 for detecting the irrigation fluid temperature, which is preferably an infrared sensor, is detachably secured. The sensor signals S, Zs which are produced by the sensors 10, 11, are transmitted to a processor unit 12 in a wireless or hard-wired manner.

[0033] Furthermore, an input 13 is provided, preferably as an interface to the laser for automatic operating parameter transfer, or alternatively in the form of a manually operable keyboard by which the operating parameters for the laser 3 can be input. For the operation of the laser 3, the laser pulse frequency f.sub.L as well as the individual pulse energy EP can be specified by the operator. These operating parameters can also be supplied via the input 13 to the processor 12, on the basis of which the laser power which can be applied to the location of the light exit aperture 4 can be computed.

[0034] An analysis unit 14 is installed in the processor 12 and which, based on the operating parameters of the laser, the irrigation flow rate S as well as the temperature Z.sub.S of the irrigation fluid detected by the sensors, determines the current temperature generated at the location of the light exit aperture 4 based on the following algorithm:

[00002]$T=\left(14.4K*\frac{\left[\mathrm{laser}\mathrm{power}\left[W\right]\right]}{\left[\mathrm{irrigation}\mathrm{flow}\mathrm{rate}\left[\frac{\mathrm{ml}}{\min }\right]\right]}\right)+\mathrm{temp}\mathrm{of}\mathrm{irrigation}\mathrm{fluid}\left[K\right]$

[0035] Next, the determined intracorporeal temperature T is compared in a comparator unit 15 with an adjustable threshold value which is preferably T.sub.K=42° C. In the case in which the threshold value T.sub.K is exceeded, the comparator unit 15 produces a signal SK which is supplied to a signal unit 16 which can then be perceived at least one of haptically, acoustically and visually by the physician who is carrying out the lithotripsy.

[0036] In addition, a microphone unit 17 is connected to the processor unit 12, by which the activity of the laser 3 is detected which ensures that the data processed by the processor 12 and the analyzer 14 implemented therein as well as the production of a signal SK based on it is synchronous with the actual operation of the laser 3.

LIST OF REFERENCE NUMERALS

[0037] 1 Endoscope [0038] 2 fiber optic cable [0039] 3 laser [0040] 4 light exit aperture [0041] 5 irrigation fluid [0042] 6 irrigation fluid delivery [0043] 7 irrigation fluid reservoir [0044] 8 stone [0045] 9 modular unit [0046] 10 flow sensor [0047] 11 temperature sensor [0048] 12 processor unit [0049] 13 input [0050] 14 analyzer [0051] 15 comparator [0052] 16 signal unit [0053] 17 microphone