CN116350182A - Circular scanning photosensitizer fluorescence quantitative detection system and working method thereof - Google Patents

Abstract

The ring-scan photosensitizer fluorescence quantitative detection system and its working method can solve the quantitative detection of the concentration distribution of the photosensitizer in the lumen, guide the precise treatment of the lesions in the lumen, and further improve the safety and effectiveness of photodynamic therapy. Including: endoscopic ring scan detection module (3), used for lesion visualization and intraluminal diagnosis and treatment; multi-modal signal detection module (16), used for collecting fluorescence signals, reflection signals of 405nm excitation light and tissue OCT signal; signal processing and control module (15), for processing the fluorescent signal that multimodal signal detection module collects, the reflected signal of 405nm laser and the OCT signal of tissue, and each device in the control endoscopic ring scanning detection module, Operation of 405nm laser (11), frequency-swept OCT (12), first avalanche photodiode (13), and second avalanche photodiode (14).

Description

Ring scan photosensitizer fluorescence quantitative detection system and its working method

technical field

The invention relates to the technical field of photoelectric detection, in particular to a ring-scan photosensitizer fluorescence quantitative detection system and a working method of the ring-sweep photosensitizer fluorescence quantitative detection system.

Background technique

Photodynamic therapy is a new type of minimally invasive therapy for the treatment of malignant tumors and precancerous lesions, which has the advantages of high selectivity and less trauma. In recent years, photodynamic therapy has shown good application prospects in intraluminal lesions such as cervical intraepithelial neoplasia and esophageal cancer. The treatment process mainly includes: administering a photosensitizer to the patient through intravenous injection or local application, and the photosensitizer can be selectively enriched in the lesion tissue; Generates cytotoxic singlet oxygen, which in turn kills tumor cells. Photosensitizer is one of the three elements of photodynamic therapy, and its concentration distribution in the body directly affects photodynamic efficacy. Therefore, in vivo quantitative detection of photosensitizer concentration is a prerequisite for personalized photodynamic precision therapy.

Quantitative detection of photosensitizer concentration is usually based on laser-induced fluorescence spectroscopy detection technology. By establishing a quantitative relationship curve between photosensitizer concentration and fluorescence intensity, the in vivo quantitative detection of photosensitizer concentration is realized. The excitation and emission transmission of the photosensitizer fluorescence in the tissue will be affected by the optical properties of the tissue. Therefore, the precise acquisition of the tissue optical property parameters and fluorescence intensity, and the establishment of a quantitative relationship between the fluorescence intensity, tissue optical properties and the concentration of the photosensitizer Relational models are essential for quantifying photosensitizer concentrations.

At present, fluorescence quantification mainly obtains tissue optical characteristic parameters through methods such as diffuse reflectance spectroscopy, spatial frequency domain imaging, and multispectral imaging, and uses them to correct the original fluorescence spectrum to obtain quantitative fluorescence spectra. However, currently commonly used fluorescence quantitative techniques are forward detection, which is difficult to obtain tissue optical properties and fluorescence distribution information in the annular lumen. Therefore, it is the key to realize the quantification of the concentration of photosensitizers in the lumen to develop new techniques for synchronous acquisition of tissue optical characteristic parameters and fluorescence distribution in the luminal exosome.

Therefore, how to realize the quantitative detection of the concentration distribution of the photosensitizer in the lumen is a specific problem to be solved by the present invention.

Contents of the invention

In order to overcome the defects of the prior art, the technical problem to be solved in the present invention is to provide a ring-scan photosensitizer fluorescence quantitative detection system, which can solve the quantitative detection of the concentration distribution of the photosensitizer in the lumen, and guide the accurate detection of the lesion in the lumen. treatment, to further improve the safety and effectiveness of photodynamic therapy.

The technical scheme of the present invention is: this ring scan photosensitizer fluorescence quantitative detection system, it comprises:

An endoscopic ring scan detection module (3), including: an endoscopic ring scan microprobe (1) and a stepping motor translation platform (2), the endoscopic ring scan detection module is used for lesion visualization and intraluminal diagnosis and treatment;

A multi-mode signal detection module (16), comprising: a double-clad fiber coupler (4), an objective lens (5), a mirror (6), a dichroic mirror (7), a wavelength division multiplexer (8), Neutral density filter (9), bandpass filter (10), 405nm laser (11), frequency-swept OCT (12), first avalanche photodiode (13), second avalanche photodiode (14), The multimodal signal detection module is used to collect fluorescence signals, reflection signals of 405nm excitation light and OCT signals of tissues;

The signal processing and control module (15) is used to process the fluorescent signal collected by the multimodal signal detection module, the reflected signal of the 405nm laser and the OCT signal of the tissue, and control each device in the endoscopic ring scan detection module, the 405nm laser ( 11), the operation of frequency-sweeping OCT (12), the first avalanche photodiode (13), and the second avalanche photodiode (14); The lesion imaging guidance, the stepping motor controls the movement of the probe to accurately locate the lesion, and the balloon is stretched to fix the probe; the frequency-sweeping OCT and 405nm laser emit frequency-sweeping laser and 405nm laser, which are combined by a wavelength division multiplexer and double-clad The optical fiber coupler transmits to the endoscopic ring-scanning microprobe and irradiates the lesion (29); after the frequency-sweeping laser irradiates the lesion, an OCT signal is generated; Signal, fluorescence signal and reflection signal of 405nm laser return to the double-clad fiber coupler through the original optical path; OCT signal returns to frequency-sweeping OCT for detection through the wavelength division multiplexer, and is transmitted to the signal processing and control module for processing; 405nm After the reflection signal and fluorescence signal of the laser are split by the dichroic mirror, the reflection signal of the 405nm laser is reflected by the mirror and filtered by the neutral density filter, then reaches the first avalanche photodiode, and is transmitted to the signal processing and control module for further processing. processing; the fluorescent signal is filtered by a band-pass filter and reaches the second avalanche photodiode, and is transmitted to the signal processing and control module for processing; the rotation of the micro-motor is controlled, and the luminal lesion is circularly scanned to obtain the complete information of the lesion. Then complete three-dimensional reconstruction of tissue, extraction of tissue optical characteristic parameters and quantification of photosensitizer concentration.

In the present invention, the endoscopic ring-scanning micro-probe is inserted into the lumen, the micro-camera realizes the lesion imaging guide in the lumen, the stepping motor controls the movement of the probe, and after reaching the bottom of the lumen, the balloon stretches to fix the probe; Frequency OCT and 405nm lasers emit frequency-sweeping laser and 405nm laser, which are combined by wavelength division multiplexer and double-clad fiber coupler to transmit to endoscopic ring-scanning microprobe and irradiate to the lesion; after the frequency-sweeping laser is irradiated to the lesion OCT signal is generated, after the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce, and the OCT signal, the fluorescence signal, and the reflected signal of the 405nm laser return to the double-clad fiber coupler through the original optical path, and are respectively transmitted to the signal processing and control module; control the rotation of the micro-motor, scan the luminal lesion circularly to obtain the complete information of the lesion, the signal processing and control module processes the OCT signal, fluorescence signal and 405nm laser, and then completes the three-dimensional reconstruction of the tissue and the optical characteristics of the tissue Acquisition of parameters and quantification of photosensitizer concentration; quantitative detection of photosensitizer concentration distribution in the lumen guides precise treatment of intraluminal lesions and further improves the safety and effectiveness of photodynamic therapy.

Also provided is a working method of a ring-scan photosensitizer fluorescence quantitative detection system, which includes the following steps:

(1) Administer photosensitizers to patients by local application or intravenous injection;

(2) The endoscopic ring-scanning micro-probe is inserted into the lumen, and the lesion is visualized and guided by the micro-camera to accurately locate the lesion. After the probe reaches the lesion, the balloon is stretched;

(3) Frequency-sweeping OCT emits a frequency-sweeping laser, and a 405nm laser emits a 405nm laser, which is combined by a wavelength division multiplexer and a double-clad fiber coupler and transmitted to the endoscopic ring-scanning microprobe, and irradiates the lesion in a ring-sweeping manner. OCT signals are generated after the high-frequency laser is irradiated to the lesion, and after the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce;

(4) OCT signal, fluorescence signal and the reflected signal of 405nm laser return to the double-clad fiber coupler through the original optical path; the OCT signal returns to the frequency-sweeping OCT for detection through the wavelength division multiplexer, and is transmitted to the signal processing and control module Processing; after the reflection signal and fluorescence signal of the 405nm laser are split by the dichroic mirror, the reflection signal of the 405nm laser is reflected by the mirror, filtered by the neutral density filter, and then reaches the first avalanche photodiode, and is transmitted to the signal processing Processing with the control module; the fluorescent signal reaches the second avalanche photodiode after being filtered by the band-pass filter, and is transmitted to the signal processing and control module for processing;

(5) The signal processing and control module controls the rotation of the micro-motor, and repeats steps (3) and (4) to obtain single-point lesion information every time a small angle is rotated, and the micro-motor rotates once to obtain the scanning information of each point on the ring, The stepping motor controls the linear movement of the optical fiber to complete the scanning of all lesions in the lumen;

(6) The signal processing and control module processes the OCT signal, the fluorescence signal and the reflection signal of the 405nm laser. The OCT signal is used for the three-dimensional reconstruction of the tissue and the extraction of the optical characteristic parameters of the tissue, and combines the fluorescence signal and the laser reflection signal to complete the measurement of the fluorescence intensity. Correction;

(7) Construct optical phantoms of tissues with different scattering and absorption, establish a quantitative relationship curve between fluorescence intensity and photosensitizer concentration, and quantify the concentration of photosensitizer in the lumen.

Description of drawings

Fig. 1 shows a schematic structural diagram of the fluorescence quantitative detection system for ring-scanning photosensitizers according to the present invention.

Fig. 2 shows a schematic diagram of a ring-scan endoscopic microprobe of the ring-scan photosensitizer fluorescence quantitative detection system according to the present invention.

Fig. 3 shows a schematic diagram of an embodiment of the esophageal mucosa according to the working method of the circular scanning photosensitizer fluorescence quantitative detection system of the present invention.

Fig. 4 shows a schematic diagram of an embodiment of the cervical mucous membrane of the working method of the ring-scan photosensitizer fluorescence quantitative detection system according to the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "comprising" and any variations in the description and claims of the present invention and the above drawings are intended to cover non-exclusive inclusion, for example, processes, methods, and devices that include a series of steps or units The process, method, product or device are not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to the process, method, product or device.

As shown in Figure 1, this ring scan photosensitizer fluorescence quantitative detection system includes:

The endoscopic ring scan detection module 3 includes: an endoscopic ring scan microprobe 1 and a stepping motor translation platform 2, the endoscopic ring scan detection module is used for lesion visualization and intraluminal diagnosis and treatment;

The multi-mode signal detection module 16 includes: a double-clad fiber coupler 4, an objective lens 5, a mirror 6, a dichroic mirror 7, a wavelength division multiplexer 8, a neutral density filter 9, and a bandpass filter Chip 10, 405nm laser 11, frequency-sweeping OCT12, first avalanche photodiode 13, second avalanche photodiode 14, the multimodal signal detection module is used to collect fluorescence signals, reflection signals of 405nm excitation light and OCT signals of tissues ;

The signal processing and control module 15 is used to process the fluorescent signal collected by the multimodal signal detection module, the reflected signal of the 405nm laser and the OCT signal of the tissue, and control each device, the 405nm laser 11, the scanning device in the endoscopic ring scanning detection module Frequency OCT12, the operation of the first avalanche photodiode 13, the second avalanche photodiode 14;

The endoscopic ring-scanning micro-probe extends into the lumen, the micro-camera realizes the imaging guidance of the lesion in the lumen, the stepping motor controls the movement of the probe to accurately locate the lesion, and the balloon is stretched to fix the probe; frequency-sweeping OCT and 405nm laser The frequency-sweeping laser and 405nm laser are emitted, which are combined by a wavelength division multiplexer and double-clad fiber coupler to transmit to the endoscopic ring-scanning microprobe, and irradiated to the lesion29; the frequency-sweeping laser is irradiated to the lesion to generate OCT signals, After the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce, and the OCT signal, the fluorescence signal, and the reflection signal of the 405nm laser return to the double-clad fiber coupler through the original optical path; the OCT signal returns to the Sweep frequency OCT for detection, and transmit to signal processing and control module for processing; 405nm laser reflection signal and fluorescence signal are split by dichroic mirror, 405nm laser reflection signal is reflected by mirror and filtered by neutral density filter The light reaches the first avalanche photodiode and is transmitted to the signal processing and control module for processing; the fluorescent signal is filtered by a bandpass filter and then reaches the second avalanche photodiode, and is transmitted to the signal processing and control module for processing; The micro-motor rotates and scans the luminal lesion circularly to obtain the complete information of the lesion, and then completes the three-dimensional reconstruction of the tissue, the extraction of the optical characteristic parameters of the tissue, and the quantification of the concentration of the photosensitizer.

In the present invention, the endoscopic ring-scanning micro-probe is inserted into the lumen, the micro-camera realizes the lesion imaging guide in the lumen, the stepping motor controls the movement of the probe, and after reaching the bottom of the lumen, the balloon stretches to fix the probe; Frequency OCT and 405nm lasers emit frequency-sweeping laser and 405nm laser, which are combined by wavelength division multiplexer and double-clad fiber coupler to transmit to endoscopic ring-scanning microprobe and irradiate to the lesion; after the frequency-sweeping laser is irradiated to the lesion OCT signal is generated, after the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce, and the OCT signal, the fluorescence signal, and the reflected signal of the 405nm laser return to the double-clad fiber coupler through the original optical path, and are respectively transmitted to the signal processing and control module; control the rotation of the micro-motor, scan the luminal lesion circularly to obtain the complete information of the lesion, the signal processing and control module processes the OCT signal, fluorescence signal and 405nm laser, and then completes the three-dimensional reconstruction of the tissue and the optical characteristics of the tissue Acquisition of parameters and quantification of photosensitizer concentration; quantitative detection of photosensitizer concentration distribution in the lumen guides precise treatment of intraluminal lesions and further improves the safety and effectiveness of photodynamic therapy.

Preferably, the endoscopic ring scan microprobe includes: micro camera power supply line 17, micro motor power supply line 18, curved mirror 19, UV curing glue 20, metal shield 21, torque coil 22, double-clad optical fiber 23. Balloon 24, self-focusing lens 25, micro motor 26, micro camera 27, transparent sleeve 28; the probe uses the micro camera to guide visual imaging of lesions, and realizes circular scanning detection of lesions in the lumen.

Preferably, the endoscopic ring scanning microprobe customizes the size of the balloon according to the size of the lumen. , The size of the esophagus, to ensure that the lumen is evenly stretched to reduce folds.

Preferably, the endoscopic ring-scanning microprobe adopts a curved mirror to eliminate chromatic aberration and astigmatism.

Preferably, the signal processing and control module collect tissue microstructure, tissue optical properties and photosensitizer fluorescence synchronously.

Preferably, the first avalanche photodiode collects the reflection signal of the 405nm laser, and the second avalanche photodiode collects the fluorescence signal of the photosensitizer at the lesion after being excited by the 405nm laser, so as to perform quantitative fluorescence detection of the photosensitizer.

Also provided is a working method of a ring-scan photosensitizer fluorescence quantitative detection system, which includes the following steps:

(1) Administer photosensitizers to patients by local application or intravenous injection;

(2) The endoscopic ring-scanning micro-probe is inserted into the lumen, and the lesion is visualized and guided by the micro-camera to accurately locate the lesion. After the probe reaches the lesion, the balloon is stretched;

(3) Frequency-sweeping OCT emits a frequency-sweeping laser, and a 405nm laser emits a 405nm laser, which is combined by a wavelength division multiplexer and a double-clad fiber coupler and transmitted to the endoscopic ring-scanning microprobe, and irradiates the lesion in a ring-sweeping manner. OCT signals are generated after the high-frequency laser is irradiated to the lesion, and after the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce;

(4) OCT signal, fluorescence signal and the reflected signal of 405nm laser return to the double-clad fiber coupler through the original optical path; the OCT signal returns to the frequency-sweeping OCT for detection through the wavelength division multiplexer, and is transmitted to the signal processing and control module Processing; after the reflection signal and fluorescence signal of the 405nm laser are split by the dichroic mirror, the reflection signal of the 405nm laser is reflected by the mirror, filtered by the neutral density filter, and then reaches the first avalanche photodiode, and is transmitted to the signal processing Processing with the control module; the fluorescent signal reaches the second avalanche photodiode after being filtered by the band-pass filter, and is transmitted to the signal processing and control module for processing;

(5) The signal processing and control module controls the rotation of the micro-motor, and repeats steps (3) and (4) to obtain single-point lesion information every time a small angle is rotated, and the micro-motor rotates once to obtain the scanning information of each point on the ring, The stepping motor controls the linear movement of the optical fiber to complete the scanning of all lesions in the lumen;

(6) The signal processing and control module processes the OCT signal, the fluorescence signal and the reflection signal of the 405nm laser. The OCT signal is used for the three-dimensional reconstruction of the tissue and the extraction of the optical characteristic parameters of the tissue, and combines the fluorescence signal and the laser reflection signal to complete the measurement of the fluorescence intensity. Correction;

(7) Construct optical phantoms of tissues with different scattering and absorption, establish a quantitative relationship curve between fluorescence intensity and photosensitizer concentration, and quantify the concentration of photosensitizer in the lumen.

Preferably, when using the OCT signal to calculate the tissue attenuation coefficient, the specific calculation method used is formula (1):

Among them, i is the i-th pixel on the A-line, I[i] is the signal intensity on the i-th pixel,

Δ is the pixel size, and μ[i] represents the attenuation coefficient of the i-th pixel of the tissue to be measured on the A-line.

Preferably, when correcting the fluorescence intensity, the specific method used is: after the tissue attenuation coefficient is calculated using the OCT signal, the collected original fluorescence signal, 405nm laser reflection signal and tissue attenuation coefficient are substituted into the formula (2) Correct for fluorescence intensity:

为校正后的荧光强度，/>

为原始荧光信号，R_x(λ)为405nm激光的漫反射率，α为经验系数。in,

is the corrected fluorescence intensity, />

is the original fluorescence signal, R _x (λ) is the diffuse reflectance of the 405nm laser, and α is the empirical coefficient.

Specific embodiments of the present invention will be described in detail below.

Example 1: The lesion tissue is esophageal mucosal tissue

As shown in Figure 3, the working process of the present invention is:

(1) Inject the photosensitizer into the body through intravenous injection in advance;

(2) The endoscopic ring-scanning micro-probe is inserted into the lumen of the esophagus, and the micro-camera is used to guide the visualization of the lesion and accurately locate the esophageal lesion. After the probe reaches the lesion, the balloon is stretched;

(3) Start the frequency-sweeping OCT and 405nm laser, and emit the frequency-sweeping laser and 405nm laser, which are combined by a wavelength division multiplexer and double-clad fiber coupler and transmitted to the endoscopic ring-scanning microprobe, irradiated to the esophageal lesion, and scanned. OCT signals are generated after the high-frequency laser is irradiated to the lesion, and after the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce;

(4) OCT signal, fluorescence signal and the reflected signal of 405nm laser return to the double-clad fiber coupler through the original optical path; the OCT signal returns to the frequency-sweeping OCT for detection through the wavelength division multiplexer, and is transmitted to the signal processing and control module Processing; after the reflection signal and fluorescence signal of the 405nm laser are split by the dichroic mirror, the reflection signal of the 405nm laser is reflected by the mirror, filtered by the neutral density filter, and then reaches the first avalanche photodiode, and is transmitted to the signal processing Processing with the control module; the fluorescent signal reaches the second avalanche photodiode after being filtered by the band-pass filter, and is transmitted to the signal processing and control module for processing;

(5) Control the rotation of the micro-motor, and repeat steps (3) and (4) to obtain single-point lesion information every time a small angle is rotated. The micro-motor rotates one circle to obtain the scanning information of each point on the ring. Linear movement to complete the scanning of all lesions in the esophageal lumen;

(6) The signal processing and control module processes the OCT signal, the fluorescence signal and the reflection signal of the 405nm laser. The OCT signal is used for the three-dimensional reconstruction of the tissue and the extraction of the optical characteristic parameters of the tissue, and combines the fluorescence signal and the laser reflection signal to complete the measurement of the fluorescence intensity. Correction;

(7) Construct a tissue optical phantom for different scattering and absorption of esophageal tissue optical properties, establish a quantitative relationship curve between fluorescence intensity and photosensitizer concentration, and quantify the concentration of photosensitizer in the esophagus lumen.

Example 2: The lesion tissue is mucosal tissue in the cervical canal

As shown in Figure 4, the working process of the present invention is:

(1) Apply the photosensitizer to the cervical canal for 4 hours in advance by local application;

(2) The endoscopic ring-scanning micro-probe is inserted into the cervical lumen, and the lesion is visualized and guided by the micro-camera to accurately locate the lesion area in the endocervical canal. After the probe reaches the lesion, the balloon is stretched;

(3) Start the frequency-sweeping OCT and 405nm laser, and emit the frequency-sweeping laser and 405nm laser, which are combined by a wavelength division multiplexer and double-clad fiber coupler and transmitted to the endoscopic ring-scanning microprobe to irradiate the cervical lesion mucosa, OCT signals are generated after the frequency-sweeping laser is irradiated to the lesion, and after the 405nm laser is irradiated to the lesion, the photosensitizer at the lesion is excited to fluoresce;

(4) OCT signal, fluorescence signal and the reflected signal of 405nm laser return to the double-clad fiber coupler through the original optical path; the OCT signal returns to the frequency-sweeping OCT for detection through the wavelength division multiplexer, and is transmitted to the signal processing and control module Processing; after the reflection signal and fluorescence signal of the 405nm laser are split by the dichroic mirror, the reflection signal of the 405nm laser is reflected by the mirror, filtered by the neutral density filter, and then reaches the first avalanche photodiode, and is transmitted to the signal processing Processing with the control module; the fluorescent signal reaches the second avalanche photodiode after being filtered by the band-pass filter, and is transmitted to the signal processing and control module for processing;

(5) Control the rotation of the micro-motor, and repeat steps (3) and (4) to obtain single-point lesion information every time a small angle is rotated. The micro-motor rotates one circle to obtain the scanning information of each point on the ring. Linear movement to complete the scanning of all lesions in the cervical canal;

(6) The signal processing and control module processes the OCT signal, the fluorescence signal and the reflection signal of the 405nm laser. The OCT signal is used for the three-dimensional reconstruction of the tissue and the extraction of the optical characteristic parameters of the tissue, and combines the fluorescence signal and the laser reflection signal to complete the measurement of the fluorescence intensity. Correction;

(7) Constructing tissue optical phantoms for different scattering and absorption of cervical tissue optical properties, establishing a quantitative relationship curve between fluorescence intensity and photosensitizer concentration, and quantifying the concentration of photosensitizer in the cervical canal.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are still within the scope of this invention. The protection scope of the technical solution of the invention.

Claims (9)

1. The circular scanning photosensitizer fluorescence quantitative detection system is characterized in that: it comprises the following steps:

an endoscopic circular scanning detection module (3) comprising: the endoscopic circular scanning detection module is used for focus visualization and diagnosis and treatment in a lumen;

a multi-modal signal detection module (16), comprising: the double-clad optical fiber coupler (4), an objective lens (5), a reflecting mirror (6), a dichroic mirror (7), a wavelength division multiplexer (8), a neutral density filter (9), a band-pass filter (10), a 405nm laser (11), a sweep OCT (12), a first avalanche photodiode (13) and a second avalanche photodiode (14), the multi-mode signal detection module is used for collecting fluorescent signals, reflection signals of 405nm excitation light and OCT signals of tissues;

the signal processing and controlling module (15) is used for processing the fluorescence signal, the reflection signal of 405nm laser and the OCT signal of tissue, which are acquired by the multi-mode signal detecting module, and controlling the operation of each device, the 405nm laser (11), the sweep OCT (12), the first avalanche photodiode (13) and the second avalanche photodiode (14) in the endoscopic circular scanning detecting module; the endoscopic circular scanning micro probe extends into the lumen, the miniature camera achieves focus imaging guidance in the lumen, the stepping motor controls the probe to move so as to accurately position the focus, and the saccule is spread so as to fix the probe; the sweep OCT and 405nm laser emit sweep laser and 405nm laser, and the sweep laser and the 405nm laser are transmitted to an endoscopic circular scanning microprobe through a wavelength division multiplexer beam combination and a double-clad optical fiber coupler and irradiated to a focus (29); after the sweep laser irradiates the focus, an OCT signal is generated, after the laser of 405nm irradiates the focus, the photosensitizer at the focus is excited to emit fluorescence, and the OCT signal, the fluorescence signal and the reflection signal of the laser of 405nm return to the double-cladding optical fiber coupler through the original optical path; the OCT signal returns to the sweep OCT through the wavelength division multiplexer for detection and is transmitted to the signal processing and control module for processing; after the reflected signal and the fluorescent signal of the 405nm laser are split by the dichroic mirror, the reflected signal of the 405nm laser is reflected by the reflecting mirror, filtered by the neutral density filter and then reaches the first avalanche photodiode, and is transmitted to the signal processing and control module for processing; the fluorescence signal reaches the second avalanche photodiode after being filtered by the band-pass filter and is transmitted to the signal processing and control module for processing; the micro motor is controlled to rotate, and the annular scanning is carried out on the focus of the tube to obtain the complete information of the focus, thereby completing the three-dimensional reconstruction of the tissue, the extraction of the optical characteristic parameters of the tissue and the quantification of the concentration of the photosensitizer.

2. The circular scanning photosensitizer fluorescence quantitative detection system according to claim 1, wherein: the endoscopic circular scanning microprobe comprises: the miniature camera power supply line (17), the miniature motor power supply line (18), the curved mirror (19), the UV curing adhesive (20), the metal protective cover (21), the torque coil (22), the double-clad optical fiber (23), the balloon (24), the self-focusing lens (25), the miniature motor (26), the miniature camera (27) and the transparent sleeve (28); the probe performs visual imaging guidance of the focus through the miniature camera and realizes annular scanning detection of the focus in the lumen.

3. The circular scanning photosensitizer fluorescence quantitative detection system according to claim 2, wherein: the endoscopic circular scanning microprobe is characterized in that the size of the balloon is customized according to the size of a lumen, and the diameters of the balloon are respectively as follows: 1.0cm, 1.5cm, 2.0cm, 2.5cm, 3.0cm, so as to adapt to the sizes of different lumens such as cervical canal and esophagus, and ensure that the lumens are uniformly spread to reduce wrinkles.

4. The circular scanning photosensitizer fluorescence quantitative detection system according to claim 3, wherein: the endoscopic circular scanning microprobe adopts a curved surface reflector for eliminating chromatic aberration and astigmatism.

5. The circular scanning photosensitizer fluorescence quantitative detection system according to claim 4, wherein: and the signal processing and control module synchronously acquires tissue microstructure, tissue optical characteristics and photosensitizer fluorescence.

6. The circular scanning photosensitizer fluorescence quantitative detection system according to claim 5, wherein: the first avalanche photodiode collects reflection signals of 405nm laser, and the second avalanche photodiode collects fluorescence signals of the focus photosensitizer excited by the 405nm laser so as to conduct photosensitizer fluorescence quantitative detection.

7. The working method of the circular scanning photosensitizer fluorescence quantitative detection system is characterized by comprising the following steps of: which comprises the following steps:

(1) Administering a photosensitizer to a patient by topical application or intravenous injection;

(2) The endoscopic circular scanning micro probe extends into the lumen, focus visual guidance is carried out through the micro camera, the focus is precisely positioned, and the saccule is opened after the probe reaches the focus;

(3) The sweep OCT emits sweep laser, the 405nm laser emits 405nm laser, the laser is transmitted to an endoscopic annular sweep microprobe through a wavelength division multiplexer beam combination and a double-cladding optical fiber coupler, and focus annular sweep is irradiated, OCT signals are generated after the sweep laser irradiates the focus, and after the focus is irradiated by the 405nm laser, the photosensitizer at the focus is excited to emit fluorescence;

(4) The OCT signal, the fluorescent signal and the reflection signal of 405nm laser return to the double-cladding optical fiber coupler through the original optical path; the OCT signal returns to the sweep OCT through the wavelength division multiplexer for detection and is transmitted to the signal processing and control module for processing; after the reflected signal and the fluorescent signal of the 405nm laser are split by the dichroic mirror, the reflected signal of the 405nm laser is reflected by the reflecting mirror, filtered by the neutral density filter and then reaches the first avalanche photodiode, and is transmitted to the signal processing and control module for processing; the fluorescence signal reaches the second avalanche photodiode after being filtered by the band-pass filter and is transmitted to the signal processing and control module for processing;

(5) The signal processing and control module controls the micro motor to rotate, each time the micro motor rotates by a small angle, the steps (3) and (4) are repeated to obtain single-point focus information, the micro motor rotates for one circle to obtain scanning information of each point on the ring, the stepping motor controls the linear movement of the optical fiber,

completing the scanning of all focus positions in the lumen;

(6) The signal processing and controlling module processes the OCT signal, the fluorescent signal and the reflection signal of 405nm laser, the OCT signal is used for three-dimensional reconstruction of tissues and extraction of optical characteristic parameters of the tissues, and the fluorescent signal and the laser reflection signal are combined to complete correction of fluorescent intensity;

(7) And constructing tissue optical imitations with different scattering and absorption, and establishing a quantitative relation curve of fluorescence intensity and photosensitizer concentration to quantify the photosensitizer concentration in the lumen.

8. The method for operating the circular scanning photosensitizer fluorescence quantitative detection system according to claim 7, wherein the method comprises the following steps: when the OCT signal is used to calculate the tissue attenuation coefficient, the specific calculation method used is formula (1):

wherein I is the ith pixel on the A-line, ii is the signal intensity on the ith pixel, delta is the pixel size, and mu I represents the attenuation coefficient of the ith pixel on the A-line of the tissue to be detected.

9. The method for operating the circular scanning photosensitizer fluorescence quantitative detection system according to claim 8, wherein the method comprises the following steps: in the correction of fluorescence intensity, the specific method used is: after the tissue attenuation coefficient is calculated by utilizing the OCT signal, substituting the collected original fluorescence signal, the 405nm laser reflection signal and the tissue attenuation coefficient into a formula (2) to correct the fluorescence intensity:

wherein,,

for the corrected fluorescence intensity, +.>

R is the original fluorescent signal _x (lambda) is the diffuse reflectance of the 405nm laser and alpha is the empirical factor.

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