STONE SENSE WITH FIBER EROSION PROTECTION AND CAMERA SATURATION PREVENTION, AND/OR ABSENCE-DETECTION SAFETY INTERLOCK

Abstract

A system and method for detecting relative location of a surgical laser fiber tip relative to a surgical laser target during a surgical laser procedure utilizes a spectrophotometer to detect radiation indicative of the relative location. For example, the detected radiation may indicate contact between the fiber tip and a stone being subjected to laser lithotripsy, so as to prompt the surgeon to withdraw the fiber tip from the stone and/or take other action to limit contact-induced erosion of the fiber tip, and to avoid saturation of the endoscope camera resulting from the flash that occurs following contact. In addition, the absence of any detected radiation by the spectrophotometer may be used to indicate that the stone is no longer present, or that the fiber tip is no longer aimed at the stone, prompting the operator to reposition the fiber and/or temporarily cease firing of the laser. The main surgical laser may be a pulsed Holmium laser, which is delivered to the target through the optical fiber together with a pulsed 532 nm aiming beam.

Claims

1. A system for detecting contact between a surgical target and a fiber tip during a surgical laser procedure, comprising: a main laser for delivering laser energy having a first wavelength 1 to a target through an optical fiber; and a spectrophotometer for detecting radiation indicative of a relative position between a tip of the optical fiber and the target.

2. A system as claimed in claim 1, wherein the spectrophotometer detects radiation indicative of contact between the target and a tip of the optical fiber, the detected radiation having at least one third wavelength 3.

3. A system as claimed in claim 2, further comprising a secondary light source for supplying light having a second wavelength 2 to the target.

4. A system as claimed in claim 3, wherein the secondary light source is one of a laser, LED, or endoscope light.

5. A system as claimed in claim 4, wherein the secondary light source serves as an aiming beam light source.

6. A system as claimed in claim 5, wherein the main laser is a pulsed Holmium laser and the secondary light source is a pulsed UV-VIS-IR laser.

7. A system as claimed in claim 2, wherein the target is a kidney stone, and the surgical laser procedure is laser lithotripsy.

8. A system as claimed in claim 1, wherein the spectrophotometer detects radiation emitted or reflected when the target is present in a path of the main laser, and whose absence indicates that the target is not present in the path of the main laser.

9. A system as claimed in claim 7, wherein the target is a kidney stone, and the surgical laser procedure is laser lithotripsy.

10. A method of detecting contact between a target and a fiber tip during a surgical laser procedure, comprising the steps of: delivering laser energy having a first wavelength 1 from a main laser to a target through an optical fiber; and using a spectrophotometer to detect radiation indicative of a relative position between a tip of the optical fiber and the target.

11. A method as claimed in claim 10, wherein the spectrophotometer detects radiation indicative of contact between the target and a tip of the optical fiber, the detected radiation having at least one third wavelength 3.

12. A method as claimed in claim 11, further comprising the step of delivering light having a second wavelength 2 from a secondary light source to the target through the optical fiber.

13. A method as claimed in claim 12, wherein the secondary light source is one of a laser, LED, or endoscope light.

14. A method as claimed in claim 13, wherein the secondary light source serves as an aiming beam light source.

15. A method as claimed in claim 14, wherein the main laser is a pulsed Ho:Yag laser and the secondary light source is a UV-VIS-IR laser.

16. A method as claimed in claim 11, wherein the target is a kidney stone, and the surgical laser procedure is laser lithotripsy.

17. A method as claimed in claim 10, wherein the spectrophotometer detects radiation emitted or reflected when the target is present in a path of the main laser, and whose absence indicates that the target is not present in the path of the main laser.

18. A method as claimed in claim 16, wherein the target is a kidney stone, and the surgical laser procedure is laser lithotripsy.

19. A method as claimed in claim 10, further comprising the step of using the spectrophotometer to analyze stone or vaporized material composition.

20. A method of preventing firing of a laser into tissues or equipment other than an intended target during laser lithotripsy, comprising the steps of: detecting radiation reflected or emitted by the target during a lithotripsy procedure; preventing the firing of the laser unless said radiation is detected.

21. A method as claimed in claim 20, wherein the laser has an active mode that allows the laser to automatically pulse after detecting radiation reflected or emitted by the target when it is in an optimal position.

22. A method as claimed in claim 20, where the equipment being protected includes an endoscope, a guide wire, and/or a stone basket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic diagram of a contact-sensing system arranged in accordance with the principles of a preferred embodiment of the invention.

[0013] FIG. 2 is a timing diagram for the system of FIG. 1.

[0014] FIG. 3 is a schematic diagram of a stone detecting safety interlock arranged in accordance with the principles of a second preferred embodiment of the invention.

[0015] FIG. 4 is a timing diagram for the system of FIG. 3

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] As illustrated in FIG. 1, the system of the invention includes a conventional laser delivery apparatus that includes a laser 1 capable of delivering stone vaporizing or destroying pulses during a laser lithotripsy procedure. The system may also include a secondary light source, which could be a laser or LED light source 2 that serves to provide an aiming beam, but which could also be an endoscope light, etc.

[0017] The main laser 1 may, by way of example and not limitation, be a Ho:YAG laser that outputs pulses of wavelength 1 at a frequency of 10 Hz. In the illustrative example where a secondary light source 2, which may for example be any pulsed UV-VIS-IR laser, is included to provide an aiming beam. By way of example and not limitation, the aiming beam may have a wavelength 2 of 532 nm (green) that causes the stone to fluoresce at the point of incidence, and that also has a pulse frequency of 10 Hz. The outputs of the of main laser 1 and secondary light source 2 are injected into an optical fiber 4, for delivery through the fiber 5 to the stone 6.

[0018] The system illustrated in FIG. 1 also includes a spectrophotometer 3 arranged to detect radiation having a wavelength(s) 3 that occurs upon and is indicative of contact between the stone 6 and the fiber tip 5. As shown in FIG. 2, laser 1 and secondary light source 2 deliver respective first and second pulses during a lithotripsy procedure in which the fiber tip 5 is normally positioned adjacent to but not in contact with the stone. However, before the third pulse, the fiber tip 5 contacts the stone 6, causing a responsive radiation emission at wavelength(s) 3, which is detected by the spectrophotometer 3. Alternatively, the secondary light source could come from the endoscope and/or the scope image detection could pick up the radiation of wavelength(s) 3 that occurs upon contact between the fiber tip 5 and the stone 6.

[0019] Detection of a threshold level of radiation at wavelength(s) 3 can be used to generate an alarm or contact signal that prompts the surgeon to withdraw the fiber tip from the stone, and/or optionally trigger cut-off, cut-on, or modulation of the main laser 1, before significant erosion and a camera-saturating flash occur. After pull-back of the laser tip 5 from the stone 6, the lithotripsy operation can proceed as normal, as indicated by the fourth main and aiming beam pulses illustrated in FIG. 2.

[0020] As an additional feature, some tissues like stones re-emit an optical signature composed of multiple wavelengths when illuminated by the light of wavelength 2, such that the stone composition can be determined with the spectrophotometer 3. As a result, the detected radiation 3 may be comprised of multiple wavelengths and intensities. This information could be useful for diagnostic purposes or help determine laser output parameters.

[0021] Alternatively, the failure to detect radiation at a wavelength indicative that the target is present and being irradiated may be used to trigger a warning that the target is not present, or to trigger an automatic shut off or attenuation of the laser. The wavelength indicative that the target is present may be the same wavelength(s) 3 used to indicate contact, but at a level lower than the contact threshold, or the wavelength or wavelengths being monitored for their presence could be different from wavelength(s) 3. Conversely, the laser may also be provided with an active mode that allows the laser to automatically pulse after detecting radiation reflected or emitted by the target when it is in an optimal position.

[0022] As shown in FIGS. 3 and 4, if the system disclosed herein is used with a SoftTip 7 of the type described in PCT Appl. No. PCT/US2017/31091, then stone contact could be limited to lasing only when the SoftTip 7 is in contact with the stone 6. This would limit the effects of retro-repulsion of the stone 6.

[0023] In the system of FIG. 3, which may be applied to an optical fiber arrangement with a SoftTip that provides a standoff, the spectrophotometer 3 detects a wavelength(s) 3 resulting from reflection or emission by the stone 6 during application of the main laser wavelength 1. The reflected or emitted wavelength(s) 3 may be separated by a beam splitter 9 after traveling back through the optical fiber 4. A main laser controller, represented by decision block 7, receives a signal from the spectrophotometer that indicates whether radiation of wavelength(s) 3 have been detected and disables the main laser 1 if the signal has not been detected.

[0024] As shown in FIG. 4, control of the laser output may be achieved by a shutter or trigger input that only allows a pulse to be injected into the fiber when presence of the stone is indicated by a high or equivalent signal output by the spectrophotometer.

[0025] By only firing the laser when the fiber tip is in the optimal position for target vaporization, thereby reducing extraneous pulses that cause target retro repulsion and wear on equipment, while optimizing efficiency and reducing overall surgical time.

[0026] Finally, according to an additional optional feature of the invention, which may be applied to either embodiment, if laser 1 vaporizes a target, the resulting free floating ions and electrons produce a spectrum that can be used to identify the elemental composition of the vaporized material. The spectrometer 3 can verify this spectrum and monitor its amplitude to determine stone distance from fiber tip.