Medical magnetic positioning system and method for determining the position of a magnetic probe

Claim 3

The method of claim 1, wherein the step of inserting the probe comprises inserting a cylindrical probe approximately 2 mm in length and 1 mm in diameter.

Claim 4

The method of claim 1, wherein said probe is an AC magnetic probe.

Claim 7

The method of claim 4, wherein the size of said probe is small, and is approximately 1 mm by 2 mm.

Claim 8

The method of claim 4, wherein said probe is an AC magnetic probe.

Claim 9

The method of claim 1 or claim 4 wherein said steps of measuring the probe's three-dimensional magnetic field and determining the location of the probe by using a non-linear computer algorithm further comprises: a. entering into a computer measured magnetic induction values B 1x , B 1y , B 1z , B 2x , B 2y , and B 2z in which x 1 , y 1 , z 1 =x, y, z coordinates of the probe with respect to a first magnetometer (B 1x , B 1y , B 1z ) and x 2 , y 2 , z 2 =x, y, z coordinates of the probe with respect to a second magnetometer (B 2x , B 2y , and B 2z ) b. entering into the computer magnetic moment magnitude, m, of the probe c. entering into the computer a value for a constant, c, wherein c=μ.sub.0 /4π in which μ 0 =the permeability of free space=4×10 -7 weber/meter-ampere d. entering into the computer input spatial offsets (Δx, Δy, Δz) of the second magnetometer from the first e. calculating in the computer the following six non-linear equations to determine the values of θ, φ, x 1 , y 1 and z 1 : ##EQU4## where: x, y, z are the coordinates of the probe with respect to the first magnetometer x 2 , y 2 , z 2 , the coordinates of the probe with respect to the second magnetometer, are given by: x.sub.2 =x.sub.1 +Δx x.sub.2 =y.sub.1 +Δy z.sub.2 =z.sub.1 +Δz x 1 , y 1 , z 1 are the coordinates of the probe with respect to the first magnetometer. x 2 , y 2 , z 2 the coordinates of the probe with respect to the second magnetometer, are given by: x.sub.2 ≧x.sub.1 +Δx y.sub.2 ≧y.sub.1 +Δy z.sub.2 ≧z.sub.1 +Δz r 1 , is a vector with components x 1 , y 1 , z 1 and magnitude ##EQU5## r 2 , is a vector with components x 2 , y 2 , z 2 and magnitude ##EQU6## m is a vector with components m x , m y , m z with: m.sub.x =m sin θ cos φ m.sub.y =m sin θ sin φ m.sub.z =m cos θ f. outputting the values of θ, φ, x 1 , y 1 and z 1 to an output.

Claim 10

A medical magnetic positioning system comprising: (a) a magnetic probe adapted to be inserted into a body of an individual, said probe having an a priori known magnetic moment magnitude; (b) at least two triaxial magnetometers adapted to be mounted on an external portion of the body proximate to an inserted location of the probe so that said magnetometers measure and provide output signals indicative of the three-dimensional magnetic field of the probe; and (c) a computer for calculating and storing information relative to the position of said probe, including its angular orientation, by using said output signals and said magnetic moment magnitude in a non-linear algorithm; and (d) a display system for displaying the position and angular orientation of said probe.

Claim 11

A medical magnetic positioning system comprising: (a) a magnetic probe adapted to be inserted into a body of an individual, said probe having an a priori known magnetic moment magnitude; (b) at least two triaxial magnetometers adapted to be mounted on an external portion of the body proximate to an inserted location of the probe so that said magnetometers measure and provide output signals indicative of the three-dimensional magnetic field of the probe; and (c) a computer for calculating and storing information relative to the position of said probe, including its angular orientation, by using said output signals and said magnetic moment magnitude in a non-linear algorithm; and (d) a display system for displaying the position and angular orientation of said probe.

Claim 12

The medical magnetic positioning system of claim 8, wherein the probe is a permanent magnet and the size of said probe is small, and is approximately 1 mm by 2 mm.

Claim 13

The medical magnetic positioning system of claim 8, wherein said probe is an AC magnetic probe.