JPH0295337A - Method for measuring position relation between multichannel squid sensor and subject - Google Patents

Abstract

PURPOSE:To execute a diagnosis with a high accuracy by superposing optical images photographed from plural directions of a subject and the fault image of the subject internal part in the same direction as them, referring to a receiver image projected on the optical image and measuring the position relation to the subject of the coordinates of a multichannel SQUID sensor reference. CONSTITUTION:The fault image and optical image are superposed after the image in the same directions are uniformized in size. Namely, a face fault image 5 and a face image 7 are superposed, simultaneously, a side fault image 6 and a side image 8 are superposed, and then, the position of a small coil 2 is correctly expressed on the fault image. On the other hand, the position of the small coil 2 is obtained as one in a coordinate system to make a multichannel SQUID sensor 3 into a reference by the multichannel SQUID sensor 3. Then, at the time of executing an adjustment mutally between position information pieces in which the position information of the small coil 2 obtained from the multichannel SQUID sensor 3 and the position of the small coil 2 expressed on the fault image are matched, the correct grasp of the position relation of a cranium 1 to the multichannel SQUID sensor 3 can be executed.

Description

[Detailed description of the invention]

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[Industrial application field]

The present invention relates to a multichannel SQUID sensor that measures minute magnetism within a living body, and particularly relates to a method for measuring its positional relationship with a subject.

[Conventional technology]

When a stimulus is applied to a living body, the polarization formed between cell membranes breaks down, causing an active current to flow. Such action currents are seen in the brain, heart, skeletal muscles, retina, etc., and are called electroencephalograms, electrocardiograms, electromyograms, electroretinograms, etc., respectively. Records of magnetic fields caused by the flow of electric current are called magnetoencephalography, magnetocardiography, magnetomyography, magnetoretinography, etc., respectively. In recent years, SQU has been used as a device to measure magnetism in living organisms.
I D (Superconducting Quan)
tum InterfaceDevice: superconducting quantum interference device) has been developed, and it has become easier to measure minute magnetic fields inside living organisms (Trigger separate volume p155-163. December 1987, Parity separate volume No. 1). 1. p26-38.1986. Medical System News vol. 1.9 No. 4 No. 100 p.
26-27.1988). By the way, such in-vivo magnetic images can be used in conjunction with tomographic images obtained by MRI (nuclear magnetic resonance imaging) devices and X+1iCT devices to identify the physical location of affected areas, etc. It is very important to accurately capture the positional relationship between the positional information acquired by the sensor and these tomographic images. Conventionally, for example, small coils or small transmitters are attached to multiple locations on the skull, and the magnetic field generated by the current flowing through the small coils is detected by the multi-channel SQUID sensor itself to determine its position. By determining the position of the transmitter with a receiver attached to the dewar (cooling container) that houses the sensor, we can obtain their position information in the coordinates of the multi-channel SQUID sensor, and use the multi-channel SQUID relative to the skull. We are trying to understand the positional relationship of the sensors. In other words, since we know where the small coil etc. is attached to the skull, we know where it will be located on the tomographic image, and this allows us to perform multichannel S
This involves understanding the relationship between the position information obtained by the QUID sensor and the tomographic image (S, N, Erne, et al.
The Positioning Problem
Biomagnetic Measurement:
A 5 solution for Arrays of
Superconducting 5 sensors
IEEETransactions on Mag
netics, vol, MAG-23, No, 2゜Ma
rch 1987).

[Problem B that the invention attempts to solve]

However, in the conventional method as described above, the positional relationship of where a small coil or the like is attached to the skull or the like on a tomographic image is determined visually, and there is a problem in that it is not accurate. Inaccuracies in such positional relationships may lead to errors in the final diagnosis. An object of the present invention is to provide a method for accurately measuring the positional relationship between a multichannel SQUID sensor and a subject.

[Means to solve the problem]

In order to achieve the above object, a method for measuring the positional relationship between a multi-channel SQUID sensor and a subject according to the present invention is as follows:
Multiple transmitters (small coils, small transmitters, etc.) that generate positioning signals are attached to appropriate locations on the surface of the subject, and the multi-channel SQUID sensor detects the above signals and uses the multi-channel SQUID sensor as a reference. The position of the transmitter is determined on the coordinates, and the optical images taken from multiple directions of the subject are superimposed on the tomographic images inside the subject in the same direction, and the transmitter image appearing on the optical image is determined. The present invention is characterized in that the positional relationship of the coordinates of the multi-channel SQUID sensor reference with respect to the subject is measured with reference.

[For production]

Since a transmitter such as a small coil is attached to the subject,
When this object is photographed optically, the image of the transmitter is captured in the optical image. Therefore, if this optical image is superimposed with a tomographic image in the same direction,
It is possible to know exactly where the transmitter is located on the tomographic image. Therefore, by using the optical image containing the transmitter image as a medium, it is possible to accurately match the position information acquired by the multi-channel 5QUID sensor with the position information on the tomographic image using the transmitter position as an index. can be done.

【Example】

Next, an embodiment of the present invention will be described with reference to the drawings. First, as shown in FIG. 1, small coils 2 are attached to appropriate locations on the cranium l, here three locations on the exposed skin of the face, at the center of the microscope and below both ears. Then, a current is passed through the small coil 2, and the resulting magnetic field is detected by the multi-channel SQUID sensor 3,
Obtain position information of the small coil 2. On the other hand, MRI imaging is performed on this head M1 to obtain a three-dimensional image 4 as shown in FIG. Then, a front tomographic image 5 and a side tomographic image 6 are created from this three-dimensional image 4. Furthermore, with the three small coils 2 attached as described above, a front view of the skull 1 and side views from the right and left are shown.
Photographs are taken with a regular optical camera or video camera. Since the image of the small coil 2 is reflected in these optical images, the contours of the cranium 1 and the small coil 2 are extracted from these camera-captured image data. Then, a front image 7 as shown in FIG. 3 and a side image 8 as shown in FIG. 4 are obtained. Next, the above-mentioned tomographic image and optical image are superimposed with the images in the same direction aligned in size. That is, as shown in FIG. 3, the front tomographic image 5 and the front image 7 are superimposed, and the side tomographic image 6 and the side image 8 are overlapped as shown in FIG.
and superimpose them. By superimposing the optical image and the tomographic image in this manner, the position of the small coil 2 is accurately represented on the tomographic image. On the other hand, as described above, the position of this small coil 2 is determined by the multi-channel SQU ID sensor 3 in a coordinate system based on the multi-channel SQU ID sensor 3. Therefore, if the positional information of the small coil 2 obtained from this multi-channel SQUID sensor 3 is matched with the position of the small coil 2 represented on this tomographic image, the mutual adjustment of the positional information is performed.
Multi-channel 5QUI D sensor 3 to skull 1
This means that we have been able to accurately grasp the positional relationship between the
This means that it is possible to know exactly where it corresponds on the tomographic image obtained by the RI device. Note that although a small coil is used as the transmitter to generate the positioning signal in the above example, a small transmitter that generates radio waves may also be used. In this case, the receiver that receives the radio waves should be placed on the side of the multi-channel SQUID sensor. After installation, the position of the transmitter relative to the receiver can be determined from the received signal of this receiver, and the position of the transmitter relative to the multi-channel SQUID sensor may be known. Moreover, although the tomographic image of the inside of the subject is obtained by the MHI apparatus in the above example, other tomographic images obtained by an X-ray CT apparatus or the like may also be used.

【Effect of the invention】

According to the method of measuring the positional relationship between the multi-channel 5QUID sensor and the subject of this invention, the positional relationship between the multi-channel SQUID sensor and the subject can be accurately determined.
The positional relationship between the magnetoencephalogram obtained by the sensor and the three-dimensional image of the brain obtained by the MRI device can be precisely matched, allowing highly accurate diagnosis such as knowing the exact location of the affected area. It is.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the positional relationship of a small coil and a multi-channel SQUID sensor with respect to the skull, and FIG. 2 is a schematic diagram showing a three-dimensional image obtained by an MRI apparatus, and FIG. 3 and 4 are schematic diagrams showing the superposition of an optical image and a tomographic image. 1... Cranium, 2... Small coil, 3... Multi-channel SQUID sensor, 4... Three-dimensional image, 5...
Frontal tomographic image, 6... side tomographic image.

Claims (1)

[Claims] (1) Multiple transmitters that generate positioning signals are attached to appropriate locations on the surface of the subject, and multi-channel SQ
The UID sensor side detects the above signal, determines the position of the transmitter on the coordinates based on the multi-channel SQUID sensor, and generates optical images taken from multiple directions of the subject and tomographic images inside the subject in the same directions. The multi-channel SQU is characterized in that the positional relationship of the coordinates of the multi-channel SQUID sensor reference with respect to the subject is measured with reference to the transmitter image shown on the optical image.
A method for measuring the positional relationship between an ID sensor and a subject.