MRI protector

• US 20030171669A1
• Filed: 03/11/2002
• Published: 09/11/2003
• Est. Priority Date: 03/11/2002
• Status: Active Grant

• Current Assignee: Keith A. Kopp
• Original Assignee: Keith A. Kopp
• Inventors: Kopp, Keith A.
• Granted Patent: US 7,489,128 B2
• Time in Patent Office: Days
• US Class Current: 600/410
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12

Abstract

An MRI protector for protecting personnel and the MRI apparatus from the introduction of ferrous articles into the magnetic field of the MRI has an array of Hall effect sensors oriented to scan the magnetic field of the MRI. The Hall effect sensors are oriented to scan the magnetic field at the access door of the shielded MRI room. The sensors are connected to a central processing unit (CPU) which analyses the output of the sensors and propagates a warning when the presence of ferrous articles affects the magnetic field of the MRI.

Claims

1. An access opening in a shielded room housing an MRI apparatus, said opening having a doorway, a detector adapted to be mounted at the access doorway, said detector comprising an array of Hall effect sensors each having an output, said sensors oriented to scan the magnetic field generated by the MRI apparatus and passing through the access doorway, said sensors detecting the introduction of ferrous articles into said magnetic field, the outputs of said sensors connected to an alarm system, said alarm system generating a warning to personnel.

2. A detector as claimed in claim 1 wherein said array is composed of a plurality of Hall effect sensors vertically aligned in pairs, one of each pair on opposite sides of the access door.

3. A detector as claimed in claim 2 wherein one or more of said outputs change in response to a change in said magnetic field, said alarm system includes a central processing unit which converts said outputs to signals, analyses said signals according to programmed parameters, and generates said warning.

4. A detector as claimed in claim 3 wherein said central processing unit includes a signal pre-amplifier and pre-processor for receiving said outputs and producing reliable signals, a signal processor for analysis of said signals, said analysis determining propagation of said warning.

5. A detector as claimed in claim 2 wherein said alarm system has a display and warning panel.

6. A detector as claimed in claim 5 wherein said panel is inside said room.

7. A detector of claim 5 wherein said panel is outside said room.

8. A detector as claimed in claim 5 wherein said panel includes an aural warning.

9. A detector as claimed in claim 5 wherein said panel includes a visual warning.

10. A detector as claimed in claim 9 wherein said panel includes visual and aural warning.

11. A detector of claim 6 wherein said panel includes an aural warning.

12. A detector of claim 6 wherein said panel includes a visual warning.

13. A detector of claim 12 wherein said panel includes visual and aural warning.

16. A detector as claimed in claim 2 wherein said array includes a door closed sensor adapted to be interposed between the access doorway and a door to deactivate said detector when said door is closed.

14. An access opening in a shielded room housing an MRI apparatus, said opening having an access doorway, a detector adapted to be mounted at the access doorway, said detector comprising an array of Hall effect sensors each having an output, said sensors oriented to scan the magnetic field generated by the MRI apparatus and passing through said access door, said sensors detecting the introduction of ferrous articles into said magnetic field, the outputs of said sensors connected to an alarm system, said alarm system including a scan disable mode, said alarm system generating a warning to personnel.

15. A detector as claimed in claim 14 wherein said array includes a door closed sensor adapted to be interposed between the access doorway and a door to deactivate said detector when said door is closed.