WO2012100995A1

WO2012100995A1 - Electro-optical probe

Info

Publication number: WO2012100995A1
Application number: PCT/EP2012/050538
Authority: WO
Inventors: Joachim Kaiser; Helmut Neumann; Rainer Kuth; Markus Neurath
Original assignee: Siemens Aktiengesellschaft
Priority date: 2011-01-26
Filing date: 2012-01-16
Publication date: 2012-08-02
Also published as: DE102011003199A1

Abstract

An electro-optical probe for endoscopic examinations is proposed. The electro-optical probe has at least one optical fibre for conveying optical signals. Moreover, the optical fibre has at least one electrically conductive coating. At the end of the optical fibre, at least one electrode tip is provided, which is coupled electrically to the electrically conductive coating.

Description

description

Electro-optical probe

The invention relates to an electro-optic probe, which in particular ^¬ sondere may be used in an endoscopic examination.

In endoscopic examinations of a patient, it is necessary to examine the tissue macroscopically as well as microscopically in order to be able to determine disease-specific tissue changes. A reliable tissue classification is important for a proper and timely treatmen ^¬ development of an existing or developing disease.

Endoscopic tissue examinations are mainly performed with the help of imaging systems. Here, an optical or fiber optic image transmission from the endoscope tip is used for a camera to represent the local Conversely ^¬ exercise of the endoscope tip on a monitor. In some systems, light sources with different optical filters can be used for illumination to represent the reflection and scattering properties of the tissue in different spectral bands.

It is an object of the present invention to provide a probe in which the reliability and reproducibility of measurement results is increased.

This object is achieved by a sensor having the features of claim 1. Advantageous embodiments and further developments are specified in the subclaims.

The sensor according to the invention is designed for use in a device for carrying out minimally invasive measures inside the body of a patient. He points we ^¬ nigstens a first optical waveguide. The first light Waveguide in turn has at least one first electrically conductive coating.

The sensor according to the invention makes it possible to use a combination of several different measuring methods. The reliability and reproducibility of tissue examinations can be increased by means of these different measurement methods. With the sensor according to the invention, electrical and optical measuring methods can be combined in order to obtain e.g. To compensate for contact force-dependent influencing of the electrical impedance measured values or / and to improve the distinction between different malignant tissue stages.

The optical waveguide used is preferably a flexible optical fiber. This is used in particular for illumination and simultaneous optical detection. For this purpose, for example, one is via a suitable coupling unit ^¬ lektrischen beam splitter, beam splitter cube polarizer or fused coupler Schliffkoppler, light coupled into the lightwave conductor and led to the sensor tip. Light reflected by the tissue, scattered, by non-linear processes it ^¬ zeugtes or fluorescence excitation light emitted is captured by the fiber probe. At the coupling unit, a spatial or polarization-optical distribution of the irradiated and the reflected-back light takes place. Then, in a suitable detection unit, the reflected-back light is evaluated via its intensity, spectral properties, polarization or the time profile taking into account known factors such as the fluorescence response or spectral characteristic of the light source.

The likewise existing electrically conductive coating, which can be made of gold, serves as Zufüh ^¬ tion of electrical signals. Hereby, the resistivity of tissue or its Frequenzab ^¬ dependence may for example be determined. These in turn can be considered as too ^¬ sätzliches measured signal in the evaluation of the optical measurement ^¬ signals. For this purpose, the elec- electrically conductive coating electrically coupled to an evaluation and control unit, which can couple the electrical signals in the coating and decoupling. In an advantageous embodiment and development of the invention, the sensor tip on an electrode tip. This serves to penetrate slightly into the tissue to be examined. The electrode tip is in a before ^¬ ferred to the execution to be examined tissue in their nature, size, depth or other characteristics fits reasonable. For example, the electrode tip can be designed as a needle, blunt needle, chamfered cylinder or hemisphere. The electrode tip is expediently electrically coupled to the first electrically conductive coating. This coupling can be done, for example, by conductive half-shells, at one end of the electrode tip and at the other end shells are mounted for receiving the optical waveguide. This approach has the advantage of the conductive Fa ^¬ serbe coating and the electrode tip from differing ^¬ chemical material to make. Thus, in an advantageous embodiment, the electrode tip can be made of platinum, for example. This allows the electrode tip to be adapted to the electrochemical properties of the tissue. The electrical contact itself can be made by joining, crimping, soldering or otherwise. In a further advantageous embodiment of the invention, the electrode tips are spring-mounted. This advantageously prevents too deep penetration into the tissue and brings the electrode into contact with the tissue region to be examined with a reproducible contact force.

It is particularly advantageous if the sensor has means ^¬ for applying an electrolyte solution to a to be examined Ge ^¬ webestelle is. This electrolyte solution provides one defined contact resistance between the tissue and the electrode tips ago.

As the counter electrode may, for example, an endoscope, in which the sensor is used, or a further electrode which ^¬ NEN, which is inserted in such a endoscope.

In a further advantageous embodiment of the invention, the optical waveguide has a plurality of conductive layers electrically separated by insulating layers. These um ^¬ give each other preferably cupped. They in turn serve to supply the signal and to detect the electrical response. Advantageous even affect the capacitive and inductive ven properties of the fiber coating may in this case be taken by an additional structural ^¬ structuring of the coatings. This can be used to optimize the influence of the supply line on the measurement result. It is expedient if, in this case, a plurality of electrode tips are provided which are each electrically coupled to one of the conductive layers. In this way, measurements are made possible with a plurality of electrodes, thus disturbing effects can be lead SUPPRESS ^¬ CKEN.

The sensor may also comprise a plurality of optical waveguides in a further embodiment. In this case, at least two of the optical waveguides are preferably provided with an electrically conductive coating. It is again expedient if each of the optical waveguides is electrically isolated from the other optical waveguides.

It is advantageous if optical elements for beam shaping are used at the fiber optic probe tip. By means of, for example, gradient index lenses (GRIN lenses), microlenses or suitably shaped fiber tips, focusing of the coupled-in radiation can be achieved in order to locally increase the irradiated intensity. This in turn may be beneficial in intensity-dependent methods such as fluorescence excitation or second-harmonic generation. The fiber core diameter can in turn also be adapted to the specific requirements. When supplying laser radiation, for example, it is possible to use a low-loss monomode fiber, including polarization-maintaining, for the supply, it being possible to use one or more fibers with a larger core diameter (multimode fibers) for the detection. In an advantageous embodiment, both the fluorescent light components or second harmonic radiation can be detected by the multimode fibers and also reflectance measurements with ultraviolet or visible radiation can be carried out. Each of the electrically conductive coatings is preferably equipped with one electrode tip each.

In an advantageous embodiment, for example, a twisting two fibers (twisted pair), the interference influence of the elec tric supply lines ^¬ is reduced by a suitable guidance of the fibers.

In a further advantageous embodiment, the sensor can be configured with one or more permanent magnets. This advantageously achieves that the sensor head can be controlled via external magnetic fields.

The sensor can also be used as an implant. For this purpose, it is equipped with a high-capacity battery or a rechargeable battery as well as an inductive charging system. Furthermore, expediently a wireless transmitting and receiving unit will be installed. For example, such an implant can continuously monitor metabolic processes.

Preferred, but in no way limiting Ausführungsbei ^¬ games for the invention will now be explained in more detail with reference to the figures of the drawing. The characteristics are shown specific ^¬ matically. Show it

1 shows a first endoscope with an optical fiber with

electrically conductive coating, FIG. 2 shows a second endoscope with an optical fiber with two electrically conductive coatings,

3 shows a third endoscope with two optical fibers having respective electrically conductive coating, Figure 4 shows a system structure for an endoscope with two optical fibers ^¬ rule.

FIG. 1 shows highly schematic sections through an endoscope structure of a first endoscope 10. The first endoscope 10 has an endoscope jacket 1 which encloses a counterelectrode. The endoscope sheath 1 of the first endoscope 10 encloses a working channel 2. The working channel 2 is designed so that a sensor can be inserted.

The sensor comprises an optical fiber 5, in this case with a core diameter of 4 μπι to 600 μπι. Furthermore, the sensor comprises an electrically conductive fiber coating 6 made of gold. The fiber coating 6 surrounds the optical fiber 5. In the region of one end of the optical fiber 5, an electrode tip 4 is provided. The electrode tip befin ^¬ det in electrical contact with the fiber coating projecting 6. Suitably, the electrode tip 4 about the end of the optical fiber 5 also, so that a slight A ^¬ penetrate into tissue to be measured is possible.

The optical fiber 5, the fiber coating 6 and parts of the electrode tip 4 are surrounded by an insulation 3. The insulation layer 3, in turn, is passed by a probe casing 7 by ^¬, which is specifically designed for insertion into the working channel of the first endoscope 10th The entire probe measures, for example, 2 to 2.5 mm in diameter.

FIG. 2 also shows a second endoscope 20 in two

Sectional views. The second endoscope 20 has a more complex construction of the sensor. As in the case of the first endoscope 10, the sensor here has the elements of the probe jacket 7, the electrically conductive fiber coating 6, an optical fiber 5, an electrode tip 4 and an insulation 3. In contrast to the sensor of the first endoscope 10, however, the electrically conductive fiber coating 6 is surrounded by an insulating layer 21 here. This insulating layer 21 in turn is surrounded by a second conductive fiber coating 22. The second conductive fiber coating 22 is electrically coupled to a second electrode tip 23. The second endoscope 20 thus has a sensor with two elec ^¬ trically insulated from each other electrodes. Figure 3 shows a third embodiment in the form of a third endoscope 30. This is in parts analogous to the ers ^¬ th two endoscopes 10, 20 constructed. The sensor again comprises an insulation 3, an optical fiber 5, an electrically conductive fiber coating 6 on the optical fiber 5, an electrode tip 4 and the probe jacket 7.

In addition to the optical fiber 5, a second optical fiber 31 is provided within the insulation 3 in the third embodiment. The second optical fiber 31 is constructed analogously to the optical fiber 5. It comprises a second elekt ^¬ driven conductive fiber coating 33 and an associated second electrode tip 32. As shown in Figure 3 can be seen, there are the optical fibers 5, 31 with their respective electrode tips 4, 32 arranged to point-symmetrically within the insulation 3 that a possible optimum space ^¬ utilization is achieved with a small diameter of the probe jacket 7. The insulation 3 insulates each of the conductive fiber coatings 6 and 33 against each other. FIG. 4 shows an overall system for the third endoscope 30.

The two optical fibers 5, 31 are led out of the Arbeitska ^¬ nal 2 of the endoscope and connected to other elements. In this case, the optical fiber 5 is connected to a first light source 43 via an optical component 44 for beam shaping and spectral filtering or a filter wheel.

The second optical fiber 31 is connected outside of the third Endo ^¬ skops 30 with an optical coupler 48. This divides the light path and leads over two more optical Components 44 on the one hand to a second light source 42 and on the other hand to a detector 45. The electrically conductive fiber coatings 6, 33 are in turn connected to a device for signal generation and detection for an impedance measurement 41st

The light sources 42, 43, the detector 45 and the device 41 are connected to a control and evaluation unit 46, which in turn outputs measured values and a result representation 47.

Claims

claims

A sensor (10, 20, 30, 40) for use in a device for carrying out minimally invasive measures inside the body of a patient, comprising at least one ers ^¬ th optical waveguide (5), wherein the first optical waveguide

(5) at least a first electrically conductive coating

(6).

2. Sensor (10, 20, 30, 40) according to claim 1 having at least one second electrically conductive coating (22) which is electrically isolated from the first electrically conductive coating (6).

3. sensor (10, 20, 30, 40) according to claim 1 or 2 with at least one second optical waveguide (31).

4. Sensor (10, 20, 30, 40) according to claim 3, wherein the second optical waveguide (31) has at least one further electrically conductive coating (33).

5. Sensor (10, 20, 30, 40) according to one of the preceding claims, wherein at least one of the electrically conductive coatings (6, 22, 33) is a gold coating.

6. sensor (10, 20, 30, 40) according to one of the preceding claims having at least one electrode tip (4, 23, 32) which is electrically coupled to one of the electrically conductive coatings (6, 22, 33).

7. sensor (10, 20, 30, 40) according to claim 6, wherein the electrically conductive part of the electrode tip (4, 23, 32) consists of platinum.

8. sensor (10, 20, 30, 40) according to claim 6 or 7, wherein the electrode tip (4, 23, 32) is resiliently mounted.

9. sensor (10, 20, 30, 40) according to one of the preceding claims with means for applying an electrolyte solution in the region of the sensor head.

10. A method for operating a sensor according to any one of vo ^¬ claims appending, in which a combination of at least one optical measuring method is used with at least one elec ^¬ cal measurement methods.