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Biomedical subjects

H G Hughes

Publications and source records attributed to H G Hughes.

8 recordsLinked to original sources
PubMed2006

Proton radiography applications with MCNP5.

A modified version of MCNP5 has been developed to treat continuous-energy proton transport. This work is summarised in companion papers by Hughes et al. and Bull et al. (in these proceedings). An intrinsic part of this development effort has involved testing, verification and validation of a capability for simulating proton radiographs. This paper presents the results of calculations simulating various different test objects and the effects of alternative physics models. The significant physics processes include elastic scattering, multiple coulomb scattering, collisional energy-loss and straggling, magnetic fields and attenuation owing to nuclear interactions. Comparisons with experimental data are presented.

Algorithms↗
PubMed2005

Magnetic field tracking with MCNP5.

With the introduction of continuous-energy heavy charged particle transport in MCNP5, the need for tracking charged particles in a magnetic field becomes increasingly important. Two methods for including magnetic field effects on charged particles are included in the proton transport version of the code. The first technique utilises transfer maps produced by the beam dynamics simulation and analysis code COSY INFINITY. This method is fast and accurate; however, its use is limited to void cells only and to ensembles of particles with a fairly small energy spread. The second technique, particle ray tracing, is based on an algorithm adopted from the MARS transport code. This method can be applied to both void and material cells and is valid over a very large range of particle energies. Results from tracking particles in a quadrupole 'identity lens' using the two techniques are compared.

Computer Simulation↗
PubMed1986

Cervical spine movement during orotracheal intubation.

We measured cervical spine movement during orotracheal intubation in 16 anesthetized patients without neck injury. Comparisons were made using straight and curved laryngoscope blades without stabilization, Philadelphia collar stabilization, and in-line stabilization by an assistant. There was cervical spine movement in all cases. There was no significant difference in movement without stabilization when comparing straight and curved laryngoscope blades (P = .8536). There was no significant decrease in movement when a Philadelphia collar was applied (P = 1.000). There was a significant decrease in movement when in-line stabilization was applied (P = 0.0056). Although none of the methods tested totally prevented cervical spine movement during orotracheal intubation, the least movement was obtained by the use of in-line stabilization by an assistant. The type of laryngoscope blade used or application of a Philadelphia collar did not reduce movement significantly.

Adult↗
PubMed1983

Traumatic disruption of the brachiocephalic artery.

We report the case of a patient presenting with blunt chest and head injuries. Initial emergency department evaluation revealed a pulmonary contusion and suspected closed head injuries. Computed tomographic scan of the head was unremarkable. An angiogram performed to further investigate the nature of his head injuries revealed a disruption of the brachiocephalic artery. The lesion was surgically repaired in the operating room and the patient was moved to the intensive care unit, where he remained comatose and died from complications of his head and chest injuries on the seventh post-operative day. The pathophysiology and clinical manifestations of injuries to the brachiocephalic artery are discussed.

Accidents, Traffic↗