The problem of synthesizing the standard 12-lead electrocardiogram (ECG) from the signals recorded using three special ECG leads is studied in detail. The implementation of that concept into the design of a new mobile ECG transtelephonic system is presented. The system has two separate units: a stationary diagnostic-calibration center and a mobile ECG device with integrated electrodes. The patient records by himself three special leads with the mobile ECG recorder and sends data via cellular phone to the personal computer in the diagnostic center where standard 12-lead ECG is numerically reconstructed on the base of the patient transformation matrix previously calculated into the calibration process. The experimental study shows high accuracy of the reconstructed ECG.
It is well known that medical linear accelerators generate activation products when operated above certain electron (photon) energies. The aim of the present work is to assess the activation behavior of a medium-energy radiotherapy linear accelerator by applying in situ gamma-ray spectrometry and dose measurements, and to estimate the additional dose to radiotherapy staff on the basis of these results. Spectral analysis was performed parallel to dose rate measurements in the isocenter of the linear accelerator, immediately after the termination of irradiation. The following radioisotopes were detected by spectral analysis: 28Al, 62Cu, 56Mn, 64Cu, 187W, and 57Ni. The short-lived isotopes such as 28Al and 62Cu are the most important factors of the clinical routine, while the contribution to the radiation dose of medium-lived isotopes such as 56Mn, 57Ni, 64Cu, and 187W increases during the working day. Measured dose rates at the isocenter ranged from 2.2 µSv/h to 10 µSv/h in various measuring points of interest for the members of the radiotherapy staff. Within the period of 10 minutes, the dose rate decreased to values of 0.8 µSv/h. According to actual workloads in radiotherapy departments, a realistic exposure scenario was set, resulting in a maximal additional annual whole body dose to the radiotherapy staff of about 3.5 mSv
This is a study on the properties of a square electrostatic rainbow lens
doublet. The said optical element consists of two square electrostatic
rainbow lenses with the second lens axially rotated for 45 degrees with
respect to the first one. The propagation of a proton beam with a kinetic
energy of 10 keV through the doublet is in the focus of our analysis. The
potential of the electrodes of both lenses is 2 kV. The electrostatic
potential and the electric field components of the lens doublet are
calculated using a 3-D computer code based on the method of moments. Spatial
and angular distributions of protons propagating through the lens doublet, as
well as the parameters defining beam quality, are investigated. As in the
case of the single square electrostatic rainbow lens, the evolution of these
distributions is determined by the evolution of corresponding rainbow lines,
generated by the use of the theory of crystal rainbows. Our study shows that
a beam core in the shape of a cusped square is formed by the spatial rainbow
line that appears first. This rainbow line occurs during proton propagation
through the first lens. The beam core retains the cusped square shape during
the propagation through the second lens. The electrostatic field of the
second lens causes the appearance of an additional spatial rainbow line,
which encompasses the beam core and defines the outer border of the beam.
This rainbow line constitutes the main difference between the cases of the
lens doublet and a single lens. [Projekat Ministarstva nauke Republike
Srbije, br. III45006]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.