CN114749796B - Device and method for welding biological tissue by using double-beam laser - Google Patents

Abstract

The present invention belongs to the field of laser medicine, and specifically relates to a device and method for welding biological tissues using dual-beam lasers. It includes a first laser, a second laser, a walking mechanism, an imaging system, a temperature detection system, a workbench and a controller; the biological tissue to be welded is placed on the workbench, the power of the second laser is greater than the power of the first laser, the walking mechanism controls the movement of the first laser and the second laser according to the control instructions of the controller, the temperature detection system is used to monitor the temperature of the biological tissue to be welded in real time, and transmit the signal to the controller, the imaging system is used to obtain a three-dimensional image of the surface of the welded biological tissue, and transmit the image to the controller, and the controller controls the walking mechanism and the laser according to the temperature and the three-dimensional image. The present invention can freely combine the most suitable laser parameters according to different tissues in different parts of the organism to achieve low-damage and high-performance laser welding of skin tissue.

Description

A device and method for welding biological tissue using dual-beam laser

Technical Field

The invention belongs to the field of laser medicine, and in particular relates to a device and a method for welding biological tissues using double-beam lasers.

Background Art

With the gradual improvement of science and technology, surgical sutures in the medical field have also undergone a series of developments. Suture materials have evolved from the most traditional needle and thread sutures to suture glue and then to absorbable sutures. Suture technology has undergone step-by-step improvement from the initial manual development to mechanical sutures. However, both the changes in suture technology and the development of suture materials have caused the formation of postoperative scars. Even if intradermal sutures are used to avoid "centipede-like" suture scars after sutures, the formation of postoperative scars cannot be avoided. However, the emergence of laser suture technology will greatly improve this situation. The laser acts on the wound to produce collagen fibers or proteins, and the thermal effect generated by the laser causes them to cross-link and fuse, eliminating wound scars to the greatest extent, reducing thermal damage, and postoperative recovery will not produce severe inflammation. In addition, the suture speed is fast and the rejection reaction is small. This technology has always attracted much attention and has been used clinically abroad.

Laser welding uses a single beam laser to weld biological tissues, which is prone to insufficient tissue bonding strength. Blood and exudate may seep into the incision, causing the incision to crack. Single-wavelength laser welding incisions connect wound gaps by producing collagen fibers or proteins, but the strength is low. If there is a lot of blood or exudate inside the wound, it will gradually soften the protein used for connection, destroying this cross-linking fusion and causing the incision to crack. In addition, the penetration ability of a single laser is single, and full-layer welding cannot be achieved. For example, infrared lasers such as CO ₂ Ho: YAG are easily absorbed by water and can produce heat deposition at 2-20um on the skin surface to cause tissue fusion, but they are only suitable for thin-layer wound welding and cannot achieve deep-layer welding. When using Nd: YAG lasers with strong tissue penetration for skin welding, they can generate appropriate heat in deep tissues to achieve deep wound welding effects, but there is damage to shallow tissues. Therefore, there are great limitations in using single-wavelength lasers for tissue welding.

Summary of the invention

The purpose of the present invention is to provide a device and method for welding biological tissues with dual-beam lasers. According to the differences in optical properties of different parts of the biological tissues, a low-energy laser is first used to stimulate the production of biological tissue proteins, and then a high-energy laser is used to achieve welding of the wound, thereby achieving the purpose of greatly improving the tensile strength of the biological tissue after welding. Compared with single-beam laser welding, the present invention uses two laser beams for collaborative welding, and the laser energy distributed in the welding area of the biological tissue is more uniform, causing less thermal damage.

The technical solution to achieve the purpose of the present invention is: a device for welding biological tissue using a dual-beam laser, comprising a first laser, a second laser, a walking mechanism, an imaging system, a temperature monitoring system, a workbench and a controller;

The biological tissue to be welded is placed on a workbench, the power of the second laser is greater than the power of the first laser, the walking mechanism controls the movement of the first laser and the second laser according to the control instruction of the controller, the temperature monitoring system is used to monitor the temperature of the biological tissue to be welded in real time and transmit the signal to the controller, the imaging system is used to obtain a three-dimensional image of the surface of the welded biological tissue and transmit the image to the controller, and the controller controls the walking mechanism and the laser according to the temperature and the three-dimensional image.

Furthermore, the walking mechanism includes a first mechanical arm for controlling the first laser and a second mechanical arm for controlling the second laser, and the first mechanical arm and the second mechanical arm respectively realize the movement of the first laser and the second laser in three directions of x, y and z.

Furthermore, the first robotic arm and the second robotic arm have the same structure. The first robotic arm includes three sub-arms. The middle sub-arm and the sub-arms at both ends are rotatably connected, and the sub-arms at the end are connected to a guide device. The movement of the laser in the x and z directions is achieved through the rotation of the middle sub-arm and the sub-arms at both ends, and the movement of the laser in the y direction is achieved through the guide device.

Further, the guide rail device includes a guide rail, a guide rail motor and a mounting block;

One end of the mounting block is connected to a laser, and the other end moves in the guide rail under the action of the guide rail motor.

Furthermore, the temperature monitoring system includes an infrared thermal imager and a thermocouple temperature measuring plate, which are used to obtain the temperature distribution of the part to be welded, transmit the signal to the walking mechanism online, and adjust the welding speed at any time; the thermocouple temperature measuring plate is set on the workbench, and the biological tissue to be welded is set on the thermocouple temperature measuring plate.

Furthermore, the imaging system includes a horizontal laser profiler and a vertical laser profiler, both of which are installed on the guide rail for scanning, and are used to obtain real-time three-dimensional images of samples with complex welding surface structures, transmit signals to the walking mechanism online, and optimize the welding path in time.

A method for welding using the above device comprises the following steps:

Step (1): using a first laser to stimulate protein chain decomposition in biological tissues to complete a pilot scanning process of the biological tissues;

Step (2): Use a second laser to perform laser tissue welding on the tissue after the pilot scan within 5-10 seconds.

Furthermore, the power of the second laser is 3 to 5 times that of the first laser.

Furthermore, the first laser is a 980nm continuous fiber laser, and the second laser is a 1064nm continuous laser.

Furthermore, the output power of the first laser is 1-2W, the scanning speed is 120-180mm/s; the output power of the second laser is 5-7W, the scanning speed is 220-280mm/s, and the duty cycle is 100%.

Compared with the prior art, the present invention has the following significant advantages:

(1) The present invention uses two independent lasers, which can move without interfering with each other, and are more flexible, and can complete welding work at various angles, thereby meeting the differences in tissue morphology of biological tissues; the first low-energy laser generator can stimulate tissue protein chain decomposition, and the second high-energy laser uses the generated protein chain decomposition products to perform tissue welding, which can reduce the use of biological solder, or even eliminate the use of biological solder, greatly reducing processing consumption;

(2) The present invention aims at the property that low heat acting on biological tissue can induce protein precipitation without damaging the tissue itself. By adjusting the frequency of the two laser beams and the time of irradiating the biological tissue, the heat input of the laser acting on the biological tissue is controlled to achieve the maximum bonding strength of tissue fusion and the minimum thermal damage.

(3) The imaging system used in the present invention adopts a collaborative profilometer to establish a three-dimensional image of the wound model for incisions of different types and structures and then feed it back to the walking mechanism to optimize the welding path in real time, ensure that the welding process is accurate and reliable, and achieve full-layer welding of the tissue;

(4) The temperature monitoring system of the present invention uses two temperature measuring instruments to monitor the temperature changes of tissues in real time, transmit the results of temperature comparison to the walking mechanism, adjust parameters such as welding distance or welding speed, so that the temperature of biological tissue welding is within the optimal range, ensure the basic welding temperature while reducing the high temperature residence time of the welding area, and finally achieve a welding effect with high continuity of the fit and small area of irreversible thermal damage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a device of the present invention.

FIG. 2 is a schematic flow chart of the method of the present invention.

FIG. 3 is a schematic diagram of the laser X and Z direction control method of the present invention.

FIG. 4 is a schematic diagram of the Y-direction control method of the laser of the present invention.

FIG. 5 is a thermocouple distribution diagram of a thermocouple temperature measuring plate in the temperature monitoring system of the present invention.

FIG. 6 is a schematic diagram of a temperature monitoring system according to the present invention.

Description of reference numerals:

1-1-first robotic arm, 1-2-second robotic arm, 2-1-first guide rail device, 2-2-second guide rail device, 2-3-guide rail motor, 3-1-first laser, 3-2-second laser, 4-temperature monitoring system, 5-workbench, 6-imaging system, 7-first measuring instrument, 8-second measuring instrument.

DETAILED DESCRIPTION

The present invention is further described in detail below in conjunction with the accompanying drawings.

In conjunction with Figure 1, the dual-beam laser welding device for biological tissue of the present invention mainly includes a first robotic arm 1-1, a second robotic arm 1-2, a first guide rail device 2-1, a second guide rail device 2-2, a guide rail motor 2-3, a first laser 3-1, a second laser 3-2, a temperature monitoring system 4, a workbench 5, an imaging system 6, a first measuring instrument 7, and a second measuring instrument 8.

Two robots and two lasers are mounted on the robot. The robot adjusts the position and angle of the two lasers according to the instructions of the imaging system and then processes the biological tissue. The two motors inside the manipulator arm drive the pulley combination to adjust the X and Z directions respectively. The specific process and assembly position are shown in Figure 3. When the wound depth changes, it can also be adjusted according to the three-dimensional image of the imaging system. Then, the laser angle is adjusted by the motor in the guide rail device (as shown in Figure 4) to change the processing Y axis direction. The pulley and guide rail combination completes the welding of various complex paths. Two lasers, the first laser 3-1 and the second laser 3-2, respectively output the most suitable lasers for stimulating protein production and the tissue to be welded according to the characteristics of the biological tissue to be processed. There is no specific restriction on the requirements of the lasers. It can be either a pulsed laser or a continuous laser. The two lasers operate separately and independently and cooperate with each other.

The workbench is mainly loaded with an imaging system 6 and a temperature monitoring system 4 .

The temperature monitoring system 4 (as shown in FIG6 ) consists of two parts, one of which uses an infrared thermal imager to record the temperature distribution of the upper surface of the welded part by thermal radiation, and the other part uses thermocouples evenly distributed on the temperature measuring plate mounted on the processing table to record the temperature distribution of the lower surface of the welded part, and can measure multiple single-point temperatures. The real-time change of the temperature at the laser action point during the whole process can be compared with the optimal temperature range, so as to transmit the adjustment information of the welding speed to the walking mechanism.

The imaging system 6 is mounted on a workbench and consists of two laser profile measuring instruments. The measuring instrument in the horizontal direction scans the model on the horizontal plane of the tissue, and the measuring instrument in the vertical direction is used to scan the model on the vertical plane of the tissue. The two-dimensional plane of the wound path can be used to complete the stimulation process of the first laser, and the data of these two planes can be combined to obtain an accurate three-dimensional image model of the biological tissue to be welded. This is beneficial to the realization of the precision of the welding path for tissues with complex surface structures. The specific path obtained after image processing is transmitted to the walking mechanism to adjust the welding path.

In conjunction with FIG2 , the process of using the mixed beam laser biological tissue welding device of the present invention is as follows:

Step 1: Select a laser that emits a laser wavelength according to the characteristics of different biological tissues, and select a laser output mode, which is usually a continuous output or a pulse output. For example: First, the first laser 3-1 uses a low-intensity fiber laser to stimulate the precipitation of proteins and related substances, and then the second laser 3-2 uses a high-intensity pulse laser to weld the wound, and the welding strength of the wound is enhanced and thermal damage is reduced through the mutual synergy of the dual-beam laser;

Step 2: according to the appearance of the incision or wound tissue, such as the shape, depth and area, the parameters of the first laser 3-1 and the second laser 3-2 are preset, mainly including the working mode, power, pulse width, repetition frequency and other parameters;

Step 3, placing and fixing the biological tissue sample on the workbench 5, first irradiating the light spot generated by the laser to the position before the starting welding position, and adjusting the light spot sizes of the two lasers according to the path of the tissue or the size of the wound surface;

Step 4: Scan the incision according to the imaging system, and plan the specific path of the wound transmission to the walking mechanism, determine the initial welding position of the tissue and the path of the tissue to be welded, and feed back to the walking mechanism to drive the laser to weld the tissue in a specific path, operate the first laser 3-1 to stimulate the tissue near the wound to produce protein, and the second laser 3-2 completes the welding of the tissue incision as a whole;

Step 5, correct the welding speed according to the combined result of the upper layer temperature measured by the infrared thermal imager of the temperature monitoring system 4 and the lower layer temperature obtained by the thermocouple temperature measuring board, so as to avoid poor welding effect caused by too low temperature or thermal damage caused by too high temperature;

Step 6: After the welding process is completed, turn off the system power and remove the target tissue.

Embodiment 1:

The present invention is further described below in conjunction with experiments.

Fresh pig skin tissue with a size of 30 mm × 20 mm × 3 mm was used as the experimental material, which was soaked in bovine protein biosolder for 15 min. After wiping off the excess biosolder, a No. 11 scalpel was used to make a 1 mm wide incision that penetrated the entire cortex.

Place the sample tissue on the workbench, operate the imaging system to scan the biological tissue first, create a three-dimensional image, and determine the initial welding parameters and scanning path.

Laser 3-1 is a 980nm continuous fiber laser with an output power of 1W and a scanning speed of 150mm/s; laser 3-2 is a 1064nm continuous laser with an output power of 5W, a scanning speed of 250mm/s, and a duty cycle of 100%.

During the whole welding process, the temperature monitoring system uses an infrared thermal imager and a thermocouple temperature measuring plate to provide real-time feedback on the temperature changes on the upper and lower surfaces of the tissue. If the upper temperature is lower than 40°C, the feedback walking mechanism will reduce the welding speed. If the temperature is higher than 40°C, the welding speed can be increased. The specific distribution of thermocouples in the thermocouple temperature measuring plate designed according to the biological tissue of this experiment is shown in Figure 5. The thermocouple has a diameter of 1.5mm and a length of 3.2mm. It is embedded in the plate. The top of the thermocouple penetrates 1mm into the biological tissue. Four thermocouples are evenly distributed on both sides of the incision. The specific temperature monitoring device is shown in Figure 6.

The first measuring instrument 7 of the imaging system is installed on the horizontal guide rail to scan the model on the horizontal plane of the sample tissue. The second measuring instrument 8 is installed on the vertical guide rail to scan the model on the vertical plane of the tissue. The image data of these two planes can be combined to obtain a three-dimensional image of the welding tissue sample. The specific welding path obtained after image information processing is fed back to the walking mechanism for real-time optimization of the welding path.

According to the results of the imaging system, the welding path is edited. Specifically, it can be divided into two stages. Stage 1: by controlling the first laser 3-1 and the matching device (1-1), the protein chain dissolution at the incision welding site is stimulated to complete the pilot scanning process of the biological tissue, and the speed is optimized according to the feedback of the temperature monitoring system; Stage 2: after stimulating the protein chain dissolution, the walking mechanism directly controls the second laser 3-2 and the matching device (1-2) (the specific moving process is shown in Figure 4, ① is the starting welding state, and this process is completed through ①→②→③, and only moves in the X direction and Z direction) and the guide device (2-2) (to achieve Y direction movement) to perform laser tissue welding on the tissue in three directions.

After welding, turn off all power to the system and remove the sample tissue.

Claims (1)

1. A method for welding biological tissues using a dual-beam laser welding device, characterized in that the device comprises a first laser, a second laser, a walking mechanism, an imaging system, a temperature monitoring system, a workbench and a controller; the biological tissue to be welded is placed on the workbench, the power of the second laser is greater than the power of the first laser, the walking mechanism controls the movement of the first laser and the second laser according to the control instruction of the controller, the temperature monitoring system is used to monitor the temperature of the biological tissue to be welded in real time and transmit the signal to the controller, the imaging system is used to obtain a three-dimensional image of the surface of the welded biological tissue and transmit the image to the controller, and the controller controls the walking mechanism and the laser according to the temperature and the three-dimensional image; the walking mechanism comprises a first mechanical arm for controlling the first laser and a second mechanical arm for controlling the second laser, and the first mechanical arm and the second mechanical arm respectively realize the movement of the first laser and the second laser in three directions of x, y and z; the structures of the first mechanical arm and the second mechanical arm are similar The first mechanical arm includes three sub-arms, the middle sub-arm and the sub-arms at both ends are rotatably connected, and the sub-arms at the end are connected to the guide rail device, the movement of the laser in the x and z directions is realized by the rotation of the middle sub-arm and the sub-arms at both ends, and the movement of the laser in the y direction is realized by the guide rail device; the guide rail device includes a guide rail, a guide rail motor and a mounting block; one end of the mounting block is connected to the laser, and the other end moves in the guide rail under the action of the guide rail motor; the temperature monitoring system includes an infrared thermal imager and a thermocouple temperature measuring plate, which are used to obtain the temperature distribution of the part to be welded, transmit the signal to the walking mechanism online, and adjust the welding speed at any time; the thermocouple temperature measuring plate is set on the workbench, and the biological tissue to be welded is set on the thermocouple temperature measuring plate; the imaging system includes a horizontal laser profile measuring instrument and a vertical laser profile measuring instrument, both of which are installed on the guide rail for scanning, and are used to obtain real-time three-dimensional images of samples with complex welding surface structures, transmit signals to the walking mechanism online, and optimize the welding path in time; The steps include: Step (1): using a first laser to stimulate protein chain decomposition in biological tissue to complete a pilot scanning process of the biological tissue; Step (2): using a second laser to perform laser tissue welding on the tissue after the pilot scan within 5-10 seconds; The power of the second laser is 3 to 5 times that of the first laser; The first laser is a 980nm continuous fiber laser, and the second laser is a 1064nm continuous laser; The output power of the first laser is 1-2W, the scanning speed is 120-180mm/s; the output power of the second laser is 5-7W, the scanning speed is 220-280mm/s, and the duty cycle is 100%.