JP3597887B2 - Scanning optical tissue inspection system - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a scanning optical tissue inspection apparatus.
[0002]
[Prior art]
A series of devices or methods are known for examining human tissue for possible tissue abnormalities. X-rays have long been used to perform such examinations. Although this method achieves a high-contrast image of the skeleton structure of the human body, the image quality that can be achieved when detecting a tumor is often insufficient to make a reliable diagnosis. In particular, if there is a lack of contrast between different types of tissue to be examined, such a method is only suitable in very limited situations for a given purpose. Another significant drawback when using X-rays is the ionizing effect and the resulting exchange with human tissue. For this reason, there has been a long-felt need for inspection methods or suitable devices that can be realized by non-ionizing electromagnetic radiation and provide sufficient image quality for evaluation.
[0003]
An apparatus that does not operate with X-rays but is suitable for detecting changes in the absorption coefficient in a scattering medium is described, for example, in US Pat. No. 4,972,331. In the proposed phase modulation spectroscopy, radiation having two wavelengths in the near-infrared range is alternately incident on the body tissue to be examined, where the radiation signal is modulated at a high frequency. On the detector side, changes in the characteristic radiation, such as phase shifts occurring in the tissue in particular, are recorded, from which the concentration of the tissue element, for example, the tumor, which absorbed the transmitted radiation is inferred.
[0004]
The described device has several disadvantages. First, sequential detection of several wavelengths is also performed due to the alternating incidence of electromagnetic radiation of different wavelength ranges and the use of the selected detector structure, resulting in a measurement Time gets longer. A further problem is that very weak optical signals in the high frequency range have to be converted into electrical signals by sensitive detectors. Such a detector must have a wide bandwidth due to the strong signal noise of the HF signal, and is therefore expensive. The electrical signals provided by the detectors are likewise particularly susceptible to high frequency interference fields from the respective surrounding environment. In addition, using the structure shown, for example, it can only be determined that a tumor is present. An accurate indication of the location and size of the tumor within the examined tissue volume is not possible.
[0005]
[Problems to be solved by the invention]
Accordingly, it is an object of the present invention to provide a scanning optical tissue inspection apparatus which guarantees that limited changes in scattering and / or absorption properties in human body tissue are defined with the highest possible contrast and the highest spatial resolution. It is to be. In addition, two-dimensional or three-dimensional image reconstruction from the measurement data should be possible. In addition, efforts are being made to reduce instrument costs while reducing measurement time, and to minimize the effects of external disturbances.
[0006]
[Means for Solving the Problems]
This object is achieved by a scanning optical tissue inspection device having the features of claim 1.
The scanning optical histology apparatus according to the present invention enables spatially resolved detection of anomalies in human tissue, such as tumors, including two-dimensional or three-dimensional image reconstruction. A possible application is the early detection of breast cancer.
This has the consequence, in particular, that the equipment costs are significantly lower compared to known devices, which is due to the configuration of the detection device according to the invention. In some embodiments of the detection device, for example, it is possible to apply a highly sensitive detector with a low bandwidth and a reasonable price.
[0007]
Furthermore, two or more different wavelengths are simultaneously coupled via a multiplex element to only one light guiding system, and the detection device is appropriately configured. Thus, in particular, by combining the demultiplexing means with the corresponding mixing means according to the invention, it is possible to reduce the measuring time by at least a factor of two compared to the prior art described above.
In addition, spatial resolution and contrast are improved by image reconstruction according to the convolution principle. For this purpose, the position of the radiation source is fixed, and the distribution of scattered light in the wide plane element on the exit side is measured using a scanning device. There are various scanning devices suitable for this.
[0008]
It has been found to be advantageous to use a solid angle selection element in the scanning device in order to suppress the disturbing "effect of external light" during image reconstruction.
Furthermore, depending on the desired design, the device according to the invention is of a modular construction, so that the individual components can be exchanged at any time without problems, for example the use of several different mixing and detection devices.
Other advantages and details of the scanning optical histological examination device according to the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings.
[0009]
【Example】
FIG. 1 shows a block diagram of a scanning optical tissue inspection apparatus according to the present invention. The device has a modular structure such that the individual components can be interchanged without problems depending on the desired design. The device according to the invention essentially comprises an optical light-emitting device 10, a modulation device 20, a scanning device 30, a detection device 40, a control device 50, and an evaluation device 60.
In this case, the optical light emitting device 10 has a wavelength λ. _i Light sources LQ emitting different radiations _i 11a, 11b and 11c are provided. Further, for example, Fa. Laser diodes having the Spectra Diode Labs model names SDL7422, SDL2431, etc. can be used, but their laser diodes have a wavelength λ from 670 nm to 950 nm. _i Occurs. That is, it operates in the range from the (visible) red spectrum to the (invisible) near-infrared spectrum. Although three different light sources 11a, 11b and 11c are shown in the block diagram of FIG. 1, it is sometimes necessary to apply four or more different light sources, that is, four or more corresponding wavelengths. Can be. Here, the wavelength λ to be used _i The only decisive factor in selecting is that it produces as different absorption characteristics as possible in the human tissue 100 to be examined.
[0010]
The light sources 11a, 11b and 11c are intensity-modulated at a high frequency via the modulator 20. To this end, the modulation device 20 includes, for example, commercially available HF oscillators for various light sources, which are available at Fa. Such as those sold by Rohde & Schwarz under the model name SMG or SMX, but for clarity of illustration the HF oscillators are not shown in FIG. Alternatively, it is based on a direct digital synthesizer (DDS) and has at least two HF output terminals in the range 100-500 MHz and is shifted by a defined offset Δf, but is fixedly coupled with respect to phase. It is also possible to use a simple oscillator.
[0011]
The modulation frequency for the individual light sources 11a, 11b, 11c is advantageously between 100 MHz and 500 MHz, and the low frequency modulation offset frequency Δf defined by the high frequency modulation fundamental frequency f. _i ). That is, as a result, the wavelength λ _i The total modulation frequency f _Gi = F + Δf _i Will occur. Modulation offset frequency Δf of each light source 11a, 11b, 11c _i Therefore, the total modulation frequency f _Gi May be the same or different depending on the detection device 40 employed. Some embodiments of the corresponding detection device 40 will be described in more detail with reference to FIGS.
[0012]
The optical light emitting device 10 further includes a light source temperature adjusting device (not shown) for operating the light sources 11a, 11b, 11c used at a stable temperature. This temperature control is essential to ensure that the phase difference and the amplitude of the emitted radiation are as stable as possible.
The optical light-emitting device 10 further comprises a multiplex element 12, shown schematically, by which the light beams emitted from the individual light sources 11a, 11b, 11c are combined by a multiplex element into a single light guiding system 15. go. As a multiplex element 12 suitable for sequential coupling, for example, a chopper wheel which is operated at a specified rotational speed and sequentially couples the radiation of the individual light sources 11a, 11b, 11c to the light guiding system 15 as described above. Can be used. During sequential multiplexing, the chopper wheel is clocked at a specified frequency via the controller 50. That is, the frequency of coupling of the individual light sources 11a, 11b, 11c to the light guiding system 15 is controlled by the external controller 50. The control device 50, which performs other functions besides such control as described below, is advantageously implemented in software via a computer.
[0013]
As an alternative to sequential multiplexing using a chopper structure, it is also possible to use well-known fiber optic multiplexing elements that allow simultaneous coupling, ie, parallel coupling and transmission, of modulated radiation to the light directing system 15. This is particularly advantageous. Such an optical fiber multiplex element is sold, for example, by the applicant, and is also described in EP0194612 and the like.
[0014]
As the light guiding system 15, it is preferable to use an optical fiber optical waveguide. This optical waveguide has a release optical system 31 on the release side for collimating the emitted light beam. The release optics 31 and / or the light directing system 15 are preferably associated with a scanning device 30 that performs a prescribed positioning on the tissue 100 to be examined in the plane of the collimated light beam.
[0015]
Here, it is indispensable for the function of the scanning device 30 and, consequently, that of the entire device according to the present invention, that the defined relationship between the point-like incidence location in the tissue 100 and the emission location on the detection side is spatially resolved by the scanning device 30. That is to generate a detector structure. Various configurations of the scanning device 30 are possible for this purpose.
[0016]
As schematically shown in FIG. 1, detection coupling optics can be provided to focus, ie, couple, the radiation transmitted through the tissue 100 to a detection and light guidance system 35, such as a fiber optic optical waveguide. The scanning device 30, which is likewise controlled via the control device 50, enables a synchronous scanning of the tissue 100 to be examined in this scanning configuration. That is, the light emitting side release optical system 31 is always synchronized with the detection side coupling system 32 and is positioned on the same axis. Accordingly, in this embodiment, the spatially resolved detector structure of the scanning device 30 includes the detection and light guiding system 35, which includes a coupling optical system that is synchronously positioned with respect to the collimated light beam. 32.
[0017]
In a second embodiment of the scanning device 30 that can be seen from FIG. 1, which is an alternative to the previous example, instead of the synchronous scanning, the light guiding system 15 or the release optical system 31 on the transmission side is directly arranged at a defined position, On the receiving side only, the position of the detection and beam guidance system 35 or its coupling optics 32 is changed in accordance with the regulations and the transmitted beam is recorded at a plurality of different points on a larger lateral flat area. Subsequently, for such a scanning process, the collimated light beam can be provided with a plurality of (eg 5 to 10) light-emitting sides fixedly held incident positions.
[0018]
Finally, in the scanning device embodiment described above, instead of a point-like spatially resolved detector structure to be moved, a CCD camera or CCD array with an optical amplifier connected in front is used on the detection side. It is possible to use a three-dimensional, ie laterally extending, spatially resolved detector structure including: In this case, the previously connected optical amplifier serves to mix the HF signal down to a lower signal frequency. One embodiment of a corresponding scanning device is shown in FIG. If the "point light source" is held fixed, it is obvious that a CCD array can be used in the spatially resolved detector structure of the scanning device as well.
[0019]
On the detector side, the scanning device, i.e., the spatially resolved detector structure, is used to record as much as possible only the light rays emerging from the tissue at a defined angle from the tissue to be examined. Advantageously, each has a solid angle selection element in between, thereby suppressing the influence of external light from another spatial direction which interferes with the signal evaluation. An apparatus suitable for this purpose will be described with reference to FIG. Such a solid angle selection element proves to be advantageous for all of the previously described embodiments of the scanning device.
Further, the scanning device 30 can be operated in a confocal configuration to suppress disturbing scattered rays from various directions.
[0020]
The weak radiation signal recorded via the scanning device 30 with a defined spatial resolution and transmitted through the tissue 100 passes through the detection light guiding system 35 and finally reaches the detection device 40. Therefore, the weak optical signal subjected to the HF amplitude modulation is mixed to a lower frequency while maintaining the phase information. Further, in some cases, necessary and appropriate amplification is performed, and the phase shift occurring in the irradiated tissue 100 is removed. The intensity or the amplitude of the transmitted radiation is recorded according to the wavelength as well as the wavelength. The recorded optical signals can be converted into suitable electrical signals in the detection device 40 and those electrical signals can be further processed by the evaluation device 60.
Serving as the basis for the detected information of the transmitted radiation signal is the signal of the modulator and of the optical light-emitting device, respectively, that is, in particular, the phase information and the amplitude information which, once applied, change when passing through the tissue.
[0021]
Some possible modifications of the detection device 40 are explicitly described in FIGS.
The changes in phase and amplitude of the individual wavelength components that occur in the irradiated tissue 100 and are detected by the detection device 40 are finally further processed by the evaluation device 60. To this end, the evaluation device 60 also makes use of the information of the control device 50 regarding the location where the signal was measured via the scanning device 30. In addition, the evaluation device 60 performs image generation signal processing and subsequent display on a display device, for example, display of a cross-sectional image of the examined tissue.
[0022]
By improving the measurement of the phase, amplitude and DC components of the transmitted or scattered radiation of the collimated light beam using the device according to the invention, phase and modulated images can be evaluated. It appears on the exit side and interprets the measured signal as a diffuse wave diffracted by the tissue structure. In this case, the phase of the measured value approximately corresponds to the average transit time of the arriving spread wave at each measurement location, and the amplitude substantially corresponds to the attenuation experienced by the spread wave. The diffraction image recorded in a plane by the scanning device 30 is processed again for image reconstruction while using the tissue model. For example, storing values representing the distribution of scattered light, such as distribution points, asymmetric constants or phase zero crossings, which determine the non-uniformity of the absorption and scatter distributions through an iterative reconstruction process in the tissue. Represents the start data above. In the next measurement step, the steps are repeated using the starting data, possibly correcting the data of the previous measurement point. This iterative method is also applied with respect to phase and modulation level, which separates the scattering and absorption changes within certain limits. At the output, the same information about the phase and amplitude changes occurring in the tissue is passed to the evaluation device 60. With respect to this method, it is advantageous to use a specific IC (ASIC) in the evaluation device 60 that enables reconstruction and image processing in a short time.
[0023]
Hereinafter, various embodiments that can be used for the detection device 40 in the device according to the present invention will be described with reference to FIGS.
These embodiments show mixing means M1, M2 used to mix the HF signal into lower frequency signals and various light sources LQ _i The only difference is in the combination with the available demultiplexing means D1, D2, D3, which plays the role of separating the signal components according to the wavelength.
[0024]
In this case, what is problematic as an appropriate mixing means is the electric mixing means M1 or the optical mixing means M2. Along with that, it is possible to use a combination of demultiplexing means operating in parallel, such as for example an optical (optical fiber) demultiplexer D2 or a digital frequency filtering means D3. Furthermore, for example, sequential demultiplexing via a known chopper structure D1 is also possible.
[0025]
Referring to the schematic block connection diagrams of FIGS. 2 to 5, the following four combinations of the mixing means and the demultiplexing means (D _i + M _i / M _i + D _i Explain):
Figure 2: M2 + D2
Figure 3: M2 + D3
Figure 4: D2 + M1
Figure 5: M1 + D3
[0026]
FIG. 2 shows a first embodiment of a detection apparatus using the optical mixing means M2 in combination with the optical demultiplexing means D2. In this case, in this configuration of the detection device, the modulation offset frequency Δf sent out from the modulation device _i Is any wavelength λ used _i Is the same for That is, Δf: = Δf _i It is.
[0027]
The HF signal in the MHz range reaching the detection device 40 via the scanning device is f _G = F + Δf, and are mixed to a lower frequency by the optical mixing means M2. Their frequencies are in the KHz range of the frequency offset Δf. As the optical mixing means M2 suitable for this purpose, a well-known acousto-optic mixing means or electro-optic mixing means, for example, an acousto-optic demodulator or an electro-optic demodulator sold by New Focus or A & A can be applied. One embodiment of a suitable acousto-optic modulator is shown in FIG. The optical mixing means M2 used respectively is operated with the high frequency signal f or f / 2 of the modulator as a reference signal. Generated as an output signal of the optical mixing means M2 is a signal having a difference frequency Δf, that is, a frequency in the KHz range. The signals reach an optical demultiplexing means D2 which is arranged subsequently and which is configured as a known optical fiber demultiplexer. Such a demultiplexer is described, for example, in the Applicant's European Patent No. EP0194612. The demultiplexing means D2 generates a signal component λ ₁ , Λ ₂ And λ ₃ And their signal components are subsequently applied to detectors DET1, DET2, DET3, which are arranged for each of their wavelengths. Therefore, what can be used as the detectors DET1, DET2, and DET3 is, for example, an NF detector having a narrow band such as a photodiode and having an affordable price. The recorded amplitude and phase measurements of the transmitted signal components are ultimately correlated in the evaluation stage A of the detection device 40 with the amplitude and phase of the input signal. A frequency offset Δf is used as a signal. After the evaluation of the phase and the amplitude in the evaluation stage A, the detected evaluation signals are sent further to an evaluation device, which further processes these signals together with the location-dependent information of the scanning device.
[0028]
FIG. 3 shows a second embodiment of the detection device 40. In this case, a combination of optical mixing means M2 and electronic-digital or analog-frequency filtering means D3 functioning as demultiplexing means is provided. Through a modulator not shown in FIG. _i Different total modulation frequency f _Gi = F + Δf _i give. That is, the modulation offset frequency Δf of each wavelength _i Are different from each other. As in the embodiment of FIG. 2 described above, the lower difference frequency .DELTA.f of the HF signal is first passed through the optical mixing means M2, also operated with the modulation frequency f or f / 2 as reference signal. _i Perform mixing to Different modulation frequency Δf _i Several wavelengths λ with _i Low-frequency signal component subsequently reaches the only one low-bandwidth NF detector DET configured as, for example, an avalanche photodiode or a multiplying phototube. Several different wavelengths of the transmitted radiation are separated off via an electronic frequency filtering means D3 which is subsequently arranged. That is, in this case, the electronic frequency filtering means D3 is used as demultiplexing means. As is well known, the electronic frequency filtering means D3 may be realized by an analog method, a digital method, or a software method. As in the previous embodiment, the transmitted various signal components Δf _i Is finally associated in the evaluation stage A with the amplitude and phase values of the input signal and is subsequently sent to an evaluation device. The evaluator further processes the information together with the location information of the scanning device. The advantage of this embodiment of the detection device 40 is that the measurement time is short, the sensitivity is high and the equipment cost is low because only one detector is required. Furthermore, the optical mixing means M2 guarantees optimal suppression of the HF scatter signal.
[0029]
A third embodiment of the detection device 40 will be described with reference to FIG. In this case, the optical demultiplexing means D2 and the electric mixing means M1 are combined for the purpose of signal processing. Therefore, various signal components of several wavelengths are all converted to the same modulation frequency f. _Gi = F + Δf _i Is modulated by That is, all wavelengths λ _i Δf _i : = Δf. First, the different signal components of the various wavelengths used are separated according to wavelength in an optical demultiplexing means D2, for example a known optical fiber demultiplexer. Subsequently, the signal still at high frequency reaches the electric mixing means M1. The electric mixing means consists essentially of three separate detectors DET1, DET2, DET3 operated by a modulation frequency f as a reference signal. The problem with suitable detectors DET1, DET2, DET3 which can be used simultaneously for the purpose of mixing HF signals is, for example, that of Fa. A multiplier phototube such as that sold under the model name R928 by Hamamatsu. After mixing, the signals separated according to wavelength then reach the evaluation stage A in the same way as in the previously described embodiment. In the evaluation stage A, the amplitude information and the phase information of the transmitted signal component are associated with the corresponding information of the input signal. The information is ultimately further processed by the evaluator in the manner described above.
[0030]
Finally, a possible fourth embodiment of the detection device 40 will be described with reference to FIG. In this case, the electric mixing means M1 is combined with an electronic frequency filtering means D3 as a demultiplexing means. Modulation frequency f of several wavelengths _Gi Are different from each other also in this embodiment. That is, the individual wavelength λ _i Is the total modulation frequency f _Gi = F + Δf _i Having. First, the electric mixing means M1 modulated with the modulation frequency f first performs mixing of the modulation offset to a lower frequency in the frequency range. For this purpose, a multiplying tube phototube whose amplification is modulated with f, including the high-voltage supply HV, is provided as electrical mixing means. Subsequently, the low-frequency signal component Δf _i Are separated for each wavelength in the electric frequency filtering means D3. After the evaluation stage A, the phase information and the amplitude information of the transmitted radiation are compared again with the input radiation. According to the previous embodiment, the information is likewise further processed by the evaluation device.
[0031]
FIG. 6 shows an optical mixing means suitable for the scanning optical tissue inspection apparatus according to the present invention. In this case, the acousto-optic modulator takes the form of, for example, an ultrasonic standing wave modulator such as that marketed by A & A. The input high-frequency signal component is coupled to a standing wave modulator 200 via an optical fiber optical waveguide 201 and a coupling optical system 202, for example, a Grin lens. This modulator is modulated at a high frequency by the ultrasonic converter 203, which frequency corresponds to one half of the frequency f of the modulator, and is shifted from the HF component of the optical signal by each offset frequency. ing. The high frequency signal component passing through the standing wave modulator 200 has an offset frequency Δf _i And the zero-order diffraction is released from the standing wave modulator 200 through the release optics 205 and further guided through another optical fiber optical waveguide 206. The use of such an optical mixing means eliminates the need to convert very weak optical signals in the HF range to corresponding electrical signals by means of expensive and sensitive detectors with a wide bandwidth, so that the equipment costs required for the detection of the HF signals are reduced. Is significantly reduced. Such sensitive detectors are usually always susceptible to HF interference fields.
[0032]
FIG. 7 schematically shows another scanning device 300. In this case, only the light guiding system 150 or its release optics 310 can be positioned by the scanning device 300 in one plane as defined. The spatially resolved recording of transmitted or scattered radiation is performed via a flat stationary detector element 350. For this purpose, a well-known CCD camera or the like, in which an optical amplifier is connected in front, can be used. The scanning device 300 shown in FIG. 6, for example, records the resulting scattered light distribution via a planar detector element 350 for a series of discrete points of incidence, respectively, in order to record the device according to the invention Can work. Image reconstruction is performed using the measured values.
[0033]
As already suggested in the description of FIG. 1, in order to ensure that the external light is more sufficiently suppressed and thereby to improve the measurement accuracy, a solid angle selection element is arranged in front of each detector element of the scanning device. Is advantageously arranged. A solid angle selection structure suitable for combination with a flat detector element is shown schematically in FIG. In this case, between the tissue 400 to be illuminated and the flat detector element 450, two microlens arrays 420a, 420b and a pinhole array 410 are present in a confocal configuration. Behind the pinhole array 420 is a suitably aligned flat detector element 450, such as a well-known CCD array or CCD camera. The effective release angle for each individual detector position depends on the focal length and diameter of the individual microlens and the diameter of the individual pinhole. Further, in the illustrated embodiment, since the diaphragm array is arranged on the exit side of the tissue between the microlens array 420 and the tissue 400 to be irradiated, the primary scattered light suppression in the adjacent region has already been performed. Can be achieved.
[0034]
Similar solid angle selection effects can also be achieved when one or more optical fiber optical waveguides are used as the spatially resolved detector structure. In this case, the core diameter of the optical fiber optical waveguide corresponds to the diameter of one pinhole of the confocal structure described above. At this time, the release angle can be variably set by selecting the jacket material and the jacket thickness of the optical fiber optical waveguide. In such a configuration, the fiber bundle array or fiber plate is attached directly to the glass plate defining the tissue or boundary to be examined, and the flat detector is adjusted to the fiber bundle exit aperture. I have.
[Brief description of the drawings]
FIG. 1 is a block diagram of a scanning optical tissue inspection apparatus according to the present invention.
FIG. 2 shows possible embodiments for the detection device, respectively.
FIG. 3 shows a possible embodiment for the detection device, respectively.
FIG. 4 shows possible embodiments of the detection device.
FIG. 5 shows a possible embodiment for the detection device, respectively.
FIG. 6 schematically shows an embodiment of a suitable optical mixing means.
FIG. 7 shows another embodiment of a possible scanning device having a laterally extending detector structure.
FIG. 8 illustrates one embodiment of a solid angle selection element located in front of a laterally extending detector structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Optical light-emitting device, 11a, 11b, 11c ... Light source, 12 ... Multiplex element, 15 ... Light guide system, 20 ... Modulator, 30 ... Scanning device, 40 ... Detection device, 50 ... Control device, 60 ... Evaluation device , 100: human body tissue, M1: electric mixing means, M2: optical mixing means, D1: chopper structure, D2: optical demultiplexing means, D3: frequency filtering means, DET1, DET2, DET3: detector, A: evaluation stage .

Claims (12)

Each independent light source (11a), (11b), (11c) and a multiplexing element (12) for combining beams of different wavelengths emitted from these light sources into a single light guiding device (15). An optical light-emitting device (10) having
A modulator (20) for intensity-modulating the emitted light from the optical light-emitting device (10) at a high frequency;
A scanning device (30) for positioning a high-frequency modulated light beam leaving the light guiding device (15) and spatially resolving and detecting radiation transmitted through the tissue (100) to be examined by a spatially resolving detector structure;
Mixer means (M1, M2) provided downstream of the scanning device (30) for mixing a high frequency signal with a high frequency signal from the scanning device (30) to obtain a lower frequency signal ; And a detecting device for separating a signal component peculiar to the device and detecting a phase and an amplitude of a recorded signal, and converting a signal transmitted from the detecting and separating device into an input signal of a signal generated from an optical light emitting device (10). A detection device (40) comprising an associating evaluation stage (A) ;
The detection device (40) evaluating device for an image forming process the generated signal from the evaluation stage (A) (60)
A scanning optical tissue inspection apparatus comprising: Each independent light source (11a), (11b), (11c) and a multiplexing element (12) for combining beams of different wavelengths emitted from these light sources into a single light guiding device (15). An optical light-emitting device (10) having
A modulator (20) for intensity-modulating the emitted light from the optical light-emitting device (10) at a high frequency;
A scanning device (30) for positioning a high-frequency modulated light beam leaving the light guiding device (15) and spatially resolving and detecting radiation transmitted through the tissue (100) to be examined by a spatially resolving detector structure;
A detector (40) for detecting the phase and intensity (amplitude) of the high-frequency signal obtained by the scanning device (30);
An evaluation device (60) for performing an image forming process on a signal from the detection device (40), wherein the scanning optical tissue inspection device comprises:
The detection device (40) includes:
An optical mixing means (M2) for obtaining a lower frequency signal by mixing a high frequency signal with the high frequency signal from the scanning device (30), and converting the low frequency signal from the optical mixing means (M2) into a wavelength. Optical fiber demultiplexing means (D2) for separating each component, detectors (DET1, DET2, DET3) for detecting the phase and amplitude of a signal having each separated wavelength component, and each of which is separated by the detector. An evaluation stage (A) for associating the output signal with an input signal of a signal generated from the optical light emitting device (10), wherein an output of the evaluation stage (A) is input to the evaluation device (60). Characteristic scanning optical tissue inspection device. Each independent light source (11a), (11b), (11c) and a multiplexing element (12) for combining beams of different wavelengths emitted from these light sources into a single light guiding device (15). An optical light-emitting device (10) having
A modulator (20) for intensity-modulating the emitted light from the optical light-emitting device (10) at a high frequency;
A scanning device (30) for positioning a high-frequency modulated light beam leaving the light guiding device (15) and spatially resolving and detecting radiation transmitted through the tissue (100) to be examined by a spatially resolving detector structure;
A detector (40) for detecting the phase and intensity (amplitude) of the high-frequency signal obtained by the scanning device (30);
An evaluation device (60) for performing an image forming process on a signal from the detection device (40), wherein the scanning optical tissue inspection device comprises:
The detection device (40) includes:
An optical mixing means (M2) for mixing a high-frequency signal with a high-frequency signal from the scanning device (30) to obtain a lower-frequency signal; and a detector (DET) for detecting the phase and amplitude of the low-frequency signal. ), An electronic frequency filtering means (D3) for separating a signal from the detector for each wavelength component, and a signal transmitted from the electronic frequency filtering means (D3) generated from the optical light emitting device (10). A scanning optical tissue inspection apparatus, comprising: an evaluation stage (A) for associating a signal with an input signal, wherein an output of the evaluation stage (A) is input to the evaluation device (60) . Each independent light source (11a), (11b), (11c) and a multiplexing element (12) for combining beams of different wavelengths emitted from these light sources into a single light guiding device (15). An optical light-emitting device (10) having
A modulator (20) for intensity-modulating the emitted light from the optical light-emitting device (10) at a high frequency;
A scanning device (30) for positioning a high-frequency modulated light beam leaving the light guiding device (15) and for spatially resolving and detecting radiation transmitted through the tissue (100) to be examined by a spatially resolving detector structure;
A detector (40) for detecting the phase and intensity (amplitude) of the high-frequency signal obtained by the scanning device (30);
An evaluation device (60) for performing an image forming process on a signal from the detection device (40), wherein the scanning optical tissue inspection device comprises:
The detection device (40) includes:
An optical fiber demultiplexing means (D2) for separating a high frequency signal from the scanning device (30) according to a wavelength; and receiving a signal for each wavelength separated by the optical fiber demultiplexing means (D2) to detect a wavelength. At the same time, detectors (DET1, DET2, DET3) functioning as an electronic mixing means (M1) for mixing a high frequency signal to a lower frequency, and a signal transmitted from the detector is generated from an optical light emitting device (10). An evaluation stage (A) for associating the output signal with the input signal of the scanning signal, wherein an output of the evaluation stage (A) is input to the evaluation device (60) . A light source (11a, 11b, 11c) in order to operate at a stable temperature, optical emission device (10) is a light source (11a, 11b, 11c) to any one of claims 1-4 comprising a temperature adjustment unit The described device. The device according to any one of the preceding claims, wherein the optical light emitting device (10) comprises a fiber optic multiplex element enabling parallel coupling to one light guiding device (15) of different wavelengths. The modulator (20) provides a high frequency modulation fundamental frequency and a low frequency modulation offset frequency, the low frequency modulation offset frequency being selectively different for all wavelengths used or Apparatus according to any of the preceding claims, wherein the same and the total modulation frequency are additively composed of a high frequency modulation fundamental frequency and a low frequency modulation offset frequency. The device according to claim 7, wherein the modulator (20) comprises a plurality of HF oscillators that can be separately controlled for different wavelengths. Scanning device (30) has a detector structure extending laterally into the detector side, apparatus according to any one of claims 1-4 having a positionable point light sources on the light emitting side. In front of the detector side of the scanning device (30) each of the spatial resolving detector structure, more of claims 1-4 comprising a solid angle selection element for reaching the detector structure only radiation emitted from one point of the tissue The apparatus according to claim 1 . The detection device (40) comprises on the input side an electronic mixing means (M1), which mixes the high-frequency signal to a lower frequency, after which the signals are separated according to wavelength. 2. The device according to claim 1, further comprising digital frequency filtering means (D3) as demultiplexing means. Evaluation unit (60) executes the image formation processing of the generated signals from the evaluation stage (A) of the detection device (40), in any one of claims 1 to 11, comprising a display device for that purpose The described device.

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