COIL ARRANGEMENT FOR A MAGNETIC INDUCTION IMPEDANCE MEASUREMENT APPARATUS COMPRISING A PARTLY COMPENSATED MAGNETIC EXCITATION FIELD IN THE DETECTION COIL

• US 20130314081A1
• Filed: 02/09/2012
• Published: 11/28/2013
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Igney, Claudia Hannelore, Rosell Ferrer, Francisco Javier, Hamsch, Matthias
• Granted Patent: US 9,448,205 B2
• Time in Patent Office: Days
• US Class Current: 324/239
• CPC Class Codes: A61B 2562/0223 Magnetic field sensors
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: G01N 27/023 where the material is placed in the field of a coil
• CPC Class Codes: G01N 27/72 by investigating magnetic variables
• CPC Class Codes: G01V 3/107 using compensating coil or loop arrangements

Abstract

A coil arrangement (215) for a magnetic induction impedance measurement apparatus comprises an excitation coil (208) configured for generating a magnetic excitation field in an object, a shimming coil (364) for generating a shimming field, and a detection coil (210-214) configured for detecting a magnetic response field generated in response to the magnetic excitation field inducing a current in the object (106). In order to enhance an accuracy of a determination of a parameter of an object, a value of a field strength of a net magnetic excitation field in the detection coil (210-214), being the sum of the excitation field and the shimming field, is approximately within a magnitude range of an average value of a field strength of the magnetic response field in the detection coil (210-214).

Claims

1. A coil arrangement (215) for a magnetic induction impedance measurement apparatus (100), the coil arrangement (215) comprising:

an excitation coil (208) configured for generating a magnetic excitation field in an object (106), and

a detection coil (210-214) configured for detecting a magnetic response field generated in response to the magnetic excitation field inducing a current in the object (106), wherein a value of a field strength of a net magnetic excitation field in the detection coil (210-214) comprises a magnitude range of an average value of a field strength of the magnetic response field in the detection coil (210-214).

2. The coil arrangement (215) according to claim 1, wherein the value of the field strength of the net magnetic excitation field in the detection coil (210-214) is equal to the average value of the field strength of the magnetic response field in the detection coil (210-214).

3. The coil arrangement (215) according to claim 1 or 2, the coil arrangement (215) further comprising:

a shimming coil (364) configured for generating a magnetic shimming field in the detection coil (210-214) such that the value of the field strength of the net magnetic excitation field in the detection coil (210-214) comprises the magnitude range of the average value of the field strength of the magnetic response field in the detection coil (210-214).

4. The coil arrangement (215) according to anyone of claims 1 to 3, the coil arrangement (215) further comprising:

at least another detection coil (210-214) configured for detecting the magnetic response field generated in response to the magnetic excitation field inducing the current in the object (106),

wherein a value of a field strength of a net magnetic excitation field in the at least another detection coil (210-214) comprises a magnitude range of an average value of a field strength of the magnetic response field in the at least another detection coil (210-214).

5. The coil arrangement (215) according to anyone of claims 1 to 4, wherein the coil arrangement (215) comprises a planar configuration.

6. A magnetic induction impedance measurement apparatus (100) for determining a parameter of an object (106), the magnetic induction impedance measurement apparatus (100) comprising:

a coil arrangement (215) according to anyone of claims 1 to 5, and

a parameter determination unit (254) configured for determining the parameter of the object (106) based on the magnetic response field and the magnetic excitation field.

7. The magnetic induction impedance measurement apparatus (100) according to claim 6, the magnetic induction impedance measurement apparatus (100) further comprising:

a phase difference value determination unit (224-228) configured for determining a phase difference value between a phase value of a phase of the magnetic excitation field and a phase value of a phase of the magnetic response field, wherein the parameter determination unit (254) is configured for determining the parameter of the object (106) based on the determined phase difference value.

8. The magnetic induction impedance measurement apparatus (100) according to claim 6 or 7, the magnetic induction impedance measurement apparatus (100) further comprising:

an excitation field phase value generating unit (218) configured for generating a excitation phase value signal indicative of a phase value of the phase of the magnetic excitation field and to be provided to the excitation coil (208) and the phase difference value determination unit (224-228).

9. The magnetic induction impedance measurement apparatus (100) according to anyone of claims 6 to 8, wherein the magnetic induction impedance measurement apparatus (100) is configured as a magnetic induction impedance tomography apparatus.

10. A method of determining a parameter of an object (106), the method comprising:

generating by an excitation coil (208) a magnetic excitation field in an object (106),

detecting by a detection coil (210-214) a magnetic response field in the detection coil (210-214), wherein the magnetic response field is generated in response to the magnetic excitation field inducing a current in the object (106), wherein a value of a field strength of a net magnetic excitation field in the detection coil (210-214) comprises a magnitude range of an average value of a field strength of the magnetic response field in the detection coil (210-214), and

determining the parameter of the object (106) based on the detected magnetic response field and the magnetic excitation field.

11. The method according to claim 10, the method further comprising:

adjusting the value of the field strength of the net magnetic excitation field in the detection coil (210-214) prior to the determining of the parameter of the object (106).

12. The method according to claim 11, wherein the adjusting comprises at least one of

adjusting a shape of the excitation coil (208) and/or the detection coil (210-214),

adjusting a relative arrangement of the excitation coil (208) and the detection coil (210-214),

adjusting a shape of a shimming coil (364), and

adjusting a relative arrangement of the shimming coil (364) and at least one of the excitation coil (208) and the detection coil (210-214).

13. The method according to claim 11 or 12, wherein the adjusting comprises at least one

arranging a reference object (106) in a vicinity of the excitation coil (208) and the detection coil (210-214), and at least one of detecting and calculating the magnetic response field, and

arranging the object (106) in a vicinity of the excitation coil (208) and the detection coil (210-214), and detecting the magnetic response field over a time period associated with the field strength of the magnetic response field comprising the average value.

14. A program element, which program element, when being executed by a processor, is configured to carry out or control a method of determining a parameter of an object (106) according to anyone of claims 10 to 13.