Device for emitting and detecting short-wave infrared for medical imaging

Abstract

The present disclosure relates to a device (100) for emitting and detecting short-wave infrared (SWIR), intended to distinguish at least one tissue structure in a human and / or animal target tissue. The device comprises an illumination module (120) for emitting SWIR radiation in a first and a second wavelength band. The device also comprises at least one SWIR camera (130) for capturing images of the target tissue in the first and the second wavelength band, and an image processing means (150) configured to correct the captured images of the tissue by applying a correction matrix to each image, the correction matrices being designed to correct the variations in said images on the basis of at least one of the wavelength bands and of the distance of the target tissue from the illumination module.

Description

[0001] Description

[0002] Title of the invention: Shortwave infrared emission and detection device for medical imaging

[0003] Technical Field

[0004] This disclosure relates to imaging using Short Wave Infrared (SWIR) radiation. It is particularly relevant for SWIR imaging for the purpose of distinguishing different human or animal tissues.

[0005] Prior art

[0006] Imaging systems are frequently used during surgical procedures to provide the clinician with a real or enhanced view of a surgical site on a screen or by analyzing a surgical site under specific spectral conditions. Imaging using shortwave infrared radiation (SWIR) is increasingly used to facilitate the identification of different structures in human or animal tissues. Shortwave infrared imaging involves the emission and detection of radiation in the wavelength range of 1000 nm to 2500 nm. It has been observed that different structures within human or animal tissues reflect and / or absorb wavelengths in the SWIR range to a different extent, making it possible to distinguish certain elements of a surgical site by comparing them.WO 2021 / 136994 describes a spectral imaging system for use in a surgical imaging and monitoring system that detects and identifies arteries, veins, and nerves using reflectance spectra. A spectral transmitter and receiver are deployed and positioned using robotics. WO 2013 / 160780 describes a system in which tissue illuminated by SWIR radiation is imaged and the image analyzed to identify the presence of inflammation or a tumor. WO2019226261 describes a system that uses visible light and SWIR emitters to image and analyze human skin and detect and identify certain forms of skin cancer.

[0007] In all such imaging systems, SWIR sources and detectors are designed to be placed close to an operating site, either under the control of robotic manipulators or as a handheld device. Both solutions have disadvantages, mainly because the emitting and detecting devices impede access to the patient for the surgical team. However, when SWIR emitters are placed far from the immediate vicinity of an operating site, there is a risk that the irradiance distribution over the illuminated part of the site may become non-homogeneous, especially when focusing optics are used. In addition, the non-homogeneity of the irradiance distribution varies depending on the SWIR wavelengths used.Since the identification of tissue structures is based on the relative reflectance or absorption of radiation of different wavelengths, this variation in illumination makes the identification of these structures very complex and unreliable.

[0008] Summary

[0009] The present disclosure aims to alleviate the problems associated with known arrangements and, more specifically, to provide a shortwave infrared emission and detection device that can be deployed in all situations while being capable of providing accurate and reliable results.

[0010] This and other objects are achieved in a shortwave infrared (SWIR) emitting and detecting device for distinguishing at least one tissue structure in a human and / or animal target tissue, the device comprising: an illumination module configured to irradiate the target tissue with SWIR radiation in at least a first wavelength band and at least a second wavelength band, the first and second wavelength bands being distinct, a SWIR camera for capturing images of the target tissue, said camera being configured to capture a first image of the target tissue in the first wavelength band and at least a second image of the target tissue in the second wavelength band, image processing means configured to correct the captured images of the tissue by applying to each image a correction matrix,the correction matrices being designed to correct variations in said images as a function of at least one of the wavelength bands and the distance of the target tissue from said illumination module.,

[0011] The use of the correction matrix eliminates the need for complex calculations or restrictive operating conditions. The two-dimensional nature of this preferred correction data compensates for the effects of irradiance inhomogeneity on each image at the pixel level, and achieves a uniform result regardless of wavelength and distance from the target tissue. The device can thus be positioned away from an operating field, freeing up this space for surgeons or other clinicians. For example, the device can be spaced at a distance of at least 50 cm, and preferably at least 80 cm or at least 100 cm from the operating field or target tissue.

[0012] Preferably, the image processing means is configured to apply to the first image a first correction matrix in order to generate a first corrected image, apply at least to the second image at least a second correction matrix in order to generate a second corrected image, and compare the first corrected image with at least a second corrected image in order to distinguish at least one tissue structure. By providing a correction matrix for each wavelength (or each wavelength band) and possibly for several different distance values, a simple and rapid correction of the data is obtained by simple selection.

[0013] Advantageously, the image processing means is configured to compare the first corrected image with at least one second corrected image by generating a reflectance quotient therefrom, more particularly by generating a reflectance quotient for at least a portion of the image, each portion comprising at least one pixel. These values ​​can be compared to quotient values ​​characteristic of specific tissues, such as nerves or arteries, in order to identify these tissues in the captured image data and also on the target tissue.

[0014] In a preferred embodiment, the illumination module is configured to emit SWIR radiation in a third wavelength band, distinct from the first and second wavelength bands, the camera being configured to capture a third image of the target tissue in the third wavelength band, and the image processing means is configured to apply to the third image a third correction matrix in order to generate a third corrected image and compare the third corrected image with the first and second corrected images in order to distinguish at least one tissue structure.

[0015] Tissue structure refers to various types of tissue. These include structures such as blood vessels, nerves, elements of the lymphatic system, adipose tissue, damaged tissue, and, in fact, any form of tissue with a structure or content that has a specific spectral fingerprint in the SWIR range.

[0016] In an advantageous embodiment the device comprises display means adapted to generate for display an image of the target tissue in which at least one distinguished tissue structure is represented in a contrasting manner. Providing information in this graphical form with highlighted structures is particularly informative and allows a surgeon or clinician to target or avoid these structures with high reliability. In a particularly advantageous embodiment, the generated image can be projected onto the target tissue to allow the clinician to identify the different tissue structures on the patient.

[0017] Preferably, the correction matrices are predefined. Advantageously, this can be achieved by characterizing each illumination module for different distances within the range of use. Furthermore, the processing is particularly fast when the device comprises storage means for storing the correction matrices, the image processing means being configured to select a correction matrix as a function of the wavelength band of the captured image and / or the distance to the target tissue.According to a preferred embodiment, the device comprises a distance sensor configured to measure the distance between the SWIR illumination module and the target tissue, more particularly, wherein the SWIR emission and detection device is configured to be used at a distance of about 50 to 150 cm, preferably between 80 and 120 cm, from the target tissue, preferably wherein the distance sensor is configured to generate a 3D map of the target tissue from the SWIR illumination module. In this way, an accurate measurement of the distance can be obtained quickly and any changes in distance can be compensated for as a result of movement of the patient or the device. Preferably the distance sensor is configured to generate a 3D map of the target tissue from the SWIR illumination module to compensate for possible tilting of the illumination module relative to the target tissue.

[0018] According to a particularly advantageous embodiment, the device is configured to be coupled to an operating lamp and / or suspended above an operating site. Thanks to the use of emitters and detectors operating in the SWIR range, the device can operate at the same time as the operating lamp without risk of interference. The operating field also remains illuminated for the surgical team.

[0019] Advantageously, the lighting module comprises at least one first emitter capable of emitting SWIR radiation in the first SWIR wavelength band and at least one second emitter capable of emitting SWIR radiation in the second SWIR wavelength band, preferably in which the first and second emitters are designed to be switched on separately.

[0020] Preferably, the SWIR lighting module comprises at least one SWIR LED. This makes it possible, among other things, to limit the energy consumption and the heat generated by the device. Preferably, the lighting module comprises at least one SWIR LED capable of emitting radiation in said first wavelength band and at least one SWIR LED capable of emitting radiation in said second wavelength band. In addition, at least one SWIR LED may be associated with a focusing optic.

[0021] In an advantageous embodiment, the SWIR illumination module comprises at least one bandpass filter. By providing a narrow spectrum, these filters improve the spectral resolution and allow better interpretation of the acquired image.

[0022] The present disclosure also provides an operating lamp comprising a SWIR emission and detection device, a method for distinguishing tissue structures in a human or animal target tissue and an image processing device for distinguishing tissue structures in a human or animal target tissue.

[0023] The present disclosure provides a method for distinguishing tissue structures in a human or animal target tissue using a SWIR emission and detection device according to any one of the preceding claims, the method comprising the steps of: illuminating the target tissue with SWIR radiation in at least a first wavelength band, capturing a first image of the target tissue in the first SWIR wavelength band, illuminating the target tissue with SWIR radiation in at least a second wavelength band, the first and second wavelength bands being distinct, capturing an image of said target tissue in said second SWIR wavelength band,correcting the first image with a first correction matrix to compensate for variations in irradiance as a function of at least one of the first SWIR wavelength band and the distance between the device and the target tissue to generate a first corrected image, and correcting the second image with a second correction matrix to compensate for variations in irradiance as a function of at least one of the second SWIR wavelength band and the distance between the device and said target tissue to generate a second corrected image.,

[0024] Preferably, the method comprises an additional step of comparing the first and second corrected image data in order to distinguish the types of human or animal tissues on said target tissue.

[0025] The method advantageously comprises an additional step of generating for display an image of the target tissue in which at least one distinguished tissue structure is represented in a contrasting manner.

[0026] The present disclosure also provides an image processing device for distinguishing tissue structures in a human or animal target tissue, the device being configured to: receive a first image of the target tissue captured in the first SWIR wavelength band, receive a second image of said target tissue in a second SWIR wavelength band, the second wavelength band being distinct from the first wavelength band, correct the first image with a first correction matrix to compensate for variations in irradiance as a function of at least one of said first SWIR wavelength band and the distance between the first emitter and the target tissue to generate a first corrected image,and correcting said second image with a second correction matrix to compensate for variations in irradiance as a function of at least one of the second SWIR wavelength band and the distance between the second SWIR emitter and the target tissue to generate a second corrected image, comparing the first and second corrected image data to distinguish between human or animal tissue types on said target tissue.,

[0027] Preferably, the image processing device is configured to generate for display an image of the target tissue in which at least one distinguished tissue structure is represented in a contrasting manner. Brief description of the drawings

[0028] This disclosure will be better understood and other advantages will appear on reading the detailed description of an embodiment taken as a non-limiting example and illustrated by the accompanying drawings in which:

[0029] Figure 1 schematically shows a graph of the spectral reflectance of a nerve and an artery;

[0030] Figure 2 schematically illustrates a device for emitting and detecting SWIR radiation according to one embodiment;

[0031] Figure 3 illustrates a device for emitting and detecting SWIR radiation according to another embodiment;

[0032] Figure 4 is a flow diagram of a method for SWIR imaging of a surgical field; and

[0033] Figure 5 is a flow diagram of a method for identifying specific tissue types from SWIR imaging data.

[0034] Detailed description

[0035] SWIR imaging of human or animal tissues can be used to identify and distinguish specific tissue types and structures, both superficially and in depth, and thus constitute a valuable tool for clinicians. Tissue structures that can be identified in this way include arteries, veins, nerves, parts of the lymphatic system, but also fat, damaged tissue or tumors among others. These structures or tissue types reflect or absorb light from the SWIR spectrum at different intensities and wavelengths depending on their structure and constituents. In other words, the spectral response of these structures can serve as a spectral fingerprint to uniquely identify the structure or to distinguish between two structures. This is described in more detail with reference to Figure 1.Figure 1 is a graph showing the reflectance (in arbitrary units) versus wavelength of two tissue structures, namely an artery, A, marked by crosses, and a nerve, N, marked by circles. The reflectance is expressed in arbitrary units, while the wavelength is expressed in nanometers. The wavelengths 1150 nm, 1450 nm, and 1750 nm are indicated by dotted vertical lines À 1 , Â 2 , and À 3 . As shown in Figure 1 , the reflectance of the two structures A and N varies differently with wavelength. At the first wavelength À 1 of 1150 nm, the reflectance of the artery, A, and the nerve, N, are essentially equal, with a value of about 0.475. At the second wavelength, A2, the nerve reflects more radiation than the artery and therefore appears brighter on an image.At the third wavelength At 3, the situation is reversed and the artery reflects more light or radiation than the nerve and therefore appears brighter on an image.

[0036] By comparing the spectral response of different parts of a target tissue, i.e. the reflectance at different wavelengths, it is possible to identify specific tissue types. For example, comparing the ratios of reflectances at wavelengths λ 1 and λ 2 and λ 3 can identify whether it is a nerve or an artery, as shown in Table 1 below where R is the reflectance.

[0037] Table 1

[0038] By selecting at least two appropriate SWIR wavelengths, it is possible to identify a large number of different structures and / or tissue types. However, the more wavelengths that can be compared, the more accurate the tissue identification will be. However, to accurately compare reflectance at different wavelengths, it must be ensured that the target area is illuminated homogeneously and that the irradiance is the same for all SWIR wavelengths used. This can be problematic, especially when the SWIR light source is located some distance from the target area and especially when one or more focusing optics are used to increase the light intensity at the surgical site; this can lead to inaccurate results.

[0039] Figures 2 and 3 schematically illustrate a SWIR imaging device for SWIR imaging of human or animal tissues capable of overcoming this drawback.

[0040] Figure 2 shows a SWIR imaging device 100 in a preferred embodiment. The device may be suspended or otherwise positioned above a surgical field 400, which symbolizes a portion of a patient (human or animal). The SWIR imaging device 100 includes an illumination module 120, which may include a plurality of SWIR emitters 122, each emitter configured to emit radiation or light at a specific and distinct wavelength λ 1 , λ 2 λ 3 in the SWIR range, i.e., between 1000 nm and 2500 nm. It is understood that, in this context, the term "wavelength" is intended to refer to a narrow range of wavelengths, for example, no more than 100 nm, and even more preferably between about 15 nm and 60 nm. In the illustrated example, three SWIR 12 emitters are shown, but the device includes at least two emitters and may include many more.The number of planned SWIR emitters depends on the type of tissue structures to be identified.

[0041] Each emitter 122 preferably comprises one or more light emitting diodes or LEDs (not shown) with associated power supply and control circuitry, but other SWIR sources are conceivable. An example of suitable LEDs would be the Ushio Epitex LED series, such as the EDC1150D-1100-S5 which are made of In-GaAsP chips in a 3.45*3.45mm package with a silicone lens emitting a typical optical power of 230 mW at 1150 nm for I = 1 A and V = 1. 4V typical or the EDC1300D-1100-S5 which are made of InGaAsP chips in a 3.45*3.45mm package with silicone lens emitting a typical optical power 160 mW at 1300 nm for I = 1A and V = 1.3V typical or the EDC 1450D-1100-S5 which are made of InGaAsP chips in a 3.45*3.45mm package with silicone lens emitting a typical optical power 80 mW at 1450 nm for I = 1 A and V = 1.3V typical.

[0042] The illumination module 120 may also include focusing or collimating optics 124 associated with each SWIR emitter.

[0043] Each emitter 122 preferably illuminates a spot with a diameter of between about 10 cm and 30 cm. The illuminated spot may be round or elliptical, but also square or rectangular. A narrowband filter 126 may be associated with each emitter 122 to obtain optimal spectral resolution. Suitable filters preferably have a bandwidth of between about 15 and 60 nm. When provided in addition to the focusing optics 124, the filter may be placed behind this optics 124 (as shown in FIG. 1) or in front of it.

[0044] The device 100 further comprises at least one camera 130 positioned to capture images of the surgical field 400. The camera 130 is capable of detecting the wavelength band emitted by the emitters 122. The camera 130 may have a spectral range limited to the SWIR range. The camera 130 may also have a broader spectral range that incorporates visible light, near infrared (NIR), and SWIR, and thus be suitable for capturing images of the surgical field under visible light. In the latter case, the camera may be provided with a removable SWIR filter to allow optimal SWIR imaging while ambient lighting is used, for example, the white light of an operating lamp.

[0045] A control unit 110 is coupled to the SWIR illumination module 120 and the camera 130. The control unit 110 controls the illumination of each of the SWIR emitters 122 and the operation of the camera so that an image of the surgical field 400 is captured for each SWIR wavelength or wavelength band used, as will be described later.

[0046] A distance sensor 140 may also be provided, coupled to the control unit 110 and configured to measure the distance between the SWIR illumination module 120 and the operating field 400. The distance sensor 140 may, for example, be an ultrasonic, infrared, time of flight (TOF) or other sensor. In some cases, the distance sensor may measure the distance from multiple points on the SWIR illumination module 122 and provide a 3D map to account for the illumination angle. It is also possible to obtain distance information from the structure supporting the illumination module 122. In another variation, it is not necessary to measure the distance, but the operator may input this information into the device 100, for example based on predefined positions of the device's supporting structure.In some cases, the SWIR illumination module 120 may also be fixed at a defined height during installation. In some embodiments, the system includes a distance sensor 140, and the measured distance is used to select one or more correction data or correction matrices for use with the captured images.

[0047] An image processing module 150 is coupled to the control unit 110 and is configured to receive image data either via the control unit 110 or directly from the camera, and to process this data. A memory 160 is coupled to the image processing module 150 and contains correction data for use in processing the captured images, as will be discussed later.

[0048] The image processing module 150 may also have access to another memory or database 500 which contains data establishing a correspondence between the structures of human or animal tissues and the absorption or reflectance spectra, i.e. a library of spectral reflectance of different tissues. This database may be located locally or on a remote server.

[0049] The image processing module 150 and the control unit 110 may be included in a common data processor. In another embodiment, at least the image processing module 150 may be part of a separate device, located remotely from the control unit 110, for example at another location in an operating room with the screen 300.

[0050] The image processing module 150 and the control unit 110 are not limited to the example configurations described herein, and may include various electronic components and software to implement the disclosed functionality.

[0051] The SWIR imaging device 100 may be connected to a display 300 to display the results of the image processing module 150. The results may be displayed as an enhanced image of the surgical field 400. For example, the display 300 may display an image of the surgical field 400 with identified tissue structures, e.g., a nerve and an artery highlighted in contrasting colors to allow a clinician to easily identify them in real time. In another embodiment not shown, the SWIR imaging device 100 may be coupled to an image projector that projects an enhanced image onto the surgical site. The image may highlight certain identified structures, such as arteries and / or nerves, using contrasting colors to facilitate identification of these structures on the target tissue directly.

[0052] A user control interface (not shown) may be coupled to the control unit 110 and / or the image processing module 150 to allow an operator to monitor and control the operation of the device 100. This control interface may also be integrated with the user interface of other systems present in the operating room.

[0053] As mentioned above, the device 100 may be suspended above an operating field 400 so as to allow free access to the target tissue so as not to hinder the movements of a clinician. For this purpose, the SWIR imaging device 100 may be arranged on an articulated arm not shown anchored to the ceiling of an operating room or on a fixed or mobile support. The SWIR imaging device 100 is arranged such that at least the illumination module 120 and the camera 130 may be positioned above an operating field 400 and spaced from the operating field 400 by approximately 80 cm to 120 cm, although this distance may be greater or smaller. In some embodiments, at least the image processing module 150 and the memory 160 may be located remote from other parts of the SWIR imaging device 100, for example near a screen 300 placed near the operating field and within view of a surgeon.

[0054] In another embodiment, schematically illustrated in Figure 3, the SWIR imaging device 100 may be attached to an operating lamp 200, of which only the dome is shown. The figure provides only a schematic representation and, in particular, does not indicate the actual scale. Operating lamps 200 or domes of this type are well known in the art; it will therefore not be described in further detail here. In the present embodiment, the lamp is equipped with a camera 220 for capturing images of the operating field under visible light (white light). The captured image data may be provided to the image processing module 150 to enable the construction of a modified image of the operating field. This is not necessary when the camera 130 of the device 100 has a spectral range covering visible light as well as SWIR.

[0055] Only the lighting module 120, the camera 130 and the distance sensor are shown in Figure 3. It will be understood that the control unit 110, the image processing module 150 and the memory 160 can also be located on the operating lamp 200 or arranged separately. In the schematic representation of Figure 3, the imaging device 100 is attached to an outer edge of the dome of the operating lamp 200 by a fixed or removable attachment. However, it is also possible for the SWIR imaging device to be integrated into the operating lamp, for example, by incorporating the lighting module 120 and the camera 130, as well as the distance sensor 140, if applicable, into the structure of the operating lamp 200, with the SWIR emitters 122 and the camera 130 being arranged in the dome.

[0056] The operating lamp 200 is typically spaced approximately 80 cm to 120 cm from an operating field 400. Depending on the location of the emitters 120 relative to the lamp 200 and the size of the latter, the distance between each emitter and the operating field may therefore be between approximately 50 and 150 cm, preferably between 80 cm and 120 cm.

[0057] As already mentioned, the difficulty in comparing images captured at different wavelengths lies in the fact that the irradiance of the operating field varies from one wavelength to another and the irradiance at one wavelength is not homogeneous over the entire operating field. In addition, the distribution of the irradiance of the operating field also varies depending on the spacing between the SWIR emitters 122 and the operating field 400. In other words, the irradiance distribution obtained when the operating field 400 is illuminated by a first SWIR emitter 122 operating at λ1 and spaced a first distance D1 from the operating field will be different from the distribution obtained when the operating field is illuminated by the same emitter 122 spaced a second distance D2 from the operating field.This problem is addressed in the present disclosure by providing correction data in memory 160 that can be used to correct image data captured at a specific SWIR wavelength prior to any comparison with images captured at other SWIR wavelengths.

[0058] The correction data, Eÿ( Â k,d) stored in the memory 160 is preferably presented in the form of a matrix of values ​​of dimension ixj, each of which represents a correction factor for an area ij of an image captured at a wavelength λ k and at a distance, d, by the camera 130. This area ij represents a portion of the image and may comprise one or more pixels

[0059] Thus, when comparing images hj captured at two wavelengths λ, λ2, it is first necessary to correct the image data to determine the actual reflectance. The reflectance at the first wavelength λ1 is therefore given by: the reflectance at A2 is given by:

[0060] Assuming that the value of be known for a specific type of tissue- tick and stored in the database 500, it is then possible to determine whether this tissue type is present in the image data and where it is present using the following relationship:

[0061] The correction matrices stored in the memory 160 are preferably determined during a test phase, for example during manufacturing or installation. They can be determined uniquely for each device 100 or for each type of device.

[0062] Figure 4 shows a flow diagram illustrating the operation of the SWIR imaging device 100 according to an example using three wavelengths. In this method, it is assumed that the SWIR imaging device 100 is positioned at a known working distance and that the values ​​of the correction matrix are valid, or can be selected, for this known distance. In step 600, a first SWIR emitter 122 is turned on to irradiate the surgical field with light at a first wavelength λ 1. In step 601, the camera 130 captures an image at this wavelength λ 1 and then, the first SWIR emitter 122 is turned off. In step 602, the image processing module 150 retrieves the correction matrix λ 1 for the wavelength λ 1 and applies it to the captured image to generate a corrected image λ 1 . In step 604, the second SWIR emitter 122 which emits light at a second wavelength λ 2 is turned on.An image I 2 is captured in step 605 and the second SWIR emitter 122 is turned off. The image is corrected using a corresponding correction matrix Ey  2 in step 606 and the corrected image data I'ij2 is stored in step 607. The process is repeated in steps 608 to 611 using light of a third wavelength  3, to capture an image Lj3 which, after correction using the associated correction matrix Eg  3, gives a corrected image l' S, which is stored.

[0063] Figure 5 shows a flowchart of an example of a method for identifying specific tissue types from imaging data. In this example, the method also uses three wavelengths.

[0064] In this method, the wavelengths are assumed to be: AT 1: 1150 nm, AT 2: 1450 nm, and AT 3: 1750 nm. It is also assumed that an artery and a nerve can be identified using the reflectance ratios shown in Table 1. It will be understood that this method can be employed to identify these or other structures using reflectance ratios at other wavelengths, if appropriate.

[0065] In step 700, the ratio between the corrected imaging data I'ij2 and I'ij is calculated area by area or pixel by pixel, i.e. for all values ​​of i, j. In step 701, the ratio between the corrected image data I'S and I'ij is calculated pixel by pixel. In step 702, it is determined whether the ratio I'ij2 / I'ij is approximately equal to 0.787. If this is the case, the method proceeds to step 703, where it is determined whether the ratio I'ÿS / I'ij is approximately equal to 1.617 for these same pixels. If this is also the case, the method proceeds to step 704, during which the image processing module 150 determines that these pixels represent an artery. These pixels can then be highlighted, for example by coloring them blue, and displayed as an overlay on an image of the operating field for the surgeon or clinician.For the values ​​i, j which do not satisfy step 702, the method proceeds to step 705 where it is determined whether, for a given value ij, the ratio I'ij2 / I'ij1 is approximately equal to 1,368. If this is the case, the method proceeds to step 706 where it is determined whether these same values ​​ij satisfy the ratio l'ijS / l'ijl approximately equal to 1,617. If this is also the case, the method proceeds to step 707 where the image processing module 150 determines that these pixels represent a nerve. These pixels can then be colored green or another contrasting color to distinguish them from the surrounding tissues and to form the nerve.

[0066] As noted above, the enhanced image may be projected onto the operating site to enable the medical team to recognize tissue identified on the patient, instead of or in addition to displaying an enhanced image of the operating site on the screen 300.

[0067] Although the use of three distinct wavelengths, as shown in the above method, can reliably distinguish and identify different tissue types, and the use of more wavelengths would increase the accuracy and reliability of any identification, it is understood that the method can be used to distinguish single tissue types from surrounding tissues using only two wavelengths.

[0068] This disclosure relates to shortwave infrared (SWIR) emitting and detecting devices, as well as methods of using such devices and arrangements. It also includes methods and devices for creating and presenting images of tissue that can be viewed by operators such as medical personnel. This disclosure includes and contemplates all electronic devices, software, processors, and the like for implementing the devices and methods disclosed herein. This disclosure is not limited to the specific examples provided, and the disclosed elements may be used in various combinations.

[0069] List of reference numbers

[0070] 100 SWIR Imaging Device

[0071] 110 Control Unit

[0072] 120 SWIR Lighting Module

[0073] 122 SWIR transmitter / LED

[0074] 124 Focusing optics

[0075] 126 Filter

[0076] 130 Camera

[0077] 140 Distance sensor

[0078] 150 Image processing module

[0079] 160 Memory

[0080] 200 Operating lamp

[0081] 220 Visible Light Camera

[0082] 300 Screen

[0083] 400 Operating field

[0084] 500 Database

Claims

Claims 1. A shortwave infrared (SWIR) emitting and detecting device (100) for distinguishing at least one tissue structure in a human and / or animal target tissue, the device comprising: an illumination module (120) configured to irradiate the target tissue by emitting SWIR radiation in at least a first SWIR wavelength band and a second SWIR wavelength band, the first and second SWIR wavelength bands being distinct, at least one SWIR camera (130) for capturing images of the target tissue, said camera being configured to capture a first image of the target tissue in the first wavelength band and at least one second image of the target tissue in the second wavelength band, an image processing means (150) configured to correct the captured images of the tissue by applying a correction matrix to each image,the correction matrices being designed to correct variations in said images as a function of at least one of the wavelength bands and the distance of the target tissue from said illumination module., 2. SWIR emission and detection device according to claim 1, wherein the image processing means (150) is further configured to apply to the first image a first correction matrix in order to generate a first corrected image, apply at least to the second image a second correction matrix in order to generate a second corrected image, and compare the first corrected image with at least one second corrected image in order to distinguish at least one tissue structure.

3. SWIR emission and detection device according to claim 2, wherein the image processing means (150) is configured to compare the first corrected image with at least a second corrected image by generating a reflectance quotient, more particularly by generating a reflectance quotient for at least a portion of the image, each portion comprising at least one pixel.

4. SWIR emission and detection device according to any one of claims 1 or 2, wherein the illumination module (120) is configured to emit SWIR radiation in a third wavelength band, distinct from the first and second wavelength bands, the camera (130) being configured to capture a third image of the target tissue in the third wavelength band, and the image processing means (150) is configured to apply to the third image a third correction matrix in order to generate a third corrected image and compare the third corrected image with the first and second corrected images in order to distinguish at least one tissue structure, 5. SWIR emission and detection device according to any one of claims 2 or 3, comprising display means (300) adapted to generate for display an image of the target tissue in which at least one distinguished tissue structure is represented in a contrasting manner.

6. SWIR emission and detection device according to any one of the preceding claims, further comprising storage means (160) for storing the predefined correction matrices, the image processing means (150) being configured to select a correction matrix depending on the wavelength band of the captured image and / or the distance from the target tissue.

7. A SWIR emission and detection device according to any preceding claim, comprising a distance sensor (140) configured to measure the distance between the SWIR illumination module (120) and the target tissue, more particularly, wherein the SWIR emission and detection device is configured to be used at a distance of about 50 to 150 cm, preferably between 80 and 120 cm, of the target tissue, preferably wherein the distance sensor (140) is configured to generate a 3D map of the target tissue from the SWIR illumination module.

8. A SWIR emission and detection device according to any preceding claim, wherein said device is configured to be coupled to an operating lamp (200) and suspended above an operating site, more particularly, wherein the SWIR emission and detection device is configured to be placed at least 80 cm from the target tissue.

9. SWIR emission and detection device according to any one of the preceding claims, wherein the lighting module (120) comprises at least one first emitter (122) capable of emitting SWIR radiation in the first SWIR wavelength band and at least one second emitter (122) capable of emitting SWIR radiation in the second SWIR wavelength band, preferably wherein the first and second emitters (122) are adapted to be switched on separately.

10. SWIR emission and detection device according to any one of the preceding claims, wherein the lighting module (120) comprises at least one SWIR LED (122), preferably at least one SWIR LED capable of emitting radiation in said first wavelength band and at least one SWIR LED capable of emitting radiation in said second wavelength band, preferably wherein at least one SWIR LED is associated with a focusing optic.

11. SWIR emission and detection device according to any one of the preceding claims, wherein the SWIR illumination module (120) comprises at least one bandpass filter (126).

12. Operating lamp comprising a SWIR emission and detection device (100) according to any one of the preceding claims.

13. A method for distinguishing tissue structures in a human or animal target tissue using a SWIR emission and detection device (100) according to any one of the preceding claims, the method comprising the following steps: illuminating (600) the target tissue with SWIR radiation in at least a first wavelength band, capturing (601) a first image of the target tissue in the first SWIR wavelength band, illuminating (604) the target tissue with SWIR radiation in at least a second wavelength band, the first and second wavelength bands being distinct, capturing (605) an image of said target tissue in said second SWIR wavelength band, correcting (602,603) said first image with a first correction matrix to compensate for variations in irradiance as a function of at least one of said first SWIR wavelength band and the distance between said arrangement and said target tissue to generate a first corrected image, and correcting (606, 607) said second image with a second correction matrix to compensate for variations in irradiance as a function of at least one of said second SWIR wavelength band and the distance between said arrangement and said target tissue to generate a second corrected image., 14. The method of claim 13, comprising a further step of comparing (702, 703; 705, 706) the first and second corrected image data to distinguish human or animal tissue types on said target tissue, more particularly in the case where the comparing step comprises generating a reflectance quotient for at least a portion of the image, each portion comprising at least one pixel.

15. Method according to claim 14, comprising a further step of generating (704; 707) for display an image of the target tissue in which at least one distinguished tissue structure is represented in a contrasting manner.

16. An image processing device (150) for distinguishing tissue structures in a human or animal target tissue, the device being configured to: receive a first image of the target tissue captured in the first SWIR wavelength band, receive a second image of said target tissue in a second SWIR wavelength band, the second wavelength band being distinct from the first wavelength band, correct (602, 603) said first image with a first correction matrix to compensate for variations in irradiance as a function of at least one of said first SWIR wavelength band and the distance between the first emitter and the target tissue to generate a first corrected image, and correct (606,607) said second image with a second correction matrix to compensate for variations in irradiance as a function of at least one of said second SWIR wavelength band and the distance between the second SWIR emitter and the target tissue in order to generate a second corrected image, comparing (702, 703; 705, 706) the first and second corrected image data in order to distinguish the types of human or animal tissues on said target tissue., 17. An image processing device according to claim 16, configured to generate for display an image of the target tissue in which at least one distinguished tissue structure is represented in a contrasting manner.

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