Patent Publication Number: US-2022221696-A1

Title: Thermal imaging endoscope

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/833,509 filed on Apr. 12, 2019. The content of this provisional application is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This patent document relates to the use of infrared thermography in otorhinolaryngological endoscopy for diagnosing and treating conditions of the ear, nose, and throat (ENT). 
     BACKGROUND 
     Endoscope is an instrument used to examine the interior of a hollow organ or cavity of a body. Endoscopes are inserted directly into an organ which needs examination during an endoscopy procedure. 
     SUMMARY 
     There is a clinical need for improved visual inspection for ENT diagnosis and surgeries. Endoscopy is often required to access locations of ENT conditions. However, assessment and identification of ENT abnormalities and pathologies remain challenging due to the difficult-to-reach ENT locations and the complex nature of many of the related pathologies. An imaging technique that could provide additional information, high-contrast and quantitative data about the patient condition will be useful, especially to assist ENT clinicians in diagnosis and surgeries and to avoid the need to resort to more expensive imaging techniques (e.g., computed tomography (CT) scans, ultrasound imaging, magnetic resonance imaging (MRI)). 
     This patent document discloses a thermographic system that can be integrated with endoscopes used in otolaryngology. The thermal imaging system can be directly integrated into an endoscope or, alternatively, designed as an add-on attachment to an endoscope. In either embodiment, the thermal imaging system can preserve normal imaging in a visible spectral range (referred to as visible-range below) function of the endoscope. The thermal imaging system can provide thermal images having the same field of view as that of the visible-range images, or the field of view in the thermal images can be larger or smaller than that of the visible-range images, depending on the needs of a particular application. The thermal camera (also referred to as thermal infrared imaging camera or thermal imaging camera or thermal-range camera) -enabled endoscope or an add-on thermal camera attachment to an endoscope will access the patient&#39;s nose or mouth through a rigid or flexible tube and transmit and/or record videos of the temperature distribution of a region of interest while simultaneously acquiring visible-spectrum images of the region. The acquired thermal-range and visible-range data can be processed and output in 1D, 2D, or 3D format and/or as a score showing, for example, severity of a disease on a scale from 1 to 10. Diagnostic procedures can involve analyzing the processed data using such metrics as temperature difference between a local area and neighboring areas, rate of temperature change in the local area as well as size, location, and features (e.g., shape of the edge) of the local area, among others. 
     In one aspect, the present patent document provides a thermal imaging system for imaging, diagnosing, or monitoring treatment of conditions of the human body, including ENT conditions. The thermal imaging system comprises an endoscope and a thermal infrared imaging camera. In one embodiment, the thermal imaging camera is integrated into the endoscope. In another embodiment, the thermal imaging camera is an add-on attachment to the endoscope. 
     In some aspects, the present patent document provides a thermal imaging system which includes one or more mirrors which can be used for adjusting direction of a field of view of the system and/or for directing light from a light source to a target area of interest. In other aspects, such field of view adjustments and/or changes of the direction of illumination can be done by means other that such mirror(s). 
     Embodiments of the technology disclosed herein can use different optical elements such as mirrors, dichroic mirrors, “hot” or “cold” mirrors, filters, beam splitters, among other optical elements. 
     In some aspects, the thermal imaging camera uses temperature as a contrast marker for lesions or abnormalities that have low contrast in a visible spectral range. 
     In another aspect, the present patent document provides a passive imaging modality adapted to be used in addition to or independent of line-of-sight visibility for external or internal inspection of the human body, through a natural orifice, surgically created openings, subdermal spaces, or laparoscopic applications. 
     In another aspect, the present patent document discloses an endoscope, comprising: a body having a proximal end and a distal end; a light source configured to emit light in a first range of wavelengths and attached to the body proximate to the proximal end of the body; a mirror attached to the body proximate to the distal end of the body; a hot mirror positioned proximate to the proximal end of the body and configured to reflect light in a second range of wavelengths and allow light in the first range of wavelengths to pass through the hot mirror; a first imaging system positioned proximate to the proximal end of the body and configured to create a first image of a target area using light in the first range of wavelengths; a second imaging system positioned proximate to the proximal end of the body and configured to create a second image of the target area using light in the second range of wavelengths; wherein: the mirror is configured to reflect light received by the mirror from the light source towards the target area, the mirror is configured to receive a first portion of light in the first range of wavelengths reflected by the target area and a second portion of light in the second range of wavelengths emitted by the target area and direct the first portion of light and the second portion of light towards the proximal end of the body, the hot mirror is configured to transmit at least a part of the first portion of light towards the first imaging system and reflect at least a part of the second portion of light towards the second imaging system. In some aspects, the hot mirror can be replaced by a “cold mirror” configured to transmit at least a part of the second portion of light towards the second imaging system and reflect at least a part of the first portion of light towards the first imaging system. 
     In another aspect, the present patent document discloses an endoscope, comprising: a first body having a proximal end and a distal end; a second body having a proximal end and a distal end, wherein the second body is attached to the first body such that the distal end of the second body is proximate to the distal end of the first body; a light source configured to emit light in a first range of wavelengths and attached to the first body proximate to the proximal end of the first body; a first mirror attached to the first body proximate to the distal end of the first body; a second mirror attached to the second body proximate to the distal end of the second body; a first imaging system positioned proximate to the proximal end of the first body; a second imaging system positioned proximate to the proximal end of the second body; wherein: the first mirror is configured to reflect light received by the first mirror from the light source towards a target area, the first mirror is configured to receive a first portion of light in the first range of wavelengths reflected by the target area and direct the first portion of light towards the proximal end of the first body, the second mirror is configured to receive a second portion of light in a second range of wavelengths emitted by the target area and direct the second portion of light towards the proximal end of the second body, the first imaging system is configured to receive at least a part of the first portion of light and create a first image of the target area corresponding to the first range of wavelengths, and the second imaging system is configured to receive at least a part of the second portion of light and create a second image of the target area corresponding to the second range of wavelengths. 
     In another aspect, the present patent document discloses an endoscope, comprising: a body having a proximal end and a distal end; a light source configured to emit light in a first range of wavelengths and attached to the body proximate to the proximal end of the body; a mirror attached to the body proximate to the distal end of the body; a first imaging system attached to the body proximate to the proximal end of the body; a second imaging system attached to the body proximate to the distal end of the body; wherein: the mirror is configured to reflect light received by the mirror from the light source towards a target area, the mirror is configured to receive a first portion of light in the first range of wavelengths reflected by the target area and direct the first portion of light towards the proximal end of the body, the first imaging system is configured to receive at least a part of the first portion of light and create a first image of the target area corresponding to the first range of wavelengths, and the second imaging system is configured to receive light emitted by the target area in a second range of wavelengths and create a second image of the target area corresponding to the second range of wavelengths. 
     In another aspect, the present patent document discloses an endoscope, comprising: a body having a proximal end and a distal end; and an imaging system attached to the body proximate to the distal end of the body; wherein the imaging system is configured to receive light emitted by a target area in a range of wavelengths and create an image of the target area corresponding to the range of wavelengths. 
     In another aspect, the present patent document discloses a method of fabrication of an endoscope, comprising: providing a body having a proximal end and a distal end; and coupling an imaging system to the body proximate to the distal end of the body; wherein the imaging system is capable of receiving light emitted by a target area in a range of wavelengths and creating an image of the target area corresponding to the range of wavelengths. 
     In another aspect, the present patent document discloses a method of fabrication of an endoscope, comprising: providing a body having a proximal end and a distal end; coupling a light source capable of producing light in a first wavelength band to the body proximate to the proximal end of the body; coupling a mirror to the body proximate to the distal end of the body; coupling a first imaging system to the body proximate to the proximal end of the body; coupling a second imaging system to the body proximate to the distal end of the body; wherein: the mirror is capable of reflecting light received by the mirror from the light source towards a target area, the mirror is capable of receiving a first portion of light in the first wavelength band reflected by the target area and directing the first portion of light towards the proximal end of the body, the first imaging system is capable of receiving at least a part of the first portion of light and creating a first image of the target area corresponding to the first wavelength band, and the second imaging system is capable of receiving light emitted by the target area in a second wavelength band and creating a second image of the target area corresponding to the second wavelength band. 
     In another aspect, the present patent document discloses a method of fabrication of an endoscope, comprising: providing a first body having a proximal end and a distal end; providing a second body having a proximal end and a distal end; coupling the second body to the first body such that the distal end of the second body is proximate to the distal end of the first body; coupling a light source capable of emitting light in a first range of wavelengths to the first body proximate to the proximal end of the first body; coupling a first mirror to the first body proximate to the distal end of the first body; coupling a second mirror to the second body proximate to the distal end of the second body; coupling a first imaging system to the first body proximate to the proximal end of the first body; coupling a second imaging system to the second body proximate to the proximal end of the second body; wherein: the first mirror is capable of reflecting light received by the first mirror from the light source towards a target area, the first mirror is capable of receiving a first portion of light in the first range of wavelengths reflected by the target area and directing the first portion of light towards the proximal end of the first body, the second mirror is capable of receiving a second portion of light in a second range of wavelengths emitted by the target area and directing the second portion of light towards the proximal end of the second body, the first imaging system is capable of receiving at least a part of the first portion of light and creating a first image of the target area corresponding to the first range of wavelengths, and the second imaging system is capable of receiving at least a part of the second portion of light and creating a second image of the target area corresponding to the second range of wavelengths. 
     In another aspect, the present patent document discloses a method of fabrication of an endoscope, comprising: providing a body having a proximal end and a distal end; coupling a light source capable of emitting light in a first range of wavelengths to the body proximate to the proximal end of the body; coupling a mirror to the body proximate to the distal end of the body; 
     coupling a hot mirror to the body proximate to the proximal end of the body, wherein the hot mirror is capable of reflecting light in a second range of wavelengths and allowing light in the first range of wavelengths to pass through the hot mirror; coupling a first imaging system to the body proximate to the proximal end of the body, wherein the first imaging system is capable of creating a first image of a target area using light in the first range of wavelengths; coupling a second imaging system to the body proximate to the proximal end of the body, wherein the second imaging system is capable of creating a second image of the target area using light in the second range of wavelengths; wherein: the mirror is capable of reflecting light received by the mirror from the light source towards the target area, the mirror is capable of receiving a first portion of light in the first range of wavelengths reflected by the target area and a second portion of light in the second range of wavelengths emitted by the target area and directing the first portion of light and the second portion of light towards the proximal end of the body, the hot mirror is capable of transmitting at least a part of the first portion of light towards the first imaging system and reflecting at least a part of the second portion of light towards the second imaging system. In some aspects, the hot mirror can be replaced by a “cold mirror” capable of transmitting at least a part of the second portion of light towards the second imaging system and reflecting at least a part of the first portion of light towards the first imaging system. 
     In another aspect, the present patent document provides a method of thermographic ENT imaging by using a thermal imaging system which comprises an endoscope and a thermal imaging camera. 
     In another aspect, the present patent document provides a method of diagnosing or treating ENT conditions by performing thermographic ENT imaging using a thermal imaging system that comprises an endoscope and a thermal imaging camera, obtaining imaging data, and processing said data to produce a quantitative diagnostic metric. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic of an endoscope incorporating a visible-range camera. 
         FIG. 2  shows a schematic of a thermal camera imaging system. 
         FIG. 3  shows a schematic of an endoscope which incorporates both a visible-range camera and a thermal-range camera and in which the thermal-range and the visible-range optical paths are integrated. 
         FIG. 4  shows a schematic of an endoscope which incorporates both a visible-range camera and a thermal-range camera and in which the thermal-range and the visible-range optical paths are separated. 
         FIG. 5  shows a schematic of a thermal imager of the endoscope shown in  FIG. 4 . 
         FIG. 6  shows a schematic of an endoscope which incorporates both a visible-range camera and a thermal-range camera. 
         FIG. 7  illustrates an embodiment of the endoscope shown in  FIG. 6 . 
         FIG. 8  illustrates another embodiment of the endoscope shown in  FIG. 6 . 
         FIG. 9  illustrates yet another embodiment of the endoscope shown in  FIG. 6 . 
         FIG. 10  shows a schematic of an endoscope which incorporates a thermal-range camera. 
         FIG. 11  illustrates an embodiment of the endoscope shown in  FIG. 10 . 
         FIG. 12  illustrates another embodiment of the endoscope shown in  FIG. 10 . 
         FIG. 13  shows a schematic of an endoscope which incorporates a mechanism for adjusting tilt of a mirror. 
         FIG. 14  shows a schematic of an interface which can be used to adjust tilt of the mirror. 
         FIG. 15  shows a schematic of a data processor which can interface with various elements of various embodiments of an endoscope according to the technology disclosed in this patent application. 
         FIG. 16  shows an example illustration of an image alignment procedure according to the technology disclosed in this patent application. 
         FIG. 17  shows an example illustration of a software which can display thermal-range image data overlaid on a visible-range image according to the technology disclosed in this patent application. 
         FIG. 18  shows an example illustration of thermal-range image data processing according to the technology disclosed in this patent application. 
     
    
    
     DETAILED DESCRIPTION 
     At ENT clinics, otolaryngologists need to examine patients who report discomfort in the ear, nose, or throat areas. For the mouth and throat, a typical outpatient procedure is endoscopic imaging, which uses either a flexible or rigid endoscope in various forms to access the mouth and/or throat and relay a visible image to the operator&#39;s field of view through an eyepiece and/or an integrated camera. The trained clinician can then inspect the image to detect physiological abnormalities and check the muscle or tissue function. 
     Currently, endoscopes acquire images using visible-range or “white” light, which crucially (1) requires an integrated light source (e.g., LED, arc lamp, halogen lamp, laser) to illuminate a field of view and (2) delivers image contrast in the visible spectral range to which human eyesight is naturally sensitive. 
     There is some variation in this approach, such as using narrowband filters or light sources or imaging in the near-infrared. These alternatives can provide enhanced contrast to features such as vasculature. Because external illumination is required, image artifacts such as glare from the lamp are prominent due to the mucosal surface on a target area. Moreover, it is difficult or not possible to detect many subsurface features or conditions using imaging in the visible part of the spectrum only. Detecting subsurface features and/or conditions using images in the visible part of the spectrum only requires a degree of trained interpretation, and the patient health assessment is highly dependent on the clinician&#39;s experience. 
     Accordingly, there is a need for a device that can be used in the clinic to improve diagnostic confidence, without physicians having to resort to expensive imaging studies and/or prescribe unnecessary treatments. Subdermal contrast has previously been achieved using thermal cameras, particularly in the area of breast cancer. Recently, the cost and size of thermal cameras have become small enough to be useful in oral and nasal endoscopy. 
       FIG. 1  is a schematic of a rigid endoscope  100  for imaging in a visible spectral range (a visible-range endoscope). Imaging target area  190  is, for example, inner throat of a patient. The endoscope  100  has a body  110  having a proximal end  111  and a distal end  112 . The endoscope  100  directs light from a light source  120  to the target area  190  and collects light reflected from the target area  190 . The light source  120  emits light in a visible spectral range (e.g., a range of wavelengths between 380 nm and 740 nm) and is attached to the body  110  at a location proximate to the proximal end of the body  110 . Light in the visible spectral range can be directly perceived by a typical human eye. 
     To image features of the throat, the endoscope  100  is passed through the patient&#39;s mouth, and a mirror  130  both delivers light to the target area  190  and collects light reflected from the target area  190 . The mirror  130  is attached to the body  110  proximate to the distal end of the body  110 . The mirror  130  can be pivotably attached to the body  110 . The mirror  130  can be removably attached to the body  110 . 
     To deliver light from the light source  120  to the mirror  130 , a beam splitter  125  located in the body  110  of the endoscope  100  can be used, for example. The beam splitter  125  reflects part of the light from the light source  120  towards the mirror  130  while another part of the light from the light source  120  passes through the beam splitter  125 . In other implementations, one or more optical fibers can be used to deliver light from the light source  120  to the mirror  130  and/or to the target area  190  directly. Such optical fibers can be at least partially enclosed by the body  110 . 
     Optical elements (e.g., single lenses or sets of several lenses)  113  and  117  housed in the body  110  of the endoscope  100  relay and magnify an image of the target area (e.g., the throat) onto an intermediate imaging plane which can be reimaged, for example, by an eyepiece for direct viewing by clinicians or by a camera  150  capable of capturing images in a visible spectral range (“visible-range camera”). For example, camera  150  can be connected to the body  110  proximate to the proximal end of the body  110 . Camera  150  can include a sensor  153  to perform image capture. Sensor  153  can be of any type. For example, sensor  153  can be a charge-coupled device (CCD) or a CMOS (complementary metal-oxide-semiconductor) -based sensor. Images captured by the camera  150  can be read out to a computer (not shown) using an analog-to-digital converter (ADC) and/or readout integrated circuit (ROIC)  155  via a wired or wireless interface (e.g., USB, Ethernet, Wi-Fi, or Bluetooth) embedded into the camera  150  or housed in the body  110  of the endoscope  100  or connected to the body  110  of the endoscope  100 . 
       FIG. 2  is a schematic of a camera imaging system  50  capable of capturing images in a thermal spectral range (“thermal-range camera” or “thermal camera”). Objects with a defined temperature emit light, whose spectrum depends on the particular temperature. Increases in temperature result in a shift of this radiation spectrum and an increase in the total amount of radiated energy, according, for example, to the formulas describing blackbody radiation. For terrestrial objects at ambient temperature, this spectrum is predominantly invisible and typically falls in the 8-14 micrometer band, which is termed the thermal infrared band. As objects get hotter, the amount of radiation in the thermal infrared band increases, while cooling objects will emit less radiation in the same band. 
     Materials that are sensitive to this thermal radiation can be calibrated to measure the temperature of objects based on the amount of received radiative power and, when defined in size and arranged into a grid, are referred to as focal plane arrays (FPA). FPA sensors can be paired, for example, with a thermal infrared transmissive lens, e.g. lens  60  in  FIG. 2 , to form a thermal camera  50  that images thermal radiation from objects (e.g., thermal radiation  195  from a target area  190  in  FIG. 2 ) onto the FPA (e.g., FPA  70  in  FIG. 2 ). FPA  70  of the camera  50  can be, for example, an uncooled bolometer focal plane array. Images captured by the thermal camera  50  can be read out to a computer (not shown) using an analog-to-digital converter and/or readout integrated circuit  75  via a wired or wireless interface (e.g., USB, Ethernet, Wi-Fi, or Bluetooth) embedded into the camera  50  and/or connected to the camera  50 . In some embodiments, the computer can be embedded into the camera  50 . 
     Lens  60  of the thermal camera  50  can be made using, for example, the following materials which are transmissive to both visible-range and thermal-range radiation: potassium bromide, sodium chloride, zinc sulfide, zinc selenide. Or, as shown in  FIG. 2 , lens  60  can be made using materials which are opaque to visible-range light but transparent (to one degree or another) to thermal-range radiation such as, for example, silicon or germanium. 
     A figure of merit of a thermal-range camera can be specified, for example, by its noise equivalent temperature difference (NETD), which is defined as the temperature difference between two points of an object that is equivalent to the noise level temperature variance in the FPA readout. 
     While thermal camera systems have remained traditionally bulky, power-hungry, and expensive due to the cooling units required to reduce NETD to a useable level (particularly for bandgap sensors such as HgCdTe), recent advances in uncooled microbolometers have allowed to produce thermal cameras which have NETD comparable to that of older thermal cameras yet have form factors similar to those of visible-range cameras and cost a fraction of the price of the older thermal cameras. 
     During processing of the acquired thermal images, scores can be assigned to the thermal images by examining a likelihood that a rise in temperature or lack thereof in a certain area of interest in the images is significant. To calculate this likelihood, factors to consider can include, for example, temperatures of the surrounding areas, temperature readings from one or more earlier time-points, and temperature readings with reference to a standard temperature in the body. Temperature dynamics and spatial averaging can also be used to provide additional data points to be correlated with specific conditions. Physicians can use the quantitative score information to make more informed decisions. 
     The obtained information (e.g., temperature of the area of interest and/or that of surrounding areas and/or calculated score values) can be overlaid on the thermal video. Presentation (e.g., visualization) of the thermal data can be provided using single and/or multiple metrics, such as, for example, 2D temperature/scoring maps, 1D temperature time histories, histograms, and various statistical metrics. Clinicians can also build a database for each patient to monitor the progress of the patient&#39;s condition or therapy. 
       FIG. 3  shows an endoscope  200  according to an embodiment of the technology disclosed in this patent document that integrates a thermal infrared and a visible spectrum optical paths within a body  110  having a proximal end  111  and a distal end  112 . As shown in  FIG. 3 , the target area  190  is imaged both in a visible spectral range and a thermal spectral range. During thermal imaging, thermal radiation  195  emitted by the target area  190  is registered by the endoscope  200 . 
     In endoscope  200 , the visible camera attachment  150  which is traditionally attached to an eyepiece of an endoscope (e.g., endoscope  100 ) is replaced with an attachment  245  connected to the body  110  proximate to its proximal end. The attachment  245  houses both a visible-range camera  150  and a thermal-range camera  50 . A “hot mirror”  210  located inside the attachment  245  is configured to reflect thermal radiation into the thermal-range camera  50  and pass visible light into the visible-range camera  150 . 
     Optical materials of the endoscope  200  are transmissive to both thermal infrared light and visible light, which can be implemented using materials such as ZnSe. Since both thermal and visible optical paths are relayed through the same optical elements of the endoscope  200  (e.g., lenses or lens sets  213  and  217 , mirror  230 , beam splitter  225 ), the optical elements of the endoscope  200  should preferably minimize aberrations in both thermal infrared and visible spectral ranges. 
     Beam splitter  225  of the endoscope  200  reflects part of the light produced by the light source  120  attached to the body  110  proximate to its proximal end towards the mirror  230  which is attached to the body  110  proximate to its distal end and which directs the light received from the light source  120  towards the target area  190 . The light source  120  emits light in a visible spectral range (e.g., a range of wavelengths between 380 nm and 740 nm or one or more wavelengths in any of the following ranges: 380-450 nm, 450-485 nm, 485-500 nm, 500-565 nm, 565-590 nm, 590-625 nm, or 625-740 nm). As with the endoscope  100 , various ways of delivering light from the light source  120  to the mirror  230  and/or directly to the target area  190  can be used. For example, the light can be delivered using an optical fiber or several optical fibers instead of or in addition to using the beam splitter  225 . 
     Mirror  230  receives light in the visible spectral range reflected by the target area  190  as well as light in a thermal infrared spectral range (e.g., a range of wavelengths between 8 μm and 14 μm) emitted by the target area and directs the light received from the target area to the optical elements housed inside the body  110  of the endoscope  200 . Optical elements  213  and  217  (each of which can be a single lens or a set of several lenses) relay and/or magnify a visible-range image of the target area (e.g., throat of a person) as well as a thermal image of the target area. The radiation (both visible and thermal infrared) from the target area  190  passes through the beam splitter  225  after which thermal part of the radiation is directed by the “hot mirror”  210  into the thermal-range camera  50  while the visible part of the radiation passes through the mirror  210  into the visible-range camera  150 . The thermal-range camera  50  and the visible-range camera  150  obtain a thermal image of the target area and a visible-range image of the target are, respectively. 
       FIG. 4  shows an example of an endoscope  300  according to an embodiment of the technology disclosed in this patent document. Endoscope  300  separates a thermal infrared and a visible spectrum optical paths. Endoscope  300  comprises an endoscope  100  which performs imaging of the target area  190  in a visible spectral range (e.g., a range between 380 nm and 740 nm) and a thermal imager  350  attached to the endoscope  100  which is used to perform imaging of the target area in a thermal infrared spectral range (e.g., a range between 8 μm and 14 μm). 
     As shown in  FIG. 5 , in some embodiments, the thermal imager attachment  350  comprises a body  310  having a proximal end  311  and a distal end  312 , and an optical system which incorporates a viewing mirror  330  attached to the body  310  at its distal end, relay and/or magnification optical systems  313  and  317  housed in the body  310 , as well as a thermal camera  50  attached to the body  310  proximate to its proximal end. The mirror  330  can be pivotably attached to the body  310 . The mirror  330  can be removably attached to the body  310 . Thermal radiation  195  emitted by the target area  190  is directed by the mirror  330  into the optical systems  313  and  317  which transmit it to the thermal-range camera  50  which captures an image of the target area in a thermal spectral range. Images captured by the visible-range camera  150  of an endoscope (e.g., endoscope  100 ) to which the thermal imager  350  is attached and images captured by the thermal-range camera  50  of the thermal imager  350  can be transmitted to, for example, a computer (not shown) or another electronic device which can process the images. Image transmission can be performed via a wired (e.g., USB, Ethernet) or a wireless interface (e.g., Wi-Fi, Bluetooth). The interface can be incorporated into any of the thermal imager  350 , thermal-range camera  50 , visible-range camera  150  or the endoscope (e.g., endoscope  100 ), for example. The computer or another electronic device can be embedded into the thermal imager  350 , for example. 
     Optical materials used in the thermal imager  350  can be selected or designed for optimal transmission and imaging in a thermal infrared spectral range (e.g., a range of wavelength from the range between 8 μm and 14 μm) to minimize both intensity loss and aberrations in the thermal infrared spectral range. The thermal imager  350  can be used as an attachment to a visible-range endoscope (e.g., endoscope  100 ) and, in some embodiments of the technology disclosed in this patent document, the thermal imager  350  can also be used by itself for thermographic-only endoscopy. If used as an attachment to an endoscope, the field of view of the endoscope and the field of view of the thermal imager  350  can be configured to overlap via mechanical alignment of the optical elements of the endoscope and/or the thermal imager  350  (e.g., mirror  130  and/or mirror  330 ) and/or through alignment of the visible-range and thermal-range images during processing of the captured visible-range and thermal-range images. 
       FIG. 6  shows an endoscope  400  according to an embodiment of the technology disclosed in this patent document. The endoscope  400  comprises a thermal camera  50  attached to the distal end of the body  110  of the endoscope  400 . The thermal camera  50  can incorporate an uncooled microbolometer focal plane array as its sensor, for example. Endoscope  400  also comprises a visible-range camera  150  and provides both thermal-range and visible-range images and/or video to a computer via a wired (e.g., USB or Ethernet) or wireless (e.g. Wi-Fi or Bluetooth) connection. The communication hardware can be embedded into one or both cameras of the endoscope  400  and/or housed in or attached to the body  110  of the endoscope  400 . Power for operation of the cameras and other electronics of the endoscope  400  can be provided via an external power source or via a battery (rechargeable or otherwise) housed in the body  110  of the endoscope  400  or attached to the endoscope  400 . Other embodiments of the technology disclosed in this patent document (e.g., endoscopes  200 ,  300 ,  500 ) can also be provided with wired or wireless communication means (e.g., USB, Ethernet, Wi-Fi, or Bluetooth interfaces) as well as means to provide power to the cameras and electronics of the embodiments from an external and/or an internal power source (e.g., a battery and/or a power connector). 
       FIG. 7  shows an indirect-viewing configuration of the endoscope  400 . The thermal camera  50  is facing a viewing mirror  130  which can be pivotably connected to the body  110  of the endoscope  400 , for example. A variety of attachment means  470  can be used to attach the camera  50  to the body  110  in this and other configurations of the endoscope  400 . For example, a bracket, a strap, or a clamp can be used for that purpose. Thermal infrared light  195  emitted by the target area  190  is directed by the mirror  130  into the thermal camera  50  while visible-range light reflected by the target area is directed by the mirror  130  into the body  110  of the endoscope  400 . 
       FIG. 8  shows another implementation of the indirect-viewing configuration of the endoscope  400 . In the implementation shown in  FIG. 8 , mirror  430  is attached to the body  110  of the endoscope  400  in addition to the mirror  130 . Any of the mirrors  130  or  430  can be fixedly or pivotably attached to the body  110 . Mirror  130  directs light in a visible spectral range reflected by the target area  190  into the body  110  of the endoscope  400  while mirror  430  directs thermal radiation  195  emitted by the target area into the thermal camera  50 . 
       FIG. 9  shows a direct-viewing configuration of the endoscope  400 . In this configuration, thermal camera  50  is facing the target area  190  (e.g., patient&#39;s throat) directly. A thermal image is directly formed from the thermal infrared light  195  emitted by the target area, without reflection from an intermediate mirror. 
       FIG. 10  shows an endoscope  500  according to an embodiment of the technology disclosed in this patent document. A rigid body  510  of the endoscope  500  has a small thermal camera unit  50  attached to its distal end  512  and facing a target area (e.g., the throat of a patient). 
     To minimize profile and complexity of the endoscope  500 , it does not perform simultaneous visible-range imaging of the target area and body  510  of the endoscope  500  has no internal optics, save for possible electronics cabling (e.g., serial, USB 3 , or Ethernet) used to transfer images from the thermal camera  50  to a computer. Camera  50  or body  510  of the endoscope  500  can also incorporate a Wi-Fi module or a Bluetooth module for wireless transfer of the captured thermal images or video to a computer. In some embodiments, the computer is incorporated into the body  510  of the endoscope  500 . The body  510  can also incorporate a battery or several batteries (rechargeable or otherwise) to provide power to the electronic elements of the endoscope  500  such as its camera  50  or elements of the communication electronics (e.g., the Wi-Fi module). Alternatively, an external power source can be used to provide power to the endoscope  500 . Such a power source can be connected to the endoscope  500  via a micro-USB port or a power connector, for example. 
       FIG. 11  shows a configuration of the endoscope  500  in which the rigid body  510  is replaced by a flexible and/or bendable body  520 . Hand-operated actuators similar to those in existing flexible endoscopes can be used to maneuver and manipulate thermal camera  50  in rotation and position. 
       FIG. 12  shows an implementation of the endoscope  500  in which thermal camera  50  is located proximate to the distal end  512  of the endoscope body  510  and is at least in part enclosed by the body  510 . The implementation of the endoscope  500  shown in  FIG. 12  includes a mirror  530  attached to the distal end of the body  510  and configured to direct thermal radiation  195  emitted by the area of interest  190  into the camera  50 . Endoscope body  510  can include cabling to provide image transfer from the camera  50  to a computer as well as to control the camera  50  via, for example, a USB or a serial interface; it can also include cables providing power to the camera  50 ; body  510  can also incorporate a power source in a form of a rechargeable battery, for example, as well as a connector (e.g., a micro-USB one) to supply power from an external power source to the endoscope  500  and/or to the rechargeable battery; body  510  of the endoscope  500  can also house one or more communication modules such as a Wi-Fi or a Bluetooth one to provide wireless transfer of the images captured by the camera  50  to a (remote) computer and/or to control the camera operation. 
     As described above, some embodiments of the technology disclosed in this patent document include a mirror which is typically attached to a distal end of an endoscope (other points of the mirror attachment are possible as well) and which is configured to direct at least one of visible-range light or thermal-range light received by the mirror from a target area to the elements of the endoscope (e.g., lenses and/or or a camera). As shown in  FIG. 13 , such a mirror  1  used in an embodiment of an endoscope according to the technology disclosed herein can be attached to the body  2  of the endoscope at a distal end  4  of the body using a hinge  5  connected to the body and allowing the mirror to be tilted at different angles in a plane containing an axis connecting a proximal end  3  and the distal end  4  of the endoscope body  2 . A thin metal rod  6  can be attached between the mirror  1  and another hinge connection  7  which connects the rod  6  and a threaded rod  8 . The threaded rod  8  is inserted into a threaded shaft  9  which allows the threaded rod  8  to move in and out of the shaft. The threaded shaft  9  can be positioned, for example, proximate to a camera  10  (e.g., an infrared one) of the endoscope. Moving the rod  8  back and forth in the shaft  9  will cause the mirror to tilt up and down along a direction which is perpendicular to the axis connecting the distal and proximal ends  4  and  3  of the endoscope body  2 . The mirror can generally rotate between 0 degrees and 90 degrees relative to the axis connecting the distal and proximal ends  4  and  3  of the endoscope body  2 . The length of the rod  8  protruding from the shaft  9  can be controlled by a knob  11  that is labelled with mirror tilt angle measurements, as shown in  FIG. 14 . The knob  11  can connect, for example, to gears within the endoscope that adjust the position of the threaded rod  8  within the threaded shaft  9 . 
     In some implementations, rod  6 , threaded rod  8  and/or threaded shaft  9  can be positioned inside the endoscope body  2 . Mechanisms other than the example one described above can be used for adjusting a tilt and/or a position and/or orientation of a mirror of an endoscope or that of a camera of the endoscope relative to a body of the endoscope according to the technology disclosed herein. 
       FIG. 14  shows an example of a proximal-end user control interface of an endoscope according to an embodiment of the technology disclosed herein. In the example design shown in  FIG. 14 , the knob  11  is used for mirror tilt adjustment and three buttons ( 13  “Picture”,  14  “Record”, and  15  “Stop”) function to control one camera (e.g. the thermal one of the embodiment  500  described above) or both cameras (the thermal one and the visible-range one included in the embodiments  200 ,  300 , or  400  described above) of the endoscope. Markings  12  shown on the knob  11  (e.g., “0”, “30”, “60”, “90” as shown in  FIG. 14 ) correspond to the tilt angle of the mirror  1  of the endoscope, as described above. In response to a user pressing the button  13  (“Picture”), each camera of the endoscope can take a single picture of a target area and transfer it to a (remote) computer. In response to the user pressing the button  14  (“Record”), each camera of the endoscope can start taking a video of the target area and transferring it to a (remote) computer until the user presses the button  15  (“Stop”). 
     The mirror tilting means and/or the proximal-end user control interface described above can be incorporated into any embodiment of the endoscope according to the technology disclosed herein. 
       FIG. 15  shows a block diagram of an example embodiment of an electronic device (data processor)  1000  which can interface with various elements of various embodiments of an endoscope according to the technology disclosed in this patent application which will be referred to as endoscope  2000  below. 
     In some embodiments, data processor  1000  can include a processor  1020  to process data, a memory  1010  in communication with the processor  1020  to store data, and an input/output (I/O) communication interface  1030  to interface the processor  1020  and/or the memory  1010  to other elements of the endoscope  2000  as well as to various modules, units, or devices, including external computing devices, data storage devices, or communication devices, for example. 
     For example, the processor  1020  can include a central processing unit (CPU) or a microcontroller unit (MCU) or a graphics processing unit (GPU). For example, the memory  1010  can include and store processor-executable code, which, when executed by the processor  1020 , configures the data processor  1000  to perform various operations, e.g., such as receiving information, commands, and/or data, processing information, commands, and/or data, and transmitting or providing information, commands, and/or data to another element of the endoscope  2000  and/or to other devices external to the endoscope  2000 . 
     In some implementations, the data processor  1000  can transmit raw or processed data (e.g., images captured by a visible-range camera or a thermal-range camera of the endoscope  2000 ) to a computer system or a computer network which can be accessible via a communication network such as the Internet (such computer systems or networks are sometimes referred to as being located ‘in the cloud’) that includes one or more remote computational processing devices (e.g., servers). 
     To support various functions of the data processor  1000 , the memory  1010  can store information and data, such as instructions, software, values, images, and other data processed or referenced by the processor  1020 . For example, various types of Random-Access Memory (RAM) devices, Read Only Memory (ROM) devices, Flash Memory devices, and other suitable storage media can be used to implement storage functions of the memory  1010 . 
     The I/O  1030  can include at least one of the wireless communication interface  1031  or wired communication interface  1032 . The wireless communication interface  1031  can be a wireless transmitter to transmit stored and/or processed data, for example, or a wireless transceiver (Tx/Rx) to transmit and receive data, for example. The wired communication interface  1032  can be a wired transmitter to transmit stored and/or processed data, for example, or a wired transceiver (Tx/Rx) to transmit and receive data, for example. 
     The I/O  1030  of the data processor  1000  can utilize various types of wired interfaces  1032  or wireless interfaces  1031  compatible with typical data communication standards which can be used in communications of the data processor  1000  with other devices, e.g., including, but not limited to, Bluetooth, Bluetooth low energy, Zigbee, IEEE 802.11, Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN), Wireless Wide Area Network (WWAN), WiMAX, IEEE 802.16 (Worldwide Interoperability for Microwave Access (WiMAX)), 3G/4G/LTE/5G cellular communication methods, NFC (Near Field Communication), serial and parallel interfaces, USB, Ethernet. 
     In some embodiments, the data processor  1000  can include or be communicatively coupled to a display unit  1040 , which can include a visual display such as a display screen, an audio display such as a speaker, or other type of a display or a combination thereof 
     The I/O  1030  of the data processor  1000  can also interface with external interfaces, sources of data, data storage devices, and/or visual, audio, or haptic display and/or feedback devices, etc. to retrieve and transfer data and information, for example, which can be processed by the processor  1020 , and/or stored in the memory  1010 , and/or exhibited using an output unit (e.g., the display unit  1040 ). 
     For example, the display unit  1040  can be configured to be in data communication with the data processor  1000 , e.g., via the I/O  1030  ( FIG. 15 ), and to provide a visual display, or an audio display, and/or other sensory display of images, data and/or other information to a user. In some examples, the display unit  1040  can include various types of screen displays, speakers, or printing interfaces, e.g., including but not limited to, light emitting diode (LED), or liquid crystal display (LCD) monitor or screen, cathode ray tube (CRT) as a visual display; audio signal transducer apparatuses as an audio display; toner, liquid inkjet, solid ink, dye sublimation, inkless (e.g., such as thermal or UV) printing apparatuses, etc. 
     As shown in  FIG. 15 , in some embodiments, data processor  1000  can be communicatively coupled to a camera  1100  of the endoscope  2000  which can be a visible-range camera or a thermal-range camera. Data processor  1000  can also be communicatively coupled to more than one camera of the endoscope  2000 . For example, the data processor  1000  can be communicatively coupled to both a visible-range camera and a thermal-range camera of the endoscope  2000 . 
     In some embodiments, data processor  1000  can be included into a visible-range camera of the endoscope  2000 . In some embodiments, data processor  1000  can be included into a thermal-range camera of the endoscope  2000 . Some embodiments of an endoscope according to the technology disclosed herein involve both a visible-range camera and a thermal-range camera of the endoscope having a copy of the data processor  1000 . In some embodiments, data processor  1000  can be housed in a body of the endoscope  2000 . 
     In various implementations, the data processor  1000  can be operable to store and execute software applications and algorithms and implement various controls of an endoscope according to the technology disclosed in the present patent application. 
     Because thermal-range camera and visible-range camera of an endoscope according to some embodiments of the technology disclosed in this patent document can have different fields of view, the same features of an imaged target area can have different positions within a thermal-range image and a visible-range image acquired by the cameras. Image processing of the captured visible-range and thermal-range images can include a step of aligning corresponding features in these images. This step can compensate for misalignment of the cameras. 
     Transformation of one of the thermal-range image or visible-range image or both of those images which compensates for misalignments between them can be determined before conducting an endoscopic procedure. For example, the steps of determining properties (e.g., coefficients) of such a transformation can include steps of taking images of a checkerboard with black and white squares using both the thermal-range camera and the visible-range camera, manually clicking on four corners of a checkerboard square in an image produced by the visible-range camera and the corresponding four points in a thermal-range image, and estimating geometric transformation to map the four points from the visible-range image to the four points in the thermal-range image. Any image alignment method or procedure other than the one described above can be used for alignment of the thermal-range and visible-range images. 
     After the properties of the image transformation are established, it can be applied to visible-range images, for example, to align them with the corresponding thermal-range ones. As a result of this image alignment, every pixel location in the visible-range image will be mapped to a point or an area in a corresponding thermal-range image. After the thermal -range and the visible-range images are aligned, they can be displayed as overlaid one on top of another in software, for example. The software can allow a user to adjust a degree of transparency of the thermal-range image overlaid on top of the visible-range one, for example, to provide a possibility to convey information in both visible-range and thermal-range modalities simultaneously. 
       FIG. 16  shows an image  700  acquired by a thermal-range camera of an endoscope according to an embodiment of the technology disclosed in the present patent application and a visible-range image  800  acquired by a visible-range camera of the endoscope after performing an image alignment procedure described above. Line  600  connects corresponding areas in the visible-range image and the thermal-range image which were aligned during the image alignment procedure. 
     After the images are aligned, software can allow a user to click on a region or select a region in a visible-range image of the target area and, in response to the click or the selection, the software will display a part of the thermal-range image corresponding to the region of the visible-range image. The part of the thermal-range image can be shown as overlaid on the visible-range image, for example. 
       FIG. 17  shows that when a user clicks on the area  850  or selects the area  850  of the visible-range image  800 , the area  750  of the thermal-range image  700  is displayed as overlaid on top of the area  850 . Area  750  of the thermal-range image was aligned with the area  850  of the visible-range image during an image alignment procedure (e.g., the one described above). 
     Methods of image processing according to some embodiments of the technology disclosed in this patent document can include determining temporal evolution of the temperature of one or more regions of an area of interest (e.g., tongue or throat of a patient). 
       FIG. 18  shows image  710  captured by a thermal-range camera of an endoscope according to an embodiment of the technology disclosed herein. Image  710  corresponds to time point t 1 . Target area of interest  720  captured in the image  710  has two regions:  721  and  722 . Color of pixels of the thermal image  710  can be calibrated to correspond to the temperature values of the elements of a scene captured in the image, wherein each pixel of the image corresponds to an element of the scene. Color scale  730  which can be displayed proximate to the image  720  by a software illustrates that correspondence. 
     Plot  900  in  FIG. 18  shows evolution of the temperature values corresponding to the pixels of the image  710  in time. In particular, plot  900  shows for a number of pixels or for all pixels of the image  710 , changes of the temperature values corresponding to the pixels at time t relative to the temperature values at an initial time t 0 . Therefore, all curves shown in plot  900  originate from the same point (0; 0) in the (time; ΔT) coordinates where ΔT is the temperature difference. 
     As shown in  FIG. 18 , temperatures corresponding to the pixels in the region  721  remained relatively constant over time, as illustrated by the curves  910  in the plot  900  corresponding to those pixels. As shown in  FIG. 18 , temperatures corresponding to the pixels in the region  722  exhibited various rates of decrease over time, as illustrated by the curves  920  in the plot  900  corresponding to the pixels in the region  722  of the target area  720 . 
     Images  750  and  770  shown in  FIG. 18  correspond to time points t 2  and t 3  such that t 1 &lt;t 2 &lt;t 3 . As discussed above, based on the temperature information captured in the thermal-range images and/or based on the temperature dynamics information captured in the sequences of the thermal-range images, a score value can be assigned to a thermal-range image and/or to an area of interest in the thermal-range image which would reflect a likelihood of the observed temperature in the area of interest and/or the observed temperature change in the area of interest being, for example, abnormal or otherwise clinically significant. For example, the score can indicate a likelihood of an inflammation in the area of interest. 
     Thermographic imaging capability of the embodiments of the technology disclosed in this patent document provides additional information to what is available through visual inspection. When implemented in an embodiment of the disclosed technology, thermographic imaging can provide information about the temperature patterns of ENT areas, enabling sub-surface imaging and higher contrast imaging of abnormal conditions in a patient which are accompanied by alterations of thermal properties of tissues or organs. Asymmetric muscular activity and skin conditions (e.g., inflammation, infection, lesions of various nature), together with the evolution of such pathologies and treatment, can be monitored, processed, and recorded as well. 
     Embodiments of the presently disclosed technology enable development of effective imaging tools to assist ENT clinicians to obtain thermographic imaging and perform sub-surface detection of ENT conditions. The presently disclosed technology can lead to development and improvement of ENT diagnosis and surgery, endoscopic surgeries, telemedicine, point of care diagnostics, and medical education. 
     Example Technical Solutions 
     The following examples may be preferable features of possible implementations of an endoscope according to the technology disclosed in this patent application. 
     Example 1 includes an endoscope which has a body having a proximal end and a distal end. 
     Example 2 includes the endoscope of Example 1 which comprises a visible-range camera attached proximate to the proximal end of the endoscope body. 
     Example 3 includes the endoscope of Example 2 wherein the visible-range camera is removably attached to the endoscope body. 
     Example 4 includes the endoscope as in any of Examples 1-3 which comprises an endoscope mirror attached proximate to the distal end of the endoscope body. 
     Example 5 includes the endoscope of Example 4 wherein the endoscope mirror is pivotably attached to the endoscope body. 
     Example 6 includes the endoscope as in any of Examples 4 or 5 wherein the endoscope mirror is removably attached to the endoscope body. 
     Example 7 includes the endoscope as in any of Examples 1-6 which comprises a thermal-range camera. 
     Example 8 includes the endoscope as in Example 7 wherein the thermal-range camera is attached proximate to the proximal end of the endoscope body. 
     Example 9 includes the endoscope as in Example 7 wherein the thermal-range camera is attached proximate to the distal end of the endoscope body. 
     Example 10 includes the endoscope as in any of Examples 7-9 wherein the thermal-range camera can capture images using light in a range of wavelengths from the range between 8 μm and 14 μm. 
     Example 11 includes the endoscope as in any of Examples 1-10 which comprises a light source attached proximate to the proximal end of the endoscope body. 
     Example 12 includes the endoscope of Example 11 wherein the light source can emit light in a range of wavelengths from the range between 380 nm and 740 nm. 
     Example 13 includes the endoscope of Example 11 wherein the light source can emit light on one or more wavelengths from any of the following ranges: 380-450 nm, 450-485 nm, 485-500 nm, 500-565 nm, 565-590 nm, 590-625 nm, or 625-740 nm. 
     Example 14 includes the endoscope as in any of Examples 2-13 wherein the visible-range camera can register an image using light on one or more wavelengths from the range of wavelengths between 380 nm and 740 nm. 
     Example 15 includes the endoscope as in any of Examples 1-14 which comprises one or more optical elements inside the endoscope body which relay and/or magnify an image transmitted by light within the endoscope body. 
     Example 16 includes the endoscope of Example 15 wherein at least one optical element of the one or more optical elements is a lens or a set of two or more lenses. 
     Example 17 includes the endoscope as in any of Examples 11-16 wherein light from the light source is delivered to the endoscope mirror using at least one of a beam splitter housed inside the endoscope body or one or more optical fibers either housed inside the endoscope body or at least partially disposed outside the endoscope body. 
     Example 18 includes the endoscope as in any of Examples 11-17 wherein the endoscope mirror is configured to reflect at least a part of the light received by the endoscope mirror from the light source to a target area. 
     Example 19 includes the endoscope as in any of Examples 4-18 wherein the endoscope mirror is configured to direct at least a part of the light reflected from an area of interest or emitted by the area of interest towards at least one of the visible-range camera or the thermal-range camera. 
     Example 20 includes the endoscope as in any of Examples 7-19 which comprises a second mirror configured to at least partially reflect light in a wavelength band from the range between 8 μm and 14 μm towards the thermal-range camera and configured to at least partially transmit light in a wavelength band from the range between 380 nm and 740 nm towards the visible-range camera. 
     Example 21 includes the endoscope as in Example 20 wherein the second mirror is positioned between the optical elements and the visible-range camera. 
     Example 22 includes the endoscope as in any of Examples 1-21 which comprises a thermal imager. 
     Example 23 includes the endoscope as in Example 22 wherein the thermal imager has a body which has a proximal end and a distal end. 
     Example 24 includes the endoscope as in Example 22 wherein the thermal imager is a second thermal-range camera. 
     Example 25 includes the endoscope as in any of Examples 22-24 wherein the thermal imager is attached to the body of the endoscope proximate to the distal end of the endoscope body. 
     Example 26 includes the endoscope as in Example 23 wherein the thermal imager is attached to the endoscope body such that the distal end of the thermal imager is closer to the distal end of the endoscope body than the proximal end of the thermal imager. 
     Example 27 includes the endoscope as in Example 26 which comprises an imager mirror attached proximate to the distal end of the thermal imager body. 
     Example 28 includes the endoscope of Example 27 in which the imager mirror is pivotably attached to the thermal imager body. 
     Example 29 includes the endoscope as in any of Examples 27-28 wherein the imager mirror is removably attached to the thermal imager body. 
     Example 30 includes the endoscope as in any of Examples 27-29 which comprises an imager thermal-range camera. 
     Example 31 includes the endoscope as in Example 30 wherein the imager thermal-range camera is attached proximate to the proximal end of the thermal imager body. 
     Example 32 includes the endoscope as in Example 30 in which the imager thermal-range camera can capture images using light in a range of wavelengths from the range between 8 μm and 14 μm. 
     Example 33 includes the endoscope as in Example 24 in which the second thermal-range camera can capture images using light in a range of wavelengths from the range between 8 μm and 14 μm. 
     Example 34 includes the endoscope as in any of Examples 27-32 which comprises one or more optical elements inside the thermal imager body which relay and/or magnify an image transmitted by light propagating between the imager mirror and the imager thermal-range camera. 
     Example 35 includes the endoscope of Example 34 wherein at least one optical element of the one or more optical elements is a lens or a set of two or more lenses. 
     Example 36 includes the endoscope of Example 24 wherein the second thermal camera is configured to receive light reflected by a mirror. 
     Example 37 includes the endoscope of Example 24 wherein the second thermal camera is configured to receive light directly from an area of interest. 
     Example 38 includes the endoscope of Example 24 wherein the endoscope comprises a third endoscope mirror attached to the endoscope body proximate to the distal end of the endoscope body, wherein the second thermal camera is configured to receive light reflected by the third endoscope mirror. 
     Example 39 includes the endoscope of Example 1 comprising a third thermal-range camera attached proximate to the distal end of the endoscope body. 
     Example 40 includes the endoscope as in any of Examples 1-39 wherein the body of the endoscope is rigid. 
     Example 41 includes the endoscope as in any of Examples 1-39 wherein the body of the endoscope is flexible and/or bendable. 
     Example 42 includes the endoscope as in Example 39 comprising a fourth mirror attached to the body of the endoscope proximate to the distal end of the endoscope body. 
     Example 43 includes the endoscope as in Example 42 wherein the third thermal-range camera is at least partially enclosed by the endoscope body. 
     Example 44 includes the endoscope as in any of Examples 42-43 wherein the third thermal-range camera is configured to receive at least a portion of the light reflected by the fourth mirror. 
     Example 45 includes the endoscope as in any of Examples 1-44 comprising a data processor. 
     Example 46 includes the endoscope as in Example 45 wherein the data processor comprises at least one of a memory, a processor, or a communication interface. 
     Example 47 includes the endoscope as in Example 46 wherein the processor is communicatively coupled to at least one of the memory or the communication interface. 
     Example 48 includes the endoscope as in any of Examples 45-47 wherein the data processor is communicatively coupled to at least one of the visible-range camera or the thermal-range camera. 
     Example 49 includes the endoscope as in any of Examples 45-48 wherein the data processor is included into the visible-range camera. 
     Example 50 includes the endoscope as in any of Examples 45-49 comprising a second data processor. 
     Example 51 includes the endoscope as in Example 50 wherein the second data processor comprises at least one of a second memory, a second processor, or a second communication interface. 
     Example 52 includes the endoscope as in Example 51 wherein the second processor is communicatively coupled to at least one of the second memory or the second communication interface. 
     Example 53 includes the endoscope as in any of Examples 50-52 wherein the second data processor is communicatively coupled to at least one of the visible-range camera or the thermal-range camera. 
     Example 54 includes the endoscope as in any of Examples 50-53 wherein the second data processor is included into the thermal-range camera. 
     Example 55 includes the endoscope as in any of Examples 50-54 wherein the data processor is communicatively coupled to the second data processor. 
     Example 56 includes the endoscope as in any of Examples 46-55 wherein the communication interface provides communication between the data processor and a computer via at least one of USB, Ethernet, serial, parallel, or Bluetooth interfaces. 
     Example 57 includes the endoscope as in any of Examples 51-56 wherein the second communication interface provides communication between the second data processor and a computer via at least one of USB, Ethernet, serial, parallel, or Bluetooth interfaces. 
     Example 58 includes the endoscope as in any of Examples 56-57 wherein the computer is a cloud-based or remote computer. 
     Example 59 includes the endoscope as in any of Examples 56-58 wherein the data processor and/or the second data processor are used to transfer raw or processed images or video streams between at least one of the visible-range camera or the thermal-range camera and the computer. 
     Example 60 includes the endoscope as in any of Examples 1-59 which comprises a power source or an interface to a power source. 
     Example 61 includes the endoscope as in Example 60 wherein the power source is a rechargeable battery. 
     Example 62 includes the endoscope as in Example 61 wherein the rechargeable battery is housed within at least one of the body of the endoscope, the visible-range camera, the thermal-range camera, or the thermal imager. 
     Example 63 includes the endoscope as in Example 60 wherein the interface to a power source is a power connector. 
     Example 64 includes the endoscope as in any of Examples 1-63 wherein a tilt angle between the endoscope mirror and the endoscope body is adjustable. 
     Example 65 includes the endoscope as in any of Examples 1-64 wherein a tilt angle between the imager mirror and the imager body is adjustable. 
     Example 66 includes the endoscope as in any of Examples 1-65 wherein a tilt angle between the third endoscope mirror and the endoscope body is adjustable. 
     Example 67 includes the endoscope as in any of Examples 1-66 wherein a tilt angle between the fourth mirror and the endoscope body is adjustable. 
     Example 68 includes the endoscope as in any of Examples 7-67 which comprises a second mirror configured to at least partially reflect light in a wavelength band from the range between 380 nm and 740 nm towards the visible-range camera and configured to at least partially transmit light in a wavelength band from the range between 8 μm and 14 μm towards the thermal-range camera. 
     It is intended that the specification, together with the drawings, be considered exemplary only, where exemplary means an example. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Additionally, the use of “or” is intended to include “and/or”, unless the context clearly indicates otherwise. 
     While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
     Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments. 
     Only a few implementations and examples are described, and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document.