System for displaying an estimated current source

• US 5,285,385 A
• Filed: 03/16/1990
• Issued: 02/08/1994
• Est. Priority Date: 03/17/1989
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shimura, Takaki, Hayashi, Takehiko, Igarashi, Yutaka
• Primary Examiner(s): Envall, Jr., Roy N.
• Assistant Examiner(s): Tran, Khai
• Application Number:
  US07/495,801
• Time in Patent Office: 1,425 Days
• Field of Search: 364/413.43, 364/413.22, 324/200, 324/245, 324/248, 358/110, 361/38, 361/400, 250/363, 128/653, 128/630, 128/653 R, 128/731
• US Class Current: 600/409
• CPC Class Codes: A61B 5/242 Detecting biomagnetic fields, e.g. magnetic fields produced by bioelectric currents

Abstract

An estimated current dipole displaying system in which a weak magnetic field generated from the heart or brain is measured to estimate the position, direction, magnitude and depth from a body surface of a current dipole which is equivalent to a heart current or a current flowing in a nerve and the estimated current dipole is displayed on a two-dimensional display. A parameter, other than that used to indicate the magnitude and those inappropriate for combined use with the magnitude indicating parameter, is used as a depth indicating parameter and the current dipole is thus displayed.

Claims

1. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display control means indicating the magnitude of the estimated current dipole by controlling a length of the arrow on the two-dimensional display; and

said display control means indicating a depth from the body surface by controlling one of a group of display parameters thickness, shape, lightness, saturation or hue of the arrow on the two-dimensional display.

2. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display control means indicating the magnitude of the estimated current dipole by controlling a thickness of the arrow on the two-dimensional display; and

said display control means indicating a depth from the body surface by controlling one of a group of display parameters length, shape, lightness, saturation or hue of said arrow on said two-dimensional display.

3. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display control means indicating the magnitude of the estimated current dipole by controlling a shape of said arrow on the two-dimensional display; and

said display control means indicating a depth from the body surface by controlling one of a group of display parameters lightness, saturation or hue of the arrow on said two-dimensional display.

4. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display control means indicating the magnitude of the estimated current dipole by controlling a scale of the arrow on the two-dimensional display; and

said display control means indicating a depth from the body surface by controlling one of a group of display parameters lightness, saturation or hue of said arrow on said two-dimensional display.

5. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display control means indicating the magnitude of the estimated current dipole by controlling a lightness of said arrow on the two-dimensional display; and

said display control means indicating a depth from the body surface by controlling one of a group of display parameters thickness, lightness, shape, saturation or hue of the arrow on said two-dimensional display.

6. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display control means indicating the display of the magnitude of the estimated current dipole by controlling a saturation of said arrow on the two-dimensional display; and

said display control means indicating a depth from a body surface by controlling one of a display parameters thickness, length, shape, scale, lightness, or hue of said arrow on said two-dimensional display.

7. A display system for displaying on a two-dimensional display an estimated current dipole for a measurement of biomagnetism, comprising:

display control means receiving information relating to a position, a direction, and a magnitude of the estimated current dipole below a surface of a body, for controlling the appearance of an image on the two-dimensional display;

said display control means causing the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

said display means indicating the display of the magnitude of the estimated current dipole by controlling a hue of said arrow on the two-dimensional display; and

said display control means indicating a depth from the body surface by controlling one of a group of display parameters thickness, length, shape, scale, saturation or lightness of said arrow on said two-dimensional display.

8. A display method for displaying on a two-dimensional display an estimated current dipole by a measurement of biomagnetism comprising the steps of:

providing a two-dimensional display means for displaying indicia representing the measurement of biomagnetism;

providing sensing means for detecting a component of a magnetic field at a surface of a body;

providing an interface means for controlling said sensing means and for supplying an output representing the detected component of said magnetic field;

providing computing means receiving the output of said interface means, for computing an estimate of a location, direction, and depth of the current dipole, and for controlling the appearance of an image on said two-dimensional display means;

said computing means having a display control means which controls the appearance of the image on the two-dimensional display, and wherein said display control means causes the two-dimension display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

using said sensing means to detect the component of said magnetic field at the surface of the body at a plurality of locations;

using said interface means to produce an output representing the detected component of said magnetic field at said plurality of locations, to said computing means;

using said computing means for differentiating the detected components of the magnetic field with respect to a distance r, said detected components of the magnetic field being perpendicular to the surface of the body;

using said computing means for determining a local minimum of the magnetic field at the surface of the body and a local maximum of the magnetic field at the surface of the body, and replacing a result of the differentiation with O to find a relation between a depth D from the surface of the body at which said current dipole exists and a value of r at which said detected component of the magnetic field assumes an extreme value;

finding a relation between local maximum and minimum points of a magnitude of the magnetic field on the surface of the body using a predetermined formula relating the values of D and r; and

using said computing means for finding the magnitude of said current dipole from said relation between D and r and from said relation between said local maximum and minimum points of the magnitudes of the detected components of the magnetic field.

9. A display method for displaying on a two-dimensional display an estimated current dipole from a measurement of biomagnetism comprising the steps of:

providing a two-dimensional display means for displaying indicia representing the measurement of biomagnetism;

providing computing means receiving measured output values representing detected values of a detected component of a magnetic field of the current dipole and for controlling the appearance of an image on said two-dimensional display means;

said computing means having a display control means which controls the appearance of the image on the two-dimensional display, and wherein said display control means causes the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

repeatedly entering said measured output values representing the detected components of the magnetic field of the current dipole perpendicular to a surface of a body at a plurality of points using coordinates to indicate position of each point measured on the surface of the body until a number of measured points reaches a predetermined number;

using said computing means for deriving an iso map consisting of lines connecting points of equal magnetic field intensity from magnetic flux values at said measured points;

using said computing means for determining local maximum and minimum points of the detected magnetic field components from said iso map;

using said computing means for estimating the position, direction, magnitude and depth of said current dipole from aid positions of said local maximum and minimum points and from extreme values of the detected magnetic field components; and

using said computing means for assigning the estimated position, direction, magnitude and depth of said current dipole to display parameters of the arrow on said two-dimensional display means.

10. A display system for displaying on a two-dimensional display an estimated current dipole from a measurement of biomagnetism, comprising:

computing means receiving measured output values representing detected values of a detected component of a magnetic field of the current dipole and for controlling the appearance of an image on said two-dimensional display means;

said computing means having a display control means which controls the appearance of the image on the two-dimensional display, and wherein said display control means causes the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling a position and a direction, respectively, of an arrow on the two-dimensional display;

wherein an original figure of an arrow for displaying said estimated current dipole is displayed using four corners of a rectangle centered at an origin of an x-y coordinate plane and a point of an x axis outside the rectangle, and wherein said original figure of said arrow is displayed in enlarged or reduced form, displaced parallel to the x-y coordinates according to a determined position of said current dipole and rotated according to a determined direction of said current dipole.

11. A display system for displaying on a two-dimensional display an estimated current dipole from a measurement of biomagnetism, comprising:

computing means receiving measured output values representing detected values of a detected component of a magnetic field of the current dipole and for controlling the appearance of an image on said two-dimensional display means;

said computing means having a display control means which controls the appearance of the image on the two-dimensional display, and wherein said display control means causes the two-dimensional display to indicate a position and direction of the estimated current dipole by controlling a position and a direction, respectively, of an arrow on the two-dimensional display;

wherein an original figure of an arrow is displayed for using four points, two of which are two corners of a rectangle centered at an origin of an x-y coordinate plane in a positive x direction;

one of which is an intersection of a point of a line connecting the other two corners of said rectangle in a negative x direction, and an x axis; and

the other of which is on the x axis in a positive x direction, outside said rectangle;

wherein said original figure of said arrow is displayed in enlarged or reduced form, displaced parallel to the x-y coordinates according to a determined position of said current dipole and rotated according to a determined direction of said current dipole.

12. A display method for displaying on a two-dimensional display an estimated current dipole by a measurement of biomagnetism, comprising the steps of:

providing a two-dimensional display means for displaying indicia representing the measurement of biomagnetism;

providing computing means receiving measured output values representing detected values of a detected component of a magnetic field of the current dipole and for controlling the appearance of an image on said two-dimensional display means;

said computing means having a display control means which controls the appearance of the image on the two-dimensional display, and wherein said display control means causes the two-dimensional display to indicate a position a nd direction of the estimated current dipole by controlling the position and the direction, respectively, of an arrow on the two-dimensional display;

determing a pixel conversion coefficient for converting the position of said estimated current dipole to a position of a pixel on the display screen,

determining a magnitude conversion coefficient for converting a magnitude of said current dipole to a magnitude indicating parameter of the arrow on the display screen,

determining a depth conversion coefficient for converting a depth from a surface of a body at which said current dipole exists to a depth indicating parameter of said arrow, and an original figure of said arrow;

using said computing means for determining the position, direction, magnitude and depth from a body surface of said current dipole;

deriving said magnitude indicating parameter and said depth indicating parameter of said arrow for displaying said current dipole; and

displaying said arrow in accordance with said magnitude indicating parameter and said depth indicating parameter.