The present invention relates in general to devices for diagnosing tissue via detecting spectra and the linking of those devices to a therapeutic modality for the concurrent diagnosis and treatment of abnormal tissue.
Surgical excision of neoplastic tumor tissue has historically been performed manually using steel blades and lasers. In recent years, robotic devices have been employed to assist the surgeon. Currently, many surgeons advocate the use of the Mohs technique to diagnose and remove malignant tissues. The Mohs technique includes taking a mapped specimen of tumor tissue, staining the tissue, and evaluating the tissue under a microscope to determine the amount and location of the residual tumor cells. In particular, the area with the tumor is marked and frozen with a local anesthetic. The tissue is surgically removed, divided and mapped with reference points on the patient. The slides of the frozen sections are analyzed by the surgeon. If any section of the slide contains tumor, the map guides the surgeon to the precise location where the tumor root remains. This process is repeated until no tumor is seen on the slides. There are many disadvantages to this treatment system. There may be unnecessary tissue removal and cosmetic damage. Lengthy treatment sessions are necessary due to the manual viewing and determination of cancer cells within each layer removed. Freezing of tissue samples may also be required, which can affect the accuracy of the analysis. A simpler, more efficient and concurrent method of diagnosis and removal of abnormal tissue would represent a significant enhancement for patient care.
Disclosed herein are embodiments of a medical device for diagnosing and treating anomalous tissue. Selected embodiments are summarized here. In one embodiment the medical device comprises an energy source configured to emit at least an excitation beam and a therapeutic beam, a probe coupled to the energy source and configured to propagate the excitation and therapeutic beams with the beams capable of contact with the tissue, a sensor coupled to the probe that detects at least one predefined attribute of radiation emanating from the tissue when the tissue is subjected to the excitation beam and a controller coupled to the energy source and the sensor and programmed to selectively alternatively actuate the energy source to emit the excitation beam and the therapeutic beam in response to the detection of the at least one predefined attribute by the sensor.
In another embodiment, the medical device comprises a probe, a spectrometer coupled to the probe, a database of tissue fingerprints, a controller coupled to the probe and the spectrometer and a first energy source coupled to the probe and configured to emit one or more of a diagnostic excitation, a therapeutic ablation and a diagnostic ablation as directed by the controller or a user on a target tissue. The first energy source delivers excitation energy through the probe to the tissue during the diagnostic excitation and the spectrometer receives a scatter from the diagnostic excitation and identifies the scatter against the database, the controller receiving a signal from the spectrometer of normal or abnormal. The first energy source can also deliver ablative energy through the probe to an anomalous target tissue during the therapeutic ablation depending on the signal and deliver ablative energy through the probe to normal target tissue during the diagnostic ablation depending on the signal.
In yet another embodiment, the medical device for diagnosing and treating anomalous tissue comprises an electromagnetic energy source, a Raman spectrometer, a central processing unit having a database of tissue fingerprints and a probe configured to deliver the electromagnetic energy to perform a diagnostic excitation, a therapeutic ablation and a diagnostic ablation in any order as directed by the controller or a user on a target tissue. The diagnostic excitation comprises delivering excitation electromagnetic energy from the electromagnetic energy source through the probe to the target tissue suitable to cause Raman scattering, collecting a Raman scatter produced by the target tissue with the probe and delivering the Raman scatter to the Raman spectrometer, fingerprinting the Raman scatter with the Raman spectrometer, comparing the fingerprint to the database of tissue fingerprints and determining if the target tissue is anomalous. The therapeutic ablation comprises delivering ablative electromagnetic energy through the probe from the electromagnetic energy source to an anomalous target tissue, and the diagnostic ablation comprises delivering ablative electromagnetic energy through the probe from the electromagnetic energy source to a normal target tissue. The therapeutic and diagnostic ablation source can be any combination of a coherent or incoherent electromagnetic energy source, electrosurgical generator or plasma scalpel.
Also disclosed are methods of diagnosing and treating anomalous tissue with the medical device. One such method comprises positioning a probe coupled to an energy source proximate a target tissue, delivering one of an excitation energy and an ablative energy through the probe from the energy source to the target tissue depending on a signal from a controller, capturing a scatter reflected from the target tissue with the probe when excitation energy has been delivered, relaying the scatter to a spectrometer and fingerprinting the scatter's spectra against a tissue fingerprint database in the controller and providing the signal from the controller to the energy source.
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
In the various figures, like reference numbers refer to like parts. The figures are exemplary and are not drawn to scale.
Medical device 10 with probe 70 can be used as follows. Probe 70 is positioned with its distal end relative to target tissue site 130. The positioning of probe 70 during a procedure can be, for example, within one to two millimeters of target tissue 130, or can contact target tissue 130. This distance is provided by way of example and not limitation, and any distance known to be practiced by those skilled in the art is contemplated. As used herein, the term “procedure” refers to any use of embodiments of the medical device on a patient. Referring to
Medical device 10 can be used to diagnose target tissue 130. The general tissue area targeted to undergo a procedure can be determined by any process known to those skilled in the art to assess tissue conditions. A non-limiting example can be a physician visually determining that a spot on skin is suspect and requires further assessment Another non-limiting example might be that the tissue is already known to be malignant, thus requiring removal. As used herein, “target tissue” is any tissue, whether normal, malignant, or denatured that is subject to diagnosis. Once probe 70 is positioned at target tissue 130, energy source 20 can be triggered to deliver an excitation beam through probe 70 to target tissue 130 (S1).
As used herein, the terms “energy” and “light” refers to ultraviolet, visible or infrared electromagnetic energy. However, it is to be understood that other appropriate forms of electromagnetic energy can be used by those skilled in the art. For example, a plasma scalpel as well as an electrosurgical device can be used with the medical device for therapeutic ablation.
The beam of diagnostic excitation energy can pass through lens 90 to focus the excitation energy if desired or required directly on target tissue 130 to be diagnosed. Probe 70 and/or conduit 50 can be, by way of example, a fiber optic made of quartz, sapphire, or other energy transmitting material with diameters in the range of about 100 μm to about 600 μm. Probe and/or conduit 50 can be any length required, and specifically can be two to four meters. Diagnostic excitation energy is that energy sufficient to deliver photons incident to target tissue 130 without damaging the tissue. Typical excitation wavelengths include 785 nm, 830 nm, 632.8 nm and 532 nm. Longer wavelengths, such as 1,064 nm, 980 nm and 810 nm can also be used, Depending on the focal spot size, the power to the tissue can be in the range of about 5 mw to about 500 mw. Focal beam diameters can be as small as 20 micrometers. The excitation power can vary depending upon the sensitivity of the spectrometer, the tissue spot size and the absorption characteristics of the tissue. Non-limiting examples of energy sources that can produce diagnostic excitation light with the appropriate strength include carbon dioxide, homium, Nd:YAG, diode, and argon. The use of lasers and other light sources known to those skilled in the art to produce the desired energy is also contemplated.
The photons of the diagnostic excitation beam incident on target tissue 130 produce at least on e predefined attribute of radiation, such as a scatter. The sensor 30 detects the at least one predefined attribute of radiation emanating from the tissue when the tissue is subjected to the excitation beam. By means of example and not limitation, embodiments herein will be described using Raman scatter as the at least one predefined attribute of radiation. The Raman scatter varies depending on the molecules found in target tissue 130. The incident photons can be collected by probe 70 and relayed to sensor 30 (S2). An example of a sensor for use with Raman scatter is a spectrometer. Probe 70 and/or collecting/sensing conduit 60 can be a fiber optic made of quartz (fused silica, or other optical materials well known in the art, similar to excitation/ablation conduit 50. Sensing conduit 60 is preferably a multimode fiber but can be a single mode fiber or fiber bundle. Its length should generally match that of conduit 50. As seen in
Spontaneous Raman scattering is typically very weak, and as a result, the weak scattered light should be separated from the intense Rayleigh scattered light. Rayleigh scattering is defined as the scattered light that is the same energy as the incident excitation light. To address this, the Raman scatter can be collected by first lens 100 and passes through filter 110 and second lens 120. First lens 100 directs the Raman scatter to filter 110, where the Rayleigh scatter is removed. Non-limiting examples of filters that can be used include long pass filters, edge filters, band pass filters, notch filters and diffraction gratings. The Raman scatter passing through filter 110 can be focused through second lens 120 to be collected by sensing light conduit 60. Sensing light conduit 60 carries the Raman scatter to spectrometer 30. Any suitable spectrometer can be used. A non-limiting example of a suitable spectrometer is the Perkin-Elmer RamanFlex 400 Fiber Optic Raman analyzer. It should be noted that the location of the filter 110 is not limited to that shown in
Spectrometer 30 receives the Raman scatter and can fingerprint the scatter. As used herein, “fingerprint” refers to the wavelength and intensity of the spectral distribution produced by spectrometer 30 that are associated with the scatter produced by the incident photons. The composition of target tissue 130 can be determined from the wavelength and intensity of the spectral distribution, or the fingerprint, produced by spectrometer 30.
The resultant fingerprint can be used to determine the composition of target tissue 130 (S3). This determination can be made by comparing the fingerprint to a memory or database of known fingerprints. The database, which can be populated by multivariate analyses of samples of tissue anomalies, normal tissue samples, and varying degrees of denatured tissue samples. As used herein, “denatured tissue samples” refer to either normal or malignant tissue that has been thermally denatured by varying degrees of ablation or have any degree of overlying char due to ablation, as denatured tissue will have a different pattern of scatter.
It is also contemplated that the actual fingerprint of the anomaly can be obtained during a biopsy and programmed into the computer for comparison during treatment with medical device 10. It is also contemplated that normal tissue fingerprint data can populate the database, and an anomalous fingerprint can be determined by variations from the normal tissue fingerprints. It is further contemplated that fingerprint data of denatured tissue be stored in the database and an anomalous fingerprint can be determined by comparison with the denatured fingerprint data as well. The memory or database can be configured to store each fingerprint. The fingerprints can be associated with the particular treatment session and/or added to the database for future use as desired or required. Display 80 can be configured to display the fingerprints as a virtual biopsy for documentation of anomalous tissue removed. It is also contemplated that the surgeon can view the fingerprint or virtual biopsy displayed and make the determination of normal or anomalous. The functions of the database are provided by way of example and not limitation, and other uses of the database well known in the surgical art are contemplated.
Controller 40, or surgeon where desired, determines based on the fingerprint of target tissue 130 whether target tissue 130 is anomalous or normal (S4). As used herein, the term “anomalous” or “anomaly” refers to that tissue which is desirable to remove. The anomaly can be, for example, cancer or precancerous lesions or abnormalities and other pathology. If the determination is made that the fingerprint of target tissue 130 is anomalous, then controller 40 actuates the energy source 20 to emit a therapeutic beam, initiating ablation of the target tissue 130 (S5). As used herein, an “anomalous fingerprint” can be a malignant fingerprint not yet ablated and a denatured anomalous fingerprint that has been one or more times ablated but not yet free of malignancy. Energy source 20, through probe 70, delivers ablative energy to that same target tissue 130 sufficient to ablate at least a portion of target tissue 130. This therapeutic ablative light delivered by energy source 20 may be delivered in one or a plurality of doses as desired or required, or in a continuous mode. One or both of the intensity of the dose and the duration of the dose may be varied as required to sufficiently ablate the anomalous tissue. As used herein, the term “ablate” refers to effectively removing the anomaly by separation or destruction by vaporization, evaporation, melting, or the like. Non-limiting examples of sources that can produce the therapeutic ablative with the appropriate strength are provided in Table 1. Energy source 20 can be used to deliver both the diagnostic excitation beam and the therapeutic beam as described, using appropriate wavelengths and irradiance depending on the trigger or signal received from the controller 40 or surgeon. It is also contemplated that separate energy sources can be used, one producing the diagnostic beam and another producing the therapeutic, or ablative, beam. Energy sources are not limited to light sources such as lasers and can be any light source known to those skilled in the art that is sufficient to achieve the results desired. One or more lenses can be used to focus the therapeutic laser energy on the target tissue to be ablated.
1Continuous Wave (CW) mode includes gating the laser to a predetermined duration (typically in the range of 0.1-2 sec) and frequency.
If the determination is made that the fingerprint of target tissue 130 is normal, the procedure can proceed differently depending on the required or desired result (S6). Probe 70 of medical device 10 can move to the next anatomical location (S7). The new target tissue can be directly adjacent to target tissue 130, or can be any other tissue site requiring attention. At the new target tissue, diagnosis will be performed in the same manner as discusses above, beginning with step S1.
It may be necessary to diagnose remaining target tissue 130 after the therapeutic ablation or to diagnose subcutaneous tissue below a tissue layer. A decision can be made by the controller 40 or surgeon to deliver ablative energy (S5) to the same target tissue 130 rather than move to another anatomical location (S7). If this decision is made, probe 70 may remain on target tissue 130 and controller 40 will trigger energy source 20 to ablate the tissue even though it has a normal fingerprint. In this case, the “diagnostic” ablation can be done, for example, to diagnose the tissue lying underneath the normal tissue. This step is particularly important when diagnosing and treating at the edges of abnormal masses to ensure the entire abnormality is removed. During this procedure, for example, the fingerprints of denatured tissue are used to determine normalcy or malignancy based on tissue that has been ablated one or more times. For example, with basal cell carcinomas, the malignant tissue can be hidden by normal tissue on the surface while the malignancy is growing underneath. Some anomalies may be known to be entirely under one or more layers of normal tissue, requiring the normal tissue to be removed to access the anomalous tissue. After ablating the normal target tissue 130, medical device 10 can then proceed to diagnosis (SI). As used herein, “normal target tissue” can be normal tissue or denatured normal tissue. As noted, whether to move to a new target tissue site or ablate the normal tissue can be decided by the surgeon before or during treatment. It is contemplated that controller 40 can be preprogrammed with specific dimensions or with a specific sequence of the steps described above. A non-limiting example of a programmed dimension is continued diagnosis until reaching one millimeter beyond and/or below the last anomalous fingerprint. A non-limiting example of a specific sequence might be to repeat the therapeutic sequence three times after an anomalous fingerprint and before performing another diagnosis. Any combination of diagnosis and therapeutic and diagnostic ablation can be programmed in controller 40 and used by one skilled in the surgical art. It is also contemplated that the surgeon can determine the necessary sequence during treatment or over ride a programmed sequence as required. Alternatively, a triggering device within or connected to controller 40 can initiate the necessary sequence based on pre-programmed information.
Display 80, shown in
Probe 70 of medical device 10 can be manually driven by the surgeon during treatment. Due to the minute scale and precise nature of the diagnosis and treatment, probe 70 can also be robotically driven. For example, a robot mechanism can be driven by 40 to precisely control the location of probe 70 during the treatment process. The robot mechanism can be, for example, an articulated robotic arm. Alternatively, the robotic apparatus can be an optical scanner. These robotic devices are provided by way of example and not limitation, and other robotic apparatus known in the art can be used to control the movement of the probe.
Probe 70 is not limited to the embodiment described above. Probe 70 can be configured with a specimen-engagement portion that physically contacts the target tissue to be diagnosed and/or treated. Another probe embodiment is shown in
Also shown in this embodiment is protective window 200 on the distal end of probe 170. Protective window 200 prevents debris from entering probe 170 and decreasing the life of the fiber optics. Protective window 200 can be made of quartz (fused silica), sapphire or a material known by those skilled in the art with similar optical characteristics. Protective window 200 is removable and easily cleaned or replaced as desired or required. Although protective window 200 is shown in
A third embodiment of a probe for use with medical device 10 is shown in
A fourth embodiment of a probe for use with medical device 10 is shown in
A fifth embodiment of a probe for use with medical device 10 is shown in
It is contemplated that other useful devices may be incorporated into the probe embodiments as desired or required. For example, a vacuum removal tube can be configured to remove debris from the tissue area after ablation has occurred. The vacuum tube can transmit the debris to a chamber (not shown) attached to the distal end. The chamber can be any specimen or waste container well known and used in the art. Alternatively to or in addition to the chamber, a gas spectrometer (not shown) can be connected to vacuum tube for spectrometric analysis of the tissue debris.
A camera may be incorporated into the medical device to capture images of the procedure or target tissue. The camera can be a still camera or a video camera as desired or required.
Another example that may be incorporated into the probe embodiments is an electrosurgical conduit. The electrosurgical conduit can contain an electrosurgical device configured as a cautery or hemostatic waveguide to maintain hemostasis after the target tissue has been ablated. The electrosurgical conduit can also contain a cutting or ablating device as desired or required. The end of the electrosurgical conduit opposite the target tissue can comprise, for example, a heat source to cauterize the treated tissue with heat or a caustic source to cauterize the treated tissue with caustic. These are provided by way of example and not limitation, and other cauterization devices known in the art may be used. The electrosurgical conduit can take the place of or be used in addition to a laser used to produce ablative energy. Controller 40 can be configured to control the electrosurgical conduit alone or in addition to an energy source.
The target tissue can be any tissue to which the probe of the medical device can reach, for example, skin tissue. Any of the probes disclosed herein can be located on the end of an endoscope, laparoscope, intervaginal probe, bronchoscope, cystoscope, or any similar device known in the art to diagnose and treat internal tissue anomalies.
When used internally on the end of an endoscope, for example, any of probe embodiments discussed above can be farther equipped in the end of an endoscope or similar device. The probe embodiments discussed herein may further comprise a light carrying fiber optic with a visualization optic. The light carrying fiber optic and visualization optic allow direct visualization of the probe tip and target tissue site during diagnosis and treatment of internal tissues. Visual display of the probe tip and target tissue site can be produced on a display device well known in the art and depicted as display 80 in
Also disclosed herein are methods for diagnosing and treating tissue anomalies. One such method comprises the following steps, as outlined in
Another embodiment of a method for diagnosing and treating tissue anomalies comprises positioning a probe coupled to an energy source proximate a target tissue; delivering one of an excitation energy and an ablative energy through the probe from the energy source to the target tissue depending on a signal from a controller; capturing a scatter reflected from the target tissue with the probe when excitation energy has been delivered, relaying the scatter to a spectrometer and fingerprinting the scatter's spectra against a tissue fingerprint database in the controller; and providing the signal from the controller to the energy source.
The actuation of the particular beam of energy is determined by a surgeon or pre-programmed in the controller. The method is repeated until all of the target tissue has been diagnosed and treated. To move the probe from target tissue site to target tissue site, a robotic apparatus can be used as discussed above, or the probe can be moved manually.
The probe can comprise a first conduit and a second conduit, so that the first conduit delivers the excitation and ablation energy and the second conduit senses the scatter. Alternatively, the excitation beam may be delivered through a conduit in addition to the conduit that delivers the ablation energy. The probe can further comprise an inert gas catheter as described above.
With procedures in which the probe is positioned in an endoscope or the like, a light carrying fiber optic with a visualization optic can be employed during the diagnosis and treatment for directly viewing the probe tip and the target tissue site.
The methods can further comprise storing the fingerprints received by the sensor in the database and displaying a virtual biopsy on a display device.
Advantages of the medical devices and methods disclosed herein are significant. The medical device and procedure disclosed herein can non-invasively diagnose anomalies in tissue and can contemporaneously treat any tissue positively diagnosed. By only ablating the tissue that requires it, surrounding healthy tissue is left in tact, providing a better tool for areas of tissue where cosmesis is a concern. For tissue located on the integument, subcutaneously or with a cavity of the body, the device and procedure provide real time diagnosis without having to biopsy a sample, analyze the sample, and later treat the area based on the tissue sample removed. Samples of tissue do not have to be frozen, which can decrease accuracy of diagnosis. This list is exemplary. Many more advantages can be realized by those skilled in the art.
While the invention has been described in connection with certain embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
This application claims priority from U.S. Provisional Application Ser. No. 61/051,705, filed May 9, 2008, which is incorporated herein in its entirety by reference.
Number | Date | Country | |
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61051705 | May 2008 | US |