A rare-earth fiber-based temperature monitoring and photothermal therapy system

Abstract

This invention discloses a temperature monitoring and photothermal therapy system based on rare-earth optical fiber, comprising a computer, a spectrometer, a laser source, a coupler, a Y-type optical fiber (including a temperature-sensing fiber, a dual-mode fiber, and a laser fiber), a fiber optic probe, and a temperature monitor. The probe is filled with a photothermal therapy composite material and has a detachable structure for easy replacement with different filling materials. The laser is coupled to the temperature-sensing fiber via the laser fiber and the coupler, and then transmitted to the probe through the Y-type fiber to excite the photothermal therapy composite material. The excited fluorescence is transmitted to the spectrometer through the Y-type fiber for spectral analysis to read the fluorescence intensity of two different wavelengths. The computer performs real-time calculations using the fluorescence intensity ratio method to obtain the real-time temperature of the probe. The laser power is controlled by a temperature controller, thereby achieving real-time monitoring and temperature control. This invention is small in size, allows for real-time monitoring and control, has modular features, and allows for replacement of the laser source, optical fiber, and probe, achieving low-cost and safe treatment.

Description

Technical Field

[0001] This invention relates to a temperature monitoring and photothermal therapy system based on rare-earth optical fibers. Background Technology

[0002] With the continuous advancement of modern medical technology, laser therapy has become increasingly widespread. Lasers possess characteristics such as high monochromaticity, high coherence, high directionality, and high brightness. High directionality means that compared to everyday light sources, lasers have a smaller divergence angle during transmission, allowing energy to be concentrated effectively. The high energy of the laser irradiates objects, rapidly heating them and altering their structure. Therefore, lasers have become a novel processing and treatment method. Using optical fibers to irradiate the affected area with laser light raises the temperature of the irradiated biological tissue, killing diseased cells; this is commonly used in tumor treatment. However, traditional laser thermotherapy suffers from problems such as delayed temperature monitoring, poor heating effect, excessively large treatment devices, and the toxicity and residue of indirect heat-conducting materials. When the temperature rises above 45°C, diseased cells are gradually killed. If the laser's heating rate is too rapid, or if temperature monitoring is delayed, it may damage normal cells, leading to unnecessary secondary harm. Current real-time temperature monitoring probes are too large to penetrate certain parts of the body for treatment, and are complex to replace and have low maintainability.

[0003] Fluorescence intensity ratio thermometry is widely used because it can overcome the influence of ambient environment, pump light intensity fluctuations, and spectral losses on temperature measurement results. Currently, most fluorescence intensity ratio thermometry techniques are based on the fluorescence intensity ratio of thermally coupled energy level pairs of rare-earth ions for temperature sensing. To achieve temperature measurement in accordance with the Boltzmann distribution rule, the energy level difference of the thermally coupled energy levels should be between 200 and 2000 cm⁻¹. -1 Between, such as Er 3+ of 2 H 11 / 2 and 4 S 3 / 2 Energy levels. Since the sensitivity of temperature measurement is proportional to the energy level difference of thermally coupled energy levels, this severely hinders further improvement of the sensitivity of rare-earth-based luminescent thermometric materials. Summary of the Invention

[0004] In this invention, after the probe tip penetrates the tissue, a laser excites the internal filling material. Due to the material's excellent photothermal effect, it can rapidly heat up. The addition of nano-thermal conductive materials improves thermal conductivity and enhances thermal conductivity. Heat is rapidly conducted through the thermal conductive material coated on the probe. The heat diffuses through the probe tip into the human tissue, killing diseased tissue cells through high temperature to achieve the purpose of photothermal therapy. To monitor the heating effect in real time, temperature monitoring is performed using fluorescence thermometry with rare-earth luminescent materials. Utilizing the dependence of fluorescence intensity ratio on temperature, this overcomes the shortcomings of existing temperature measurement technologies, such as low sensitivity, low signal resolution, and high-temperature quenching. The rare-earth luminescent material emits fluorescence under external laser excitation, and the luminescence intensity changes with increasing temperature. The fluorescence emitted by the filling material can be transmitted to an external detector through a temperature-sensing optical fiber. After signal demodulation, fluorescence thermometry is achieved using the fluorescence intensity ratio method, thereby achieving the purpose of temperature measurement and monitoring. To prevent reflected laser light from entering the temperature-sensing optical fiber, a grating is etched inside the fiber to eliminate reflected laser light. This invention has the advantages of minimal trauma, good photothermal effect, high temperature monitoring accuracy, and good real-time performance.

[0005] The specific technical solution for implementing this invention is as follows:

[0006] An integrated system for photothermal therapy and temperature monitoring with replaceable probes is characterized by comprising a computer, a spectrometer, a laser source, a coupler, a temperature-sensing fiber, a dual-mode fiber, a laser fiber, a probe, and a temperature controller. The probe is filled with a photothermal therapy composite material and has a detachable structure for easy replacement with probes filled with different materials. The laser emitted by the laser source is coupled to the temperature-sensing fiber via the laser fiber and the coupler, and then transmitted to the probe through a dual-beam fiber to excite the photothermal therapy composite material. The excited fluorescence is transmitted to the spectrometer through the dual-beam fiber and the temperature-sensing fiber for spectral analysis to read the fluorescence intensity of two different wavelengths. The computer performs real-time calculations using the fluorescence intensity ratio method to obtain the real-time temperature of the probe. The temperature controller controls the power of the laser, thereby achieving real-time monitoring and real-time temperature control.

[0007] According to the integrated system of claim 1, the spectrometer has a detection range of 200nm-1600nm; the spectrometer has a spectral dispersive system composed of a tunable grating in hardware, which selectively receives light of a specific wavelength through two optical paths, and the grating has an adjustment range of 200nm-1600nm.

[0008] According to the integrated system of claim 1, the laser wavelength transmitted by the laser fiber is 200nm-2000nm, which is a continuous laser, and the power is 0.1W-100W, and the receiving wavelength of the temperature measuring fiber is 200nm-1600nm.

[0009] According to the integrated system of claim 1, the coupler can combine two optical fibers in the same outer cladding, and the connection between the coupler and the input optical fibers at both ends is a detachable structure, which facilitates the replacement of the spectrometer and optical fibers.

[0010] According to the integrated system of claim 1, the probe has a length of 20mm-100mm, a diameter of 1mm-4mm, a shell thickness of 0.5mm-1.5mm, and the shell material is quartz glass.

[0011] The aforementioned photothermal therapy composite material includes rare-earth doped materials and nano-photothermal materials. The rare-earth doped materials emit fluorescence upon laser excitation, while the nano-photothermal materials generate heat under laser irradiation. The emission spectrum of the rare-earth doped materials ranges from 200 nm to 1600 nm. The rare-earth dopant ions include Nd... 3+ Yb 3+ Er 3+ The aforementioned nanophotothermal materials include graphene, carbon nanotubes, graphite, gold nanorods, gold nanosheets, or copper nanospheres.

[0012] The temperature controller receives temperatures ranging from 50°C to 70°C and can adjust the laser power from 0.01W to 10W.

[0013] The beneficial effects of this invention:

[0014] The probe section utilizes a photothermal composite material, including rare-earth-doped materials and nano-photothermal materials. Under laser excitation, it emits fluorescence, the intensity of which changes with temperature. The nano-photothermal materials generate heat under laser irradiation. The probe shell is made of a highly thermally conductive material. One optical fiber transmits the laser to excite the rare-earth-doped material to emit light, while another optical fiber collects the fluorescence emitted by the excited photothermal material. The two optical fibers are coupled together using an optical fiber coupler. The fiber transmitting fluorescence passes through the coupler and connects to a spectrometer. The spectrometer's built-in spectroscopic path disperses the incident fluorescence and obtains the emission intensity. Finally, a computer analyzes the ratio and uses a functional relationship to determine the real-time temperature.

[0015] The relationship between the luminous intensity of rare earth-doped materials and temperature can generally be defined by the fluorescence intensity ratio method. The fluorescence intensity ratio method obtains the corresponding functional relationship of the material by fitting the ratio of the fluorescence luminous intensity of two different wavelengths with temperature. In practical applications, the real-time temperature can be obtained based on the ratio of the luminous intensity of two different wavelengths.

[0016] The coupler's function is to enable the modularity of the system's modules. Each module is connected to the coupler via optical fiber as the transmission carrier, achieving modular assembly and facilitating the replacement of components such as optical fibers, laser sources, and probes. This invention offers advantages such as real-time temperature measurement, high temperature detection accuracy, small heating probe size, controllable heating effect, and high modularity for easy maintenance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the system of the present invention.

[0018] Figure 2 This is a schematic diagram of a probe structure.

[0019] Among them, there are: computer 1, spectrometer 2, laser source 3, temperature measuring fiber 4, laser fiber 5, dual-mode fiber 6, coupler 7, temperature monitor 8, protective cover 9, and photothermal therapy composite material 10.

[0020] Figure 3 This refers to the temperature monitoring error of the system. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.

[0022] See Figure 1 The system comprises a computer 1, a spectrometer 2, a laser source 3, a temperature-sensing fiber 4, a laser fiber 5, a dual-mode fiber 6, a coupler 7, a temperature controller 8, and a probe. The probe is filled with a photothermal therapy composite material 10 and has a detachable structure for easy replacement with probes containing different filling materials. The laser emitted by the laser source 3 is coupled to the temperature-sensing fiber 5 via the laser fiber 4 through the coupler, and then transmitted to the probe via the dual-mode fiber 6 to excite the photothermal therapy composite material 10. The emitted fluorescence is transmitted to the spectrometer 2 via the dual-mode fiber 6 and the temperature-sensing fiber 5 for reading. The computer 1 then performs real-time calculations to obtain the real-time temperature of the probe. The laser source 3 then controls the power of the laser, thereby achieving real-time monitoring and temperature control.

[0023] Example

[0024] This invention relates to an integrated system for photothermal therapy and temperature monitoring with a replaceable probe. The probe is needle-shaped, 100mm in length, 4mm in diameter, and has a shell thickness of 1.5mm. It features a raised locking structure, is made of gold, and is internally filled with a photothermal therapy composite material. A 1W laser emits a 980nm laser beam, which is transmitted through a laser fiber to irradiate the Nd2+ filled probe. 3+ Yb 3+ Er 3+ Rare-earth-doped materials and carbon nanotube photothermal materials are used. The photothermal composite material generates heat and emits fluorescence, which is transferred to biological tissue and heats it. The fluorescence range is 600nm-1200nm, and the fluorescence fiber has a receiving range of 500nm-1500nm. After the fluorescence enters the spectrometer, the fluorescence at 667nm and 780nm is separated by a grating spectral system and transmitted to a computer for calculation to obtain the real-time temperature of the probe. When the temperature controller receives the temperature signal and reaches 60℃, it adjusts the laser power to 0W in 10W increments to complete the entire treatment process. Figure 3 This represents the temperature measurement error throughout the entire process.

Claims

1. An integrated system for photothermal therapy and temperature monitoring with replaceable probes, characterized in that... The system includes a computer, spectrometer, laser source, coupler, temperature-sensing fiber, dual-mode fiber, laser fiber, probe, and temperature controller. The probe is filled with photothermal therapy composite material and has a detachable structure for easy replacement with probes containing different filling materials. The laser emitted by the laser source is coupled to the temperature-sensing fiber via the laser fiber and the coupler, and then transmitted to the probe through the dual-mode fiber to excite the photothermal therapy composite material. The excited fluorescence is transmitted to the spectrometer through the dual-mode fiber and the temperature-sensing fiber for spectral analysis to read the fluorescence intensity of two different wavelengths. The computer performs real-time calculations using the fluorescence intensity ratio method to obtain the real-time temperature of the probe. The temperature controller controls the power of the laser, thereby achieving real-time monitoring and real-time temperature control. The aforementioned photothermal therapy composite material includes rare-earth doped materials and nano-photothermal materials. The rare-earth doped materials emit fluorescence upon laser excitation, while the nano-photothermal materials generate heat under laser irradiation. The emission spectrum of the rare-earth doped materials ranges from 200 nm to 1600 nm. The rare-earth dopant ions include Nd... 3+ Er 3+ Yb 3+ The aforementioned nanophotothermal materials include graphene, carbon nanotubes, graphite, gold nanorods, gold nanosheets, or copper nanospheres.

2. The integrated system according to claim 1, characterized in that, The spectrometer has a detection range of 200nm-1600nm; the spectrometer has a spectral dispersive system composed of a tunable grating in its hardware, which selectively receives light of a specific wavelength through two optical paths, and the grating can be adjusted in the range of 200nm-1600nm.

3. The integrated system according to claim 1, characterized in that, The laser wavelength transmitted by the laser fiber is 200nm-2000nm, which is a continuous laser, and the power is 0.1W-10W. The receiving wavelength of the temperature measuring fiber is 200nm-1600nm.

4. The integrated system according to claim 1, characterized in that, The coupler can combine two optical fibers into the same outer cladding, and the connection between the coupler and the input optical fibers at both ends is a detachable structure, which facilitates the replacement of the spectrometer and optical fibers.

5. The integrated system according to claim 1, characterized in that, The probe has a length of 20mm-100mm, a diameter of 1mm-4mm, a shell thickness of 0.5mm-1.5mm, and the shell material is quartz glass.

6. The integrated system according to claim 1, characterized in that, The temperature controller receives temperatures ranging from 50°C to 70°C and can adjust the laser power from 0.01W to 10W.

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