In this paper, we present a portable NMR relaxometry system optimized for the point-of-care analysis of body liquids such as blood. The presented system is centered on an NMR-on-a-chip transceiver ASIC, a reference frequency generator with arbitrary phase control, and a custom-designed miniaturized NMR magnet with a field strength of 0.29 T and a total weight of 330 g. The NMR-ASIC co-integrates a low-IF receiver, a power amplifier, and a PLL-based frequency synthesizer on a total chip area of 1100 $$ 900 $\mu$ m$^2$. The arbitrary reference frequency generator enables the use of conventional CPMG and inversion sequences, as well as modified water-suppression sequences. Moreover, it is used to implement an automatic frequency lock to correct temperature-induced magnetic field drifts. Proof-of-concept measurements on NMR phantoms and human blood samples show an excellent concentration sensitivity of v$_c,min$ = 2.2 mM/$\rmHz$. This very good performance renders the presented system an ideal candidate for the future NMR-based point-of-care detection of biomarkers such as the blood glucose concentration.
%0 Journal Article
%1 10155209
%A Dreyer, Frederik
%A Yang, Qing
%A Alnajjar, Belal
%A Krüger, Daniel
%A Blümich, Bernhard
%A Anders, Jens
%D 2023
%J IEEE Transactions on Biomedical Circuits and Systems
%K
%P 1-12
%R 10.1109/TBCAS.2023.3287281
%T A portable chip-based NMR relaxometry system with arbitrary phase control for point-of-care blood analysis
%X In this paper, we present a portable NMR relaxometry system optimized for the point-of-care analysis of body liquids such as blood. The presented system is centered on an NMR-on-a-chip transceiver ASIC, a reference frequency generator with arbitrary phase control, and a custom-designed miniaturized NMR magnet with a field strength of 0.29 T and a total weight of 330 g. The NMR-ASIC co-integrates a low-IF receiver, a power amplifier, and a PLL-based frequency synthesizer on a total chip area of 1100 $$ 900 $\mu$ m$^2$. The arbitrary reference frequency generator enables the use of conventional CPMG and inversion sequences, as well as modified water-suppression sequences. Moreover, it is used to implement an automatic frequency lock to correct temperature-induced magnetic field drifts. Proof-of-concept measurements on NMR phantoms and human blood samples show an excellent concentration sensitivity of v$_c,min$ = 2.2 mM/$\rmHz$. This very good performance renders the presented system an ideal candidate for the future NMR-based point-of-care detection of biomarkers such as the blood glucose concentration.
@article{10155209,
abstract = {In this paper, we present a portable NMR relaxometry system optimized for the point-of-care analysis of body liquids such as blood. The presented system is centered on an NMR-on-a-chip transceiver ASIC, a reference frequency generator with arbitrary phase control, and a custom-designed miniaturized NMR magnet with a field strength of 0.29 T and a total weight of 330 g. The NMR-ASIC co-integrates a low-IF receiver, a power amplifier, and a PLL-based frequency synthesizer on a total chip area of 1100 $\bm {\times }$ 900 $\mu$ m$\bm {^{2}}$. The arbitrary reference frequency generator enables the use of conventional CPMG and inversion sequences, as well as modified water-suppression sequences. Moreover, it is used to implement an automatic frequency lock to correct temperature-induced magnetic field drifts. Proof-of-concept measurements on NMR phantoms and human blood samples show an excellent concentration sensitivity of v$\bm {_\rm{c,min}}$ = 2.2 mM/$\bm {\sqrt{\rm{Hz}}}$. This very good performance renders the presented system an ideal candidate for the future NMR-based point-of-care detection of biomarkers such as the blood glucose concentration.},
added-at = {2023-07-21T21:24:37.000+0200},
author = {Dreyer, Frederik and Yang, Qing and Alnajjar, Belal and Krüger, Daniel and Blümich, Bernhard and Anders, Jens},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/26daedfa163ab19eb8aafd111da731e5a/qingyang},
doi = {10.1109/TBCAS.2023.3287281},
interhash = {6fa70ff20cadb082b80dc5381994fc32},
intrahash = {6daedfa163ab19eb8aafd111da731e5a},
issn = {1940-9990},
journal = {IEEE Transactions on Biomedical Circuits and Systems},
keywords = {},
pages = {1-12},
timestamp = {2023-07-21T21:27:38.000+0200},
title = {A portable chip-based NMR relaxometry system with arbitrary phase control for point-of-care blood analysis},
year = 2023
}
