Medical instrument with an imaging sensor and use

Abstract

A medical instrument (10) comprising an image sensor (14) sensitive to electromagnetic radiation at least with wavelengths in a first wavelength range of 450 nm to 650 nm and in a second wavelength range of 9 µm to 9.5 µm, and a processing device (16) configured to process first image information corresponding to the first wavelength range and second image information corresponding to the second wavelength range, output by the image sensor (14) such that the second image information is converted into first color tones and output together with the first image information as modified image information, characterized in that the processing device (16) attenuates or suppresses image information obtained from wavelengths lying in an intermediate wavelength range between the first wavelength range and the second wavelength range.

Description

[0001] The invention relates to a medical instrument with an imager.

[0002] In the field of medical technology, medical instruments, especially endoscopes, are used to image internal structures. This allows for diagnoses or surgical interventions. This is primarily based on assessing the situation visually, in the visible range, and implementing appropriate actions.

[0003] However, the inventor recognized that these optical detections capture the superficial situation, that is, what is visible to the human eye. This is usually the visible part of light.

[0004] It is therefore an object of the present invention to provide an improved medical instrument which provides the user with further information in order to be able to recognise and assess structures on the basis of a pictorial representation.

[0005] DE 10 2014 115 738 A1 discloses an endoscope for detecting light emitted by an object to be observed. It comprises an objective lens at the distal end of the endoscope, a wavelength-dependent reflecting surface for reflecting light in a wavelength range visible to the human eye and for transmitting light in an infrared wavelength range, and an image sensor for converting light into an image signal. The wavelength-dependent reflecting surface and the image sensor are arranged near the distal end of the endoscope.

[0006] DE69630026 T2 describes an endo-diagnostic device with an infrared imager for imaging infrared emissions. The infrared imager comprises a lens, a relay section, and a coupling lens. An infrared video camera is connected to the infrared imager via an adapter with an opening in a curved rear surface. The infrared imager can be used with a visible imager.

[0007] EP2608532 A2 discloses thermal imaging cameras for use in image recapturing and methods for image recapturing with thermal imaging cameras, comprising the creation and use of a pose template that helps guide the camera back to the position where the original image was captured.

[0008] The object is achieved by a medical instrument having an image generator which is sensitive to electromagnetic radiation at least with wavelengths in a first wavelength range from 450 nm to 650 nm and in a second wavelength range from 9 µm to 9.5 µm, and having a processing device which is designed to process first image information output by the image generator which corresponds to the first wavelength range and second image information which corresponds to the second wavelength range in such a way that the second image information is converted into first color tones and is output together with the first image information as modified image information.

[0009] Such an instrument makes it possible to provide the user with additional important information visually. The visible image information, i.e., the image information obtained from visible light, is presented directly to the user, as before. The thermal image information is then presented to the user via false-color display as the first colors. It is now also possible to capture deep or internal structures, or the thermal or energy distribution in a deep structure can be displayed live.

[0010] This is particularly informative when high-frequency (HF) energy is applied using appropriate instruments. This often occurs during surgery using HF devices. When these HF devices are used, energy is introduced into the tissue at various high frequencies.

[0011] The initial color tones can, in principle, be freely chosen. However, it is preferable to select these tones within a narrow range of the visible spectrum, particularly so narrow that the colors are understood as belonging together in intuitive human perception, e.g., within a range from light green through yellow to orange, from light blue through medium blue to dark blue, from cyan through dark green to light green, or from magenta through violet to dark blue.

[0012] The first color tones can also be specifically assigned to specific wavelengths. A pixel from the second image information is displayed in the color that most closely matches the detected wavelength, according to Table 1 below: Temperature [°C] Temp [K] λ [µm] Color 34 307,15 9,44 dark blue 35 308,15 9,40 medium blue 36 309,15 9,37 green-blue 37 310,15 9,34 green 38 311,15 9,31 light green 39 312,15 9,28 yellow 40 313,15 9,25 orange 41 314,15 9,22 red 42 315,15 9,20 light red

[0013] Depending on the specific application and the desired display, these specifically determined wavelengths can also be distributed over a wider temperature range. A pixel from the second image information is displayed in the color tone that most closely matches the detected wavelength, according to Table 2 below: Temperature [°C] Temp [K] λ [µm] Color 40 313,15 9,25 dark blue 45 318,15 9,11 medium blue 50 323,15 8,97 green-blue 55 328,15 8,83 green 60 333,15 8,70 light green 65 338,15 8,57 yellow 70 343,15 8,45 orange 75 348,15 8,32 red 80 353,15 8,21 light red

[0014] When selecting the initial color tones, priority is given to ensuring that the resulting representation allows the user to distinguish the false color representation of thermal radiation from radiation in the visible light range. Shades associated with green and blue are particularly suitable for this purpose.

[0015] It may be preferred that the second image information is converted into the first color tones while maintaining an intensity or that the intensity of a pixel of the second image information is converted into the intensity of the respective color tone with a proportional assignment.

[0016] Some of the advantages that can be realized in this way are described below as examples. The effects of applying RF energy (RF effects), e.g., during cutting or coagulation, can be visualized live, particularly with regard to the distribution of the RF energy. Because the thermal radiation is converted into a visible spectrum, the effects and results resulting from the application of RF energy can now be documented as images.

[0017] Since thermal radiation can be recorded in real time and automatically evaluated, it is possible to implement monitoring or a safety loop via the endoscope and RF device. In particular, this false-color display can also verify RF energy input via automatic safety assistance evaluation. Furthermore, the additional information can also assist in the optical delineation of structures, as the user can utilize a wider spectral range and is not solely dependent on obtaining information from visible light. Finally, simple array temperature measurement can also be enabled and used in the surgical process.

[0018] It was explained that the imager of the medical instrument is sensitive in a second wavelength range from 9 µm to 9.5 µm. In some preferred embodiments, the second wavelength range is from 8.5 µm to 10.5 µm, preferably from 8 µm to 11.5 µm, and particularly preferably from 7.5 µm to 13 µm. In some preferred embodiments, a hybrid chip or a hybrid camera is used as the imager. These provide a "visible" image and a "thermal image" using exactly one image chip. As a result, the "visible" image and the "thermal image" are necessarily congruent, so that objects / subjects are automatically in the same position.

[0019] Visible light, as used herein, refers to electromagnetic radiation with a wavelength in the range between 380 nm and 750 nm. This wavelength is typically within the range that the human eye can perceive. The term "medical" in the context of a medical instrument means that the instrument is a medical device, which is subject to legal regulations, among other things, to protect patients. For example, in Germany, the Medical Devices Act (MdG) applies, or in the USA, the Federal Food, Drug, and Cosmetic Act applies.

[0020] The term "sensitive" here means that the imager can deterministically distinguish between a sufficient number of different intensities of the electromagnetic radiation emitted by the observed object in the respective wavelength range. The term "sufficient" means that the user considers the distinguishable number of different intensities to be suitable for their work. Preferably, at least four, more preferably at least 16, and especially 256 different intensities should be distinguishable. The imager is selected according to this requirement.

[0021] It should be noted that the imager can also be sensitive in broader wavelength ranges. However, the specified wavelength ranges are considered sources of important information, both in the visible light range and in the mid-infrared range. Therefore, the imager should provide the sensitivity desired by the expert at least in these wavelength ranges.

[0022] This completely solves the problem.

[0023] In a preferred embodiment, the processing device attenuates or suppresses image information obtained due to wavelengths lying in an intermediate wavelength range between the first wavelength range and the second wavelength range.

[0024] This embodiment results in the modified image information containing at least substantially only electromagnetic radiation from the wavelength ranges of interest, i.e., the first wavelength range and the second wavelength range. The wavelength range in between is referred to here as the masking range.

[0025] For example, if the observed object emits additional infrared radiation that should not be detected, this additional infrared radiation can be suppressed or at least attenuated. Infrared radiation that should not be detected can be caused by fluorescence, for example.

[0026] Depending on the desired effect, the blanking range can be selected to be rather narrow, for example, from 800 nm to 850 nm, 775 nm to 900 nm, or 750 nm to 950 nm, or rather broad, for example, 800 nm to 1000 nm, 775 nm to 1500 nm, or 750 nm to 2000 nm. Additionally, the upper limit can be increased further, as long as the wavelength range required for the desired thermal information acquisition, especially the second wavelength range, is not compromised.

[0027] In a further preferred embodiment, the processing device is designed to process third image information output by the image generator, which corresponds to an intermediate wavelength range lying between the first wavelength range and the second wavelength range, in such a way that the third image information is converted into second color tones.

[0028] This embodiment makes it possible to visualize additional information in the infrared range, particularly in the near-infrared range. The second color tones differ from the first color tones, allowing the user to immediately distinguish whether a color information in the modified image information originates from the second wavelength range or from the intermediate wavelength range.

[0029] In particular, the first and second color tones can be selected such that the first and second color tones each belong to a color such as red, green, blue, brown, violet, yellow, magenta, cyan, or similar, while the first and second color tones belong to different colors compared to each other. For example, the first color tones can be assigned to the color blue, and the second color tones can be assigned to the color green.

[0030] One possible application is to display infrared radiation in false colors caused by fluorescence. This type of infrared radiation can be used, for example, to visualize blood flow. This design makes it possible to visualize both thermal information from the mid-infrared range and fluorescence information from the near-infrared range. This provides the user with a large amount of information simultaneously, allowing them to recognize and assess a situation particularly well.

[0031] In a further preferred embodiment, the imager comprises an array of electromagnetic radiation sensitive elements, each electromagnetic radiation sensitive element having a first portion sensitive to electromagnetic radiation in the first wavelength range and a second portion sensitive to electromagnetic radiation in the second wavelength range.

[0032] In this embodiment, each element sensitive to electromagnetic radiation is sensitive to both wavelength ranges. This allows for a compact design and a simple optical system of the instrument, since the electromagnetic radiation from the observed object or scene can be guided to the imager via a single optical path.

[0033] In a further preferred embodiment, the imager comprises a first part comprising a first array of electromagnetic radiation sensitive elements sensitive to electromagnetic radiation in the first wavelength range and a second part comprising a second array of electromagnetic radiation sensitive elements sensitive to electromagnetic radiation in the second wavelength range.

[0034] This embodiment uses two arrays, each capturing electromagnetic information from different wavelength ranges, namely the first and second wavelength ranges. This allows for particularly flexible adaptation of the arrays to the respective application. For example, the first array can be designed for a particularly high resolution, while the second array has a lower resolution but is particularly sensitive to the second wavelength range.

[0035] The electromagnetic radiation can be guided from the observed object or scene via exactly one optical path to a beam splitter, which is directed on the one hand to the first array and on the other hand to the second array.

[0036] In a further preferred embodiment, a filter is arranged in front of the imager, which filter is designed to attenuate wavelengths between the first and the second wavelength range.

[0037] This embodiment results in the imager receiving at least substantially only electromagnetic radiation from the wavelength ranges of interest, i.e., the first wavelength range and the second wavelength range. The wavelength range in between is referred to here as the attenuation range.

[0038] For example, if the observed object emits additional infrared radiation that should not be detected, this additional infrared radiation can be suppressed or at least attenuated. Infrared radiation that should not be detected can be caused by fluorescence, for example.

[0039] The maximum attenuation in the attenuation range is preferably at least 3 dB, particularly preferably at least 10 dB, and especially at least 20 dB. A minimum attenuation in the attenuation range of at least 3 dB is preferably achieved in a wavelength range from 1.5 µm to 6 µm, particularly preferably 1 µm to 7 µm, and especially 0.8 µm to 8 µm.

[0040] In a further preferred embodiment, the instrument can be switched to a mode in which the processing device outputs only the first image information or only the second image information as modified image information.

[0041] This embodiment gives the user the option of selecting only the first image information or only the second image information for display. This is particularly helpful when one of the two pieces of information is perceived as distracting, or when the visual separation between the first image information and the second image information is difficult in certain situations.

[0042] In a further preferred embodiment, the instrument can be switched to a mode in which the processing device selectively outputs only one or two pieces of image information selected from the group of first image information, second image information and third image information as modified image information.

[0043] This embodiment allows the user to select only the first image information, only the second image information, only the third image information, only the first and second image information, only the first and third image information, or only the second and third image information for display. This is particularly helpful when one or two of the three pieces of image information are perceived as distracting, or when the visual separation between the different pieces of image information is difficult in certain situations.

[0044] In a further preferred embodiment, the instrument further comprises a screen configured to display the modified image information to a user.

[0045] This embodiment allows the user to visually perceive the current situation live. The screen can be a monitor, a tablet, a smartphone, or part of a VR (virtual reality) headset or AR (augmented reality) headset.

[0046] In a further preferred embodiment, the instrument has an endoscope or the instrument is designed as an endoscope.

[0047] According to today's assessment, such an embodiment can particularly benefit from the present invention.

[0048] Furthermore, the object is achieved by using an imager in medical imaging by means of a medical instrument, wherein the imager is sensitive to electromagnetic radiation at least with wavelengths in a first wavelength range from 450 nm to 650 nm and in a second wavelength range from 9 µm to 9.5 µm.

[0049] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0050] An embodiment of the invention is illustrated in the drawing and explained in more detail in the following description. It shows: Fig. 1 an embodiment of a medical instrument with an imager.

[0051] Fig.Figure 1 shows a medical instrument 10, in this case a video endoscope. The medical instrument 10 has a lens system 12 that guides electromagnetic radiation from an object to be observed or from the scene to an imager 14. The imager 14 is sensitive to electromagnetic radiation at least with wavelengths in a first wavelength range from 450 nm to 650 nm and in a second wavelength range from 9 µm to 9.5 µm.

[0052] The medical instrument 10 also has a processing device 16. The processing device 16 is shown here inside the medical instrument 10, but can in principle also be arranged outside the medical instrument 10.

[0053] The processing device 16 is designed to process a first image information output by the image generator 14, which corresponds to the first wavelength range, and a second image information corresponding to the second wavelength range, such that the second image information is converted into first color tones and is output together with the first image information as modified image information.

[0054] In the embodiment shown here, the modified image information is transmitted to a screen 20 via a first conductor of a cable connection 18. Wireless transmission is also possible in principle. Furthermore, the cable connection 18 here has an optional second conductor that directly transmits the image information from the imager 14.

[0055] Also shown is an LED 22 and a light guide 24, with which an object or scene to be observed can be illuminated.

Claims

[1] A medical instrument (10) comprising an image generator (14) which is sensitive to electromagnetic radiation at least with wavelengths in a first wavelength range from 450 nm to 650 nm and in a second wavelength range from 9 µm to 9.5 µm, and comprising a processing device (16) which is designed to process first image information output by the image generator (14) which corresponds to the first wavelength range and second image information which corresponds to the second wavelength range in such a way that the second image information is converted into first color tones and is output together with the first image information as modified image information characterized by that the processing device (16) attenuates or suppresses image information obtained due to wavelengths lying in an intermediate wavelength range between the first wavelength range and the second wavelength range [2] Medical instrument (10) according to claim 1, wherein the processing device (16) is designed to process a third image information output by the imager (14) corresponding to an intermediate wavelength range lying between the first wavelength range and the second wavelength range in such a way that the third image information is converted into second color tones. [3] The medical instrument (10) of any preceding claim, wherein the imager (14) comprises an array of electromagnetic radiation sensitive elements, each electromagnetic radiation sensitive element having a first portion sensitive to electromagnetic radiation in the first wavelength range and a second portion sensitive to electromagnetic radiation in the second wavelength range. [4] A medical instrument (10) according to any one of the preceding claims, wherein the imager (14) comprises a first part comprising a first array of electromagnetic radiation sensitive elements sensitive to electromagnetic radiation in the first wavelength range and a second part comprising a second array of electromagnetic radiation sensitive elements sensitive to electromagnetic radiation in the second wavelength range. [5] Medical instrument (10) according to one of the preceding claims, wherein a filter is arranged in front of the imager (14) which is designed to attenuate wavelengths between the first and the second wavelength range. [6] Medical instrument (10) according to one of the preceding claims, wherein the instrument can be switched into a mode in which the processing device (16) outputs only the first image information or only the second image information as modified image information. [7] Medical instrument (10) according to one of claims 3 to 6, wherein the instrument can be switched into a mode in which the processing device (16) selectively outputs only one or two pieces of image information selected from the group of first image information, second image information and third image information as modified image information. [8] A medical instrument (10) according to any one of the preceding claims, further comprising a screen (20) configured to display the modified image information to a user. [9] Medical instrument (10) according to one of the preceding claims, wherein the instrument (10) comprises an endoscope or the instrument is designed as an endoscope. [10] Use of an imager (14) in medical imaging by means of a medical instrument (10) according to claim 1, wherein the imager (14) is sensitive to electromagnetic radiation at least with wavelengths in a first wavelength range from 450 nm to 650 nm and in a second wavelength range from 9 µm to 9.5 µm.

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