WAVEGUIDE AND COMPUTED TOMOGRAPHY SYSTEM WITH A WAVEGUIDE

• US 20110019792A1
• Filed: 03/12/2009
• Published: 01/27/2011
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Thijs, Jeroen Adrianus Johannes, Pinter, Robert, Muehlsteff, Jens
• Granted Patent: US 8,559,589 B2
• Time in Patent Office: Days
• US Class Current: 378/8
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/04 Positioning of patients; Tiltable beds or the like operating tables A61G13/00; operating chairs A61G15/00
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: H01P 3/16 Dielectric waveguides, i.e. without a longitudinal conductor
• CPC Class Codes: H01P 3/18 built-up from several layers to increase operating surface, i.e. alternately conductive and dielectric layers

Abstract

The invention relates to a waveguide (24) for focusing electromagnetic energy on an area of interest, said waveguide (24) comprising outer walls forming a channel with a width (w) and a height (h) for the propagation of the electromagnetic waves. In order to be able to focus the EM waves on an area of interest, i.e. the chest of a patient (20), so that influences which other moving objects in the environment have on the waves, are shielded away, the channel is provided with a first opening and a second opening wherein said walls are non-metal hollow walls filled with an electrically conductive liquid. The waveguide (24) can be used for example with a computed tomography system (12) CT with a rotating gantry (16) and a patient table (18). The waveguide (24) will not produce artefacts in the CT image by scattering the X-ray, like a metal wall would do it. Nevertheless the conductive liquid makes the construction work as a waveguide for EM waves.

Claims

1. A waveguide (24) for focusing electromagnetic energy on an area of interest, said waveguide (24) comprising outer walls (30) forming a channel (28) with a width (w) and a height (h) for the propagation of the electromagnetic waves, said channel (28) having a first opening (32) and a second opening (34), wherein said walls (30) are non-metal hollow walls filled with an electrically conductive liquid or gel.

2. A waveguide according to claim 1, wherein the width (w) and the height (h) of the channel (28) and the channel openings (32, 34) are tailored to the frequency of the electromagnetic waves that are to be transported through the channel (28).

3. A waveguide according to claim 2, wherein the width (w) is basically equal to two times the height (h).

4. The apparatus comprising a radar sensor (14) emitting electromagnetic waves said radar sensor (14) including an antenna (15), a control unit (27) and at least one waveguide (24) according to claim 1 for the focusing of said electromagnetic waves on an area of interest of a subject (20) to be examined, said at least one waveguide (24) having its first opening (32) oriented towards the radar sensor (14).

5. An apparatus according to claim 4, wherein the radar sensor (14) is a Doppler radar sensor.

6. The apparatus according to claim 4, wherein a distance piece is located between the radar antenna (15) and the subject (20) to be examined, whereby said distance piece is formed by said at least one waveguide (24).

7. The apparatus according to claim 4, wherein a support device (18) is provided upon which the subject (20) to be examined can be placed temporarily.

8. An apparatus according to claim 7, wherein the subject to be examined is a patient (20) and the support device is a patient table (18) to receive the patient (20).

9. An apparatus according to claim 8, wherein the at least one waveguide (24) is located within the patient table (18).

10. An apparatus according to claim 9, wherein the radar sensor (14) is installed in the patient table (18).

11. The apparatus according to claim 8, wherein the control unit (27) is installed in the patient table (18).

12. The apparatus according to claim 4, wherein multiple waveguides (124) form an array (26) of waveguides.

13. An apparatus according to claim 12, wherein multiple radar sensors (14) are used feeding the waveguide array (26).

14. A computed tomography system (12) with a rotating gantry (16), said computed tomography system (12) comprising a system control, the apparatus according to claim 4 and a waveguide (24) for focusing electromagnetic energy on an area of interest, said waveguide (24) comprising outer walls (30) forming a channel (28) with a width (w) and a height (h) for the propagation of the electromagnetic waves, said channel (28) having a first opening (32) and a second opening (34), wherein said walls (30) are non-metal hollow walls filled with an electrically conductive liquid or gel wherein the apparatus detects motion in the patient (20) due to respiration or due to the blood pumping of the heart and provides a gating signal to the system control said gating signal triggering the acquisition of CT data.