# US 7,609,064 B2 · Probe configured for NMR apparatus and NMR apparatus using the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,609,064 B2
- Document ID: US7609064B2
- Status: Granted
- Kind: B2
- Application number: 11/757,453
- Filed: 2007-06-04
- Published: 2008-03-13
- Granted: 2009-10-27
- Earliest claimed: 2006-05-06
- Assignees: Hitachi, Ltd.
- Inventors: Yuzo Fukuda; Kazuo Saitoh; Hiroyuki Yamamoto; Michiya Okada
- Web page: https://patentgrep.com/patent/US7609064B2

## CPC

- G01R 33/3657: {Decoupling of multiple RF coils wherein the multiple RF coils do not have the same function in MR, e.g. decoupling of a transmission coil from a receive coil}
- G01R 33/34053: {Solenoid coils; Toroidal coils}
- G01R 33/34069: {Saddle coils}
- G01R 33/34023: {Superconducting RF coils}
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

A probe for a nuclear magnetic resonance apparatus comprises: a transmission coil for irradiating a sample with a high-frequency electromagnetic wave; and a receiving coil for detecting a nuclear magnetic resonance signal emitted by the sample, wherein a selector switch is disposed to the transmission coil to reduce the deterioration of sensitivity of the receiving coil by switching the resonance state of the transmission circuit between during irradiation and during detection, even if an electromagnetic coupling remains between transmission and reception.

## Claims

### Claim 1

A probe configured for a nuclear magnetic resonance apparatus, comprising:
a transmission coil irradiating a sample with a high-frequency electromagnetic wave; and
a receiving coil detecting a nuclear magnetic resonance signal emitted by the sample,
wherein said transmission coil is provided with a selector switch made of a superconductor material having a critical temperature equal to or less than 20° K in a magnetic field,
wherein the transmission coil and the receiving coil are placed in a static magnetic field generated by a magnet, and
wherein a resonance state is switched by the selector switch.

### Claim 2 (depends on 1)

The probe configured for a nuclear magnetic resonance apparatus according to claim 1, wherein said selector switch is inserted in series with the transmission coil.

### Claim 3 (depends on 2)

The probe configured for a nuclear magnetic resonance apparatus according to claim 2, wherein said selector switch operates in order to switch to an ON state during irradiation and operates in order to switch to an OFF state during reception.

### Claim 4 (depends on 1)

The probe configured for a nuclear magnetic resonance apparatus according to claim 1, wherein said selector switch is inserted in parallel with the transmission coil.

### Claim 5 (depends on 4)

The probe configured for a nuclear magnetic resonance apparatus according to claim 4, wherein said selector switch operates in order to switch to an OFF state during irradiation and operates in order to switch to an ON state during reception.

### Claim 6 (depends on 1)

The probe configured for a nuclear magnetic resonance apparatus according to claim 1, wherein a resonance frequency and an impedance of a resonance circuit are adjusted by said selector switch.

### Claim 7 (depends on 1)

The probe configured for a nuclear magnetic resonance apparatus according to claim 1, wherein said selector switch employs the superconductor switches in a passive manner according to a transmission or reception state using a critical current as a threshold value.

### Claim 8 (depends on 1)

The probe configured for a nuclear magnetic resonance apparatus J according to claim 1, wherein said selector switch employs the superconductor switches in an active manner according to a temperature rise caused by heater heating, and wherein switching of said selector switch occurs at a temperature equal to or smaller than 20° K.

### Claim 9 (depends on 8)

The probe configured for a nuclear magnetic resonance apparatus according to claim 8, wherein when said heater is in an ON state, said selector switch is in an OFF state, and when said heater heating is in an OFF state, said selector switch is in an ON state, and
wherein during reception, said selector switch is in an OFF state (heater ON), and during irradiation, said selector switch is in an ON state (heater OFF).

### Claim 10 (depends on 1)

The probe configured for a nuclear magnetic resonance apparatus according to claim 1, wherein a semiconductor device is employed as said selector switch.

### Claim 11

A nuclear magnetic resonance apparatus, comprising:
a transmission coil irradiating a sample with a high-frequency electromagnetic wave; and
a receiving coil detecting a nuclear magnetic resonance signal emitted by the sample, wherein said transmission coil is provided with a probe having a selector switch made of a superconductor material having a critical temperature equal to or less than 20° K. in a magnetic field,
wherein the transmission coil and the receiving coil are placed in a static magnetic field generated by a magnet, and
wherein a resonance state is switched by the selector switch.

### Claim 12 (depends on 11)

The nuclear magnetic resonance apparatus according to claim 11, wherein a resonance frequency and an impedance of a resonance circuit are adjusted by said selector switch.