Magnetic resonance apparatus for fast and reliable detection and recognition of minute quantities of specific substances

摘要

Detection and recognition of taggant substances having predefined zero external field magnetic resonance signatures. An object comprising taggant substance(s) is irradiated with a sequence of specific excitation pulses of electromagnetic radiation within a predetermined time and frequency scanning pattern, responsive nuclear spin echo signals are received from the object with a predetermined time and frequency acquisition pattern and data indicative thereof is generated. The scanning and acquisition patterns used permit successive transmission of pulses of multiple frequencies using a two-pulse spin-echo excitation technique, or a steady state-spin echo excitation technique, and successive acquisition of multiple nuclear spin echo response signals, within a time slot between two successive excitation pulses of a specific excitation frequency. The generated data is correlated with reference data corresponding to predetermined taggant substance(s) and one or more taggant substances are identified based on the determined correlation.

主权项

1. An apparatus for detection and recognition of taggant substances of a type having predefined zero external field magnetic resonance signatures, wherein the apparatus is configured as a hand-held device comprising:
a signal generator configured and operable for generating a sequence of specific excitation pulses of electromagnetic radiation within a predefined frequency band; a probehead comprising a transmitter connected to said signal generator and configured and operable to receive the sequence of specific excitation pulses of electromagnetic radiation, and to irradiate an object comprising one or more of the taggant substances with the pulsed electromagnetic radiation, and a receiver configured and operable for acquiring nuclear spin echo response signals from the irradiated object and generating data indicative thereof; a control system comprising: a transmission controller configured and operable to operate the signal generator to generate said sequence of specific excitation pulses having a predetermined time and frequency scanning pattern; an acquisition controller configured and operable to operate the receiver for acquiring the nuclear spin echo response signals with a predetermined time and frequency acquisition pattern, wherein the scanning and acquisition patterns are such that the pulses of multiple frequencies are successively transmitted using a two-pulse spin-echo excitation technique or a steady state-spin echo excitation technique, and multiple nuclear spin echo response signals are successively acquired within a time slot between two successive excitation pulses of a specific excitation frequency, said successively acquired responses are associated with said specific frequency and with other resonance frequencies, and said time slot being selected in accordance with spin-lattice relaxation time of nuclei resonating at said specific frequency; and an analyzer utility for receiving data indicative of the nuclear spin echo response signals, and correlating said data with reference data corresponding to one or more predetermined taggant substances, and based on determined correlation, identifying said one or more taggant substances.