Variable-pitch rectangular cross-section radiofrequency coils for the nitrogen-14 nuclear quadrupole resonance investigation of sealed medicines packets.
The performance of rectangular radio frequency (RF) coils capable of being used to detect nuclear quadrupole resonance (NQR) signals from blister packs of medicines has been compared. The performance of a fixed-pitch RF coil was compared with that from two variable-pitch coils, one based on a design in the literature and the other optimized to obtain the most homogeneous RF field over the whole volume of the coil. It has been shown from (14)N NQR measurements with two medicines, the antibiotic ampicillin (as trihydrate) and the analgesic medicine Paracetamol, that the latter design gives NQR signal intensities almost independent of the distribution of the capsules or pills within the RF coil and is therefore more suitable for quantitative analysis.
Department of Informatics, King's College, Strand, London WC2R 2LS, London, United Kingdom. jamie.barras@kcl.ac.uk
Jamie
J
Barras
Shota
S
Katsura
Hideo
H
Sato-Akaba
Hideo
H
Itozaki
Georgia
G
Kyriakidou
Michael D
MD
Rowe
Kaspar A
KA
Althoefer
John A S
JA
Smith
D000082:Acetaminophen / Q000737:chemistry*; D000667:Ampicillin / Q000737:chemistry*; D058110:Counterfeit Drugs / Q000737:chemistry; D004349:Drug Packaging; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D011846:Radio Waves
D058110:Counterfeit Drugs; D000082:Acetaminophen; D000667:Ampicillin