Compact image guided surgical system

Abstract

Example embodiments disclosed herein include an optical system for image acquisition and projection, comprising: an illumination path including a first lens configured to receive infrared light and to direct the infrared light towards a sample; an imaging path including: a first beam splitter, a second lens configured to receive fluorescence light produced by the sample in response to illumination by the infrared light and to direct the fluorescence light towards the first beam splitter, and an imaging sensor configured to capture the fluorescence light after passing through the first beam splitter; and a projection path including a pixelated light source configured to project an image towards the sample using visible light, the image associated with the fluorescence light captured by the imaging sensor, the visible light passing through both the first beam splitter and the second lens.

Description

COMPACT IMAGE GUIDED SURGICAL SYSTEMSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0001] This invention was made with government support under Grant No. DE030682 awarded by National Institutes of Health. The government has certain rights in the invention.CROSS-REFERENCE TO RELATED APPLICATION

[0002] This patent document claims priority to and benefits of U.S. Provisional Application No 63 / 625,694, entitled “COMPACT IMAGE GUIDED SURGICAL SYSTEM,” and filed on January 26, 2024. The entire content of the above noted patent application is incorporated by reference as part of the disclosure of this patent document.TECHNICAL FIELD

[0003] This patent document is generally related visible light and infrared imaging and pattern generation techniques.BACKGROUND

[0004] Visualizing near infrared (NIR) fluorescence from a target is of interest in the medical field. Techniques that enable such visualizing can be of assistance during surgical procedures and lead to improvements in the way these procedures are carried out.SUMMARY

[0005] The disclosed embodiments relate to devices, systems and associated methods that, among other features and benefits, produce images obtained via NIR fluorescence and project patterns associated with the images onto a sample, such as a biological tissue, using visible light. Using the disclosed devices and techniques, for example, a surgeon can maintain a fixed gaze on the surgical field rather than splitting his / her attention between the patient and an external display.

[0006] In some embodiments, the disclosed devices can be implemented as a handheld device or a head-mount device which allows a person to place the device on his / her head.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 shows a diagram of an example device based on the disclosed technology.

[0008] FIGS. 2A-C shows example microLED light sources, that can be implemented in accordance with embodiments of the disclosed technology, and example features thereof.

[0009] FIGS. 3A-C show an image and schematic representations of an example handheld device based on the disclosed technology.

[0010] FIGS. 4A-D show example fluorescence images and patterns projected onto an object using visible light in accordance with implementations of the disclosed technology.

[0011] FIG. 5 shows an example layout of an optical system based on the disclosed technology.

[0012] FIG. 6 shows a schematic of an example optical system based on the disclosed technology that can be implemented as part of a head-mounted device.

[0013] FIG. 7 shows schematics of example lens system that can be implemented in embodiments based on the disclosed technology.

[0014] FIG. 8 shows a flow diagram of an example method based on the disclosed technology.DETAILED DESCRIPTION

[0015] FIG. 1 illustrates a diagram of an example device based on the disclosed technology. By the way of example, but not by limitation, a NIR illumination laser source with an operating wavelength of 785 nm is used to illuminate the sample that has been treated or otherwise tagged with a dye such as Indocyanine green (ICG). The fluorescence light produced by the sample is captured by the lens and after optional filtering is imaged at the camera. The captured image is processed, and the useful information is transferred to the image source, such as a microLED panel, an organic light-emitting diode (OLED), liquid crystal on silicon (LCoS) device, digital micromirror device (DMD), or laser scanner. A pattern associated with the captured image is projected onto the sample by the microLED display using visible light, such as green light. Without using the visible projection light, the section of the sample of interest would not be visible to human eye (it is in the IR range). But using the disclosed visible-light projection technique the imaged pattern is projected back onto the sample and is visible. One of the features of the disclosed embodiments is the microLED (in this example, operating at a wavelength of 520 nm), which is compact in size and allows implementation of the disclosedtechnology in a compact form, such as in a head mounted device.

[0016] It should be noted that the operations associated with imaging and projection of FIG. 1 can be repeated at the video frame rate to enable continuous capture and projection of images at, for example, 30 frames per second. In other words, acquiring the image and projecting the pattern can be performed alternatively and repeatedly at a particular rate. This can be advantageous if there is a change in the features imaged in the infrared (e.g., blood clot that moves around, etc.).

[0017] FIGS. 2A-C illustrate examples of commercially available microLED light sources, and some of their features and benefits. The microLED light sources may be compact, as shown in FIG. 2A using a reference pencil for scale. In one example implementation, the microLED light sources may be formed as an array. FIG. 2B shows an example of the array which may have dimensions of 1.92 mm x 2.56 mm or smaller. FIG. 2C shows an example of a pattern, having dimensions of 9.6 mm x 7.2 mm, which can be projected using visible light generated by microLED light sources.

[0018] FIGS. 3A-C illustrate an example handheld device based on the disclosed technology, including some of its features, components and method of operation as a handheld device. FIG.3 A shows a schematic representation of a cross section (viewed from side) of the handheld device. The handheld device includes a housing to enclose various elements of an optical system or device based on the disclosed technology, such as the example device previously described with reference to FIG. 1. The housing may be 3D printed. In one example, the overall dimensions of the handheld device are 14.1 cm x 9.0 cm x 7.0 cm.

[0019] FIG. 3 A provides an example of how microLED light sources, a camera, and additional optical elements may be disposed within the housing. The additional optical elements may include, but are not limited to, filters, light sources, beam splitters, and lenses configured in various arrangements. The handheld device includes optical paths for illumination, imaging, and projection. The housing may include one or more openings to allow light to propagate into or out of the handheld device. For example, input light may be received at an input of the device via a cable (far right in FIG. 3A). FIG. 3B shows a cross section (viewed from top) of the example handheld device, which includes an input for receiving incident light from a light source, such as fiber for delivery of a laser light, and a light pipe configured to direct the laser light towardsoptics disposed within the housing and improve illumination uniformity. The incident laser light includes infrared light. The infrared light exits the handheld device through an opening (top opening on the left side of FIG. 3B) to enable illumination of an object with the infrared light. For instance, a user may operate the handheld device by aiming the device at a location on an object and activating the device to illuminate the object. This method of operation is illustrated in FIG. 3C. The housing also includes another opening (lower opening on left side of FIG. 3B) to receive light, such as fluorescence light, emitted by the object in response to the illumination. In some implementations, the object is treated with a dye (e.g., ICG) to enable fluorescence. The light emitted by the object is received by the handheld device through the opening and directed towards the camera shown in FIG. 3 A, which obtains an image of the object based on the received light. In some implementations, the handheld device includes a processing unit in communication with the camera and the microLED sources. The processing unit is capable of extracting information from the image and transmitting the information to the microLED sources. The processing unit is configured to cause some or all of the microLED sources to illuminate based on the extracted information from the image. A pattern associated with the captured image is projected onto the object by the microLED sources using visible light. The microLED sources can output visible light in various colors. As shown in FIG. 3C, the visible light used for projection may exit the handheld device from the same opening which is used for imaging the object.

[0020] Table I below provides example parameters, and their associated values, of the example handheld device shown in FIGS. 3A-C.Table I: Example Parameters of the Handheld Device

[0021] FIG. 4A shows an example of a fluorescence image obtained from a stained area of an object in accordance with implementations of the disclosed technology. FIG. 4B shows a threshold image obtained based on the first image. As shown in FIG. 4D, the disclosed embodiments can be used to project the image onto a target (in this case the sample was a swine liver). Various projection patterns are possible, as demonstrated by the checkerboard pattern shown in FIG. 4C. The results indicate that the microLED display is sufficiently bright and can project an image that can be readily seen by an observer.

[0022] FIG. 5 illustrates an example optical system layout for a disclosed device. In the description that follows, FIG. 5 is explained in the context of the device shown in FIG. 1. Referring back to FIG. 1, it should be noted that the optical axis of the illumination path is at an angle with respect to the optical axis of the imaging and display system. Accordingly, the target area of the sample may not be fully illuminated unless the illumination source and / or the sample are positioned at an appropriate distance from each other. This can be problematic for the device. The configuration of FIG. 5 overcomes this problem by aligning the optical axis of the illumination path with that of the imaging and display system. A beam splitter (which can be a dichroic mirror) is used to combine optical axes of the illumination and imaging / display system. With this configuration, illumination field and imaging / display field always overlap, irrespective of the working distance.

[0023] As shown in FIG. 5, the illumination path includes a beam shaping lens and a folding mirror. The beam shaping lens receives incident light from a light source (e.g., an optical fiber) and directs the incident light towards the folding mirror. The folding mirror is configured to reflect the light incident thereupon towards a first beam splitter (Beam splitter 1 ) which directs the light from the folding mirror towards an object for illumination. The first beam splitter is also shared with the imaging path and the display path. The imaging path in FIG. 5 includes an imaging sensor (e.g., CMOS sensor), an optical filter, two lenses (Lens 0 and Lens 2), and a second beam splitter (Beam splitter 2) positioned between the two lenses. Fluorescence signals emitted by the objectupon illumination are received at the imaging sensor after propagating through the first beam splitter, the second beam splitter, the optical filter, and the two lenses. The second beam splitter is configured to direct incident light from the illumination, projection, and display paths along the optical axes shown in FIG. 5. While FIG. 5 shows the optical filter positioned in front of the imaging sensor, other locations for the optical filter are possible.

[0024] The display path in FIG. 5 includes a microLED panel, two lenses (Lens 0 and Lens 1), the second beam splitter, and the first beam splitter. Visible light representing an image obtained by the imaging sensor is output by the microLED panel, propagates through the Lens 1 and towards the second beam splitter, which reflects the visible light towards Lens 0 along the imaging path. The visible light is transmitted through the first beam splitter toward, the object. The visible light may take the form of a pattern (e.g., the letter “A” shown in FIG. 5) which is projected onto the object and associated with the image captured by the imaging sensor.

[0025] One issue in FIG. 5 is related to the active size of the microLED panel and the imaging sensor. Typically, they are different. If the same optical system for the display path with microLED panel and the imaging path with imaging sensor are used, the imaging field (i.e., the field captured by the imaging sensor) will be different from the field displayed by the microLED panel. In order to fully utilize both microLED pixels and CMOS pixels, the configuration in FIG. 5 includes two different optical systems: one that includes lens 0 and lens 2 for the imaging path, and the other that incudes lens 0 and lens 1 for the display path so that the imaging field and display field in the surgical area are the same (for example, area A in the figure).

[0026] The second beam splitter in FIG. 5 (which can be a dichroic mirror) is used to combine the imaging path and display path. In one embodiment, this beam splitter reflects visible light and transmits NIR light. In FIG. 5, the beam shaping lens is used to generate uniform illumination in the surgical field to excite the fluorescence. Depending on the contrast agent used, the excitation light will have a different wavelength.

[0027] Some of the advantages associated with the configuration of FIG. 5 include: compact dimensions, suitable for head mount application, all three fields (illumination, imaging and display) always overlap, and the imaging and display channels have the same field of view.

[0028] As noted earlier, one implementation of the disclosed devices is a system that can bemounted on the head of a surgeon. FIG. 6 illustrates an example of a configuration that is compact enough to allow implementation as a head-mounted device. The panels in FIG. 6 illustrate example dimensions of 3 cm x 8 cm x 6 cm, with optical components that correspond to those shown in FIG. 5. One or more cables may connect to the configuration. For example, one cable can be used to connect the configuration to a light source. Additional cables may enable signal transmission between the device and data acquisition or processing circuitry.

[0029] FIG. 7 illustrates example lens systems that can be used in implementations of the disclosed technology such as the configuration of FIG. 6 or the optical system of FIG. 5. The example lens system (shown top in FIG 7) may be implemented along the imaging path in FIG.5. The location of the filter in FIG. 7 may be different from that which is shown therein. Another example lens system, which can be implemented along the display path of FIG. 5, is shown in the bottom of FIG. 7. The working distance of the lens system is adjustable, for example, by adjusting the distance between lens 0 and the beam splitter from 1 mm to 1.245 mm.

[0030] FIG. 8 shows a flow diagram illustrating an example method 8000 for image acquisition and projection. At operation 8100, the method 8000 comprises illuminating an object with infrared light to cause the object to emit fluorescence light. At operation 8200, the method 8000 comprises acquiring an image by capturing the fluorescence light using an imaging sensor. At operation 8300, the method 8000 comprises activating elements of a pixelated light source based on information extracted from the image. At operation 8400, the method 8000 comprises projecting, towards the object and using visible light produced by the activated elements, a pattern associated with the image.

[0031] Embodiments of the disclosed technology support inter alia the following technical solutions that solve the technical problem of producing images obtained via NIR fluorescence and projecting patterns associated with the images onto a sample.

[0032] 1. An optical system can include some or all of the following; a light source and its beam shaping element to provide uniform illumination, an imaging sensor with optical filter in front of it to capture fluorescence light, a display unit with image source, one or more beam splitters to combine the above three systems to a common optical axis, two optical systems, one for imaging fluorescence light, and the other for projecting visible light to the field, where the two optical systems share the optical components in front of the beamsplitter, and a processor unit forprocessing the captured fluorescence image and transferring the information to the image source.

[0033] 2. The optical system of technical solution 1, wherein the image projection source is one of a microLED, OLED, LCoS, digital micromirror device (DMD), or laser scanner.

[0034] 3. Any device described in the present application.

[0035] 4. An optical system for image acquisition and projection, comprising: an illumination path including a first lens configured to receive infrared light and to direct the infrared light towards a sample; an imaging path including: a first beam splitter, a second lens configured to receive fluorescence light produced by the sample in response to illumination by the infrared light and to direct the fluorescence light towards the first beam splitter, and an imaging sensor configured to capture the fluorescence light after passing through the first beam splitter; and a projection path including a pixelated light source configured to project an image towards the sample using visible light, the image associated with the fluorescence light captured by the imaging sensor, the visible light passing through both the first beam splitter and the second lens. For example, the first lens of technical solution 4 can correspond to the beam shaping lens shown in FIG. 5, the first beam splitter of technical solution 4 can correspond to beam splitter 2 shown in FIG. 5, the second lens of technical solution 4 can correspond to lens 0 shown in FIG. 5.

[0036] In some implementations, the pixelated light source of technical solution 4 corresponds to the microLED panel shown in FIG. 5.

[0037] 5. The optical system of technical solution 4, wherein the illumination path includes an infrared light source operable to generate the infrared light, and the first lens is positioned to receive the infrared light from the infrared light source and to provide uniform illumination of the sample by the infrared light.

[0038] 6. The optical system of technical solution 4, wherein the first beam splitter is configured to combine the projection path and the imaging path such that the projection path and the imaging path are coaxial.

[0039] 7. The optical system of technical solution 4, wherein the projection path includes a third lens positioned between the first beam splitter and the pixelated light source, the imaging path includes a fourth lens positioned between the first beam splitter and the imaging sensor, and the first beam splitter is positioned to split a portion of the imaging path and projection path that otherwise form a common path. For example, the third lens of technical solution 7 can correspondto lens 1 shown in FIG. 5, and the fourth lens of technical solution 7 can correspond to lens 2 shown in FIG. 5.

[0040] 8. The optical system of technical solution 7, wherein the second lens and the fourth lens each have a predetermined magnification, wherein the predetermined magnification is selected based on a size of the imaging sensor.

[0041] 9. The optical system of technical solution 4, wherein magnification provided by a combination of the second lens and the third lens is selected to provide a size of the image projected on the sample to substantially match a size of an image produced by the imaging sensor based on the captured fluorescence light.

[0042] 10. The optical system of technical solution 9, wherein the magnification provided the combination of the second lens and the third lens is selected to substantially match a magnification provided the combination of the second lens and the fourth lens.

[0043] 11. The optical system of technical solution 1, comprising a filter positioned in the imaging path having a bandpass that allows the fluorescence light produced by the sample to pass therethrough in the direction of the imaging sensor.

[0044] In some implementations, the filter of technical solution 11 corresponds to the optical filter shown in FIG. 5.

[0045] 12. The optical system of technical solution 11, wherein the infrared light has a wavelength of 785 nm, and the filter is a long pass filter with a passband at 850 nm.

[0046] 13. The optical system of technical solution 4, further comprising a processing unit in communication with the pixelated light source and the imaging sensor, wherein: the processing unit is configured to control illumination elements of the pixelated source, to cause the image to project towards the sample based on a pattern associated with the fluorescence light captured by the imaging sensor.

[0047] 14. The optical system of technical solution 13, wherein the imaging sensor is configured to produce a fluorescence image based on the captured fluorescence light, the processing unit is configured to generate a threshold image based on the fluorescence image and to provide information extracted from the threshold image to the pixelated light source, and the pixelated light source is configured to project the pattern based on the information.

[0048] 15. The optical system of technical solution 13, wherein the illumination elements are configured to produce visible light of various colors.

[0049] 16. The optical system of technical solution 4, including a folding mirror in the illumination path, and a second beam splitter that is common between the illumination, imaging and projection paths, wherein the folding mirror is positioned to receive the infrared light from the first lens and direct the infrared light towards the second beam splitter for illuminating the sample.

[0050] In some implementations, the second beam splitter of technical solution 16 corresponds to beam splitter 1 shown in FIG. 5.

[0051] 17. The optical system of technical solution 4, wherein the sample is treated with a dye and the infrared light has a wavelength selected based on an excitation wavelength of the dye.

[0052] 18. The optical system of technical solution 4, wherein the infrared light has a wavelength in the near infrared.

[0053] 19. The optical system of technical solution 4, wherein the pixelated light source is one of a microLED, OLED, LCoS, digital micromirror device (DMD), or laser scanner.

[0054] 20. The optical system of technical solution 4, wherein the illumination path is used to produce an illumination field for illuminating the sample, the projection path is used to produce a projection field for projecting visible light towards the sample, and the first beam splitter is configured to combine optical axes of the illumination path, the imaging path, and the projection path such that the illumination field and the projection field overlap.

[0055] 21. A method for image acquisition and projection, comprising; illuminating an object with infrared light to cause the object to emit fluorescence light; acquiring an image by capturing the fluorescence light using an imaging sensor; activating elements of a pixelated light source based on information extracted from the image; and projecting, towards the object and using visible light produced by the activated elements, a pattern associated with the image.

[0056] 22. The method of technical solution 21, wherein the method is implemented using an optical system comprising: an illumination path including a first lens configured to receive the infrared light and to direct the infrared light towards a sample; an imaging path including; a first beam splitter, a second lens configured to receive the fluorescence light and to direct the fluorescence light towards the first beam splitter, and an imaging sensor configured to capture the fluorescence light after passing through the first beam splitter; and a projection path including a pixelated light source configured to project the pattern, the pattern associated with the fluorescence light captured by the imaging sensor, the visible light passing through both the first beam splitter and the second lens.

[0057] 23. The method of technical solution 21, wherein the acquiring and the projecting are performed repeatedly at a particular rate.

[0058] 24. The method of technical solution 21, wherein the object is treated with a dye and the infrared light has a wavelength selected based on an excitation wavelength of the dye.

[0059] 25. The method of technical solution 22, wherein the optical system is embodied as a handheld device and the method further comprises pointing the handheld device towards the object.

[0060] 26. The method of technical solution 21, wherein the method further comprises selecting a color in the visible range for projecting the pattern.

[0061] 27. The method of technical solution 21, wherein the pattern is produced by thresholding the image and using a particular color or combination of colors to project the pattern.

[0062] Various components may be controlled or various operations may be performed via implementations using a processor / controller that is configured to include, or be coupled to, a memory that stores processor executable code that causes the processor / controller carry out various computations and processing of information. The processor / controller can further generate and transmit / receive suitable information to / from the various system components, as well as suitable input / output (IO) capabilities (e.g., wired or wireless) to transmit and receive commands and / or data. The processor / controller may, for example, provide signals to control the operation of various components such as light sources and detectors that are disclosed herein.

[0063] Various information and data processing operations described herein may be implemented in one embodiment by a computer program product, embodied in a computer- readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), cloud storage, etc. Therefore, the computer-readable media that is described in the present application comprises non- transitory storage media. Generally, program modules may include routines, programs, objects, omponents, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures representsexamples of corresponding acts for implementing the functions described in such steps or processes.

[0064] 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.

Claims

What is claimed:

1. An optical system for image acquisition and projection, comprising: an illumination path including a first lens configured to receive infrared light and to direct the infrared light towards a sample; an imaging path including: a first beam splitter, a second lens configured to receive fluorescence light produced by the sample in response to illumination by the infrared light and to direct the fluorescence light towards the first beam splitter, and an imaging sensor configured to capture the fluorescence light after passing through the first beam splitter; and a projection path including a pixelated light source configured to project an image towards the sample using visible light, the image associated with the fluorescence light captured by the imaging sensor, the visible light passing through both the first beam splitter and the second lens.

2. The optical system of claim 1, wherein the illumination path includes an infrared light source operable to generate the infrared light, and the first lens is positioned to receive the infrared light from the infrared light source and to provide uniform illumination of the sample by the infrared light.

3. The optical system of claim 1, wherein the first beam splitter is configured to combine the projection path and the imaging path such that the projection path and the imaging path are coaxial.

4. The optical system of claim 1, wherein the projection path includes a third lens positioned between the first beam splitter and the pixelated light source, the imaging path includes a fourth lens positioned between the first beam splitter and the imaging sensor, andthe first beam splitter is positioned to split a portion of the imaging path and projection path that otherwise form a common path.

5. The optical system of claim 4, wherein the second lens and the fourth lens each have a predetermined magnification, wherein the predetermined magnification is selected based on a size of the imaging sensor.

6. The optical system of claim 4, wherein magnification provided by a combination of the second lens and the third lens is selected to provide a size of the image projected on the sample to substantially match a size of an image produced by the imaging sensor based on the captured fluorescence light.

7. The optical system of claim 6, wherein the magnification provided the combination of the second lens and the third lens is selected to substantially match a magnification provided the combination of the second lens and the fourth lens.

8. The optical system of claim 1, comprising a filter positioned in the imaging path having a bandpass that allows the fluorescence light produced by the sample to pass therethrough in the direction of the imaging sensor.

9. The optical system of claim 8, wherein the infrared light has a wavelength of 785 nm, and the filter is a long pass filter with a passband at 850 nm.

10. The optical system of claim 1, further comprising a processing unit in communication with the pixelated light source and the imaging sensor, wherein: the processing unit is configured to control illumination elements of the pixelated source, to cause the image to project towards the sample based on a pattern associated with the fluorescence light captured by the imaging sensor.

11. The optical system of claim 10, whereinthe imaging sensor is configured to produce a fluorescence image based on the captured fluorescence light, the processing unit is configured to generate a threshold image based on the fluorescence image and to provide information extracted from the threshold image to the pixelated light source, and the pixelated light source is configured to project the pattern based on the information.

12. The optical system of claim 10, wherein the illumination elements are configured to produce visible light of various colors.

13. The optical system of claim 1, including a folding mirror in the illumination path, and a second beam splitter that is common between the illumination, imaging and projection paths, wherein the folding mirror is positioned to receive the infrared light from the first lens and direct the infrared light towards the second beam splitter for illuminating the sample.

14. The optical system of claim 1, wherein the sample is treated with a dye and the infrared light has a wavelength selected based on an excitation wavelength of the dye.

15. The optical system of claim 1, wherein the infrared light has a wavelength in the near infrared.

16. The optical system of claim 1, wherein the pixelated light source is one of a microLED, OLED, LCoS, digital micromirror device (DMD), or laser scanner.

17. The optical system of claim 1, wherein the illumination path is used to produce an illumination field for illuminating the sample, the projection path is used to produce a projection field for projecting visible light towards the sample, and the first beam splitter is configured to combine optical axes of the illumination path, the imaging path, and the projection path such that the illumination field and the projection field overlap.

18. A method for image acquisition and projection, comprising: illuminating an object with infrared light to cause the object to emit fluorescence light; acquiring an image by capturing the fluorescence light using an imaging sensor; activating elements of a pixelated light source based on information extracted from the image; and projecting, towards the object and using visible light produced by the activated elements, a pattern associated with the image.

19. The method of claim 18, wherein the method is implemented using an optical system comprising: an illumination path including a first lens configured to receive the infrared light and to direct the infrared light towards a sample; an imaging path including: a first beam splitter, a second lens configured to receive the fluorescence light and to direct the fluorescence light towards the first beam splitter, and an imaging sensor configured to capture the fluorescence light after passing through the first beam splitter; and a projection path including a pixelated light source configured to project the pattern, the pattern associated with the fluorescence light captured by the imaging sensor, the visible light passing through both the first beam splitter and the second lens.

20. The method of claim 18, wherein the acquiring and the projecting are performed repeatedly at a particular rate.

21. The method of claim 18, wherein the object is treated with a dye and the infrared light has a wavelength selected based on an excitation wavelength of the dye.

22. The method of claim 19, wherein the optical system is embodied as a handheld device and the method further comprises pointing the handheld device towards the object.

23. The method of claim 18, wherein the method further comprises selecting a color in the visible range for projecting the pattern.

24. The method of claim 18, wherein the pattern is produced by thresholding the image and using a particular color or combination of colors to project the pattern.

Images