JP2007289223A - Identifying system of position of invasive instrument in living body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an identifying system of positions of invasive instruments in living bodies for easily identifying a position of an injection needle, which is an invasive instrument, in a normal surgical environment. <P>SOLUTION: The identifying system of positions of invasive instruments in living bodies comprises a measuring means provided at the distal end of the invasive instrument invading a living body for measuring light absorption and reflectance of tissues inside the living body, a conversion table which houses a correspondence relationship between the light absorption or the reflectance of the tissues inside the living body and the display brightness information on tissues in the living body in nuclear magnetic resonance images, an operation means which performs an estimation operation of an insertion position of the distal end of the invasive instrument in the nuclear magnetic resonance image by comparing the light absorption or the reflectance measured by the measuring means and the display brightness information of the tissues in the living body by referring to the conversion table, and an output means for outputting a coordinate position of the invasive instrument which is acquired by performing the estimation operation by the operation means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-vivo position identification system for an invasive instrument, and more specifically, when an invasive instrument such as an injection needle is invaded into a living body when performing a surgical operation on the living body, it is acquired in advance. In vivo position identification system for an invasive device capable of identifying the position of the invasive device in the living body by displaying the invaded position of the invasive device in the nuclear magnetic resonance image (MRI image) of the living body It is about.

  It is widely practiced to analyze neural circuit connections in the brain by inserting a needle into a living experimental animal and injecting a drug called a tracer. In recent years, attempts have been made to treat Parkinson's disease and Alzheimer's disease by inserting a needle and injecting a drug into the brain.

  However, it is not easy to inject a drug by accurately positioning the tip of the injection needle in a specific region in the brain. Currently, in a method that is normally performed, a subject is fixed to a brain stereotaxic apparatus, and then the internal structure of the brain is imaged in advance by MRI (nuclear magnetic resonance imaging), and the three-dimensional (x, (y, z) coordinates are determined, and a method of inserting an injection needle into the position of the three-dimensional (x, y, z) coordinates using a coordinate positioning device is performed. However, this method often involves failure to inject a drug into a small brain region.

  As a known example related to such a technique, as shown in Patent Document 1, a medical preparation, particularly a drug or a contrast agent is applied to a patient during an examination in a magnetic resonance tomography apparatus or an examination by an endoscope. There are proposals for devices for injection into the body. This device is a drug metering system with a manipulator controlled injection needle.

  Further, as shown in Patent Document 2, an invasive device is inserted into or through the vasculature of the body of a human or non-human animal, and the body including the device There are interventional or intraoperative MRI methods that generate partial MR images. In this method, the contrast agent is administered into the vasculature of the body by direct injection of the contrast agent through an invasive device or by direct intravenous injection of the contrast agent into a patient, thereby Facilitates fluoroscopy in images.

On the other hand, the present inventors have proposed the invention of “in vivo tissue identification device” as disclosed in Patent Document 3 as a device for identifying in vivo tissue using an invasive instrument. This in vivo tissue identification device installs an optical fiber in an invasive device such as an injection needle, and identifies tissue in the brain based on the absorbance or reflectance measured at the tip of the injection needle that is an invasive device. Identify and identify brain structures.
JP-T-2004-516859 Special table 2003-500132 gazette JP 2006-6919 A

  By the way, when injecting a drug into a specific region of the brain tissue, the position of the tip of the invasive instrument must be accurately positioned. For this purpose, for example, Patent Document 1 or Patent Document 2 shows. Thus, the apparatus becomes large-scale, and a normal surgical environment has not been developed that can easily identify the position of the injection needle.

  In addition, as shown in Patent Document 3, the present inventors identify tissues in the brain based on the absorbance or reflectance measured at the tip of an injection needle that is an invasive instrument, and determine the structure in the brain. We have developed a device for identification. By using this device, it is possible to identify the tissue of the living body when the invasive instrument is inserted into the living body. In this case, the position where the invasive instrument is inserted into the living body. Cannot be identified.

  The present invention has been made to solve the above-described situation, and an object of the present invention is to provide an in vivo living body for an invasive device that can easily identify the position of an injection needle that is an invasive device in a normal surgical environment. It is to provide a position identification system. Another object of the present invention is to identify and display the invaded position of the invasive device in the previously acquired MRI image of the living body when an invasive device such as an injection needle is invaded into the living body. It is an object of the present invention to provide an in vivo position identification system for an invasive instrument.

  In order to achieve the above object, as a first aspect of the present invention, an in vivo position identification system for an invasive instrument according to the present invention acquires a nuclear magnetic resonance image of a living body invading the invasive instrument. An in-vivo position identification system for identifying a position of an invasive instrument in the living body on the nuclear magnetic resonance image when the invasive instrument is invaded into the living body, and the tip of the invasive instrument to invade the living body A measuring means for measuring the absorbance or reflectance of the tissue inside the living body, and a conversion storing the correspondence between the absorbance or reflectance of the tissue inside the living body and the display luminance information of the in vivo tissue in the nuclear magnetic resonance image The table, the absorbance or reflectance measured by the measuring means, and the display luminance information of the tissue in the body of the nuclear magnetic resonance image are compared with reference to the conversion table to obtain the nuclear magnetic resonance image. Calculating means for the insertion position of the tip of the invasive instrument to estimate calculation that, configured and output means for outputting coordinate positions of the estimated computed invasive instrument by computing means.

  As a second aspect, in addition to the above configuration, in the in vivo position identification system for an invasive instrument according to the present invention, when the output means displays the coordinate position of the invasive instrument, The image is displayed so as to be superimposed on the nuclear magnetic resonance image, and the tip position of the invasive device in the image of the invasive device is configured as the coordinate position.

  Further, as a third aspect, in addition to the above configuration, in the in vivo position identification system for an invasive instrument according to the present invention, an input means for receiving designation of the in vivo position and direction to be displayed from the user; Display means for displaying the in-vivo position of the invasive instrument on the MRI image for the specified direction and cross-section based on the in-vivo position and direction designation received by the input means.

  According to the in vivo position identification system for an invasive instrument according to the present invention configured as described above, image data obtained by MRI (nuclear magnetic resonance imaging) and an invasive instrument (injection needle, electrode, etc.) Based on the absorbance or reflectance data of the tissue obtained from the measuring means attached to the tip, the correlation is referred to and the insertion position of the tip of the invasive instrument is estimated. This estimated position is displayed on the MRI image as an insertion position of the invasive instrument in the living body. Thereby, it becomes possible to insert while confirming the position of the tip of the injection needle which is an invasive device, and it becomes possible to inject the drug into the target brain region more accurately.

  The in vivo position identification system for an invasive instrument according to the present invention is a system with a relatively simple configuration, but can confirm the needle point position of an invasive instrument including an injection needle in real time. The invasive device can be positioned at a more accurate intracerebral position as compared to the above.

  Therefore, by using the system of the present invention, for example, a drug can be accurately injected into a minute region in the brain. Even in the conventional method, an MRI image is taken before an experiment or operation, but since the image is used as it is to measure the correlation with the structure in the brain, there is little increase in labor compared to the conventional method. .

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings based on an Example. FIG. 1 is a diagram illustrating a system configuration of an in vivo position identification system for an invasive instrument according to the present invention. In FIG. 1, reference numeral 110 denotes a target biological tissue. The biological tissue 110 includes a biological tissue surface layer 110a, a first internal tissue 110b, a second internal tissue 110c, and a third internal tissue 110d. The first internal tissue 110b, the second internal tissue 110c, and the third internal tissue 110d have different absorbances or reflectances. A syringe 111 is an invasive device. When the living tissue here is the brain and electrical stimulation is given to the brain, the invasive instrument 111 becomes an electrode.

  Reference numeral 107 denotes a measuring device that measures the absorbance or reflectance of tissue inside the living body. This measuring device 107 has been proposed by the present inventors as an in vivo tissue identification device that identifies in vivo tissue using the fact that the absorbance or reflectance of the tissue inside the living body is different (special feature). This is a measuring device that measures the absorbance or reflectance of the tissue inside the living body in this identification device.

  The measuring device 107 that measures the absorbance or reflectance of the tissue inside the living body is composed of a light amount measuring unit 107a and a light source unit 107b that are extended to the tissue position to be measured by an optical fiber. The data is displayed on a display unit provided in the measuring apparatus 107 and sent to the input unit 100 for data processing. In addition, 112 is a front-end | tip part of the syringe 111, and is a measurement point which measures the light absorbency or reflectance of the structure | tissue inside a biological body. Moreover, it is the insertion position of the invasive instrument with respect to the structure | tissue made into object. Illumination light from the light source unit 107b of the measuring device 107 is introduced to the measurement point 112 inside the living tissue via the optical fiber, and the amount of light transmitted through the tissue at the measurement point 112 or reflected by the tissue is also transmitted through the optical fiber. And is measured by the light quantity measuring unit 107a.

  In FIG. 1, reference numeral 100 denotes an input unit that receives an input operation from a keyboard and mouse and has an input port for inputting measurement data from the outside. Reference numeral 101 denotes a keyboard for input operation such as numerical data. Is a pointing device mouse for input operation to operate the system. Reference numeral 103 denotes an arithmetic unit composed of a system device such as a microprocessor (CPU) and a memory, 104 denotes an output unit composed of a display device, for example, and 105 denotes a data storage device composed of a hard disk device. Reference numeral 106 schematically shows a display screen displayed by the display device of the output unit.

  The data storage device 105 includes MRI image data 105a of a target living tissue, absorbance or reflectance of the living tissue, and nuclear magnetic resonance as data used for the process of identifying the position of the invasive instrument in the living body. A conversion table 105b that stores the correspondence relationship between the display luminance information of the in-vivo tissue in the image is stored.

  As shown in FIG. 3, the data of the conversion table 105b is obtained by the experiment so far as the correlation between the lightness (gray level) on the MRI image and the tissue reflectance, and based on this data, The correspondence between the MRI image data including the position information of the target living tissue, the absorbance or reflectance of the living tissue, and the display luminance information of the living tissue in the nuclear magnetic resonance image is created and stored. The correlation between the lightness (gray level) on the MRI image and the tissue reflectance varies depending on the tissue type and measurement conditions. Therefore, measurement is performed each time, and an optimal conversion table (multiple) is obtained together with the tissue type and measurement condition data. When a process is performed to identify the position of the invasive instrument in the living body, a conversion table suitable for each condition is used according to the living body.

  FIG. 2 is a diagram for explaining data processing in the in vivo position identification system for an invasive instrument according to the present invention. This will be described with reference to FIG. In this data processing, as preprocessing, processing on the right side of FIG. 2 (steps 301 to 304) is performed to create profile data for the introduction route of the invasive instrument, and based on the created profile data, Thereafter, the processing on the left side of FIG. 2 (steps 201 to 206) is performed in real time, and the insertion position of the invasive instrument is estimated and displayed in real time (steps 401 to 402).

  In the preprocessing, first, an MRI image of a target biological tissue is captured to obtain MRI image data (step 301). The MRI image data is stored in the data storage device 105. Next, an introduction target position and an introduction start position are set on the MRI image (step 302). In order to create profile data for the introduction route of the invasive device, an ideal introduction route and an introduction route when the position or angle of the route is shifted are set (step 303), and each of the set introduction routes is set. Then, a profile is created with the distance on the MRI image as the horizontal axis and the luminance of the pixel as the vertical axis (step 304). Further, the vertical axis of the profile is converted by a conversion table obtained from the correlation between the brightness on the MRI image and the tissue reflectance (step 305). This conversion process may be configured to be performed in a position estimation calculation process described later. As a result, profile data 306 for the route is created for a plurality of candidates that are routes from the introduction start position.

  Next, an invasive instrument is introduced into the target living body, and this invasive instrument is added with a measuring device for measuring the absorbance or reflectance of the aforementioned tissue provided with an optical fiber at the leading end of the introduction. It is a thing. When the pretreatment is completed, the invasive device with an optical fiber is introduced into the living body (step 201), and the invasive device is moved in the living body (step 202). At this time, absorbance or reflectance is measured with an optical fiber attached to the tip of the invasive instrument (step 203). Then, when the data measured here is obtained, the distance from the introduction start point and the data of absorbance or reflectance are transferred (step 204). Then, a profile is created with the movement distance of the invasive instrument on the horizontal axis and the absorbance or reflectance on the vertical axis (step 205).

  Then, the created profile data 206 associated with the movement of the invasive instrument is compared with the profile data 306 on the plurality of candidate introduction routes that are the routes from the introduction start position created earlier, and The candidate is determined, and the insertion position is estimated based on the introduction route.

  The result of the insertion position estimation calculation (step 401) is output to the display display device of the output unit 104 as a coordinate position on the display screen by the output process (step 402). In this output processing, image processing similar to that of the existing image processing program is performed. For example, when displaying the coordinate position of an invasive instrument, the image of the invasive instrument is displayed superimposed on the nuclear magnetic resonance image, the target position is displayed, and the invasive instrument in the image of the invasive instrument is displayed. The display processing is performed with the tip position of the coordinate position as the coordinate position.

  Further, in the case of performing such display processing, it is configured to display in various forms in response to an instruction from a user interface process in a normal image display process from a user. For example, in the display process here, designation of the in-vivo position and direction to be displayed from the user is received by the mouse of the pointing device, and the invasiveness on the MRI image is based on the designation of the in-vivo position and direction received by the mouse. The in-vivo position of the instrument is configured to display for a specified direction and cross section. In this display process, the insertion position of the target invasive instrument is displayed together, and the actual insertion position in the living body is displayed on the MRI image while performing calculation processing in real time.

  Illustratively, the purpose of the invasive instrument in-vivo location identification system according to the present invention is to introduce the invasive instrument into the correct location in the organism. For this purpose, optical information (absorbance or reflectance) obtained directly from an optical fiber provided at the tip of an invasive instrument is used.

  When introducing an invasive instrument, first, the living tissue is fixed to a stereo frame (fixing instrument on which a three-dimensional coordinate axis is installed), and then the MRI (Nuclear Magnetic Resonance Imaging) is used. Take a dimensional image.

  A target introduction position on the MRI image and a tissue surface position for starting the introduction are determined as coordinates on the stereo frame.

  In starting an experiment (or operation) for introducing an instrument into a living tissue, an invasive instrument is installed using a manipulator at the coordinates of the introduction start position assumed from the position on the stereo frame.

  In the stage of actually inserting the invasive instrument, the movement distance (depth in the tissue) from the introduction start point of the invasive instrument tip is measured from the scale of the manipulator. Furthermore, optical information of absorbance or reflectance can be obtained simultaneously from the optical fiber provided at the tip of the invasive instrument. Two pieces of information, “movement distance from the introduction start point” and “absorbance or reflectance”, are sent to the PC. A profile 206 is created on the PC with the movement distance of the instrument on the horizontal axis and the absorbance or reflectance on the vertical axis.

  On the other hand, an ideal introduction route is set from the introduction target position and the introduction start position set on the MRI image. Furthermore, a route when the position or angle of the route is deviated from the ideal introduction route is also set. For each of the set introduction routes, a profile 306 is created with the distance on the MRI image as the horizontal axis and the luminance of the pixel as the vertical axis.

  By fitting the profile 206 obtained from the instrument and the profile 306 obtained from the MRI, it is estimated where the invasive instrument is currently located in the living body. When these profiles are compared, conversion processing for matching the data on the vertical axis (data between the brightness on the MRI image and the tissue reflectance) is performed.

  By using this method, it becomes possible to introduce an invasive instrument at a more accurate position than the conventional introduction method that relies only on the coordinates of the stereo frame.

  According to the in vivo position identification system of an invasive instrument according to the present invention, a calculation is performed to adapt the correlation between the change in absorbance or reflectance obtained from the tip and the MRI image in real time when the injection needle is inserted. Thus, the position of the tip of the injection needle in the brain can be displayed in real time on the MRI image, and an invasive instrument can be introduced at a more accurate position in the tissue than the conventional method. it can.

It is a figure explaining the system configuration | structure of the in-vivo position identification system of the invasive instrument by this invention. It is a figure explaining the data processing in the in-vivo position identification system of the invasive instrument by this invention. It is a figure which shows the correlation of the brightness on a MRI image, and a tissue reflectance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Input part 101 Keyboard 102 Mouse 103 Calculation part 104 Output part 105 Data storage apparatus 106 Display screen 107 Measuring apparatus 110 Living tissue 111 Syringe (syringe)
112 Syringe tip

Claims (3)

An in-vivo position for acquiring a nuclear magnetic resonance image of a living body that invades an invasive instrument and identifying the position of the invasive instrument in the living body on the nuclear magnetic resonance image when the invasive instrument is invaded into the living body. An identification system,
A measuring means provided at the tip of an invasive instrument for invading the living body to measure the absorbance or reflectance of the tissue inside the living body;
A conversion table storing the correspondence between the absorbance or reflectance of the tissue inside the living body and the display luminance information of the tissue inside the living body in the nuclear magnetic resonance image;
The insertion position of the tip of the invasive instrument in the nuclear magnetic resonance image by comparing the absorbance or reflectance measured by the measuring means with the display luminance information of the tissue in the body of the nuclear magnetic resonance image with reference to the conversion table Computing means for estimating
An in vivo position identification system for an invasive instrument, comprising: output means for outputting a coordinate position of the invasive instrument estimated and calculated by the calculation means. The in vivo position identification system for an invasive instrument according to claim 1,
When the coordinate position of the invasive instrument is displayed, the output means displays the image of the invasive instrument superimposed on the nuclear magnetic resonance image, and the tip position of the invasive instrument in the image of the invasive instrument is the coordinate position. An in-vivo position identification system for an invasive instrument characterized by: The in vivo position identification system for an invasive instrument according to claim 1, further comprising:
Input means for accepting designation of the in-vivo position and direction to be displayed from the user;
An invasive device comprising: display means for displaying the in-vivo position of the invasive device on the MRI image based on the designation of the in-vivo position and direction received by the input unit with respect to the designated direction and cross section. In vivo position identification system.

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