KR102011975B1 - Photoacoustic and ultrasonic endoscopy system including a coaxially-configured optical and electromagnetic rotary waveguide assembly and embodiment method thereof - Google Patents

Abstract

An optoacoustic-ultrasound endoscope according to an embodiment of the present invention includes a probe and a probe driving unit, wherein the probe includes a fiber including a core and a cladding and a rotating coaxial light including a conductive passage coaxially disposed with the optical fiber. An electromagnetic waveguide assembly, a scanning tip disposed at one end of the rotatable coaxial optical-electromagnetic waveguide assembly, and scanning a photoacoustic-ultrasound signal generated from the subject by sending a laser beam to the subject and the rotating coaxial optical-electromagnetic And a plastic catheter surrounding the outside of the waveguide assembly and the scanning tip, wherein the conductive passageway comprises a first conductive passageway comprising a portion coaxially disposed with the optical fiber and a portion coaxially disposed with the optical fiber; And a second conductive passageway insulated from the conductive passageway.

Description

Photoacoustic and ultrasonic endoscopy system including a coaxially-configured optical and electromagnetic rotary waveguide assembly and embodiment method according to the present invention.

The present invention relates to a medical tomography endoscopy device that can be implemented in the form of an elongated probe, such as an ultrasound endoscope currently used in the clinic, to be inserted into a subject and provide a tomography image around the object. The photoacoustic imaging principle was applied to obtain the tomographic image of the inside of the subject, and the endoscopy system proposed by the present invention provides high quality photoacoustics based on the probe flexibility and rotational uniformity which are significantly improved than the previous systems. Tomography images as well as traditional ultrasound images can be obtained simultaneously. The present invention can be applied to various medical imaging fields such as diagnosing gastrointestinal diseases and cardiovascular diseases in the future.

The present invention is intended to be applied to the medical field such as digestive or cardiovascular diagnosis in a similar manner to the ultrasound-based mini-probe (aka endoscopic ultrasound mini-probe) or vascular diagnostic catheter probe (also known as intravascular ultrasound catheter) currently used in clinical practice The present invention relates to a tomography endoscopy system in the field of photoacoustic endoscopy.

Photoacoustic endoscopy is a small diameter probe inserted into a subject, and then an ultrasonic signal is generated by instantaneously irradiating an electromagnetic wave having a very short pulse width (typically 1 ㎲ or less) to a region of interest, and generating the ultrasonic signal. Refers to tomographic endoscopy that acquires (ie, scans) over an area to obtain a tomographic image inside the tissue.

The general principle of how electromagnetic waves irradiated into biological tissues are converted into ultrasonic signals has been known since the 1880s under the name of photoacoustic effect, but based on this principle, it is possible to obtain tomographic images from subjects such as biological tissues. This was after the commercialization of pulsed light sources, such as Q-switched lasers, in the early 1990s. Since then, various medical applications have been realized, and they have been implemented in various types of systems. In a broader sense, techniques for obtaining tomographic images in tissues based on optoacoustic effects are collectively referred to as photoacoustic imaging or photoacoustic tomography.

The reason why photoacoustic imaging technology is currently attracting much attention in the medical imaging field is that existing technology provides as well as satisfying various technical conditions such as image depth, resolution, image speed, and safety issues that can be applied in actual clinical field. This is because it provides new and useful video information that cannot be done. The present invention relates to an endoscopic application of this optoacoustic imaging technique, and to provide a more advanced configuration and operation principle of the device and its implementation method that can solve the problems of the previously proposed optoacoustic endoscope systems.

As with the well-known photoacoustic imaging system (i.e., not limited to the endoscope), a photoacoustic endoscopy system is provided by a light source that generates pulsed electromagnetic waves. Three device elements are required: an imaging probe for acquiring an acoustic tomographic signal, and a data processor and displayer for processing the acquired tomographic signal and presenting it to a user. However, the most distinguishing technical condition is that the imaging probe must be implemented in a very small or thin shape in order to achieve a specific application purpose of endoscopy.

Thus, although various types of optoacoustic endoscopy probes have been proposed to satisfy these morphological and functional conditions, a commercially available optoacoustic endoscopy system that can be applied to actual clinical sites has been developed. No bar In order to establish an optoacoustic endoscopy system, it is a key requirement that the optical and ultrasonic devices are effectively integrated into a small space called a probe and a series of scanning methods are applied to obtain a tomographic image. Accordingly, the present invention proposes a probe structure capable of obtaining an image much more effectively than the prior art with respect to an image probe part inserted into a subject to obtain an optoacoustic tomography signal.

Although the optoacoustic endoscope has a distinctive characteristic of obtaining an image by generating an ultrasonic wave with a pulsed electromagnetic wave, this technique also uses an endoscopic ultrasound that is currently used in clinical practice in terms of obtaining an image signal through an ultrasound. Is very closely related to EUS. In other words, it can be considered that the optoacoustic endoscope is an optical or electromagnetic wave transmission and launch function added to the system elements of the conventional ultrasonic endoscope technology, and due to the characteristics of the system configuration, most of the optoacoustic endoscopes The systems can provide photoacoustic images as well as conventional ultrasound images simultaneously.

Therefore, in the photoacoustic endoscope probe, it is currently used in clinical ultrasound endoscopes (EUS) devices, considering only the configuration method of the ultrasonic detection unit, except for the area that transmits the electromagnetic wave (generally the laser beam) and fires toward the subject. Both mechanical scanning based on single-element ultrasonic transducers and electronic scanning based on array transducers can be applied. Let's take a quick look at the pros and cons of applying each scan method.

First of all, when the latter is applied, data necessary for constructing a 2D or 3D tomographic image can be simultaneously acquired through multiple channels using only one laser pulse based on a plurality of transducer elements. In other words, it is possible to obtain a tomographic image of a predetermined region by only one laser pulse firing without shifting the position of the sensor or probe spatially. However, compared to the former, it is difficult to miniaturize a device, which may cause problems such as cross talk between channels, and may require a high cost for system implementation. Therefore, due to this very problem of arrayed transducers, in the field of ultrasound endoscopy (EUS), which is currently used in clinical practice, it is mainly applied to the endoscope device for diagnosing digestive organs that does not require high miniaturization. No work is required).

On the other hand, when the electron is applied, since only one ultrasonic transducer capable of detecting a signal traveling from a specific direction is mounted in the endoscope probe, in order to obtain a two-dimensional or more tomographic image, a laser pulse is emitted and There is a disadvantage in that a series of processes for detecting the generated ultrasonic signal have to be repeated by changing the physical position (generally rotating). However, since the space occupied by one ultrasonic transducer is not so large, it can be implemented in a very small and thin form, and the cost required for device configuration may be relatively low. For this reason, in the field of ultrasound endoscopy (EUS), an intravascular ultrasound (IVUS) catheter probe or a mini probe that can be inserted into an instrument channel or an accessory channel of a video endoscope can be used. , EUS mini-probe) and the like has been widely applied to microscopic endoscope devices having a probe diameter of less than 1 mm to 3 mm.

Due to these advantages and disadvantages, various systems using these two ultrasonic detection methods have been proposed in the field of optoacoustic endoscopic surgery, and as a representative example of the prior art adopting a single ultrasonic transducer-based mechanical scan method related to the present invention. Prior art 1 (US Patent Publication No. 2011-0021924), prior art document 2 (US Patent Publication No. 2011-0275890), prior art 3 (Journal of Biomedical Optics 19 (6), 066001 (2014)), prior art Document 4 (PloS One 9 (3), e92463 (2014)).

The endoscope systems disclosed in the above four documents all have a light unit coupled to an optical fiber end for transmitting light, and a single ultrasonic transducer for detecting the generated ultrasonic wave at the probe end portion and a predetermined rotational motion. It adopts a mechanical scanning method to obtain an image through. However, there is a significant difference in how the optical fiber, the light and the ultrasonic transducer are placed, and the detailed scanning method of obtaining the image through proper combination and driving thereof.

First, in the case of the endoscope system disclosed in Prior Art 1, a single ultrasonic transducer is installed at a scanning tip and a system using a mechanical element called a torque coil, similar to a conventional ultrasound-based IVUS catheter probe. Rotational scans are performed by transmitting power from the base to the scanning tip (actually, a commercial IVUS catheter is placed in the center of the endoscope probe). Of course, in order to achieve optoacoustic imaging, a number of optical fibers capable of transmitting light were placed at regular intervals around the IVUS catheter, which allows the centered ultrasonic transducer to be physically rotated while installed around the plastic catheter. The biggest feature is that the optical fibers are statically connected to their base point. However, this structure has a disadvantage in that a plurality of optical fibers are arranged in the probe section, and thus the flexibility thereof is not high, and the light illumination is not uniform for 360 ° directions.

On the contrary, the endoscope systems of Prior Documents 2 to 4 have a structure without such a problem, and each has the following characteristics.

In the case of the endoscope system shown in the prior reference 2, a scanning mirror capable of reflecting both light and ultrasonic waves and having a physically rotatable movement is placed at the end of the probe so that both the optical fiber and the signal line of the transducer can be statically extended to the probe base. (static) The connection is the biggest feature and advantage. In this case, however, there is a problem that the flexibility of the distal end is inferior because an actuator capable of driving the scanning mirror is mounted at the distal end of the probe. Can cause many problems).

The endoscope system of Prior Art 3 is derived from the endoscope system of Prior Art 2, which rotates only one strand of optical fiber disposed along the probe central axis, and the ultrasonic transducer and its electrical signal line are connected at the probe end along the outer surface of the plastic catheter. It is characterized by a static combination of the base. Of course, by applying this method, the length of the rigid section of the probe end point can be significantly reduced than that of the endoscope system of Prior Art 2, but a part of the angular field-of-view In addition to the problem of being obscured by the transducer's signal line (i.e. blind spot formation), the signal line has an asymmetrical probe (when rotating scans with the entire probe bent in a complex shape). There is a problem that the rotation speed is not uniform.

The endoscope system of Prior Art 4 provides a significant improvement in these aspects, once in its construction, a small ultrasonic transducer and light illumination are placed at the scanning tip at the probe end, Signal lines that receive electrical signals from the ultrasonic transducers mentioned above and optical fibers that transmit the laser beam to the above-mentioned light fixtures are flexible and bendable tube-shaped coils called torque coils or flexible shafts. Installed inside, they are then rotated with the power provided by the probe base (ie, the proximal actuation mechanism) to perform a rotational scan.

In fact, the method of realizing an optoacoustic endoscope by arranging signal lines and optical fiber strands of an ultrasonic transducer in parallel has already been proposed by prior art 5 in 1997 and has since been applied to various optoacoustic endoscope systems (Prior Art 6, Prior Art 7). And 8), a method of performing a rotational scan by transferring a physical rotational force from the base of the endoscope probe to the scanning tip using a mechanical element called a torque coil, and also uses an ultrasound-based mini endoscope probe or optical coherence tomography (OCT). ) Endoscopic probes (ie, endoscopic OCT) have been applied consistently (prior document 9 and prior art 10).

In this respect, the torque coil-based base-actuated optoacoustic endoscope, which is currently mentioned, is simply a single ultrasonic element-based, mechanical scanning method that is currently used in clinical practice. It's an optoacoustic version of the EUS mini-probe. However, the biggest difference from this ultrasonic mini probe is that it needs an additional fiber optic line for transmitting optical energy in addition to the existing signal line inside the torque coil, and it can effectively transmit and receive both optical energy and electric signal without twisting at the probe base. System components that are needed. In other words, when the base actuation method, such as the optoacoustic endoscopy system presented in prior art 4, is adopted, a rotary optical-electric junction (i.e., rotary optical and electrical junction) having a much more complicated structure than the conventional ultrasonic mini probe at the probe base To be configured.

Nevertheless, this donation actuation method is considered to be very important in the related art because, when applied, the entire catheter section of the endoscope probe is much more flexible than the endoscope system of Literatures 1 to 3. The key advantage is that it can be implemented. In practice, this flexibility issue is most important in ultrasonic mini-probes whose main purpose is to be inserted into the equipment channel of video endoscopes, and ultrasonic catheter probes whose main purpose is to diagnose the inside of blood vessels having physically very weak properties. As such, many of the photoacoustic endoscopic systems (ie, Literature 4 and Literature 8), which are being developed based on the device as well as similar applications and probe types, are all adopting this donation method. It is true.

Prior Document 1: US Patent Publication No. 2011-0021924 (2011.01.27.) Prior Document 2: US Patent Publication No. 2011-0275890 (Nov. 10, 2011) Prior Art 7: US Patent Publication No. 2011-0098572 (2011.04.28.) Prior Art 10: US Patent No. 6134003 (2000. 10.17.)

Prior Art 3: JM Yang, et al., "Catheter based photoacoustic endoscope", Journal of Biomedical Optics 19 (6), 066001 (2014) Prior Art 4: X Bai, et al., "Intravascular optical-resolution photoacoustic tomography with a 1.1 mm diameter catheter", PloS One 9 (3), e92463 (2014) Prior Art 5: Oraevsky, et al., Proc. SPIE, 2979, 59 (1997) Prior Art 6: Viator, et al., "Design and testing of an endoscopic photoacoustic probe for determination of treatment depth after photodynamic therapy", Proc. SPIE 4256, 16-27 (2001) Prior Art 8: Da Xing, et al., "Characterization of lipid-rich aortic plaques by intravascular photoacoustic tomography", Journal of the American college of cardiology 64 (4), 385-390 (2014) Prior Art 9: G. J. Tearney, et al., "Scanning single-mode fiber optic catheter-endoscope for optical coherence tomography", Optics Letters 21 (7), 543-545 (1996) Prior Art 11: JM Yang, et al., “Simultaneous functional photoacoustic and ultrasonic endoscopy of internal organs in vivo,” Nature Medicine 18 (8), 1297 (2012).

However, conventional photoacoustic endoscope systems (ie, prior art documents 4, 7, and 8) employing such a torque coil-based base actuation method simply place the optical fiber and the signal line in parallel inside the torque coil, thereby providing a mechanical rotational force. There was a problem that cannot be delivered evenly from the scanning tip. In practice, this problem is particularly acute when the endoscope probe is inserted into a narrow curved passageway, where the conventional probe has a rotationally symmetrical structure in which the optical fiber and the signal line are rotated about the central axis of rotation of the torque coil. In the severely curved situation, power is not evenly transmitted to the scanning tip at the end of the probe, resulting in a major deterioration of the image quality.

If the base point of the torque coil has rotated by a certain angle and the scanning tip at its opposite end does not rotate by the same angle, and this deviation also varies greatly with every change of the probe's curvature, It is obvious that it is impossible to construct a three-dimensional image based on several two-dimensional tomographic images, as well as to reduce the reliability of the image. Therefore, the related field has considered the problem of non-uniform rotation of this scanning tip very deeply, using the designation term non uniform rotational distortion (NURD), and any conventional optoacoustic endoscopy system can provide flexibility and scanning tips for the entire probe. It does not satisfy both core elements of uniformity of movement.

In addition to these key issues, the endoscope system disclosed in Prior Art 4, which employs a torque coil-based basal actuation method, and similar types of optoacoustic endoscopy systems, are all equipped with conventional gastrointestinal diagnostic ultrasonography mini probes or vascular diagnostic ultrasound catheter probes. It does not have an element such as a plastic catheter or a kind of protective cover called a sheath, and how the scanning tip within the probe can be isolated from the subject when it is physically rotated to protect the subject. It did not provide a concrete structure and method. And in addition to these most basic features, covering the entire scanning tip with a plastic catheter is a very important part of the technology because, in a similar way, like conventional ultrasonic mini probes developed for use by inserting into the instrument channel of a video endoscope. In the case of the photoacoustic endoscope probe being developed for use, the appropriate matching fluid must be filled in the probe and permanently sealed. However, in the case of the preceding optoacoustic endoscope systems (Patent Documents 4 to 8), there is no specific structure and method of how to cover the scanning tip and the torque coil whole area with a plastic catheter.

In other words, in a torque coil-based base actuated optoacoustic endoscope system, it is also very important to properly seal the entire physically rotating torque coil and scanning tip with a plastic catheter and effectively implement the rotating opto-electric coupling at the base of the probe. An important issue is that the literature does not provide a specific way of doing this.

An embodiment of the present invention includes a probe and a probe driving unit, wherein the probe includes a rotating coaxial optical-electromagnetic waveguide assembly including an optical fiber including a core and a cladding and a conductive passage disposed coaxially with the optical fiber. A scanning tip disposed at one end of the rotatable coaxial opto-electromagnetic waveguide assembly and configured to send a laser beam to the subject to detect optoacoustic-ultrasound signals generated from the subject and the rotatable coaxial opto-electromagnetic waveguide assembly and the scanning tip And a plastic catheter surrounding the outside of the conductive passage, wherein the conductive passage includes a first conductive passage including a portion coaxially disposed with the optical fiber and a portion coaxially disposed with the optical fiber, and insulated from the first conductive passage. An optoacoustic-ultrasound endoscope comprising a second conductive passageway is provided.

The first conductive passage may be provided to surround the optical fiber, and the second conductive passage may be provided to surround the first conductive passage coaxially with the first conductive passage.

At least one of the first conductive passage and the second conductive passage may be provided in a tubular shape.

At least one of the first conductive passage and the second conductive passage may include a torque coil set provided to be located outside the optical fiber in the form of a coil.

The first conductive passage and the second conductive passage may be provided to surround at least a portion of the optical fiber.

The rotatable coaxial opto-electromagnetic waveguide assembly may include an insulating coating layer interposed between the first conductive passage and the second conductive passage.

The cladding may include a first cladding capable of propagating light waves and a second cladding surrounding the first cladding.

Another embodiment of the present invention includes a probe and a probe driving unit, wherein the probe comprises: a coaxial optical-electromagnetic waveguide assembly disposed coaxially with the optical fiber and a conductive passage, the optical fiber including a core and a cladding; A scanning tip disposed at one end of the rotatable coaxial opto-electromagnetic waveguide assembly, the scanning tip for sending a laser beam to the subject to detect an optoacoustic-ultrasound signal generated from the subject, the rotatable coaxial opto-electromagnetic waveguide assembly and the scanning A plastic catheter that wraps around the outside of the tip and

And a rotary transformer electrically connected to the conductive passage, wherein the probe driving unit includes an optical input unit for transmitting optical energy to the rotating optical fiber and an ultrasonic pulser-receiver electrically connected to the rotary transformer. Provide an endoscope.

The rotation The transformer may include a primary coil part electrically connected to the conductive passage; And a secondary coil unit facing the primary coil unit and electrically connected to the ultrasonic pulser-receiver.

The optoacoustic-ultrasound endoscope according to one embodiment may further include a mesh-like reinforcement disposed inside the plastic catheter.

The probe may further include a fluid inlet.

The optoacoustic-ultrasound endoscope according to one embodiment may further include a guiding catheter surrounding the plastic catheter and including a guiding catheter fluid inlet and a guiding wire inserted into the guiding catheter fluid inlet.

The photoacoustic-ultrasound endoscope according to an embodiment may further include a light source for an OCT that provides a light wave for optical coherence tomography to the optical fiber.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to one embodiment of the present invention including an optical fiber and a conductive passage coaxial with the optical fiber as described above, the probe has a completely rotationally symmetrical structure, which greatly improves probe flexibility and uniformity of rotational scans over existing similar class of optoacoustic endoscopes. This can effectively solve the problem of non-uniform rotational distortion (NURD). Of course, the scope of the present invention is not limited by these effects.

1 is a schematic diagram schematically showing the configuration of an optoacoustic-ultrasound endoscope according to an embodiment.
FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1.
3 is a schematic diagram schematically showing the configuration of an optoacoustic-ultrasound endoscope including a waveguide assembly according to another embodiment.
FIG. 4 is a schematic diagram showing a specific configuration of the waveguide assembly of part A of FIG. 3.
FIG. 5 is a photograph actually implementing the waveguide assembly of FIG. 4. FIG.
6 is a schematic view showing the configuration of the waveguide assembly according to an embodiment and a cross-sectional view thereof.
7 is a schematic view and a cross-sectional view showing the configuration of a waveguide assembly according to another embodiment.
8 is a schematic view showing a fiber according to an embodiment and a cross-sectional view thereof.
9 is a schematic view showing the configuration of a plastic catheter according to an embodiment.
FIG. 10 is a schematic diagram illustrating the shape of a plastic catheter and a fluid injection method for use as a vascular endoscope according to an embodiment.
FIG. 11 is a schematic diagram for configuring a plastic catheter and performing a pullback scan for using a guiding wire according to an embodiment.
12 is a schematic diagram showing the configuration of a probe base and a drive unit according to an embodiment.
FIG. 13 is a conceptual diagram showing an optoacoustic-ultrasound endoscope probe, a probe drive unit, and a system console for driving and controlling the two.
FIG. 14 is a conceptual diagram illustrating system components and their connection relationships for implementing the photoacoustic-ultrasound-OCT triple image mode by taking the optical acoustic-ultrasound imaging mode shown in FIG.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. Effects and features of the present invention, and methods of achieving them will be apparent with reference to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various forms.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be denoted by the same reference numerals, and redundant description thereof will be omitted. .

In the following embodiments, the terms first, second, etc. are used for the purpose of distinguishing one component from other components rather than having a limiting meaning.

In the following examples, the singular forms "a", "an" and "the" include plural forms unless the context clearly indicates otherwise.

In the following examples, the terms including or having have meant that there is a feature or component described in the specification and does not preclude the possibility of adding one or more other features or components.

In the following embodiments, when a component is "connected" to another component, this includes not only a direct connection with the other component but also an indirect connection by another component. .

1 is a schematic diagram schematically showing the configuration of an optoacoustic-ultrasound endoscope according to an embodiment.

Referring to FIG. 1, the photoacoustic-ultrasound endoscope according to an embodiment includes a probe 200 and a probe driving unit 100, and the probe 200 includes a core 241Co (FIG. 7) and a cladding 241Cd, 7, a coaxial optical-electromagnetic waveguide assembly 240 and a coaxial optical-electromagnetic waveguide assembly 240 including a conductive channel CP disposed coaxially with the optical fiber 241. A scanning tip 250 and a rotating coaxial opto-electromagnetic waveguide assembly 240 and scanning tip 250 disposed at one end of the beam and sending a laser beam to the subject to detect an optoacoustic-ultrasound signal generated from the subject. And a plastic catheter 220 surrounding the outside of the conductive passage, wherein the conductive passage CP is disposed coaxially with the first conductive passage 242 and the optical fiber 241 including a portion disposed coaxially with the optical fiber 241. A second conductive passageway 243 comprising a portion and insulated from the first conductive passageway 242. Include.

In the present invention, in order to solve the problems of the prior art, an optoacoustic-coaxial optical-electromagnetic waveguide assembly (240, hereinafter, waveguide assembly) and the rotary optical-electromagnetic coupler (102, 241, 211) as the core concept An ultrasonic endoscope probe 200 and a probe driving unit 100 for driving the same are disclosed.

The concept of waveguide assembly 240 and rotating opto-electromagnetic couplers 102, 241 and 211 In the photoacoustic-ultrasound endoscope probe 200 shown in FIG. 1, a probe driving unit (in a flexible section inserted into a subject called a plastic catheter 220 formed in a thin and elongated body) and at the point of the probe base 210 are provided. It is applied to each site connected with 100).

Referring to FIG. 1, the photoacoustic-ultrasound endoscope probe 200 includes a portion enclosed by the plastic catheter 220 and a portion covered by the name of the probe base 210, that is, the base frame 216 is physically enclosed. Divided into parts. Among them, the section wrapped by the plastic catheter 220 is not only physically flexible but also has a very thin and long tube structure, so that the plastic catheter 220 can be effectively inserted into a subject that is accessible only through a narrow and curved passage.

In addition, the plastic catheter 220 blocks the waveguide assembly 240 and the scanning tip 250 disposed along the inner space from the outer space and isolates the inner space so that the 240 and 250 do not directly touch the subject. It plays a role. At the same time, the plastic catheter 220 may also serve to trap the matching fluid 230 filled therein so that it does not leak out. In the material of the plastic catheter 220, since the laser beam and the ultrasonic signal pass through the wall surface, it is preferable to use a polymer-based material that can pass both light and sound waves well.

The matching fluid 230 filling the inner space of the plastic catheter 220 may use ultra-pure water such as deionized water, but may be biocompatible and semi-permanently used, such as low viscosity silicone oil. Preference is given to using substances which can be used. If the matching fluid 230 is water, it is important to electrically insulate the two conductive passages (described below) of the waveguide assembly 240 submerged together in the matching fluid 230.

The plastic catheter 220 is configured in the form of an elongated tube structure so that the plastic catheter 220 can be effectively inserted into a subject that can be accessed only through a narrow and curved passage. Thus, the diameter of the plastic catheter 220 is about 1 mm or more and about 3 mm or less, and the overall length may be formed to about 0.5 m or more and about 3 m or less.

Inside the probe covered with the plastic catheter 220, the waveguide assembly 240 is disposed to extend from the probe base 210 to the scanning tip 250. The waveguide assembly 240 also has a physically flexible characteristic, and also serves to transmit the photoacoustic-ultrasound electrical signal detected by the piezoelectric element 251.

At one end of the waveguide assembly 240 a scanning tip 250 is disposed. The scanning tip 250 sends an ultrasonic pulse generated by the laser beam or the piezoelectric element 251 transmitted through the optical fiber 241 in the waveguide assembly 240 to the subject, and thus optoacoustic generated in the subject. It also plays a role of detecting an ultrasonic signal reflected from the signal or the subject. The scanning tip 250 is an optical reflector 252 that reflects a laser beam transmitted through an optical fiber 241 in the waveguide assembly 240 to a target point, and generates an extremely short ultrasonic pulse or an ultrasonic wave generated from a subject. It may include a piezoelectric element 251 for detecting a signal, a sound absorbing layer 253 capable of eliminating acoustic noise caused by irregular reflection of sound waves, and a metal casing 254 surrounding the elements 251, 252, and 253. have.

At the other end of the waveguide assembly 240, a probe base 210 is disposed to surround the waveguide assembly 240 and receive rotational force from the probe driving unit 100. The probe base 210 includes a base gear 217, a rotary transformer 211, a ball bearing module 212, an o-ring seal 213, a through shaft 214, an epoxy filling part 215, and the components ( It may include a base frame 216 surrounding the 211, 212, 213, 214, 215, 217.

The base gear 217 receives the rotational force from the probe driving unit 100 and transmits it to the waveguide assembly 240. The rotary transformer 211 is located on the probe base 210 and receives the electric pulse generated from the ultrasonic pulser-receiver 101 and sends it to the piezoelectric element 251 or vice versa. The relay 101 may serve as a relay to the receiver 101. Of course, all electrical signals mentioned in these two processes are via the waveguide assembly 240.

The o-ring type airtight portion 213 serves to prevent the matching fluid 230 filling the inside of the plastic catheter 220 from leaking out. The ball bearing module 212 may serve to provide mechanical conditions for the through shaft 214 to rotate smoothly in a stable position.

The probe driving unit 100 is a physically independent unit that can be separated from the photoacoustic-ultrasound probe 200. The probe driving unit 100 may input or receive a laser pulse to the rotating optical fiber 241 and the ultrasonic pulser-receiver 101, which may transmit or receive an electrical signal to the rotating transformer 211 and may also amplify the received electrical signal. Drive gear 103 for driving rotational force to the optical input device 102 and waveguide assembly 240 which serve to make the optical rotary 241 in association with the optical fiber 241 and form a so-called optical rotary junction. An actuator 104 coupled to the gear 103 and an actuator driver 105 for controlling the actuator 104 may be included. This will be described later.

Of course, the components of the present invention shown in FIG. 1 only present the essential elements necessary to explain the main results derived through the present invention, and system elements required by the common sense in the clear may be added as the case may be. For example, the end metal casing 254 may be composed of several pieces instead of one.

Hereinafter, the optical fiber 241 and the conductive passage CP included in the waveguide assembly 240 will be described.

FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1.

Referring to FIG. 2, the optical fiber 241 generally includes a core and a cladding structure, and may include a protective coating layer 241PCL made of a material such as a polymer. Outside the optical fiber 241, a conductive path (CP) is disposed coaxially with the optical fiber 241, surrounds the optical fiber 241, and transmits an electrical signal. The conductive passage CP includes a first conductive passage 242 including a portion coaxially disposed with the optical fiber 241 and a portion disposed coaxially with the optical fiber 241, and is insulated from the first conductive passage 242. A second conductive passageway 243.

In the present invention, all three of these elements 241, 242, 243 are arranged coaxially with respect to one reference point, which is the central axis of rotation of the waveguide assembly 240, and all of them are integrally rotated at the same angular velocity during the rotational movement. Is a key feature. This will be described later.

Meanwhile, to electrically insulate the two conductive passages 242 and 243, the surfaces of the two conductive passages 242 and 243 may be coated with an insulating layer IL. The insulating layer IL may include a polymer. Alternatively, a tube-shaped structure made of an insulating material may be additionally disposed between the two conductive passages 242 and 243.

Referring back to FIGS. 1 and 2, the optical fiber 241 is disposed at the center of the waveguide assembly 240, and the first conductive passage 242 and the second conductive passage 243 are coaxially disposed outside thereof. Due to this unique structure, the optical fiber 241 located at the center serves as an optical waveguide for transmitting light, and the two conductive passages 242 and 243 are electric signals of high frequency, like electric cables having a coaxial structure. It acts as a kind of electromagnetic waveguide in the radio frequency band which can transmit very effectively. For reference, the electrical signals dealt with in the present invention mainly lie in the 0.1-100 MHz band, and in the case of the optical fiber 241, among the multi-mode, single-mode, or a mixture of the two types. It can optionally be installed according to the desired application.

In addition to the optical and electromagnetic waveguide roles described above, the waveguide assembly 240 also provides a dynamic rotational force to the probe base 210 as if the elements 241, 242, 243 constituting the assembly became an integrated new mechanical module. It may also serve as a kind of flexible shaft that passes from) to the scanning tip 250. This is another important feature that distinguishes it from the prior art. For this reason, the first conductive passage 242 and the second conductive passage 243 should take the form or structure that can be physically well bent. For example, the optical waveguide 241 may be implemented in such a form that the waveguide assembly 240 may be bent more flexibly and at the same time effectively transmit the rotational force with a certain physical distance between the two conductive passages.

The core of the present invention is to use a waveguide assembly 240 that can simultaneously transmit light and electrical signals as well as mechanical rotational force in a single ultrasonic transducer-based base actuation photoacoustic endoscope system. Hereinafter, a detailed method of effectively implementing the waveguide assembly 240 will be described.

3 is a schematic diagram illustrating a configuration method of the waveguide assembly 240 according to an embodiment, FIG. 4 is a schematic diagram showing a detailed configuration of part A of FIG. 3, and FIG. 5 is based on the structure shown in FIG. 4. The waveguide assembly 240 is a real picture. In particular, FIG. 3 schematically shows how the waveguide assembly 240 implemented based on the present embodiment should be installed and electrically connected within the entire system called the optoacoustic-endoscopic probe 200.

As described above, the waveguide assembly 240 includes an optical fiber 241 capable of transmitting light, a first conductive passage including a portion coaxially disposed with the optical fiber 241, and a portion coaxially disposed with the optical fiber 241. And a conductive passage CP including a second conductive passage insulated from the first conductive passage.

According to one embodiment, the first conductive passage 244 is provided to surround the optical fiber 241, the second conductive passage 245 is coaxial with the first conductive passage 244 to the first conductive passage 244 It may be provided to wrap. That is, a cross section of the optical fiber 241, the first conductive passage 244, and the second conductive passage 245 may have a concentric shape as shown in FIG. 2. In this case, at least one of the first conductive passage 244 and the second conductive passage 245 may be provided in a tubular shape. In this case, the tubular means that the first conductive passage 244 and / or the second conductive passage 245 in the form of a hollow tube surround the outer surface of the optical fiber 241 to a certain thickness. In this case, at least one of the first conductive passage 244 and the second conductive passage 245 may be formed by directly coating a conductive material on the surface of the optical fiber 241 in a manner such as deposition.

According to one embodiment, the first conductive passage 244 is provided to surround the optical fiber 241, the second conductive passage 245 is coaxial with the first conductive passage 244 to the first conductive passage 244 It is provided to surround, and at least one of the first conductive passage 244 and the second conductive passage 245 may include a torque coil set provided to be located outside the optical fiber 241 in the form of a coil.

Referring to FIG. 4, the first conductive passage 244 and the second conductive passage 245 surrounding the optical fiber 241 may include the torque coil sets 244 and 245. In the present invention, these two torque coil sets 244 and 245 are referred to as an inner torque coil set 244 and an outer torque coil set 245, respectively. In this case, the reason why each name is set is not only that each torque coil is manufactured in one layer (or layer) as shown in FIG. 4 but also several layers of torque coils are superimposed so that all of them are in one unit ( It is because it can take the form which functions as a unit). For example, referring to FIG. 5, each torque coil set 244, 245 may be configured in such a way that a plurality of wires form a two-layer structure (see cross-sectional view). This structure has the advantage of more effectively transmitting mechanical rotational force over very long sections, typically over 1 meter. On the other hand, if a given space is limited and flexibility is more important, each torque coil set 244, 245 may be composed of only one layer as shown in FIG.

In order to increase the electrical conductivity of each of these two torque coil sets 244, 245, their surfaces may optionally be coated or plated with a material having high electrical conductivity. The outermost surface of each torque coil set is coated with a polymer-based insulator or another tubular polymer between the two sets 244, 245 for electrical insulation between the inner and outer torque coil sets 244, 245. Tubes can be inserted (see 244PT in FIG. 5). Of course, both methods can be applied in one embodiment.

In the above, the method of implementing the waveguide assembly 240 using the torque coil set based on the embodiment of FIG. 5 has been presented. However, in addition to the torque coil, two conductive tubes having a thin wall thickness and the like are sandwiched and stacked. The waveguide assembly 240 may be implemented.

Referring back to FIG. 3, the inner torque coil set 244 serving as the first conductive passageway and the outer torque coil set 245 serving as the second conductive passage are connected to the two electrodes of the piezoelectric element 251 and are scanned. It provides a passage through which electricity flows from the tip 250 to the rotating transformer 211 at the probe base 210. Of course, the two torque coil sets 244 and 245 included in the waveguide assembly 240 are electrically connected to the left coil part 211-1 of the rotary transformer 211 that rotates with them.

6 and 7 are schematic diagrams showing the structure of the waveguide assembly 240 according to another embodiment.

According to one embodiment of FIG. 6, the first conductive passage 248 and the second conductive passage 249 may be provided to surround at least a portion of the optical fiber 241. Referring to the cross-sectional view taken along the line VI-VI ′ of the waveguide assembly of FIG. 6, the conductive passage CP includes two first conductive passages 248 formed in a U-shape and a second conductive passage 249 formed in an inverted U-shape. It is separated into parts. The first and second conductive passages 248 and 249 divided into two portions surround portions of the optical fiber 241, respectively. In this case, too, the two conductive passages CP provide a passage through which an electrical signal flows while maintaining the basic characteristic of the optical fiber 241, which is geometrically coaxial. Therefore, even if the waveguide assembly is bent, the mechanical rotational force is very uniform. Can be delivered. Meanwhile, an insulating coating layer 246 may be disposed on an outer layer of the conductive passage CP to prevent electrical leakage due to contact with the matching fluid 230.

Referring to FIG. 7, the waveguide assembly 240 according to an embodiment may include an insulating coating layer 246 interposed between the first conductive passage (inner conductive layer 242) and the second conductive passage 247. have. That is, the waveguide assembly 240 surrounds the entire surface of the cladding 241Cd of the optical fiber 241 and has tubular first conductive passages CP and 242 formed therein, an insulating coating layer 246 surrounding the outside thereof, and a torque coil set. The second conductive passages 247 implemented as may be configured to be arranged in order from the inside. In this case, the insulating coating layer 246 also serves to electrically insulate the two conductive passages 242 and 247. Of course, in this embodiment the first conductive passage 242 may be formed in such a way that it is directly coated over the entire surface of the cladding 241Cd of the optical fiber 241.

6 and 7 may be more effective when applied to an intravascular imaging endoscope or the like in which the overall diameter of the probe is very small.

8 is a schematic diagram illustrating an optical fiber 241 according to an embodiment. According to this embodiment, the optical fiber used for the waveguide assembly 240 surrounds the first cladding 241Cd-1 in addition to the basic structure of the core 241Co and the first cladding 241Cd-1, which may transmit light. The second cladding 241Cd-2 may be included.

1 discloses an opto-electromagnetic waveguide assembly 240 in which only one of a multimode fiber or a single mode fiber is selected. In general, multi-mode optical fiber has the advantage of delivering a large amount of optical energy, and in the case of single-mode optical fiber, although the total energy can be transmitted, the advantage of being able to focus the light by mounting a lens at the exit point have. By the way, if a large amount of light energy transfer and light concentration is required at the same time, the waveguide assembly 240 may be configured using the double cladding optical fiber 241 as shown in FIG. In the double cladding optical fiber 241, a core 241Co is disposed at the center of the waveguide assembly of FIG. 8 along the line VII-VII ', and the outside of the core 241Co is disposed. The first cladding 241Cd-1, which is another light propagation layer capable of transmitting mode light, surrounds the core 241Co. At this time, the second cladding 241Cd-2 is disposed at the outermost portion so that the first cladding 241Cd-1 may also serve as an optical fiber capable of propagating light.

As described above, when both the optical fiber 241 and the two conductive passages CP are coaxially disposed, the rotational force acting on the probe base 210 may be uniformly transmitted to the scanning tip 250 disposed at the probe end.

Hereinafter, an optoacoustic-ultrasound endoscope including the rotating transformer 211 and the rotating optical coupling units 102 and 241 will be described. For reference, in the present invention, the two are collectively referred to as rotating photo-electromagnetic couplers (211, 102, 241).

The optoacoustic-ultrasound endoscope according to one embodiment includes a probe 200 and a probe driving unit 100, and the probe 200 includes a core 241Co (FIG. 7) and a cladding 241Cd (FIG. 7). A waveguide assembly 240 including an optical fiber 241 and a conductive passage (CP) coaxially arranged with the optical fiber 241, and disposed at one end of the waveguide assembly 240, and sending a laser beam to the subject, Scanning tip 250 and waveguide assembly 240 for detecting the generated optoacoustic-ultrasound signal and a rotating transformer 211 electrically connected to the plastic catheter 220 and the conductive passageway CP surrounding the outside of the scanning tip 250. The probe driving unit 100 includes an ultrasonic pulser-receiver 101 electrically connected to the optical input unit 102 and the rotating transformer 211 that transmit optical energy to the rotating optical fiber 241.

Referring again to FIG. 1, the rotary transformer 211 is a pair of electric coils wound in parallel with the inner or side edges of the magnetic core shaped like a donut in the same direction (ie, a donut). The primary coil part 211-1 forming a group, and another joining secondary coil part 211-2 having the same structure are formed to have a symmetrical structure opposite to the primary coil part. Refers to the device.

Here, the primary coil portion 211-1 is electrically connected to the conductive passage CP of the waveguide assembly 240, and the secondary coil portion 211-2 is electrically connected to an input portion (not shown) of the ultrasonic pulser-receiver 101. Is connected. Thus, as the base gear 217 rotates, the waveguide assembly 240 as well as the through-shaft 214 connected thereto and the primary coil part 211-1 formed in a ring shape along the periphery thereof are together. Even if it rotates, the base frame 216 and the secondary coil portion 211-2 do not rotate at all by the ball bearing module 212. That is, unlike the primary coil portion 211-1 electrically connected to the two conductive passages CP of the waveguide assembly 240, the secondary coil portion 211-2 is fixed to the base frame 216 to rotate. It will not be done. As a result, the electrical signal called the rotary transformer 211 enables the electrical signal to be extracted from the rotating waveguide assembly 240 without the problem of twisting the wires or the like.

That is, the rotary transformer 211 is an electric element capable of transmitting and receiving an electric signal without direct physical contact or connection through two wires, which are relatively moving, and is a device operating by the principle of electromagnetic induction. Of course, due to this principle of operation, there is a limit that the rotary transformer can only transmit an AC signal, but there is a key advantage that can exchange electrical signals from the rotor without physically contacting directly. In addition to the benefits mentioned, the proper combination of coil ratios in each set allows the voltage to be converted or the electrical impedance to be converted during the transmission of the electrical signal.

The optical input unit 102 refers to a convex lens, an objective lens, or the like, and inputs light energy to the rotating optical fiber 241. That is, when the laser pulse is generated in the light source unit 300, the laser pulse is first moved to the optical input unit 102 through a separate guiding optical fiber (not shown), wherein the optical input unit 102 is induced It serves to deliver the laser pulse to the optical fiber 241 installed on the central axis of the waveguide assembly 240. The important point here is that the optical energy 241 of the waveguide assembly 240 is rotated while the optical input 102 is not rotated but the light energy is transmitted. That is, the optical input unit 102 for inputting light and the optical fiber 241 for receiving light form a kind of optical rotary junction.

In some cases, the aforementioned guiding optical fiber (not shown) may be used as a waveguide assembly without using the optical input unit 102 having a shape such as a convex lens or an objective lens shown in FIG. 1. The rotating optical coupling part may also be configured to directly engage the optical fiber 241 of the 240. Of course, in this case, the ends of the guiding optical fiber (not shown) should be disposed as close as possible to the optical fiber 241 of the waveguide assembly 240, and using optical fibers having the same specs as each other for more efficient optical energy transfer. It is preferable.

The ultrasonic pulser-receiver 101 is electrically connected to the rotary transformer 211, and receives the photoacoustic signal detected and electrically converted by the piezoelectric element 251. This will be described later.

9 to 11 are schematic diagrams showing the configuration of a probe of an optoacoustic-ultrasound endoscope according to an embodiment.

According to one embodiment, the optoacoustic-ultrasound endoscope may further include a mesh-like reinforcement 260 disposed inside the plastic catheter 220. Referring to FIG. 9, a braided or mesh type reinforcement 260 made of a metal material or the like may be inserted into the plastic catheter 220. This can extend the physical life of the plastic catheter 220.

According to one embodiment of FIG. 10, the base frame 216 may further include a fluid inlet 261. If the photoacoustic-ultrasound endoscope probe 200 proposed by the present invention is intended to be used in a format such as a vascular endoscope, unlike the method of inserting it into a device channel of a video endoscope currently used in clinical practice, FIG. 10 Opening the distal portion of the plastic catheter 220 as shown in the fluid discharge port 262, and additionally installed the fluid inlet 261 in the base frame 216, blood vessels in the same manner as conventional ultrasound-based IVUS catheter probe It can be used to diagnose diseases. In this case, saline solution or the like may be used as the fluid injected through the fluid inlet 261. In this case, all of the matching fluid 230 filling the inner space of the probe is also replaced.

Meanwhile, referring to FIG. 11, the optoacoustic-ultrasound endoscope surrounds the plastic catheter 220 and includes a guiding catheter 290 and a guiding catheter fluid inlet 280 including a guiding catheter fluid inlet 280. It may further include a guiding wire 270 is inserted.

That is, by additionally using a guiding catheter 290 having a dual lumen structure as shown in FIG. 11, the guiding wire 270 is simultaneously injected with fluid through the guiding catheter fluid inlet 280. The channel can be inserted, and the plastic catheter 220 has a thickness smaller than that of the guiding catheter 290 and can be physically inserted and retracted, thereby obtaining an image by changing the position of the scanning tip 250 from the subject. Can be.

12 is a portion of the probe drive unit 100 and the probe base 210 in accordance with one embodiment, the power transmission and electrical signals in a manner different from the principle of the power transmission and rotary transformer 211 shown in FIG. It is a schematic diagram showing how to deposit.

In the embodiment of FIG. 1, the probe driving unit 100 includes a driving gear 103 connected to and rotated from the actuator 104, and the probe base 210 is engaged with the driving gear 103 to rotate in a base gear ( Photoacoustic-ultrasound endoscope, including 217). That is, the power required for the waveguide assembly 240 to rotate was transmitted by the base gear 217 directly fastened to the drive gear 103.

However, according to the exemplary embodiment of FIG. 12, the probe driving unit 100 includes a driving timing pulley 106 that is connected to the actuator 104 and rotates, and the probe base 210 of the optoacoustic-ultrasound endoscope is And a base belt pulley 218 that rotates in engagement with the drive timing pulley 106 and may further include a timing belt 107 that transmits power between the drive timing pulley 106 and the base timing pulley 218. . Thus, in this case, the power required for the waveguide assembly 240 to rotate is transmitted through the drive timing pulley 106 and the base timing pulley 218 and the timing belt 107 connecting the two.

Meanwhile, FIGS. 1 and 3 show a structure in which a rotary transformer 211 is mounted on the probe base 210 to receive an electric signal generated from the piezoelectric element 251 from the waveguide assembly 240. By the way, if mechanical noise is not a problem, this rotary transformer 211 part is composed of two slip rings 219-1 and two brushes 219-2 respectively contacting them as shown in FIG. The configured electrical signal entry / exit system can be used. Of course, in this case, the two brushes 219-2 are electrically connected to the ultrasonic pulser-receiver 101 through the signal cable 219-3.

12 illustrates a case where the base timing pulley 218 and the slip ring 219-1 are used together, the base timing pulley 218 may be used together with the rotary transformer 211 or the base gear 217. May be used together with the slip ring 219-1.

The configuration of the optoacoustic-endoscopic probe 200 and the probe driving unit 100 has been described above. In order to actually perform the photoacoustic-endoscopic imaging using them, the light source is similarly known to conventional photoacoustic imaging systems. Additional ancillary systems such as data acquisition systems (DAQ systems) are needed.

FIG. 13 is a conceptual diagram illustrating an optoacoustic-ultrasound endoscope probe 200, a probe driving unit 100, and a peripheral system for driving the two. Representative peripheral systems include a light source 300 for generating laser pulses, and a system console 400 that allows the user to control the entire system.

First of all, a key switch constituting the light source unit 300 is a Q-switch laser capable of providing a laser beam having a very short pulse width. In addition to these characteristics, a sufficient pulse energy is required to satisfy an application purpose required by the endoscope system. It must have a repetition rate. When multi-wavelength optoacoustic imaging of two or more wavelengths is to be performed simultaneously, a plurality of laser systems capable of providing the two wavelengths or a laser system having wavelength tunable capability may be used.

In the case of the system console 400, the data acquisition system 402, which receives the amplified and optimized optoacoustic-ultrasound signal from the ultrasonic pulser-receiver 101 and converts it into a computer-recognized numeric signal, converts this signal into a signal. Data processing unit 401 for processing and converting into image data, video image presenting apparatus 403 for presenting the image data to the user for viewing, and detailed system control unit 404 for controlling various subsystems do.

Hereinafter, the operation principle of the photoacoustic-ultrasound endoscope probe 200 and the probe driving unit 100 shown in FIG. 1 will be described with reference to FIGS. 1 and 13.

The user first inserts the optoacoustic-ultrasound endoscope probe 200 into the subject so that a portion of the scanning tip 250 is placed in the region of interest, and then the actuator 104 is operated to drive the drive gear 103 and the base gear engaged therewith ( 217 starts a rotational movement and accelerates to reach a predetermined speed. For example, if an imaging of a typical video rate is desired, it may be accelerated to about 30 Hz.

When the base gear 217 starts the rotational movement, the through shaft 214 physically directly connected to the base gear 217 also rotates, and the rotational force is also transmitted to the through shaft 214 by the rotary transformer. The left coil portion 211-1, the waveguide assembly 240, and the scanning tip 250 positioned at the distal end of the waveguide assembly 240 are directly transmitted to rotate together at a predetermined speed. Of course, at this time, the ball bearing module 212 located at the base provides a mechanical condition that allows the through shaft 214 to rotate smoothly in a stable state, and the O-ring type airtight portion 213 is optoacoustic during this physical rotation process. The matching fluid 230 filling the inner space of the ultrasonic endoscope probe 200 serves to prevent leakage.

When the interlocked mechanical elements reach a fixed speed as described above, the actuator driver 105 triggers whenever the actuator 104, which is the actual power source of physical rotation, rotates by a certain angular step. A series of imaging sequences for generating the optoacoustic and ultrasonic one-dimensional image data (commonly called A-line data) in a form synchronized with the trigger pulse signal within the entire system, starting to generate a pulse signal. (imaging sequences) alternate in sequence. That is, for each trigger pulse signal, optoacoustic and ultrasonic one-dimensional data containing depth direction decomposition information is obtained for a specific direction toward which the scanning tip 250 is directed at that time. By repeating continuously during rotation, the two-dimensional image data of spatially coregistered optoacoustic and ultrasonic waves are obtained. In addition, this series of procedures can be performed by pushing or pulling probes to obtain data for 3D images. Here, the trigger pulse used to trigger the above-described imaging sequences is preferably a transistor-transistor logic (TTL) type.

Of course, in order to obtain the photoacoustic and ultrasonic one-dimensional days sequentially in the manner described, a series of trigger pulse train signals provided by the actuator driver 105 are first sent to the detailed system control unit 404, where the predetermined It should be divided into two different pulse trains with time difference, and used to initiate optoacoustic and ultrasonic imaging respectively. Normally tens of microseconds of time is adequate, and the reason for this time-induced photoacoustic and ultrasonic one-dimensional data acquisition is that the subject is sufficiently relaxed for alternating photoacoustic and ultrasonic modes. This is to give time to relax. For reference, as an example of actually applying such an image sequence, there is a prior document 11.

The following describes how one-dimensional optoacoustic and ultrasonic image data are obtained for a single trigger pulse.

First, when an optoacoustic imaging mode for obtaining one-dimensional optoacoustic data is started at a specific point in time, a laser pulse is first generated from the light source unit 300, and the laser pulse is inputted through an optical fiber (not shown) installed separately. And then to the scanning tip 250 from the probe base 210 along the optical fiber 241 installed at the central axis of the waveguide assembly 240, and finally to the light reflector 252. Is sent to the subject. However, if the light source unit 300 is implemented in an integrated form with the probe driving unit 100, a separate optical fiber for transmitting the laser pulse generated by the light source unit 300 to the probe driving unit 100 is not required.

As soon as the laser beam is delivered into the subject, an optoacoustic signal is immediately induced. A part of the induced optoacoustic wave propagates toward the piezoelectric element 251 and is converted into an electric signal. The electrical signal is again probe drive unit through a rotating transformer 211 in the probe base 210 along the electromagnetic waveguide formed by the first conductive passage 242 and the second conductive passage 243 of the waveguide assembly 240. It is sent to an ultrasonic pulser-receiver 101 located within 100. Of course, the ultrasonic pulser-receiver 101 also serves to receive the photoacoustic signal detected by the piezoelectric element 251 and electrically converted, but in the ultrasonic imaging mode, the piezoelectric element 251 emits an ultrasonic pulse to the subject. It also serves to provide an electric pulse to the piezoelectric element 251 to be sent to, and to receive the ultrasonic echo signal detected by the piezoelectric element 251 again.

In addition, the ultrasonic pulser-receiver 101 may also include signal conditioning, which amplifies the signal and filters only the appropriate frequency bands. These optimized signals are sent to the data acquisition system 402 and then the entire system console. The data is processed by the data processing unit 401 within the 400 and stored temporarily or long term.

As described above, when a series of processes for obtaining one-dimensional optoacoustic data are all completed, an ultrasonic imaging mode in which one-dimensional ultrasound data can be obtained at a predetermined set time difference mentioned above is started. Of course, during this time difference the scanning tip may already be slightly rotated.

In any case, when this process is initiated, first, a very short electric pulse is generated in the aforementioned ultrasonic pulser-receiver 101, which is generated by the first conductivity of the waveguide assembly 240 via the rotary transformer 211. Along the passage 242 and the second conductive passage 243, the piezoelectric element 251 mounted inside the scanning tip 250 is transferred to an ultrasonic pulse. Then, the ultrasonic pulse proceeds in the direction of the subject as in the conventional ultrasonic imaging method, and some of the energy is reflected and returned, and is detected by the same piezoelectric element 251 that originally emitted the ultrasonic pulse, and eventually converted into an electrical signal form. This electrical signal is then transmitted to the rotating transformer 211 along the first conductive passage 242 and the second conductive passage 243 of the waveguide assembly 240 in the reverse order of the above-described process and terminated by an ultrasonic pulser-receiver 101. Is received and amplified. The amplified ultrasonic signal is then sent to the data acquisition system 402 like the photoacoustic signal described above, and then processed by the data processing unit 401 within the entire system console 400 to be temporarily or long-term stored.

 After obtaining a certain amount of photoacoustic and ultrasonic one-dimensional image data (usually during the complete rotation of the scanning tip 250 once) in the manner described above, after processing the relevant data in the data processing unit 401, the image image display device ( 403) to the user.

The present invention has been devised for the main purpose of using it in an optoacoustic-ultrasound imaging mode. However, if the portion of the optical fiber 241 required for the waveguide assembly 240 is used as a double cladding fiber or a single mode optical fiber and the peripheral systems are configured as shown in FIG. 14, photoacoustic-ultrasound imaging as well as optical coherence tomography (OCT) Can also be implemented at the same time.

FIG. 14 is a conceptual diagram illustrating system components and their connection relationships for implementing the photoacoustic-ultrasound-OCT triple image mode by taking the optical acoustic-ultrasound imaging mode shown in FIG.

Referring to FIG. 14, an optoacoustic-ultrasound endoscope system according to an embodiment may include a light source 302 for an OCT that provides optical energy for optical coherence tomography to an optical fiber 241. The biggest difference between FIG. 13 and FIG. 14 is in the internal configuration of the light source unit 300 and the probe driving unit 100. First, in the case of the light source unit 300, a swept source or the like is used to perform optical coherence tomography. The same OCT light source 302 has been added. For reference, the additional meaning used herein means a functional addition, and does not necessarily mean that a device having physically separate units must be added. For example, one light source may simultaneously provide the light waves required for optoacoustic imaging and OCT imaging. In any case, in FIG. 14, in addition to the addition of the OCT light source 302, an optical interferometer and an optical signal detector 108, which are commonly used for OCT images, are installed inside the probe driving unit 100. OCT imaging can be performed by taking over the light. Of course, in order to effectively transmit the light received from the photoacoustic light source 301 and the light received from the OCT light source 302 to the photoacoustic-ultrasound-OCT endoscope probe 200, a beam combiner is provided in front of the optical input unit 102. It is preferable to install (beam combiner, 109).

In order to obtain a spatially overlapping photoacoustic-ultrasound-OCT image, the photoacoustic, ultrasonic, and OCT one-dimensional image modes may be sequentially performed while the scanning tip 250 rotates in a manner similar to the above-described method.

The method of obtaining both photoacoustic, ultrasonic and OCT image information using the endoscope system presented by the present invention has been described above. However, in some cases, the present invention may be implemented in a system form in which only some of the image information (ie, photoacoustic or ultrasonic images) is obtained. In the configuration and arrangement of the various detailed system elements 100, 300, and 400 shown in FIGS. 13 and 14, some elements may be integrated into one physical unit as necessary and may be implemented. The spatial position can also be changed appropriately. For example, the light source unit 300, the probe driving unit 100, and the system console 400 may be integrally formed, and the position of the OCT light source 302 may be moved into the probe driving unit 100.

In the present invention, using the principle and structure of the rotating coaxial optical-electromagnetic waveguide assembly 240 and the rotating optical-electromagnetic coupler (102, 241, 211), a single ultrasonic transducer based base actuation rotational scanning photoacoustic endoscope probe In this regard, the present invention proposes a method for solving the problem of processing the optical fiber 241 and the electric signal line, and the problem of entering and exiting the optical-electric signal at the probe base 210.

In the case of an optoacoustic endoscope which performs a base-driven rotational scan, it is necessary to form an electric path for transmitting and receiving an optical signal along an inside of a predetermined rotating body (ie, a torque coil, etc.). As a core condition, the existing inventions represented by the preceding invention 4 have been implemented by simply placing the two elements in parallel in a rotating torque coil, thereby failing to transmit a uniform rotational force from the base to the probe end. In other words, in the optoacoustic endoscope system applying the aforementioned scan method, the flexible probe section inserted into the subject is a very important passage for transmitting optical energy and electrical signals as well as rotational force required for mechanical scanning. It could not provide a deeper configuration method for

In this technical context, the present invention relates to an electrical signal line which has been commonly used using a commercially available optical fiber 241 and a conductive passage CP including coaxial first and second conductive passages 242 and 243, for example. The structure and economic implementation method that can effectively transmit both light energy and electric signal are presented.

Therefore, when implementing the optoacoustic endoscope based on the proposed invention, since the probe 200 has a completely rotationally symmetrical structure, the probe 200 has a significantly improved probe flexibility and uniformity of the rotational scan than the existing similar types of photoacoustic endoscopes. In addition to effectively solving the problem of uniform rotational distortion (NURD), the signal-to-noise ratio can be greatly improved by being less affected by electromagnetic interference noise present in the external environment. Indeed, this improved performance can reduce problems such as severe twists and kinks in the probe in deep insertion depths (ie, long probe implementations) and in high bend conditions, resulting in improved image quality as well as longer probe life. It can be greatly improved. For example, it can be more easily inserted into the equipment channel of the video endoscope currently used in the clinic.

And in the present invention solved the problem of installing the plastic catheter 220 on the outside of the rotating body, and filling and sealing the inside with a matching fluid 230, which is not solved in the prior invention, the probe base 210 for the first time in the related art To construct a rotating photo-electromagnetic coupler (102, 241, 211) for exchanging electrical signals using a rotating transformer (211) as well as a laser beam, and photoacoustic-ultrasound imaging as well as OCT imaging in one system Also shown is a method to perform together.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

100: probe drive unit 101: ultrasonic pulser receiver
102: optical input 103: drive gear
104: actuator 105: actuator driver
106: driving timing pulley 107: timing belt
108: Optical interferometer and optical signal detector for OCT
109: beam combiner
200: probe 210: probe base
211: rotary transformer 212: ball bearing module
213: O-ring type airtight 214: through shaft
215: epoxy charging unit
216: base frame 217: base gear
218: base timing pulley 219-1: slip ring
219-2: Brush 219-3: Signal Cable
220: plastic catheter 230: matching fluid
240: waveguide assembly 241: optical fiber
241Co: fiber core 241Cd: fiber cladding
241PCL: fiber optic protective coating
242, 244, 248: first conductive passage
243, 245, 247, and 249: second conductive passages
244PT: polymer tube
246: insulation coating layer
250: scanning tip 251: piezoelectric element
252: light reflector 253: sound absorption layer
254: metal casing
260: reinforcement 261: fluid inlet
262: fluid outlet 270: guiding wire
280: guiding catheter fluid inlet
290: guiding catheter 300: light source unit
301: photoacoustic light source 302: OCT light source
400: system console 401: data processing unit
402: data acquisition system
403: video image presentation device
404: detailed system control

Claims (6)

In an optoacoustic-ultrasound endoscope comprising a probe,
The probe,
A rotating coaxial opto-electromagnetic waveguide assembly comprising an optical fiber comprising a core and a cladding and a conductive passage disposed coaxially with the optical fiber;
A scanning tip disposed at one end of the rotatable coaxial optical-electromagnetic waveguide assembly that directs a laser beam guided through the optical fiber to the subject and detects an optoacoustic signal generated thereafter;
A plastic catheter surrounding the outer side of the rotatable coaxial optical-electromagnetic waveguide assembly and the scanning tip and provided with a matching fluid therein; And
And a probe base electrically connected to the conductive passageway, coupled to the plastic catheter, and configured to receive a mechanical rotational force and a laser beam from the outside.
The probe base is,
A base frame coupled with the plastic catheter;
A through shaft for transmitting the mechanical rotational force to the rotatable coaxial optical-electromagnetic waveguide assembly; And
And an o-ring-type hermetic portion interposed between the through shaft and the base frame. The method of claim 1,
Further comprising a rotary transformer electrically connected with the conductive passage,
The rotation Transformers,
A primary coil portion electrically connected to the conductive passageway and provided to rotate together with the rotatable coaxial optical-electromagnetic waveguide assembly; And
Optoacoustic-ultrasound endoscope facing the primary coil portion, comprising a secondary coil portion provided to maintain a stationary state with the base frame. The method of claim 1,
The probe further comprises a fluid inlet, optoacoustic-ultrasound endoscope. The method of claim 1,
A guiding catheter inserted along an outer surface of the plastic catheter and including a guiding catheter fluid inlet;
And further comprising a guiding wire inserted into the guiding catheter fluid inlet. The said conductive path of any one of Claims 1-4,
A first conductive passage disposed coaxially with the optical fiber and transmitting an electrical signal; And
And a second conductive passage disposed coaxially with the optical fiber and transmitting an electrical signal, the second conductive passage being insulated from the first conductive passage.
At least one of the first conductive passageway and the second conductive passageway is provided with a torque coil set. The said conductive path of any one of Claims 1-4,
A first conductive passage disposed coaxially with the optical fiber, transmitting an electrical signal, and having a U-shaped cross section; And
And a second conductive passage disposed coaxially with the optical fiber and transmitting an electrical signal, the second conductive passage being in an inverted U-shaped cross section and insulated from the first conductive passage.

Images