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Magnetopneumography (MPG) as a non‐invasive method for pneumoconiosis diagnosis has been developed to evaluate the load and spatial distribution of particles within the human lungs through scanning of remanent magnetic fields after magnetization of the subject in a strong direct current field. The measurement of particle spatial distribution is very important for pneumoconiosis diagnosis because localized deposits may be associated with some pathological changes such as pulmonary fibrosis. Previous research found that loads of magnetite particles were proportional to their magnetic dipole moments. The three‐dimensional (3D) MPG magnetic dipole model (MDM) proposed in this paper and based on Biot–Savart Law and matrix manipulation provides a means of precise measurement of the particle distribution and load amount. A styrofoam + magnetite powder phantom with magnetization was laid on a nonmagnetic board. Two first‐order fluxgate gradiometers with 10–12 T sensitivity were coaxially applied over and under the phantom and used for scanning remanent magnetic fields. This paper provides validation results using 3D MPG MDM through two experiments. The overall error of the simulation results is 0.2–2.7% in the center and 7.28–9.42% in the corners of the subject. Finally, this paper gives clinical experiments with a welder suffering stage‐II pneumoconiosis and states that the 3D MPG MDM shows similar results to X‐ray chest films in pneumoconiosis diagnosis. The results suggest that the 3D MPG MDM is potentially a reasonable and accurate algorithmic model to inversely track the load amount and distribution of magnetite particles within the lungs. Bioelectromagnetics. 2019;40:472–487. © 2019 Wiley Periodicals, Inc

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This article proposes a new algorithm for real-time sub-nanosecond level time synchronization based on GNSS RTK technique and the Kalman Filtering. It is able to improve the performance of time synchronization system as well as a sub-nanosecond level, with a real time response. Although the IGS products theoretically improve the accuracy up to a sub-nanosecond or even higher level, the weakness of more pool performance in a shorter duration and of a lower update rate make us scarcely possibly get an accurate timekeeping upper than nanosecond level only relying on the IGS products. The RTK TIC algorithm uses the RTK position results of (xrtk, yrtk, zrtk) to inversely and iteratively update the time keeping results from pseudorange PVT equations to a high level accuracy. Meanwhile, in order to suppress the error coming from ephemeris change, the FS725 Stanford Rubidium Atomic Clock are used as a compensation equipment for coupling the GNSS timekeeping results via the Kalman Filtering. Then, this paper gives the validation of the RTK TIC algorithm with a two-channel system and compares mean values and standard deviations between our system and two SYN4505As, the results shows our system has a better timekeeping accuracy than the SYN4505As. At last, this paper calibratesthe accuracy of our system via the standard clock source in the NTCS, and gives the results that our system has an excellent performance on the real-time sub-nanosecond level time synchronization.