JP7536028B2 - Tissue detection system and method of use thereof - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62/810,510, filed February 26, 2019, No. 62/823,252, filed March 25, 2019, and No. 62/840,609, filed April 30, 2019, which are hereby incorporated by reference in their entireties.

The present technology generally relates to a tissue detection system and method of use for detecting and allowing a user to efficiently identify a surgical area of interest in a human body having area(s) that are not visible or not easily visible to the human eye by illuminating and stimulating the area(s).

In many processes, including surgery, the area(s) of interest within a region of the human body may not be visible to the eye of the person performing the process, although these areas may be detectable by other means. However, fluorescence may be used to identify areas of a region of the human body that contain the area(s) of interest for surgery. Some materials may exhibit fluorescence at non-visible wavelengths. Other areas of interest may have too low contrast with the human eye to be easily visible. Thus, there is a need for a tissue detection system and method of use thereof to detect non-visible or not easily visible areas targeted for the purpose of such stimulation by stimulating fluorescence in the area(s) of interest in the human body, and to efficiently identify these areas of interest.

The technology disclosed herein generally relates to tissue detection systems and methods of use thereof.

In one aspect, the present disclosure provides a tissue detection system for locally stimulating fluorescence in a surgical field and identifying fluorescent areas in the surgical field, the system comprising: a probe having a distal end, the distal end configured to be placed in contact or near contact with tissue material of interest in the surgical field; at least one emitter and at least one emitter optical fiber, the at least one emitter configured to emit radiation to stimulate fluorescence in the tissue material of interest, the at least one emitter optical fiber coupled to the at least one emitter and extending through at least a portion of the probe; and at least one detector and at least one detector optical fiber, the at least one detector configured to detect fluorescence from the tissue material in the surgical field of interest, the at least one The detector optical fiber includes at least one detector and at least one detector optical fiber coupled to the at least one detector and extending through at least a portion of the probe, and a controller and a user interface coupled to the emitter and the detector, the controller configured to initiate operation of the at least one emitter and the at least one detector, and the user interface configured to provide feedback to an operator regarding operation of the tissue detection system, and the distal ends of the at least one emitter optical fiber and the at least one detector optical fiber are juxtaposed with the distal end of the probe, the at least one emitter optical fiber configured to transmit radiation from the emitter to the distal end, and the at least one detector optical fiber configured to transmit a signal corresponding to the fluorescent light to the detector.

In another aspect, the present disclosure provides a tissue detection system for locally stimulating fluorescence in a surgical field and identifying fluorescent areas in the surgical field, the system including a probe having a distal end, the distal end configured to be placed in contact or near contact with tissue material of interest in the surgical field, at least one emitter and at least one emitter optical fiber, the at least one emitter configured to emit radiation to stimulate fluorescence in the tissue material of interest, the at least one emitter optical fiber coupled to the at least one emitter and extending through at least a portion of the probe, and a tissue detection system for detecting fluorescence from tissue material in the surgical field of interest. and at least one camera configured to emit fluorescence from the at least one emitter and the at least one camera; and a controller and a user interface coupled to the emitter and the detector, the controller configured to initiate operation of the at least one emitter and the at least one camera, and the user interface configured to provide feedback to an operator regarding operation of the tissue detection system, the distal end of the at least one emitter optical fiber is collocated with the distal end of the probe, the at least one emitter optical fiber is configured to transmit radiation from the emitter to its distal end, the at least one camera is spaced above the surgical area, and the at least one camera detects fluorescence over a wide field of view.

In yet another aspect, the present disclosure provides a method of tissue detection and surgery using a tissue detection system, the method comprising: positioning a distal end of a probe of the tissue detection system in contact or near contact with a target tissue material; generating radiation using at least one emitter, the at least one emitter coupled to at least one emitter optical fiber, the at least one emitter optical fiber extending through at least a portion of the probe to the distal end of the probe; and transmitting radiation through the at least one emitter optical fiber to the target tissue material. transmitting radiation from at least one emitter at the distal end of the probe to stimulate fluorescence of the target tissue material using radiation from at least one emitter at the distal end of the probe; detecting the stimulated fluorescence using at least one detector, the at least one detector being connected to at least one detector optical fiber, the at least one detector optical fiber extending through at least a portion of the probe to the distal end of the probe; identifying the target tissue material using the detected stimulated fluorescence; and removing the target tissue material during surgery after identifying the target tissue material.

The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the technology described in this disclosure will become apparent from the specification and drawings, and from the claims.

1 is an overview of a tissue detection system showing the tissue detection system in relationship to a patient and a user, with the patient's internal areas enlarged and the locations of the internal areas shown for reference. FIG. 2 is a partial block diagram illustrating tissue detection. 2B shows an enlarged distal end of a probe of the tissue detection system of FIG. 2A. FIG. 1 is a perspective view showing an endoscopic probe for use in a tissue detection system. FIG. 3B shows an enlarged distal end of the endoscopic probe of FIG. 3A. 1 is an overview of a tissue detection system in which a camera is used, showing the tissue detection system and camera in relationship to the patient and user, with an internal area of the patient zoomed in and the location of the internal area indicated for reference. FIG. 1 is a block diagram of a tissue detection system illustrating the use of a camera and corresponding lens. FIG. 1 is a block diagram of a tissue detection system illustrating the use of a near-infrared camera and corresponding lens. 1 is a flow chart illustrating a method for tissue detection. 1 is a flow chart illustrating a calibration method to facilitate tissue detection. FIG. 1 is a block diagram of a tissue detection system using a near-infrared camera with pixel-by-pixel demodulation. FIG. 1 is a block diagram of a tissue detection system with pixel-by-pixel demodulation using a camera and a near-infrared camera.

As described below, devices and methods are provided for stimulating fluorescence via illumination of an area(s) of interest in the human body, detecting non-visible or not readily visible areas of interest for such stimulation, and efficiently identifying these areas of interest. Tissue detection systems and methods of using tissue detection systems are used to facilitate such stimulation, detection, and identification. As discussed below, embodiments of tissue detection systems are used to stimulate fluorescence in tissues of interest and to quickly and conveniently detect fluorescence from those tissues of interest.

In some embodiments of the tissue detection system, the emitter and detector may be placed in direct or near contact with potentially fluorescent tissue material in the area(s) of interest such that stimulation and detection are performed in a confined area. For illustrative purposes, the emitter and detector may be separate from or part of the probe, with or without optical fiber, and the probe may be positioned in contact or in close proximity within the area(s), where fluorescence in the area(s) may be stimulated with the emitter, and if such fluorescence exceeds a threshold, the fluorescence in the area(s) may be detected with the detector. In some embodiments, the emission and detection are in the near infrared (IR) spectral band, which may be selected to stimulate and detect fluorescence in, for example, parathyroid tissue.

A method of using autofluorescence to distinguish parathyroid material from thyroid material or other tissues in the neck region is described in U.S. Application No. 13/065,469, which is incorporated herein by reference in its entirety. U.S. Application No. 13/065,469 discloses that when exposed to radiation in a narrow wavelength range around 785 nm, just outside the visible range, both the thyroid and parathyroid glands autofluoresce in a wavelength range above 800 nm and in some cases centered around 822 nm. The wavelength range above 800 nm is also not visible, and the fluorescence intensity of parathyroid material is significantly higher than that of thyroid material.

This difference in the relative amounts of fluorescence can be used to distinguish tissues of interest for surgery (e.g., parathyroid material, thyroid material, and other tissues in the neck region). By way of illustration, even if the general location of the parathyroid material is known, the parathyroid material can be difficult to distinguish visually and accurately enough for surgery, which can be problematic in surgical procedures requiring identification of the parathyroid material.

The tissue detection systems 10, 10', and 10" and methods of using the tissue detection systems 10, 10', and 10" disclosed herein may be applicable to surgical procedures requiring tissue identification. The tissue detection systems 10, 10', and 10" may be used to identify tissue, such as, for example, parathyroid material, thyroid material, and other tissue in the neck region to facilitate removal during surgery. In other words, tissue identification by the tissue detection systems 10, 10', and 10" allows for the identification of tissue material using positive or negative identification of the tissue. Once identified (via positive or negative identification), the tissue material may be removed during surgery.

As shown in FIG. 1, tissue detection system 10 includes probe 100, controller 140, and user interface 150. Controller 140 and user interface 150 can be combined with one another or separate from one another, and controller 140 and/or user interface 150 can include a display (such as display 210 from FIGS. 5A and 5B) for displaying images, such as a video, created using tissue detection system 10.

As shown in FIG. 1, the probe 100 may be positioned by an operator O relative to a patient P accommodated on an operating table 160. FIG. 1 illustrates the probe 100 positioned by the operator O to contact or be brought into close proximity with potentially fluorescent tissue material, such as parathyroid material 300, of the patient P during surgery. Thus, according to an embodiment of the present disclosure, the tissue detection system 10 may be used to detect (via positive or negative identification) parathyroid material 300 in the exposed internal neck region of the patient P during surgery.

Identification of parathyroid material 300 is an example of a process by which an operator O, e.g., a surgeon, nurse, surgical assistant, or other operating room individual, may use tissue detection system 10 to facilitate the performance of surgery in an area(s) of interest where the area(s) of interest cannot be seen by eye. In the case of identification of parathyroid material, parathyroid material is not visible because it fluoresces in the near infrared. The fluorescence intensity of adjacent thyroid material, etc., differs from that of parathyroid material. Thus, tissue material that is parathyroid material (positive identification) can be identified from tissue material that is not parathyroid material (negative identification). Thus, the probe 100 may be used in combination with the controller/user interface 140/150 to tactilely identify the area of interest. Specific parameters suitable for parathyroid tissue, including stimulation and detection, are described below, but the basic concepts disclosed may be applied to other applications where fluorescence may be stimulated.

2A shows additional elements of the tissue detection system 10. The probe 100 may include one or more probe bodies 130, which in some embodiments may be tubular in shape or of some other shape that is conveniently handheld and may be made of a variety of possible materials, including metal, plastic, and/or composites, among others.

2A, a single probe body 130 is provided, and the tissue detection system 10 also includes emitter(s) 105 coupled to emitter optical fiber(s) 115 and detector(s) 110 coupled to detector optical fiber(s) 120, respectively. The emitter 105 may be configured to emit radiation at a selected wavelength to stimulate fluorescence in the region of interest via rotation and/or device selection, and an optical element 125 may be provided to modify the radiation emitted from the emitter 105 to be lower or higher via filtering. Additionally, the detector 110 is configured to process the radiation captured by the probe 100. In the case of parathyroid material identification, the emitter 105 (with or without the use of the optical element 125) emits radiation at a wavelength of about 785 nm to facilitate autofluorescence of the parathyroid material, and the detector 110 is configured to process radiation captured by the probe 100 at wavelengths in the range of 808-1000 nm where the parathyroid material autofluoresces.

The emitter 105 and the detector 110 can be separate from or part of the probe body 130. The probe body 130 includes a distal end 135 (FIG. 2B), with at least a portion of the emitter optical fiber(s) 115 extending at least through the probe body 130 to facilitate transmission of radiation from the emitter 105 to the distal end 135 of the probe body 130, and at least a portion of the detector optical fiber(s) 120 extending at least through the probe body 130 to facilitate capture and transmission of radiation from the distal end 135 of the probe body 130 to the detector 110. As shown in FIG. 2B, the emitter optical fiber(s) 115 and the detector optical fiber(s) 120 can terminate at the distal end 135 of the probe body 130. However, other arrangements, such as multiple fibers in multiple bundled probe bodies, may also be suitable. In either case, the emission and detection fibers can terminate together or close to each other at the distal end 135 of the probe body 130.

The controller 140 can be used to control the transmission of radiation from the emitter 105 and the detection of radiation at the detector 110, and the user interface 150 can be used to interact with and control the operation of the controller 140. In use, the emitter 105 (through control using the controller/user interface 140/150) is configured to deliver selected radiation to stimulate fluorescence through the emitter optical fiber(s) 115 to the distal end 135 of the probe body 130 together with the optical element(s) 125 (such as one or more optical lenses and/or filters, etc.). In use, the detector 110 (through control using the controller/user interface 140/150) is configured to detect collected radiation through the detector optical fiber(s) 120 to the distal end 135 of the probe body 130 together with the optical element(s) 125. Although optical element(s) 125 are provided at the end of the probe body 130 in FIG. 2A, other arrangements for filtering in the fiber coupling, or the emitter and detector themselves, are possible. Additionally, the user interface 150 may include switches (not shown), for example in the form of hand or foot switches, for initiating emission of illumination and detection of fluorescence from the emitter 105 and detector 110, respectively. Additionally, there may be an audio and/or visual indication that a suitable fluorescence signal has been detected.

During surgical use, the distal end 135 of the probe body 130 is in physical contact or near contact (i.e., within at least 1-2 cm) with potentially fluorescent tissue material in a region of interest within the body, and the operator O via the user interface 150 instructs the controller 140 to perform both emission and detection when the distal end 135 of the probe body 130 is in contact or near contact with the surface of the region of interest. The detected fluorescent signal for the tissue of interest is then compared to a threshold fluorescent signal for a reference tissue to determine whether the detected fluorescent signal indicates the presence of the reference tissue. The emitter optical fiber(s) 115 and the detector optical fiber(s) 120 terminate at the distal end 135 of the probe body 130 in a small area, approximately the size of the fiber end(s), which allows for precise identification of the tissue of interest when the small area is in contact or near contact with the surface, as the area exposed to illumination/stimulation and detection is very small.

For parathyroid material identification, the emitter 105 may be a narrowband light source, such as a solid-state laser, laser diode, or other suitable light source, whose radiation output wavelength, through a combination of tuning, device selection, and/or filtering using the optical element(s) 125, is at or near 785 nm in a narrow band. The detector 110 may be a 2D array of avalanche photodiodes or other near infrared or IR detectors, which may be used in concert with demodulation, for example, using a high-pass (or long-pass) optical filter (of the optical element(s) 125), such that radiation with wavelengths higher than the source wavelength (e.g., greater than 800 nm, in the range of 808-1000 nm) is detected. The radiation wavelength output by the emitter 105 (through the use of tuning, device selection, and/or filtering using the optical element(s) 125) may be altered to be lower or higher than that used for parathyroid material 300 identification to facilitate identification of other tissue materials.

One advantage of contacting the surface of the region of interest with a small area at the distal end 135 of the probe body 130 (where the emitter optical fiber(s) 115 and detector optical fiber(s) 120 terminate) is that the optical signal is not affected by ambient light, which in the case of an operating room can have a significant near-infrared component. Resistance to such ambient light can be further increased by modulating the emitter radiation and collecting the fluorescent signal using phase-locking techniques such as lock-in detection or FFT (Fast Fourier Transform) techniques.

As shown in FIG. 3A, the tissue detection system 10 or at least the probe 100 may be integrated with an endoscopic probe 170. In this arrangement, the endoscopic probe 170 includes an endoscopic camera 175, an endoscopic probe body 180, and the emitter optical fiber(s) 115 and the detector optical fiber(s) 120 are brought to the endoscopic probe body 180 and integrated with the endoscopic optics 185 at least at the distal end 190 (FIG. 3B) of the endoscopic probe body 180. The endoscopic probe body 180 includes a lumen 195 extending therethrough that terminates at the distal end 190, and the endoscopic camera 175 can visualize the area of interest adjacent the distal end 190 via the lumen 195. This allows probing to be performed using the endoscopic camera 175 as a guide to position the distal end 190 of the endoscopic probe body 180, and accordingly supports the use of a much smaller area that needs to be surgically opened.

Probing using the tissue detection system 10 may be enhanced by using an external camera 200, which can be used as a detector to capture radiation from fluorescent tissue of interest, as shown in FIG. 4. Using an external camera 200 with the tissue detection system 10 may provide increased illumination and clarity as opposed to visually indicating the operation of the tissue detection system 10, because the external camera 200 can indicate potentially fluorescent tissue material over a wider field of view. Whereas using only the tissue detection system 10 and the probe 100 would require visual identification of potential candidates for potentially fluorescent tissue material, the use of the probe 100 facilitates providing confirmatory information via the fluorescence of potential candidates. By using the external camera 200 in combination with the probe 100, the imaging area provided by the external camera 200 can be used to identify potential fluorescent tissue material candidates over a wider field of view, and then the probe 100 can be used for confirmation via fluorescence information obtained from each of the potential fluorescent tissue material candidates by bringing the probe into contact or near contact with the surface of the potential fluorescent tissue material. The external camera 200 provides a level of image contrast that may be useful but not conclusive, while the probe 100 can be used to provide highly sensitive and quantitative measurements in each of the potential fluorescent tissue materials, with the distal end 135 of the probe body 130 positioned in contact or near contact therewith to obtain and measure a conclusive indication of fluorescence. Thus, combining the use of the tissue detection system 10 and the probe 100 with the external camera 200 can provide a powerful solution for identifying the areas of highest fluorescence.

5A illustrates another arrangement of the tissue detection system 10 using a camera, including an endoscopic camera 175, an external camera 200, or the like, in which the camera optics 205 (such as one or more optical lenses and/or filters, etc.) and a display 210 (such as a computer monitor/screen) are used with the tissue detection system 10 using the probe 100 and the controller/user interface 140/150. Although not shown in FIG. 5A, the emitter 105 may be inserted between the controller/user interface 140/150, which may be used to control the operation of the endoscopic camera 175, the external camera 200, and the display 210. Additionally, the display 210 may be separate from or integrated with the controller 140 and/or the user interface 150.

5B illustrates a schematic representation of yet another arrangement of tissue detection system 10 using an alternative probe 220 and an alternative camera 225 embodiment, where probe 220 provides illumination only and detection is by camera 225. Probe 220 is a handheld flexible illumination probe that can be positioned by operator O in contact or near contact with the surface of potentially fluorescent tissue material. Additionally, camera 225 is used as a detector to capture radiation from the fluorescent tissue of interest. Although not shown in FIG. 5B, emitter 105 can be interposed between controller/user interface 140/150, which can be used to control the operation of camera 225 and display 210. Additionally, display 210 can be separate from or integrated with controller 140 and/or user interface 150.

The probe 220 can be in contact or near contact with the potentially fluorescent tissue material or at any desired angle to the tissue in which the fluorescence is excited. The use of the probe 220 allows for illumination/stimulation of areas of interest that illumination would not normally reach. However, the fluorescence stimulated in the tissue of interest may be difficult to see with the detector optical fiber(s) 120 incorporated in the probe body 130. An example of this could be a sub-surface area where the fluorescence is usually too weak to be detected by the detector optical fiber(s) 120. Another example could be fluorescing tissue material at or just outside the boundary of the field of view of the detector optical fiber(s) 120. The probe 220 brings the light source closer to the area of interest, which in turn increases the emitted fluorescence, allowing the camera 225 to see and capture it. The external camera 225 can point to the potentially fluorescent tissue material over a wider field of view that includes the entire area of interest. The probe 220 can include only the illumination fiber, and as few as one fiber, selected to maximize the penetration of radiation therefrom. The illumination fiber(s) may also have one or more lenses and/or filters, etc., at its end(s) (ultimately directed toward the tissue) that can filter out any fluorescence emitted by the fiber material in response to illumination.

When illumination/stimulation is accomplished with a handheld illumination probe 220, but detection is accomplished by viewing an image of the entire area of interest, e.g., using a camera 225, the problem of background light, e.g., from operating room lighting, is different than when illumination and detection are both accomplished at the distal end 135 of the probe 100. The camera 225 is essentially equivalent to multiple detectors in parallel, and the area of fluorescence can be anywhere within the imaged area, so the demodulation techniques described above cannot be directly applied.

6 illustrates one embodiment of a method for using the tissue detection system 10. Beginning at 20, a probe 100 is provided, including emitter optical fiber(s) 115 extending therethrough to a distal end of a probe body 135, and detector optical fiber(s) 120. At 22, an operator O receives an indication (visual or otherwise) that the distal end 135 of the probe body 130 is in contact or near contact with a surface of potentially fluorescent tissue material. At 24, the potentially fluorescent tissue material is illuminated with radiation from the emitter 105 via the optical element(s) 125 and the emitter optical fiber(s) 115. At 26, the fluorescence (if any) is detected by the detector 110 via the optical element(s) 125 and the detector optical fiber(s) 120. At 28, the controller 140 and/or the user interface 150 can provide an indication if the fluorescence detected by the detector 110 exceeds a threshold. Steps 24, 26, and 28 can also be performed using other embodiments disclosed herein.

7 illustrates one embodiment of a method used to calibrate the tissue detection system 10. First, at 30, the distal end 135 of the probe body 130 is positioned at various locations on the surface of the potentially fluorescent tissue material. At 32, emission and detection using the emitter 105 and detector 110, respectively, are initiated at each of the various locations. Detected fluorescence signals corresponding to the detected fluorescence (if any) are acquired by the controller 140. At 34, the controller 140 discards any data corresponding to the detected fluorescence signals that are outside of a predetermined range. At 36, a threshold level is statistically derived from the remaining data of the corresponding detected fluorescence signals. Thus, using such a calibration, threshold levels of potentially fluorescent tissue material and other tissues that are clearly different from potentially fluorescent tissue material can be obtained. These threshold levels can be used to calculate a ratio, and the controller 140 and/or the user interface 150 can provide an indication if the ratio is lower or higher than the threshold ratio. Steps 32, 34, and 36 may also be performed using other embodiments disclosed herein.

8, an alternative embodiment of a tissue detection system generally referred to by the numeral 10' is shown. The tissue detection system 10' includes an emitter 230 (which may be similar to the emitter 105), such as a solid-state laser, laser diode, or other suitable light source that can be configured to emit radiation at a selected wavelength, which can be modulated by a modulator 235 to change the emitted radiation to a lower or higher wavelength. The modulator 235 can be of various types, such as a chopper, a Pockels cell, an acousto-optical modulator, or other light modulation device. The modulated emitter signal is delivered from the emitter 230 through the modulator 235 to a probe 240 (which may be similar to the alternative probe 220), and the modulated probe signal from the probe 240 is applied to the area of interest. A near-infrared camera 245 then views the area of interest, with or without the use of camera optics 250 (such as one or more optical lenses and/or filters, etc.). The near-infrared camera 245 can be used as a detector to capture radiation from the fluorescent tissue of interest. The signal from the near-infrared camera 245 may pass through a demodulator 255, which may also use the modulator frequency from the modulator 235 as an input, before the demodulated signal from the demodulator 255 is passed to the display 260. Like the display 210, the display 260 may be separate from or integrated with the controller 140 and/or the user interface 150.

The demodulator 255 may be in the form of a high speed digital processor, such as a graphics or game processor, or an FPGA (field programmable gate array) capable of implementing a number of high speed parallel processing algorithms. Successive frames of images from the near infrared camera 245 are subjected to a pixel-by-pixel demodulation function, i.e., each pixel is demodulated by a high speed parallel processor by the demodulator. The pixel-by-pixel demodulation function may include digital lock-in to the modulation frequency or Fourier transform demodulation.

A rolling window of demodulated video frames may be continuously passed from the demodulator 255 to the display 260 for display, resulting in real-time demodulated video with little start-up delay, very high gain of the emitted light stimulated by the modulated probe signal, and significant rejection of background illumination from, for example, operating room lighting.

In one embodiment, near-infrared camera 245 may include outputs directly corresponding to the fluorescence detected by each detector in the camera imaging array of near-infrared camera 245. In this case, the intensity values of the detected fluorescence may be analyzed pixel by pixel, and the demodulation function may be performed in parallel in a high speed digital processor of demodulator 255. In one embodiment, an Nvidia Tegra processor may be programmed to analyze hundreds of pixels in parallel at video rates to perform a digital lock-in operation.

9, an alternative embodiment of a tissue detection system is shown, referenced by the numeral 10″. The tissue detection system 10″ is similar to the tissue detection system 10′, but instead the tissue detection system 10″ may employ a standard video camera 270 (which may employ camera optics 205) and a near-infrared camera 275 (which may employ camera optics 250), both of which image the same area of interest. The near-infrared camera 275 may be used as a detector to capture radiation from the fluorescent tissue of interest. In this embodiment, pixel lock-in is performed on the output from the near-infrared camera 275 by the demodulator 255, and pixels that meet a predetermined criteria are mixed with the output from the standard video camera 270 by the demodulator 255 to generate a video highlight from the standard video camera 270 for pixels that exhibit fluorescence in the image that is ultimately displayed on the display 260.

Various aspects of the embodiments may include computing devices that execute software routines, e.g., devices including computers and personal electronic devices, as well as any combination of processing elements and memory, which may include programmable electronics, logic circuits, and other electronic implementations. Various combinations of optical elements, including lasers, LEDs, and other light sources, filters, lenses, mirrors, beam splitters, and the like, may be employed. The details of the optical, electronic, and processing embodiments described herein are exemplary and are not intended to be limiting, as alternative approaches using other combinations of similar elements may be used to achieve the same results in essentially the same manner.

It should be understood that the various aspects disclosed herein can be combined in different combinations than those specifically presented in the description and accompanying drawings. It should also be understood that certain acts or events of any of the processes or methods described herein may be performed in different orders, or may be added, combined, or omitted entirely (e.g., not all described acts or events may be necessary to perform the techniques). In addition, while certain aspects of the disclosure are described as being performed by a single module or unit for clarity, it should be understood that the techniques of the disclosure may be performed by a combination of units or modules associated with, for example, a medical device.

Claims (8)

1. A tissue detection system for locally stimulating fluorescence within a surgical field and identifying areas of fluorescence within the surgical field, comprising:
a probe having a distal end, the distal end configured to be placed in contact or near contact with tissue material of interest in the surgical field;
at least one emitter and at least one emitter optical fiber, the at least one emitter configured to emit radiation for stimulating fluorescence in the tissue material of interest, the at least one emitter optical fiber coupled to the at least one emitter and extending through a portion of the probe;
at least one detector and at least one detector optical fiber, the at least one detector configured to detect fluorescence from the tissue material in the surgical field of interest, the at least one detector optical fiber coupled to the at least one detector and extending through at least a portion of the probe;
a controller and a user interface coupled to the emitter and the detector, the controller configured to initiate operation of the at least one emitter and the at least one detector, and the user interface configured to provide feedback to an operator regarding operation of the tissue detection system;
a distal end of the at least one emitter optical fiber and the at least one detector optical fiber are juxtaposed with the distal end of the probe, the at least one emitter optical fiber configured to transmit the radiation from the emitter to the distal end thereof, and the at least one detector optical fiber configured to transmit a signal corresponding to the fluorescent light to the detector.
In a tissue detection system,
at least one modulator configured to modulate the radiation from the emitter and at least one demodulator configured to demodulate the signal corresponding to the fluorescent light.
Tissue detection system . The tissue detection system of claim 1, wherein the target tissue material is parathyroid tissue. The tissue detection system of claim 2, wherein the emitter comprises a narrowband radiation source having a frequency centered at 785 nm ± 10 nm. The tissue detection system of claim 3, further comprising a filter to further limit an emitter bandwidth, the emitter being a solid-state laser or a laser diode. The tissue detection system of claim 4, wherein the detector is a near-infrared camera having a high-pass filter configured to pass wavelengths of light that exceed the emitted wavelength of the emitter. The tissue detection system of claim 5, wherein the high-pass filter is configured to pass optical wavelengths greater than 800 nm. The tissue detection system of claim 1, wherein the probe is part of an endoscopic probe system. The tissue detection system of claim 1 , wherein the signal corresponding to the fluorescence is demodulated by the demodulator on a pixel-by-pixel basis.