Radio frequency shielded and acoustically insulated enclosure

(54) RADIO FREQUENCY SHIELDED AND

ACOUSTICALLY INSULATED ENCLOSURE

(75) Inventor: Walter J. Christen, Wettingen (CH)

(73) Assignee: IGT, Reno, NV (US)

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 10/000,109

(22) Filed: Oct. 30, 2001

(51) Int. C I. H05K 9/00

(52) U.S. CI 181/290; 174/35 MS; 52/79.1;

455/300

(58) Field of Search 174/35 MS; 455/300;

181/290, 285, 294, 295, 284; 52/79.1

(56) References Cited

U.S. PATENT DOCUMENTS

1,789,827 A 1/1931 McKay

2,440,763 A 5/1948 Todhunter

3,557,777 A 1/1971 Cohen

4,370,831 A 2/1983 Hamilton

(List continued on next page.)

OTHER PUBLICATIONS

Magnetically shielded rooms in diagnostics and semi-conductor technology written by Karl-Jiirgen Best, Jochen Bork, published Edition 2/91.

Noise Reduction and Sound Attention Properties (website) written by www.steelceilings.com, printed Oct. 24, 2001.

The present invention provides a radio frequency ("RF") shielded and acoustically isolated enclosure that efficiently employs multiple layers of sound insulation and absorbs airborne noise and the noise provided by magnetic resonance imaging ("MRI") equipment through the supports of such equipment. The RF enclosure uses multiple layers and types of insulating materials positioned to maximize the noise absorption of the RF enclosure. This reduces the cost and space required by the enclosure. In one embodiment the enclosure includes a ceiling, a floor and a plurality of walls. The ceiling and walls include one or more multiple layers of different indulating materials that either abut each other or form air gaps. In one embodiment the floor includes a heavy metal plate on which the MRI equipment sits. The plate elastically couples to a conductive shield. The elastic coupling attenuates certain frequencies above the natural frequency of the metal sheet.

33 Claims, 6 Drawing Sheets

Page 2

6,085,865 A 7/2000 Delverdier et al.
6,170,203 Bl 1/2001 Schlapfer
6,282,848 Bl 9/2001 Schlapfer

OTHER PUBLICATIONS

IMEDCO Protective Shielding for MRI Equipment Brochure written by Imedco, published prior to Oct. 30, 2001. IMEDCO Custom RF Window Options written by Imedco, published prior to Oct. 30, 2001.

PRB Gyroscan written by Philips Medical Systems, published in 2000.

Heavily Magnetically Shielded Room For Measurements of
Extremely Weak Magnetic Fields, written by A. Mager, L.
Borek, published prior to Oct. 30, 2001.
Superconducting Shield For Biomagnetism Measurement
Coupled With Ferro-Magnetic written by H. Matsuba, D.
Irisawa, A. Yahara, published prior to Oct. 30, 2001.
A Two-Shell Magnetically Shielded Room For Magneto-
physiology written by Y. Okada, B. Shah, published prior to
Oct. 30, 2001.

High Tc Superconducting Magnetic Shields For Biomagnetic Applications written by Y. Shimbo, K. Nakada, K. Niki, M. Kabasawa, Y. Uchikawa, M. Kotani, published prior to Oct. 30, 2001.

A Clinically Oriented Shielded Facility For Biomagnetism written R.J.P. Bain, G.B. Donaldson, CM. Pegrum, P. Maas, A.I. Weir, published prior to Oct. 30, 2001. Designing and Inspecting System of Prefabricated Magnetically Shielded Room For Biomagnetism written by K. Okuda, J. Takeuchi, M. Mukai, S. Kuriki, Y. Uchikawa, M. Kotani, published prior to Oct. 30, 2001. Shielding Factor of the Box-Shaped MSR for SQUID Measurement written by N. Ishikawa, N. Kasai, H. Kado, published prior to Oct. 30, 2001.

Magnetically Shielded Rooms for Biomagnetic Investigations written by Vacuumschmelze GmbH, published prior to Oct. 30, 2001.

Understanding Shielding written by James. P. Antonic, published prior to Oct. 30, 2001.

Design, Construction, and Performance of a Large-Volume Magnetic Shield written by Vaino O. Kelha, Jussi M. Pukki, Risto S. Peltonen, Auvo J. Penttinen, Risto J. Ilmonimi, and Jarmo J. Heino, published Jan. 1982.