Results 251 to 260 of about 2,307,247 (300)

Compensators for intensity-modulated beams

Medical Dosimetry, 2002
This study describes the importance of attenuator scatter in the construction of compensators. The attenuator used in this study was Lipowitz metal, commonly referred to as cerrobend. Linear attenuation coefficients of cerrobend were measured in air for different thickness of cerrobend sheets and different field sizes for a 6-MV photon beam.
D M, Dimitriadis, B G, Fallone
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Intensity modulated moire and its intensity-phase analysis

Proceedings. Fourteenth International Conference on Pattern Recognition (Cat. No.98EX170), 2002
Moire topography has the advantage that it just requires a single image, but it cannot discern the fringe order. So, it is difficult to discern the connection among fringes in the case where the fringe orders are not continuous. In our work, an intensity modulated moire is presented. By modulating the transmission of projection and observation grating,
Cunwei Lu, Akashi Yamaguchi, Seiji Inokuchi   +2 more
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Achromatic Intensity Modulator

Spatial Light Modulators and Applications, 1993
The limits of polarization rotation as a means of intensity modulation can be significantly improved using a system employing chiral smectic liquid crystals.
J. E. Stockley, G. D. Sharp, D. Doroski, K. M. Johnson   +3 more
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Modulation of the intensity of formalized attributes

1988
A ‘mechanism’ to commit modifiers for the specification of at tributes is presented in this paper. Such a mechanism consists in a proce dure of Approximate Reasoning.
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Acoustooptic modulator intensity servo

Applied Optics, 1979
A device has been constructed that combines optical isolation and amplitude noise reduction by the use of a servo controlled acoustooptic intensity modulator. The isolation can, in principle, be perfect while the noise reduction can be significant up to about 100 kHz and as large as 80 dB at low frequency.
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Intensity modulated radiotherapy

2012
Intensity-modulated radiotherapy (IMRT) is a radiation delivery technique that allows “dose sculpting” to improve target coverage while sparing normal tissues. In an IMRT plan, the number of photons delivered (or “fluence”) varies within a field. Such variability can be used to avoid normal structures with lower radiation tolerance than the cancer and ...
Bridget F. Koontz, Devon Godfrey, W. Robert Lee   +2 more
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Reshapable physical modulator for intensity modulated radiation therapy

Medical Physics, 2002
A new method of generating beam intensity modulation filters for intensity modulated radiation therapy (IMRT) is presented. The modulator was based on a reshapable material, which is not compressible but can be deformed under pressure. A two‐dimensional (2D) piston array was used to repeatedly shape the attenuating material.
Tong, Xu, Polad M, Shikhaliev, Muthana, Al-Ghazi, Sabee, Molloi   +3 more
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Treatment planning considerations of reshapeable automatic intensity modulator for intensity modulated radiation therapy

Medical Physics, 2004
As compared with multi-leaf collimator based intensity modulated radiation therapy (IMRT) techniques, physical modulators have the major advantage of temporally invariant intensity map delivery which makes it more flexible with monitor unit rate, simpler resolution of interrupted treatment and easier implementation and use with respiratory gating ...
Tong, Xu, Muthana S, Al-Ghazi, Sabee, Molloi   +2 more
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Respiratory modulation of shivering intensity in the pigeon

Acta Physiologica Scandinavica, 1987
Respiration and shivering were measured in unanaesthetized, cold‐exposed pigeons using pneumotachography and electromyography, respectively. The instantaneous intensity of shivering in the pectoral muscle varied in phase with respiration. Power spectral analysis showed that the main frequency components of respiration and demodulated EMG coincided ...
E, Hohtola, K, Johansen
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A review of intensity-modulated radiation therapy

Current Oncology Reports, 2008
Intensity-modulated radiation therapy (IMRT) is a sophisticated form of three-dimensional treatment planning and delivery. In some situations, IMRT allows more conformal radiation therapy to complex targets within the lung. As problems related to organ motion are increasingly addressed, the use of IMRT in the treatment of lung cancer, particularly in ...
Laurie E, Gaspar, Meisong, Ding
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