Magnetic resonance apparatus

U.S. Patent Number: 5387868

Abstract: In magnetic resonance apparatus in a magnet system (1) for generating a steady magnetic field, a coil system (3) for generating gradient fields, and at least one RF coil (9) which is tuned to a predetermined frequency and connected to first and second input terminals (53, 55) of an input amplifier circuit (43) of a receiving device (13) for RF order to enable simulation of the loading of the RF coil (9) by a patient during installation and testing of the operation of the apparatus without utilizing a load phantom, the circuit formed by the RF coil (9) and the input amplifier circuit (43) comprises a load network (61 ). In one embodiments first and second input terminals (53, 55) of the input amplifier circuit (43) are interconnected via the load network (61) which comprises a series connection of a switch (63) and a resistor (65). The switch is preferably formed by a diode (63), one electrode of which is connected to one of the input terminals (53) of the input amplifier circuit (43), its other electrode being connected to one end of the resistor (65), the other end of which is connected to the other input terminal (55) via a capacitor (73). The junction point of the resistor (65) and the capacitor (73) is connected to a control terminal (71) whereto a positive or a negative direct voltage, relative to the first input terminal (53), can be applied as desired in order to set the diode (63) to a conductive state or a blocked state.

Inventors: Rust; Johan W. (Eindhoven, NL), Van Heelsbergen; Teunis R. (Eindhoven, NL)

Assignee: U.S. Philips Corporation (New York, NY)

Application Number: 08/116,387

Issued: 1995-02-07

Expired: 2007-02-07

Classes: 324/318 ; 324/322; 600/416; 600/422

Field of search: 324/322,318,314,309,307 128/653.5

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