System and method for hand-held NQR-based in-field screening of substances

1. An integrated nuclear quadrupole resonance-based detection system comprising:

a front-end device having a hand-held form factor, wherein the front-end device is configured to scan a sample in or near a sample coil using inbuild electronics and acquire a nuclear quadrupole resonance measurement,

a swappable sample coil that is attached to an opening at a face of the front-end device and is tuned to a resonant frequency of the sample; and

a swappable impedance matching network that is attached to the opening at the face of the front-end device and is configured to tune the resonant frequency of the sample coil,

wherein the inbuild electronics comprises a wireless transfer module that is configured to communicate the acquired nuclear quadrupole resonance measurement with a back-end device of the integrated nuclear quadrupole resonance-based detection system.

2. The system of claim 1 , wherein the swappable sample coil comprises a cylindrical coil without a Faraday cage and the inbuild electronics comprises active noise cancellation circuitry to reduce unwanted radio frequency (RF) interference.

3. The system of claim 1 , wherein the swappable sample coil comprises a planar coil.

4. The system of claim 1 , wherein the swappable sample coil is tuned over 1.5 MHz to 3 MHz for 14N nuclear quadrupole resonance measurements.

5. The system of claim 1 , wherein the swappable sample coil is tuned over 20 MHz to 35 MHz for 35Cl nuclear quadrupole resonance measurements.

6. The system of claim 1 , wherein the inbuild electronics comprise at least the impedance matching network, the wireless transfer module, a transmitter, a preamplifier, a duplexer, an analog to digital converter, and a digital to analog converter, wherein the inbuild electronics are integrated within a single custom application-specific integrated circuit.

7. The system of claim 1 , further comprising the back-end device, wherein the back-end device is physically separate from the front-end device.

8. The system of claim 7 , wherein the back-end device is configured to wirelessly receive the nuclear quadrupole resonance measurement for the sample and generate a nuclear quadrupole resonance signature for the sample from the nuclear quadrupole resonance measurement.

9. The system of claim 8 , wherein the back-end device is further configured to compare the nuclear quadrupole resonance signature of the sample with nuclear quadrupole resonance signatures of known chemicals and generate a test report based on the comparison.

10. A method comprising:

providing the front-end device of claim 1 ;

selecting the swappable sample coil based on a size of the sample to be scanned, wherein a planar coil is selected for a sample having a planar geometry; a cylindrical coil is selected for a sample that can fit in a center space of the cylindrical coil; and a U-shaped coil is selected for a sample that has a length that is longer than a width of the sample;

scanning the sample to acquire the nuclear quadrupole resonance measurement; and

transmitting the nuclear quadrupole resonance measurement to the back-end device.

11. The method of claim 10 , further comprising:

generating a nuclear quadrupole resonance signature for the sample from the nuclear quadrupole resonance measurement received by the back-end device;

comparing the nuclear quadrupole resonance signature of the sample with nuclear quadrupole resonance signatures of known chemicals;

generating a test report based on the comparison that identifies the sample; and

wireless transmitting the test report to the front-end device or a mobile user device.

12. An integrated nuclear quadrupole resonance-based detection method comprising:

attaching a swappable sample coil to an opening at a face of a front-end device of an integrated nuclear quadrupole resonance-based detection system;

positioning a sample in or near a sample coil of the front-end device, wherein the front-end device has a hand-held form factor;

tuning the sample coil to a resonant frequency of the sample by an impedance matching network;

acquiring a nuclear quadrupole resonance measurement of the sample; and

wirelessly communicating the acquired nuclear quadrupole resonance measurement to a back-end device of the integrated nuclear quadrupole resonance-based detection system.

13. The method of claim 12 , wherein the impedance matching network comprises a swappable impedance matching network, the method further comprising attaching the swappable impedance matching network to the opening at the face of the front-end device.

14. The method of claim 12 , further comprising:

generating a nuclear quadrupole resonance signature for the sample from the nuclear quadrupole resonance measurement received by the back-end device;

comparing the nuclear quadrupole resonance signature of the sample with nuclear quadrupole resonance signatures of known chemicals;

generating a test report based on the comparison that identifies the sample; and

wireless transmitting the test report to the front-end device or a mobile user device.

15. The method of claim 14 , further comprising generating a nuclear quadrupole resonance signature for the sample from the nuclear quadrupole resonance measurement.

16. The method of claim 12 , wherein the swappable sample coil comprises a cylindrical coil without a Faraday cage.

17. The method of claim 12 , wherein the swappable sample coil is tuned over 1.5 MHz to 3 MHz for 14N nuclear quadrupole resonance measurements.

18. The method of claim 12 , wherein the swappable sample coil is tuned over 20 MHz to 35 MHz for 35Cl nuclear quadrupole resonance measurements.

19. The method of claim 12 , further comprising selecting between two output stages with different power handling capabilities based on an input signal received from the back-end device.

20. The method of claim 19 , wherein the input signal comprises a differential square wave.