Anti-fogging device for endoscope systems

Abstract

An apparatus for maintaining an optical path of an optical imaging system against fogging includes an elongated member having a distal end and a proximal end, a near-infrared (NIR) light-absorbing optical window disposed at the distal end, and an optical system disposed along the optical path. The apparatus also includes a coupling module coupled to the elongated member at the proximal end and configured to transmit near-infrared light along the optical path to the NIR-light-absorbing optical window and to receive light rays in a region of interest along the optical path.

Description

Technical Field

[0001] Cross - reference to Related Applications

[0001] This application claims priority to Chinese Patent Application Publication No. 202010095217.0, filed on February 17, 2020, and U.S. Patent No. 17 / 162,181, titled "DEVICE FOR ANTI - FOG ENDOSCOPE SYSTEM", filed on January 29, 2021, and the entire contents of these are incorporated herein by reference in their entirety for all purposes as part of this specification.

Background Art

[0002]

[0002] When using a rigid endoscope for minimally invasive surgery, especially for laparoscopic (abdominal) surgery, in addition to the internal humidity state, due to the temperature difference between the endoscope and the internal body, fogging occurs on the protective window of the endoscope. The image generated by the fogged window becomes unclear, which has been a problem in this industry for decades. To date, no satisfactory technical solution exists.

[0003]

[0003] Therefore, there is a need for new devices and methods that can prevent fogging of endoscope systems and / or equipment or medical devices.

Summary of the Invention

Problems to be Solved by the Invention

[0004]

[0004] This disclosure generally relates to endoscopes, and more particularly to an anti - fog optical imaging system for endoscopes and other minimally invasive medical devices.

[0005]

[0005] The objective of this disclosure is to provide a new solution for removing fogging of endoscopes and mechanical medical devices that can avoid the problem of image quality degradation associated with the prior art.

Means for Solving the Problems

[0006]

[0006] In one embodiment, a device for maintaining the optical path of an optical imaging system to prevent fogging includes an elongated member having a distal end and a proximal end, a near-infrared (NIR) light-absorbing optical window disposed at the distal end, and an optical system disposed along the optical path. The device also includes a coupling module connected to the elongated member at the proximal end and configured to transmit near-infrared light along the optical path to the NIR light-absorbing optical window and to receive light rays having a first range of wavelengths along the optical path.

[0007]

[0007] One embodiment of the present disclosure provides a method for operating an optical imaging system that prevents fogging, comprising an elongated member having a distal end and a proximal end, a near-infrared (NIR) light-absorbing optical window disposed at the distal end, and an optical system along the optical path. The method includes connecting a coupling module having a light source that emits NIR light to the elongated member at the proximal end, activating the light source to transmit NIR light along the optical path to the NIR light-absorbing optical window for an illumination period, and receiving visible light reflected from a region of interest along the optical path.

[0008]

[0008] Embodiments of the Disclosure provide improvements in safety, image quality, and convenience for the user or operator by preventing fogging in optical imaging systems. Embodiments of the Disclosure also reduce the possibility of overlooking tissue disease or the extent (boundaries) of tissue disease, the possibility of misinterpreting problematic tissue as good tissue, and the possibility of misunderstandings that may necessitate reoperation. Other advantages and benefits of the Disclosure include reduced surgical procedure time and fatigue of operating room (OR) personnel by not having to constantly strive to obtain sharp images.

[0009]

[0009] These embodiments and other embodiments of the present disclosure, along with their many advantages and features, will be described in further detail in conjunction with the following text and accompanying drawings. [Brief explanation of the drawing]

[0010] [Figure 1A]This is a cross-sectional view of an anti-fogging device for removing fogging from an endoscope or medical device according to one embodiment of the present disclosure. [Figure 1B] This is a cross-sectional view of an anti-fogging device for removing fogging from an endoscope or medical device according to one embodiment of the present disclosure. [Figure 1C] This is a cross-sectional view of an NIR light-shielding filter according to one embodiment of the present disclosure. [Figure 2A] This is a simplified schematic diagram of a second semiconductor light source for an anti-fogging device according to one embodiment of the present disclosure. [Figure 2B] This is a simplified schematic diagram of a second semiconductor light source for an anti-fogging device according to another embodiment of the present disclosure. [Figure 3] This figure shows a front view of an elongated member according to some embodiments of the present disclosure. [Figure 4A] This is a cross-sectional view of an enlarged portion of an elongated member having a near-infrared (NIR) light absorbing optical window, including a sapphire substrate with an NIR absorbing glass plate, a doped sapphire substrate, and a sapphire substrate having an NIR absorbing coating, according to an embodiment of the present disclosure. [Figure 4B] This is a cross-sectional view of an enlarged portion of an elongated member having a near-infrared (NIR) light absorbing optical window, including a sapphire substrate with an NIR absorbing glass plate, a doped sapphire substrate, and a sapphire substrate having an NIR absorbing coating, according to an embodiment of the present disclosure. [Figure 4C] This is a cross-sectional view of an enlarged portion of an elongated member having a near-infrared (NIR) light absorbing optical window, including a sapphire substrate with an NIR absorbing glass plate, a doped sapphire substrate, and a sapphire substrate having an NIR absorbing coating, according to an embodiment of the present disclosure. [Figure 5] This is a cross-sectional view of an anti-fogging device for removing fogging from an endoscope or medical device, according to another embodiment of the present disclosure. [Figure 6] This is a simplified schematic diagram of a basic optical imaging system for preventing fogging, according to some embodiments of the present disclosure. [Figure 7]This is a simplified schematic diagram of a control system for an anti-fogging device according to one embodiment of the present disclosure. [Figure 8] This is a simplified flowchart illustrating a method for operating an optical imaging system for preventing fogging, according to one embodiment of the present disclosure. [Figure 9A] An image of a medium provided by a viewing device before activating an NIR light source, according to one embodiment of the present disclosure. [Figure 9B] This is an image of a medium provided by a viewing device after the NIR light source has been activated, according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0011]

[0023] This disclosure generally relates to endoscopes and medical devices. More specifically, this disclosure relates to anti-fogging devices that can operate to reduce or eliminate fogging of endoscopes and other minimally invasive medical devices. The anti-fogging devices can be operated in conjunction with some kind of viewing or illumination device to maintain a fogging-free optical image.

[0012]

[0024] While embodiments of this disclosure describe anti-fogging devices operating in endoscopic systems, it should be noted that the present invention is not limited thereto. For example, anti-fogging devices can be used in any viewing or lighting device that may face the problem of moisture accumulating on the surface of an optical window. Examples of such viewing or lighting devices include eyeglasses, safety goggles, and surgical protective headgear. Other examples may include medical flexible endoscopes and flexible fiberscopes or borescopes, telescopes (astronomy), rifle scope sights, binoculars, and camera lenses (e.g., mobile phone camera lenses).

[0013]

[0025] In one solution for removing the fogging caused by the temperature difference between the endoscope and the inside of the body, current is used to heat the protective window of the endoscope. However, this solution is not widely used because it may cause accidental tissue damage.

[0014]

[0026] As another solution, a light source that irradiates light having a specific wavelength onto the window of the endoscope is provided for safe heating for the purpose of reducing the occurrence of fogging. For example, Chinese Patent Application Publication No. 201210324982.0 discloses an apparatus and method for removing fogging of an endoscope using light to raise the temperature and remove the fogging. However, the image quality deteriorates due to the reflection of stray light from the front window, thereby reducing the marketability of the product.

[0015]

[0027] Figure 1A is a cross-sectional view of an anti-fog device 100A for removing fogging from an endoscope or medical device according to one embodiment of the present disclosure. The anti-fog device (also referred to herein as the “device”) 100A includes an elongated member 1 having a distal end 1a and a proximal end 1b, an optical adapter module 2, and an image sensor 3. The elongated member 1 may include a (rigid) endoscope system or laparoscope system, or a part of an endoscope system or laparoscope system, and includes a front optical window 11 and an optical system 12. The optical system 12 and the optical adapter module 2 each have an imaging wavelength range in the range of λ1 to λ2 (λ2 > λ1). In some embodiments, the anti-fog device 100A may include an imaging system for visible light only. In this case, the imaging wavelength range λ1 to λ2 may be in the range of 400 nm to 700 nm, or a subset of 400 nm to 700 nm, and since NIR imaging such as ICG is not performed as long as the front optical window (NIR absorption window) 11 is properly fitted, the near-infrared (NIR) anti-fogging light may be longer than 700 nm. In other embodiments, the anti-fogging device 100A may include a visible light and a near-infrared (NIR) imaging system. In this case, the NIR anti-fogging light must have a wavelength longer than the fluorescence wavelength range for ICG (e.g., longer than 900 nm). That is, the optical system 12 and the optical adapter module 2 may each include an additional near-infrared region λ3 based on fluorescence emission around 814 nm with a bandwidth of 40 nm from NIR excitation light having a wavelength range of about 780 nm to about 800 nm. The optical system 12 and the optical adapter module 2 are arranged along a common optical path 122. The optical system 12 may include a plurality of optical lens elements and one or more optical guides 13. In one embodiment, the plurality of optical lens elements may include a first set of optical lens elements 12a disposed near the distal end 1a and a second set of optical lens elements 12b disposed near the proximal end 1b of the elongated member 1. The front optical window 11 may include a material that can transmit light in the wavelength range of λ1 to λ2 and exhibits significant absorption in the near-infrared band.The optical adapter module 2 may include a plurality of optical lens elements configured to adjust the focal length of the anti-fogging device 100A. Although the anti-fogging device 100A is described with respect to the ICG excitation wavelength, it will be understood that the concept of anti-fogging is currently unknown and applicable to fluorescent agents having one or more fluorescent dyes that may be fabricated or developed in the future.

[0016]

[0028] The anti-fogging device 100A also includes a coaxial coupling module 4 and a near-infrared (NIR) light blocking filter 5, also referred to as a near-infrared (NIR) band-stop filter or NIR band-removing filter, which passes most wavelengths but attenuates a very low level of a specific NIR wavelength range. The NIR light blocking filter 5 is disposed along the common optical path 122 between the elongated member 1 and the image sensor 3. The coaxial coupling module 4 may include a semiconductor near-infrared (NIR) source 41, a collimator lens or a group of collimator lenses 42, and a dichroic mirror 43. In an embodiment where the anti-fogging device 100A is a visible light only imaging system, the semiconductor light source 41 may transmit near-infrared light having a radiation wavelength range of λ4 (λ4>λ2) that can be longer than 700 nm since NIR imaging such as ICG is not performed. In an embodiment where the anti-fogging device 100A is a visible and NIR (ICG) imaging system, the semiconductor light source 41 may transmit a near-infrared light wavelength range of λ4 that is longer than the wavelength of ICG (i.e., greater than 900 nm).

[0017]

[0029] In some embodiments, the semiconductor NIR light source 41 is configured to emit near-infrared (NIR) light with wavelengths longer than 780 nm, more preferably in the region around 808 nm for commercially available lasers, for systems operating only in visible light 400-700 nm, since NIR imaging (i.e., ICG) is not performed. In some other embodiments, the semiconductor NIR light source 41 is configured to emit near-infrared (NIR) light with wavelengths longer than the ICG wavelength (around 850 nm). As a result, the NIR light source 41 emits NIR rays with wavelengths longer than 900 nm. In one embodiment, the semiconductor light source 41 may include a laser diode (LD) or a vertical cavity surface emitting laser (VCSEL) device having an optical output greater than 1 W. The collimator lens group 42 aligns the light emitted from the semiconductor light source 41, forming parallel rays that propagate toward the dichroic mirror 43. The radiating surface of the semiconductor light source 41 is located near the collimator lens or lens group 42 or at their focal plane. In other words, the LD or VCSEL device is located near the collimator lens or lens group 42 or at their focal plane.

[0018]

[0030] The dichroic mirror 43 includes an incident illumination surface 431 facing the collimator lens group 42, a dichroic surface 432 configured to reflect parallel light rays parallelized by the collimator lens group 42 toward the elongated member 1 along the common optical path 122, an imaging incident surface 433 facing the elongated member 1, and an imaging exit surface 434 facing the image sensor 3. As used herein, the term “incident” refers to the light ray before conversion. Therefore, the incident surface is the initial region that first receives the light ray.

[0019]

[0031] The incident illumination surface 431 is the incident surface of near-infrared light on the dichroic mirror 43. The dichroic surface 432 is the transmission surface of imaging rays 52. This includes reflected light that returns after visible light is irradiated onto the region of interest 51 and reflected from, for example, the region of interest of the surgical field in an endoscopic system having visible light only. The dichroic surface 432 is also the reflection surface of near-infrared light having a wavelength longer than 700 nm from a semiconductor NIR light source 41 for visible light in an optical imaging system only. In an endoscopic system having visible light for endoscopic examination only, the visible light may be generated by a second semiconductor light source 6. Details of the second semiconductor light source will be described below. With respect to an endoscopic system having only visible light and NIR (ICG) light endoscopy, the dichroic surface 432 is a transmission surface for the imaging beam, which includes reflected visible light and fluorescent light returning from the visible light and NIR (excitation) light emitted from the second semiconductor light source 6 after irradiating the region of interest with visible light and NIR (excitation) light emitted from the second light source 6.

[0020]

[0032] The imaging input surface 433 is the input surface for the imaging beam of the endoscope system on the coaxial coupling module 4. The imaging output surface 434 is the output surface for the imaging beam of the endoscope system on the coaxial coupling module 4.

[0021]

[0033] The dichroic mirror 43 includes an optical axis Z1, which is an optical path connecting the center of the incident illumination surface 431 and the center of the dichroic surface 432. Optical axis Z1 is the incident optical axis of near-infrared light on the dichroic mirror 43. The dichroic mirror 43 also includes an optical axis Z2, which is a line or optical path connecting the center of the imaging incident surface 433 to the center of the dichroic surface 432. Optical axis Z2 is the incident optical axis of the imaging beam of the endoscope system on the coaxial coupling module 4. The dichroic mirror 43 further includes an optical axis Z3, which is a line or optical path connecting the center of the imaging ray of the endoscope system after it has passed through the dichroic surface 432 to the center of the imaging exit surface 434. Optical axis Z3 is the exit axis of the imaging beam of the endoscope system on the coaxial coupling module 4.

[0022]

[0034] In one embodiment, the imaging incident surface 433 is parallel to the imaging exit surface 434. The imaging incident surface 433 and the imaging exit surface 434 are typically perpendicular to the incident illumination surface 431. In the embodiment shown in Figure 1, the dichroic surface 432 and the incident illumination surface 431 form a 45° angle. In an embodiment where the anti-fogging device 100A is a visible light-only imaging system, the dichroic surface 432 is arranged with a dichroic film that reflects light in the wavelength range beyond 780 nm, preferably around 808 nm, and transmits light in the wavelength range of λ1 (400 nm) to λ2 (700 nm). The direction of the reflected light is toward the imaging incident surface 433. The optical axis Z1 coincides with the optical axis Z5 of the collimator lens group 42.

[0023]

[0035] In one embodiment, the second optical axis Z2, the third optical axis Z3, and the common optical path 122 are aligned linearly with respect to each other, and the NIR light-shielding filter 5 is disposed between the coaxial coupling module 4 and the image sensor 3 along the common optical path 122, i.e., along the second optical axis Z2 and the third optical axis Z3. In an embodiment in which the anti-fogging device 100A is a visible light-only system, the NIR light-shielding filter 5 is a filter that transmits light in the wavelength range of λ1 to λ2 and interrupts (blocks) light in the wavelength range longer than 700 nm from the light source 41 (e.g., around 808 nm). For example, the NIR light-shielding filter 5 may be a near-infrared light-shielding filter. In one embodiment, the NIR light-shielding filter 5 may have a transmittance of less than 0.001 percent for wavelengths longer than 700 nm, preferably longer than 780 nm.

[0024]

[0036] In embodiments where the anti-fogging device 100A is a visible light and NIR(ICG) light system, the dichroic surface 432 is arranged with a dichroic film that reflects light in the range of 920 nm to 960 nm, preferably in the range of 935 nm to 945 nm, and transmits light in the range of about 400 nm to about 900 nm. In some embodiments, the excitation wavelength of the semiconductor light source 6 is about 780 nm to about 800 nm, and may be 780 nm to 805 nm when an LED device is used for the semiconductor light source 6. In one embodiment, the center of the excitation wavelength is around 789 nm, and the center of the emission wavelength is around 814 nm with a bandwidth of 40 nm (i.e., in the range of 794 nm to 834 nm). In one embodiment, the center of the excitation wavelength may be selected in the range of 780 nm to 785 nm, making concessions in excitation efficiency and emission efficiency. In one embodiment, the NIR light-shielding filter 5 may be a light-shielding filter for blocking the ICG excitation wavelength of 780 nm to 800 nm and the anti-fogging wavelength of the semiconductor NIR light source 41 that is longer than the ICG wavelength (e.g., 850 nm). In another embodiment, the NIR light-shielding filter 5 may include a first filter configured to block the ICG excitation wavelength (780 nm to 800 nm) and a second filter configured to block the anti-fogging wavelength.

[0025]

[0037] Figure 1C is a cross-sectional view of an NIR light-shielding filter 5 according to one embodiment of the present disclosure. As shown in Figure 1C, the NIR light-shielding filter 5 may include an ICG blocking filter 5a and a continuously connected anti-fogging blocking filter 5b. The ICG blocking filter is shown in front of the anti-fogging blocking filter, but other configurations are possible. For example, the ICG blocking filter may be positioned after the anti-fogging blocking filter, but these filters may be positioned apart from each other. Alternatively, they may be assembled together with a single NIR blocking filter.

[0026]

[0038] In one embodiment, the absorption of the front optical window 11 exceeds 80 percent in the wavelength range from the light source 41. Absorption exceeding 80 percent allows for effective removal of fogging from the anti-fogging device 100A with a short heating time. It will be understood that other absorptions below 80 percent (e.g., 50 percent, 60 percent, 70 percent) may also be used in the anti-fogging device 100A. In such cases, the time required for defog removal will be longer. Therefore, embodiments of the present disclosure are not limited to absorption exceeding 80 percent. In one embodiment, the optical elements of the optical system 12 (i.e., optical lens elements 12a, 12b, optical guide 13) and the optical adapter module 2 are coated with an anti-reflective coating in the wavelength range λ1 to λ4. As an example, the anti-reflective coating can reflect less than 1 percent of the incident light on the anti-reflective coating. In one embodiment of a visible light-only system, the semiconductor light source 41 may be an IR laser having an IR wavelength longer than 700 nm (e.g., around 808 nm), and the optical elements of the optical system 12 (i.e., optical lens elements 12a, 12b, optical guide 13) and the optical adapter module 2 are coated with an anti-reflective coating in the wavelength range of about 400 nm to about 850 nm. In one embodiment of a visible light and NIR (ICG) light system, the excitation wavelengths of the NIR lasers of the visible light source and the NIR (ICG) light source (described in more detail below) are about 780 nm to 800 nm, and the semiconductor light source 41 may be an IR laser having an IR wavelength spectrum around 935 nm to 945 nm. The optical elements of the optical system 12 (i.e., optical lens elements 12a, 12b, optical guide 13) and the optical adapter module 2 are coated with an anti-reflective coating in the wavelength range of about 400 nm to about 950 nm.

[0027]

[0039] In one embodiment, referring to Figure 1A, the dichroic mirror 43 is shown as having a cubic shape with a dichroic mirror (i.e., optical coating) between two prisms. In an exemplary embodiment, the two right-angle prisms may be coupled together and have an optical coating (dichroic mirror) positioned between them. In one embodiment, the dichroic mirror 43 may be a flat dichroic mirror.

[0028]

[0040] In one embodiment, the anti-fogging device 100A may further include a second semiconductor light source 6. In one embodiment, the second semiconductor light source 6 may include a plurality of LEDs (e.g., a green LED for emitting green light, a blue LED for emitting blue light, and a red LED for emitting red light) for emitting visible light. In some embodiments, the output light from the green, blue, and red LEDs is sent through a fiber optic cable 61 to the elongated member 1 to illuminate the target 51. In other embodiments, the anti-fogging device 100A may include a visible light and NIR (ICG) imaging system. In this case, the second semiconductor light source 6 may additionally include an NIR light source (e.g., an NIR laser device). In one embodiment, the visible light source (e.g., red LED, green LED, blue LED) and the NIR light source are arranged along the same optical axis. Exemplary and detailed embodiments of the second semiconductor device 6 are provided below with reference to Figures 2A and 2B. In one embodiment, the fiber optic cable 61 is attached to the interface portion 15 of the elongated member 1. In one embodiment, the interface portion 15 is disposed close to the proximal end 1b of the elongated member 1. The fiber cable 61 includes a plurality of optical fibers 611 arranged along the inner surface of the elongated member 1. In one embodiment, the plurality of optical fibers 611 are arranged circumferentially around at least a portion of the circumference of the front optical window 11, providing visible light and / or excitation light 53 to the target 51. The light 52 reflected from the target 51 travels through the front optical window 11, the optical system 12, the optical adapter module 2, and the coaxial coupling module 4, is captured by the image sensor 3, and converted into an electrical signal. In one embodiment, the second semiconductor light source 6 may further include an NIR laser apparatus for observing fluorescence using ICG. The NIR laser apparatus is configured to emit excitation light having wavelengths of the NIR spectrum around 800 nm, such as 780 nm to 800 nm, for ICG fluorescence imaging. In one embodiment, the second semiconductor light source 6 may further include a UV light device that emits UV light having a spectral wavelength of approximately 414 nm.Note that the light 53 emitted by the second semiconductor light source 6 propagates through the optical fiber 611 arranged along the inner surface of the elongated member 1 (i.e., outside the front optical window 11), and the light 52 reflected from the illuminated target 51 passes through the front optical window 11 and the optical system 12 along the optical axis 122.

[0029]

[0041] Figure 1B is a cross-sectional view of an anti-fog device 100B for removing fogging of an endoscope, instrument, or medical device according to one embodiment of the present disclosure. Referring to Figure 1B, the anti-fog device 100B includes an elongated member 1, an optical module 2, a coaxial coupling module 4, an NIR light-shielding filter 5, and an image sensor 3, which are arranged in this order in a continuous manner along a common optical axis 122. The elongated member 1 may include an endoscope system or a laparoscope system, or a part of an endoscope system or laparoscope system, and includes a front optical window 11 and an optical system 12. In some embodiments, the optical system 12 may include a plurality of optical lens elements and one or more optical guides 13. In one embodiment, the plurality of optical lens elements may include a set of a plurality of distal lens elements 12a and a set of proximal lens elements 12b, which are disposed at both ends of the elongated member 1. One or more optical guides 13 and the plurality of optical lens elements 12a, 12b are arranged along the optical axis 122. The coaxial coupling module 4 includes a first semiconductor light source 41, a collimator lens or a group of collimator lenses 42, and a dichroic mirror 43, all arranged along the optical axis Z1. The first semiconductor light source 41 may include a laser diode (LD) or a vertical-resonant surface-emitting laser (VCSEL) device having an optical output of more than 1 W and located near or at the focal plane of the collimator lens 42.

[0030]

[0042] The anti-fogging device 100B can support at least two imaging systems, such as a visible light-only imaging system and a visible light and NIR-excited light (e.g., ICG) imaging system. In embodiments of the visible light-only imaging system, the first semiconductor light source 41 is configured to emit near-infrared light wavelengths longer than 700 nm. In embodiments of the visible light and NIR-excited light (e.g., ICG) imaging system, the first semiconductor light source 41 emits NIR wavelengths in the range of 900 nm to 1300 nm, more preferably in the range of 900 nm to 1000 nm. The anti-fogging devices 100A and 100B may have similar structures. In the example shown in Figure 1B, a common control system is shown within the anti-fogging device 100B to control different components. However, it is understood that the first semiconductor light source 41, the second semiconductor light source 6, and the image sensor 3 may each have their own dedicated controllers. The following illustrative description is intended to facilitate understanding of the present disclosure and is not limiting.

[0031]

[0043] The dichroic mirror 43 includes an incident illumination surface 431 facing the collimator lens group 42, a dichroic surface 432 configured to reflect parallel light rays parallelized by the collimator lens group 42 toward the elongated member 1 along the common optical path 122, an imaging incident surface 433 facing the elongated member 1, and an imaging exit surface 434 facing the image sensor 3.

[0032]

[0044] In one embodiment, the anti-fogging device 100B further includes a second semiconductor light source 6 connected to the elongated member 1 via a fiber cable 61 at an interface portion 15 of the elongated member 1. The fiber cable 61 may include a plurality of optical fibers 611 arranged along the inner surface of the elongated member 1. The second semiconductor light source 6 is configured to generate NIR excitation light having wavelengths of visible light (e.g., about 400 nm to 700 nm) and around 800 nm (e.g., about 780 nm to 800 nm). The second semiconductor light source 6 can operate in different modes depending on the imaging mode. As will be more fully described below, the second semiconductor light source 6 can be operated to output both visible light and NIR light by independently controlling each wavelength region. In one embodiment, the second semiconductor light source 6 can output NIR light that does not contain visible light. In one embodiment, the second semiconductor light source 6 can output visible light that does not contain NIR light. In one embodiment, the second semiconductor light source 6 can output both visible light and NIR light simultaneously. In one embodiment, the second semiconductor light source 6 can output visible light that does not include NIR light. In another embodiment, the second semiconductor light source 6 can output both visible light and NIR light simultaneously and continuously. The output light from the second semiconductor light source 6 is sent along the elongated member 1 through the fiber cable 61 to the optical fiber 611, illuminating a target positioned near the front optical window 11. The reflected visible light and excited fluorescence emission having a second NIR spectrum (for example, 814 nm with a bandwidth of approximately 790 nm to 850 nm, preferably 40 nm) are received by the anti-fogging device 100B and imaged by the image sensor 3.

[0033]

[0045] In one embodiment, the anti-fogging device 100B also includes a control system 7 having a camera cable 77 connected to an image sensor 3, a first control cable 78 connected to a first semiconductor light source 41, and a second control cable 79 connected to a second semiconductor light source 6. The control system may also include an image display device or monitor (e.g., a liquid crystal display: LCD) configured to generate an image from an electrical signal received from the image sensor 3, an input port configured to receive user input, a power module configured to supply power to the components of the anti-fogging device 100B (i.e., to the image sensor 3), the first semiconductor light source 41, and the second semiconductor light source 6. The control system 7 may also include a plurality of separate control boxes containing one or more controllers. For example, the control system may include a first control box containing a processor connected to at least one controller or image sensor 3, a second control box containing a processor connected to at least one controller or first semiconductor light source 41, and a third control box containing a processor connected to at least one controller or second semiconductor light source 6. The first control box is configured to process electrical signals received from the image sensor 3, and the second and third control boxes are configured to control the intensity of reflected visible light and the intensities of the first and second semiconductor light sources, respectively. The control system 7 and control boxes will be described in more detail below.

[0034]

[0046] In one embodiment, the coaxial coupling module 4 is located between the adapter optical system 2 and the NIR light-shielding filter 5, as shown in Figures 1A and 1B. Referring to Figures 1A and 1B, the anti-fogging devices 100A and 100B each include an elongated member 1, an optical adapter module 2, a coaxial coupling module 4, an NIR light-shielding filter 5, and an image sensor 3, which are arranged in this order in a continuous sequence. Of course, other modifications and substitutions are possible without departing from the scope of this disclosure.

[0035]

[0047] Figure 2A is a simplified schematic diagram of a second semiconductor light source 200A for an anti-fogging device according to one embodiment of the present disclosure. The second semiconductor light source 200A may be the second light source 6 in Figures 1A and 1B. Referring to Figure 2A, the NIR laser 220 generates excitation light at wavelengths of the NIR spectrum (e.g., 780 nm to 800 nm). In some embodiments, the NIR laser 220 is a semiconductor laser. However, other lasers, LEDs, VCSELs, etc., may also be used. The excitation light from the NIR laser 220 passes through a laser beam filter 227 characterized by a very narrow passband (e.g., 10 nm width). The laser beam filter 227 transmits the desired excitation wavelength while suppressing sideband radiation.

[0036]

[0048] In the embodiment shown in Figure 2A, a plurality of visible light sources (e.g., a red LED 221, a green LED 222, and a blue LED 223) provide light used to generate visible light emission for use in the anti-fogging device. The red light from the red LED 221, the green light from the green LED 222, and the blue light from the blue LED 223 are combined using an appropriate ratio of light intensity from each source, as will be further explained below, to form white light. Color combiners 224, 225, and 226 combine the light from the NIR laser 220 and the red LED 221, green LED 222, and blue LED 223 to form a multispectral output that is input to the anti-fogging device through a fiber optic cable 61. In one embodiment, a second semiconductor light source 200A may also include optical lenses 229 positioned in front of each of the red, green, and blue LEDs and configured to parallelize the light emitted from these LEDs to the color combiners.

[0037]

[0049] In some embodiments, the second semiconductor light source 200A may include an ultraviolet (UV) light emission diode or laser diode 231 and a UV light combiner 232 that combines light from an NIR laser or LED 220 or light from red LED 221, green LED 222 and blue LED 223 to form a multispectral output that is input to the anti-fogging device through a fiber optic cable 61. As shown in Figure 2A, the combined light from the NIR light source and the visible light source is coupled by an optical lens 235 and passed through the fiber optic cable 61 to the anti-fogging device for illumination. The NIR laser 220, red LED 221, green LED 222, blue LED 223 and / or UV LED or laser diode 231 can be arranged together with a light source such as the second semiconductor light source 6 shown in Figures 1A and 1B.

[0038]

[0050] The NIR laser 220, red LED 221, green LED 222, blue LED 223, and / or UV LED or laser diode 231 are each independently controlled by the controller 704. Using the controller, the intensity of the NIR excitation light, visible light, and / or UV light can be adjusted, for example, by changing the drive current supplied to the NIR laser and LEDs. In one embodiment of the anti-fogging device, the visible light intensity is adjusted (e.g., attenuated) to achieve a desired contrast between the fluorescence image and the visible light image. Additional optical approaches, such as using a neutral density filter, or electrical approaches, such as modulation schemes, may be applied to significantly attenuate the visible light and / or adjust the light intensity with a desired precision.

[0039]

[0051] In one embodiment, the red LED 221 may be a red amber LED. In some embodiments, the second semiconductor light source 200A may include a combination of a luminance signal RYGB and NIR excitation light. In an exemplary embodiment, the second semiconductor light source 200A may include a photoelectric converter that generates a luminance signal RYGB according to predetermined coefficients of red, green, and blue components. In other embodiments, the second semiconductor light source 200A may include a combined excitation light of NIR wavelengths and a white light source. In some embodiments, the white light may include four primary colors such as red, yellow, green, and blue, represented as RYGB. In some other embodiments, the red LED 221, green LED 222, and blue LED 223 may be replaced by one or more white LED devices. This disclosure is not limited to any particular embodiment. Alternative embodiments may be apparent to those skilled in the art based on the teachings contained herein. It will be understood that the positions of the red, green, blue, and UV LEDs can be interchangeable with each other without affecting the operation of the second semiconductor light source.

[0040]

[0052] Figure 2B is a simplified schematic diagram of a second semiconductor light source 200B for an anti-fogging device according to another embodiment of the present disclosure. The second semiconductor light source 200B may be the second light source 6 in Figures 1A and 1B. Referring to Figure 2B, the NIR laser 220 generates excitation light at wavelengths of the NIR spectrum (e.g., 780 nm to 800 nm). In some embodiments, the NIR laser 220 is a semiconductor laser. However, other lasers, LEDs, VCSELs, etc., may also be used. The excitation light from the NIR laser 220 passes through a laser beam filter 227 characterized by a very narrow passband (e.g., 10 nm width). The laser beam filter 227 transmits the desired excitation wavelength while suppressing sideband radiation.

[0041]

[0053] In the embodiment shown in Figure 2B, the white light source 243 provides light used to generate visible light emission for use in the anti-fogging device. The white light source 243 may include one or more white LED devices that emit white light, or a xenon light source that emits illumination light continuously or temporally. The color combiner 226 combines the light from the NIR laser 220 and the light from the white light source 243 to form a multispectral output that is input to the anti-fogging device through the fiber optic cable 61. In one embodiment, the second semiconductor light source 200B may also include an optical lens 229 positioned in front of the white light source 243 and configured to parallelize the light emitted from the white light source 243 to the color combiner 226.

[0042]

[0054] In some embodiments, the second semiconductor light source 200B may include an ultraviolet (UV) light-emitting diode or laser diode 231 and a UV light combiner 232 that combines UV light with light from an NIR laser or LED 220 or light from a white light source 243 to form a multispectral output that is input to the anti-fogging device via a fiber optic cable 61. In one embodiment, an optical lens 229 may be positioned in front of the UV light and configured to parallelize the UV light emitted from the UV LED or UV laser diode 231. As shown in Figure 2B, the combined light from the NIR light source and the white light source is combined by the optical lens 235 and then provided to the anti-fogging device via the fiber optic cable 61 for illumination.

[0043]

[0055] The NIR laser 220, the white light source 243, and / or the UV LED or laser diode 231 are each independently controlled by a controller 704 located within the control system (e.g., control system 7 in Figure 1B). Using the controller, the intensity of the NIR excitation light and the white light can be adjusted, for example, by changing the drive current supplied to the NIR laser and LED. In one embodiment of the anti-fogging device, the visible light intensity is adjusted (e.g., attenuated) to achieve a desired contrast between the fluorescence image and the white light image. Additional optical approaches, such as using a neutral density filter, or electrical approaches, such as modulation schemes, may be applied to significantly attenuate the visible light and / or adjust the light intensity with desired precision. It will be understood that the positions of the white light source and UV LED are interchangeable as needed.

[0044]

[0056] Figure 3 shows a front view of an elongated member 1 according to several embodiments of the present disclosure. Referring to Figure 3, the elongated member 1 includes an outer tube 101 and an inner hollow tube 102 disposed coaxially with respect to the outer tube 101. Multiple optical fibers 611 are uniformly and densely distributed in the space (gap) 103 between the outer tube 101 and the inner hollow tube 102 of the elongated member 1. In one embodiment, the optical fibers 611 are fully or completely packed in the space or gap 103. A front optical window 11 is also shown. In the example shown in Figure 3, the optical fibers 611 are shown arranged in a single layer along the outer circumference of the inner hollow tube 102. However, it is understood that multiple layers of optical fibers may be uniformly arranged to completely fill the gap between the outer tube and the inner hollow tube. For example, multiple optical fibers may be packed together sufficiently densely in one or more layers filling the space between the outer tube and the inner hollow tube. In actual applications, hundreds of individual fibers (e.g., glass strands) are uniformly and densely distributed on the inner hollow tube 102. Note that the dimensions of the optical fibers and the cross-section of the elongated member 1 are emphasized relative to each other for clarity. The optical system 12 is disposed in the hollow portion of the inner tube 102 facing the back of the front optical window 11.

[0045]

[0057] Figure 4A is a cross-sectional view of a magnified portion of an elongated member 1 having a near-infrared (NIR) light-absorbing optical window 11 according to one embodiment of the present disclosure. Referring to Figure 4A, light (visible light and / or NIR excitation light) 453 emitted by a second semiconductor light source 6 (not shown) propagates through optical fibers 611 arranged around an inner hollow tube 402 of the elongated member 1 to illuminate a target area. The NIR light-absorbing optical window 11 includes a sapphire glass or sapphire substrate 110 having a first surface 11a facing away from the elongated member 1, a second surface 11b facing toward the optical system 12, and a glass plate 111 disposed on the second surface 11b of the sapphire substrate 110. In one embodiment, the glass plate 111 is attached (e.g., using adhesive) or bonded to the second surface of the NIR light-absorbing optical window 11, and is configured to absorb infrared and near-infrared light emitted from the first semiconductor light source 41 while allowing the transmission of reflected light 452 (visible light and / or fluorescence radiation reflected from the target area). It is understood that the elongated member 1 can be used in both visible light-only endoscopy systems and visible light + IR (ICG) endoscopy systems.

[0046]

[0058] Figure 4B is a cross-sectional view of a magnified portion of an elongated member 1 having a near-infrared (NIR) light-absorbing optical window 11 according to one embodiment of the present disclosure. Similar to the embodiment shown in Figure 4A, light (visible light and / or NIR excitation light) 453 emitted by a second semiconductor light source 6 (not shown) propagates through optical fibers 611 arranged along an inner hollow tube 402 of the elongated member 1 to illuminate a target area. In this embodiment, the NIR light-absorbing optical window 11 includes impurity-doped sapphire glass 112 that, upon irradiation with IR light, absorbs IR light emitted from the first semiconductor light source 41, causing its temperature to rise, while transmitting visible incident light through the NIR light-absorbing optical window 11. In one embodiment, the sapphire glass 112 is doped with ytterbium (Yb) and erbium (Er). It is understood that this embodiment can be used in both visible light-only endoscopy systems and visible light + IR (ICG) endoscopy systems.

[0047]

[0059] Figure 4C is a cross-sectional view of a magnified portion of an elongated member 1 having a near-infrared (NIR) light-absorbing optical window 11 according to one embodiment of the present disclosure. Similar to the embodiment shown in Figure 4A, light (visible light and / or NIR excitation light) 453 emitted by a second semiconductor light source 6 (not shown) propagates through optical fibers 611 arranged along an inner hollow tube 402 of the elongated member 1 to illuminate a target area. Referring to Figure 4C, in one embodiment, the NIR light-absorbing optical window 11 may include sapphire glass 113 having a thermal absorption coating 114 deposited on a second surface 11b facing the optical system 12. In one embodiment, the thermal absorption coating 114 may be deposited using a physical vapor deposition (PVD) or chemical vapor deposition (CVD) process. ITO and other materials that absorb at infrared wavelengths and transmit light in the visible wavelength range can be used. It will be understood that various embodiments of the elongated members can be used in both visible light-only endoscopic systems and visible light + IR (ICG) endoscopic systems.

[0048]

[0060] An alternative implementation of the anti-fog device 500 for removing fogging from an endoscope or medical device is shown in Figure 5. Figure 5 is a cross-sectional view of the anti-fog device 500 for removing fogging from an endoscope or medical device according to another embodiment of the present disclosure. Referring to Figure 5, the anti-fog device 500 is substantially similar to the anti-fog device 100A, except for the differences described herein. Thus, the descriptions provided with respect to the elements shown in Figure 1A can be applied to the elements shown in Figure 5 as necessary.

[0049]

[0061] Specifically, as shown in Figure 5, the coaxial coupling module 4 is positioned between the optical system 12 and the optical adapter module 2. As described above, the optical adapter module 2 may include a plurality of optical lens elements 21a, 21b for adjusting the focal length of the device 500 by adjusting the variation in the focal lengths of the optical elements of the optical system 12. Similarly, the elongated member 1 has a hollow body with a distal end 1a and a proximal end 1b having a near-infrared light absorbing optical window 11, and the optical system 12 is positioned between the near-infrared light absorbing optical window 11 and the proximal end 1b. The optical system 12 may include a plurality of optical lens elements 12a, 12b and one or more optical guides 13, which may be part of an endoscope, medical device, or observation system. While the NIR light-shielding filter 5 is shown positioned between the coaxial coupling module 4 and the optical adapter member 2, it should be noted that other modifications and substitutions are also possible. For example, in one embodiment, the NIR light-shielding filter 5 can be positioned between the optical adapter member 2 and the image sensor 3. In one embodiment, the optical system 12 includes an endoscope or part of an endoscope system. The light source 6 and the control system 7 are not shown for clarity. Embodiments of the anti-fogging devices 100A, 100B, and 500 shown in Figures 1A, 1B, and 5, respectively, differ in the position of the optical coupling module. These embodiments are presented for illustrative purposes and are not intended to limit the disclosure. Alternative embodiments different from those described herein may be apparent to those skilled in the art based on the teachings contained herein.

[0050]

[0062] Figure 6 is a simplified schematic diagram of a basic anti-fogging optical imaging system 60 according to several embodiments of the present disclosure. The basic anti-fogging optical imaging system 60 may include the anti-fogging devices 100A, 100B in Figures 1A and 1B, or the anti-fogging device 500 in Figure 5. As described herein, embodiments of the present disclosure are particularly useful for removing fogging from endoscopes or medical and observation instruments inserted into moisture-containing media (e.g., tissue) when a user requires fogging-free images of a moisture-containing medium during examination. The anti-fogging optical imaging system 60 includes an optical imaging device 600 and a control system 67 connected to the optical imaging device 600. The optical imaging device 600 includes an elongated member 601 having a hollow body for receiving an endoscope 612, an optical adapter module 602 for adjusting the focal length of the optical imaging device 600 due to variations in the focal lengths of the optical elements of the endoscope and variations in the position of the image sensor, a coaxial coupling module 604, an NIR light-shielding filter 605, and an image sensor 603. The control system 67 may include an image display device 672 connected to the image sensor 603, an input port 673 for receiving input or commands from a user, and at least one controller 674 for providing control signals 678, 679 to different semiconductor light sources 641 and 66. In one embodiment, the at least one controller 674 may include a plurality of separate controllers configured to provide control signals 678 and 679 to the semiconductor light sources 641 and 66. The semiconductor light source 66 may be a semiconductor light source 200A or 200B shown and described with reference to Figures 2A and 2B. In one embodiment, the semiconductor light source 66 may emit visible light and NIR light (780 nm to 800 nm) for ICG. In another embodiment, the semiconductor light source 66 may emit visible light, NIR light for ICG, and UV light. The light emitted by the semiconductor light source 66 is supplied to a plurality of optical fiber strands 6611 through the fiber cable 661.Optical fiber strands 6611 are arranged circumferentially around the elongated member 601 and the front optical window 611, providing light 653 to illuminate the target 51. In one embodiment, the elongated member 601 may be similar to or identical to the elongated member described and shown in Figure 3. Although the basic fogging-preventing optical imaging system 60 is described for use in endoscopes, the fogging-preventing optical imaging system 60 may be used in various types of medical devices and / or surgical instruments, such as laparoscopes, cystoscopes, and other minimally invasive surgical applications.

[0051]

[0063] The elongated member 601 has a front optical window 611 for receiving NIR light rays 643 emitted by a semiconductor light source 641. In some embodiments, the semiconductor light source 641 is located in a coaxial coupling module 604. In other embodiments, the semiconductor light source 641 is connected to the coaxial coupling module 604 by a collimator device (not shown). The coaxial coupling module 604 and the semiconductor light source 641 may be the respective coaxial coupling module 4 and semiconductor light source 41 shown and described in detail with respect to Figure 1A. These descriptions are omitted herein for brevity. Exemplary structures of the front optical window 611 are described in detail above with reference to Figures 4A to 4C. In some embodiments, the positions of the coaxial coupling module 604 and the optical adapter module 602 can be swapped with each other. For example, the coaxial coupling module 604 may be located between the elongated member 601 and the optical adapter module 602. In other words, the components of the optical imaging apparatus 600 having a common optical axis are not fixedly connected but can be swapped with each other. The components of the elongated member 601, including the endoscope (laparoscope, cystoscope) 612, optical adapter module 602, coaxial coupling module 604, NIR light-shielding filter 605, and image sensor 603, are arranged in a straight line along the common optical axis 622.

[0052]

[0064] The image sensor 603 receives visible light and / or NIR fluorescence 652 reflected from the region of interest 51 of the moisture-containing medium. The visible light and / or NIR fluorescence 652 passes through the coaxial coupling module 604 and the NIR light-shielding filter 605 and reaches the image sensor 603. The image sensor 603 converts the light 652, which can be displayed by the image display device 672 of the control system 67, into an electrical signal. The controller 674 is connected to the semiconductor light source 641 and is configured to control the illumination period of the NIR light 643 emitted by the semiconductor light source 641 and to raise the temperature of the front optical window 611.

[0053]

[0065] In some embodiments, the controller 674 illuminates the semiconductor light source 641 for a predetermined time in the range of 3 to 50 seconds, preferably 5 to 40 seconds, and more preferably 10 to 30 seconds. In other embodiments, the controller 674 illuminates the semiconductor light source 641 based on an algorithm. For example, the controller 674 performs an inter-frame comparison to determine how much the image has become clearer between frames and calculates the illumination period of the NIR light based on the comparison data. In addition to inter-frame comparison, the comparison may be performed using a set of frames other than consecutive frames. In yet another embodiment, the controller 674 may have an input port 673 configured to receive commands or inputs from a user or operator and to illuminate and extinguish the semiconductor light source 641. The input port 673 may support wired (e.g., USB, I2C) and wireless (e.g., Bluetooth, WiFi) standards commonly used in the computer industry, the communications industry and other proprietary communication protocols.

[0054]

[0066] According to a first exemplary embodiment of a visible light-only imaging system, the semiconductor light source 41 includes a laser diode (LD) having a radiation wavelength longer than 700 nm, preferably in the wavelength range of 805 nm to 810 nm, and a radiation output of about 1 W. The front optical window 11 has an absorption rate of about 80% at wavelengths of 805 nm to 810 nm. The optical system 12 and the optical adapter module 2 have an imaging wavelength range of about 400 nm to about 700 nm that transmits visible light. The optical elements of the optical system 12 and the adapter optical module 2 are coated with an anti-reflective coating in the wavelength range of about 400 nm to about 810 nm. The dichroic mirror 43 may include a plurality of prisms. In one embodiment, the dichroic mirror 43 may include right-angled triangular prisms joined together. In one embodiment, the prisms are joined together using an adhesive. The dichroic film of the dichroic surface 432 reflects incident wavelengths of approximately 805 nm to 810 nm and transmits wavelengths in the range of approximately 400 nm to 700 nm. The coaxial coupling module 4 is located between the adapter optical module 2 and the image sensor 3, as shown in Figures 1A and 1B. The NIR light-shielding filter 5 transmits (passes through) wavelengths in the range of approximately 400 nm to 700 nm and has a transmittance of less than 0.001% of wavelengths in the range of approximately 805 nm to 810 nm. The NIR light-shielding filter 5 is located between the coaxial coupling module 4 and the image sensor 3.

[0055]

[0067] Near-infrared (NIR) light with a wavelength of 805 nm to 810 nm is emitted by the LD and passes through the collimator lens group 42 to form a slightly radial NIR ray. The degree of divergence matches the degree of convergence of the optical imaging system after passing through the optical adapter module 2. After the NIR ray is incident on the dichroic surface 432, according to the principle of reversibility of light, this ray is reflected and exits the imaging incident surface 433 and is incident on the optical adapter module 2. After passing through the optical adapter module 2 and the optical system 12, this reflected NIR ray is irradiated onto the front optical window 11. The inventors observed that 1 W of near-infrared light generates approximately 0.5 W of photopower when irradiated onto the front optical window 11. As a result of the absorption of near-infrared light by the front optical window 11, the temperature of the front optical window 11 rises. The inventors further observed that the temperature of the front optical window 11 can rise from room temperature (20°C) to 37°C within 1 minute. It should be noted that room temperature (20°C) is approximately the room temperature of an operating room, and 37°C is approximately the temperature of the human body. During this time, no fogging occurs in the optical system 12, but the optical system is inserted into a moisture-containing medium such as moisture-containing tissue. Imaging light rays with wavelengths in the range of approximately 400 nm to 700 nm pass through the optical system 12, the optical adapter module 2, and the imaging incident surface 433 of the dichroic mirror 43, and are incident on a dichroic surface 432 that can be optically coated with a dichroic film that reflects light with wavelengths in the range of approximately 805 nm to 810 nm and transmits wavelengths in the range of approximately 400 nm to 700 nm. Imaging light rays with wavelengths in the range of approximately 400 nm to 700 nm pass through the dichroic surface 432, exit the imaging exit surface 434, and reach the NIR light-shielding filter 5. The NIR light-shielding filter 5 transmits light in the wavelength range of approximately 400 nm to approximately 700 nm and blocks wavelengths in the range of approximately 805 nm to approximately 810 nm. Therefore, imaging light that does not contain NIR light in the 805 nm to 810 nm range is ultimately focused on the image sensor 3, which converts the imaging light into an electrical signal. The image sensor 3 is provided with the NIR light-shielding filter 5, which interrupts (blocks) light in the wavelength range of approximately 780 nm to approximately 810 nm.This is excitation light emitted by the LD, and even if the NIR light emitted by the LD is incident on the optical system and adapter optical module by reflection, the NIR light cannot reach the image sensor and therefore does not affect its image quality. The first exemplary embodiment describes a configuration with reference to Figures 1A and 1B, but a visible light-only imaging system may also be applied to the configuration shown in Figure 5.

[0056]

[0068] According to a second exemplary embodiment, the semiconductor light source 41 includes a vertical-resonant surface-emitting laser (VCSEL) with an emission wavelength of 935 nm to 945 nm and an emission power of approximately 2 W, and the front optical window 11 has an absorption rate of approximately 80% of the wavelengths of approximately 935 nm to 945 nm. The optical system 12 has an imaging wavelength in the range of approximately 400 nm to approximately 900 nm. The optical elements of the optical system 12 are coated with an anti-reflective coating in the wavelength range of 400 nm to 945 nm. The dichroic mirror 43 is a flat dichroic mirror having a dichroic film disposed on a dichroic surface 432 that reflects light in the wavelength range of approximately 935 nm to approximately 945 nm and transmits wavelengths of approximately 400 nm to approximately 900 nm. As shown in Figure 5, the coaxial coupling module 4 is located between the optical system 12 and the optical adapter module 2. The NIR shielding filter 5 allows light in the wavelength range of approximately 400 nm to approximately 900 nm to pass through and has a transmittance of 0.001% at wavelengths of approximately 935 nm to 945 nm. The NIR shielding filter 5 is located between the coaxial coupling module 4 and the optical adapter module 2, as shown in Figure 5. The NIR shielding filter 5 is configured to block both the excitation light wavelength spectrum and the anti-fogging laser wavelength spectrum. In one embodiment, the NIR shielding filter 5 may include an ICG shielding filter 5a and a continuously connected anti-fogging shielding filter 5b, as shown in Figure 1C.

[0057]

[0069] The operating principle of the second exemplary embodiment is the same as that of the first exemplary embodiment. After NIR light rays with wavelengths in the range of 935 nm to 945 nm emitted by the VCSEL 41 are incident on the dichroic surface 432, according to the principle of reversibility of light, these rays are reflected and exit the imaging incident surface 433 and are incident on the optical system 12. After passing through the optical system 12, these reflected NIR rays are irradiated onto the front optical window 11. The 2W output of the VCSEL raises the temperature of the front optical window 11 and prevents fogging of the front optical window. It will be understood that the front optical window 11 may be any one of the NIR light absorbing optical windows described and shown in Figures 4A to 4C. For example, the front optical window 11 may be an NIR light absorbing optical window, including a sapphire substrate, a sapphire substrate with a glass plate that absorbs infrared and near-infrared light having an NIR spectrum longer than 900 nm while allowing transmission of reflected visible light and / or fluorescence radiation from a target region, a sapphire substrate doped with Yb and Er, and a sapphire substrate with an NIR absorption coating.

[0058]

[0070] It will be understood that the operating principle of the second exemplary embodiment described with reference to Figure 5 may also apply to other embodiments, such as the embodiments described and shown in Figures 1A and 1B. In such embodiments, the optical coupling module 2 is disposed between an elongated member 1 containing an optical system 12 and a coaxial coupling module 4. The optical system 12 and the optical adapter module 2 have an imaging wavelength range of about 400 nm to about 900 nm. The optical elements of the optical system 12 and the optical adapter module are coated with an anti-reflective coating in the wavelength range of 400 nm to 945 nm. In some embodiments, the elongated member 1 may be the one described and shown in Figure 3, and the optical system 12 may be any one of the NIR light absorbing optical windows described and shown in Figures 4A to 4C.

[0059]

[0071] Figure 7 is a simplified schematic diagram of a control system 700 for an anti-fogging device according to one embodiment of the present disclosure. The control system 700 may include a plurality of control boxes, each control box may include an image sensor support 701 for receiving electrical signals from an image sensor, a display device 702 for displaying an image corresponding to the received electrical signals, an input port 703 for receiving user input and commands, a controller 704 for providing control signals to different light sources (e.g., a first light source 41 and a second light source 6 in Figure 1B), and a memory device 705 configured to store data and commands executed by the controller 704. The image sensor support 701, the display device 702, the input port 703, the controller 704, the memory device 705, and a communication bus 706 are interconnected. The control system 700 may also include a power supply module 707 configured to provide power to an optical imaging system including a first semiconductor light source and a second semiconductor light source, and an image sensor. The control system 700 may also include additional components such as a mouse and keyboard, and other functions such as on-screen display menus and touch input.

[0060]

[0072] Figure 8 is a simplified flowchart illustrating a method 800 for operating a fogging-preventing optical imaging system according to one embodiment of the present disclosure. For example, the apparatus shown in Figures 1A, 1B, 5, and 6 can use the process shown in Figure 8 to remove fogging from a front optical window. Method 800 provides for operating a fogging-preventing optical imaging system having an elongated member having a distal end and a proximal end, a near-infrared (NIR) light-absorbing optical window disposed at the distal end, and an optical system disposed between the NIR light-absorbing optical window and the proximal end along an optical path (801). For example, the fogging-preventing optical imaging system may be the optical imaging system 60 of Figure 6. Method 800 also includes connecting a coupling module to the elongated member at the proximal end (802). The coupling module may include a dichroic mirror, a collimator, and a light source that emits NIR light. The NIR light can be transmitted along the optical path to the NIR light-absorbing optical window. Method 800 includes activating a light source to transmit NIR light along an optical path to an NIR light absorbing optical window over an illumination period (803), receiving visible light reflected from the region of interest with an image sensor positioned along the optical path (804), and converting the visible light into an electrical signal using the image sensor (805). The image sensor may include, for example, a CCD or a CMOS image sensor.

[0061]

[0073] In some embodiments, method 800 further includes converting an electrical signal into frame data, comparing the frame data between two frames to determine the illumination period of a light source using a controller, and stopping the light source using the controller after the illumination period has ended. The frames being compared may be consecutive frames.

[0062]

[0074] In other embodiments, method 800 includes converting an electrical signal into an image frame, determining the image quality of one or more of the image frames by a user or operator, and stopping the light source by the user or operator if the user (operator) determines that the image quality is satisfactory. In one embodiment, the image quality may be based on the user's observation and subjective judgment. In one embodiment, the image quality may be based on a comparison of the obtained image with a predetermined set of images stored in a database or library. In one embodiment, the image quality may be based on artificial intelligence for image recognition.

[0063]

[0075] In one embodiment, method 800 may also include adjusting the focal length of an optical imaging system to prevent fogging by using an optical adapter disposed between an elongated member and an image sensor. In one embodiment, method 800 may also include attenuating a portion of the reflected NIR light with an NIR light-shielding filter disposed between a coupling module and an image sensor.

[0064]

[0076] It should be understood that the specific steps shown in Figure 8 provide a concrete method for operating a fogging-preventing optical imaging system according to one embodiment of the present disclosure. In some embodiments, the light source in the coupling module is activated before the fogging-preventing optical imaging system is inserted into a moisture-containing medium. In other embodiments, the light source in the coupling module is activated after the fogging-preventing optical imaging system is inserted into a moisture-containing medium. In yet another embodiment, the light source is activated only for a predetermined illumination period. In another embodiment, the user or operator may stop the light source when the NIR light-absorbing optical window reaches a predetermined temperature, such as 36.2°C (human body temperature) or the body temperature of another mammal. Those skilled in the art will recognize many changes, modifications, and substitutions.

[0065]

[0077] Figure 9A is an image of a moisture-containing medium provided by a viewing device before activating an NIR light source, according to one embodiment of the present disclosure. In the image shown in Figure 9A, if the NIR light-absorbing optical window is cloudy either internally, externally, or both, visible light reflected from the region of interest will not pass through the cloudy NIR light-absorbing optical window. Also, if the intensity of visible light captured by the image sensor is weak, the image displayed on the image display device will be blurry.

[0066]

[0078] Figure 9B shows an image of a medium provided by a viewing device after NIR light has been activated, according to one embodiment of the present disclosure. As shown in Figure 9B, the NIR light absorbing optical window is de-fogging after being illuminated by a light source for a certain period of time. As a result, the visible light of the image reflected from the region of interest passes through the de-fogging NIR light absorbing optical window, and the image display device displays a sharp image.

[0067]

[0079] Embodiments of this disclosure provide anti-fogging devices for visible light-only endoscopic imaging systems and anti-fogging devices for visible light and NIR(ICG) light endoscopic imaging systems. In one exemplary embodiment of the anti-fogging device for a visible light-only endoscopic imaging system, the first semiconductor light source 41 may have an infrared laser device having a wavelength spectrum longer than 700 nm (e.g., around 808 nm). The optical elements of the optical system 12 and / or the optical adapter module 2 may have an anti-reflective coating covering the range of 400 nm to 850 nm. In one exemplary embodiment of the anti-fogging device for a visible light and NIR(ICG) light endoscopic imaging system, the excitation wavelength of the IR laser device in the second semiconductor light source 6 may be about 780 nm to 800 nm (e.g., 780 nm to 785 nm). An LED device having a wavelength range of 780 nm to 805 nm may also be used.

[0068]

[0080] In one embodiment, the excitation wavelength is concentrated at 789 nm, and the emission wavelength is concentrated around 814 nm with a bandwidth of approximately 40 nm. The NIR light-shielding filter 5 is configured to block both the excitation wavelength (780 nm to 800 nm) and the NIR wavelength (935 nm to 945 nm), while allowing visible light wavelengths (400 nm to 700 nm) and fluorescence emission light (wavelengths longer than the excitation wavelength) to pass through. For example, if the excitation wavelength is in the range of 780 nm to 800 nm (e.g., 789 nm), the fluorescence emission light is in the range of 790 nm to 830 nm (e.g., 814 nm). In one embodiment, the NIR light-shielding filter 5 may include an ICG blocking filter for blocking the excitation wavelength (780 nm to 800 nm) and an anti-fogging blocking filter for blocking the NIR wavelength (935 nm to 945 nm). The ICG blocking filter and the anti-fogging blocking filter are connected in series. In one embodiment, the NIR light-shielding filter 5 may include a single multi-notch filter having at least a first attenuation region configured to attenuate excitation wavelengths in the range of 780 to 800 nm, and a second attenuation region configured to attenuate NIR wavelengths in the range of 935 to 945 nm.

[0069]

[0081] In one embodiment, the second semiconductor light source 6 may include a white light source, UV light, and an NIR laser or NIR LED. In one embodiment, the UV light has a wavelength concentrated at approximately 415 nm.

[0070]

[0082] While embodiments are described in detail, it should be understood that various changes, substitutions, and modifications may be made without departing from the scope of this disclosure as set forth in the attached claims.

Claims

1. A device for maintaining the optical path of an optical imaging system to prevent fogging, wherein the device is An elongated member arranged along the optical axis and having a distal end and a proximal end; an interface portion positioned between the distal end and the proximal end; and a near-infrared (NIR) light absorbing optical window provided at the distal end. An optical system arranged along the optical axis, comprising at least one optical lens element arranged along the optical axis, A coupling module connected to the elongated member at its proximal end, having an NIR light source operable to provide NIR light, and configured to transmit the NIR light to the NIR light absorbing optical window through the proximal end and the at least one optical lens element positioned along the optical axis, and to receive light rays from a region of interest along the optical axis, The aforementioned coupling module, A dichroic mirror having a first surface, a second surface, a third surface facing the proximal end of the elongated member, and a fourth surface facing the image sensor, A collimator located in front of the first surface of the dichroic mirror along the first optical axis, Equipped with, The NIR light source is positioned at the focal plane of the collimator along the first optical axis, The second surface is configured to reflect the NIR light and allow the light rays to pass through. Device.

2. The apparatus according to claim 1, wherein the NIR light absorbing optical window comprises a sapphire glass having a glass plate attached to the inner surface of the sapphire glass facing the optical system and configured to transmit visible light while absorbing the NIR light, or a sapphire glass having a heat-absorbing coating facing the optical system.

3. The apparatus according to claim 1, wherein the NIR light absorbing optical window comprises impurity-doped sapphire glass that is operable to allow visible light to pass through and absorb the NIR light.

4. The apparatus according to claim 1, wherein the NIR light source comprises a laser diode (LD) or a vertical-resonant surface-emitting laser (VCSEL) having an optical output of 1 W or more.

5. The apparatus according to claim 1, wherein the light ray includes a spectral range of 400 nm to 700 nm, or a spectral range of 400 nm to 700 nm and an emission wavelength longer than the excitation light wavelength.

6. Image sensor and, An NIR light-shielding filter is disposed in front of the image sensor and configured to allow the light rays to pass through and block the NIR light, The apparatus according to claim 1, further comprising:

7. The apparatus according to claim 6, wherein the NIR light-shielding filter comprises a first shielding filter configured to block the excitation wavelength and a second shielding filter configured to block the NIR light, or a single multi-notch filter having a first attenuation region configured to attenuate the excitation wavelength and a second attenuation region configured to attenuate the NIR light.

8. The apparatus according to claim 1, wherein the NIR light absorption optical window has an absorption rate of about 80% in the wavelength range of 805 nm to 810 nm or 935 nm to 945 nm.

9. An optical adapter is disposed between the elongated member and the image sensor and configured to adjust the focal length of the optical imaging system that prevents fogging. The apparatus according to claim 1, further comprising:

10. A controller connected to the coupling module and configured to control the illumination period of the NIR light source of the coupling module in order to maintain the optical path of the optical imaging system that prevents fogging. The apparatus according to claim 1, further comprising:

11. The apparatus according to claim 10, wherein the controller is configured to determine the illumination period by comparing the sharpness of images between frames.

12. The apparatus according to claim 1, wherein the elongated member is configured to receive an endoscope.

13. The apparatus according to claim 1, further comprising a second light source that emits visible light, near-infrared (NIR) light, and ultraviolet (UV) light.

14. A method for operating an optical imaging system to prevent fogging, comprising: an elongated member arranged along an optical axis and having a distal end and a proximal end; an interface portion disposed between the distal end and the proximal end; a near-infrared (NIR) light absorbing optical window disposed at the distal end; and an optical system having at least one optical lens element arranged along the optical axis, wherein the method is: The coupling module is connected to the elongated member at its proximal end, wherein the coupling module is equipped with an NIR light source that emits NIR light. Activating means for emitting early NIR light from the NIR light source along the optical axis over the illumination period, such that the NIR light is transmitted to the NIR light absorbing optical window through the proximal end and the at least one optical lens element, Activating means for receiving visible light reflected from the region of interest along the optical axis, Includes, The aforementioned coupling module, A dichroic mirror having a first surface, a second surface, a third surface and a fourth surface, A collimator located in front of the first surface of the dichroic mirror, along the first optical axis, Equipped with, The NIR light source is positioned at the focal plane of the collimator. The second surface is configured to reflect the NIR light and allow the visible light to pass through. method.

15. The image sensor converts the visible light into an electrical signal, Converting the aforementioned electrical signal into frame data, The frame data is compared between the two frames, and the controller determines the illumination period of the NIR light source. After the illumination period ends, the controller stops the means for emitting the NIR light, The method according to claim 14, further comprising:

16. Converting the aforementioned electrical signal into an image frame, The user determines the image quality of the aforementioned image frame, If it is determined that the image quality is satisfactory, the user may stop the means that emits the NIR light, The method according to claim 15, further comprising:

17. By using the optical adapter disposed between the elongated member and the image sensor, the focal length of the optical imaging system that prevents fogging is adjusted. The method according to claim 14, further comprising:

18. The NIR light-shielding filter, positioned between the coupling module and the image sensor, attenuates a portion of the reflected NIR light. The method according to claim 14, further comprising:

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