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Biomedical subjects

Roger Phillips

Publications and source records attributed to Roger Phillips.

5 recordsLinked to original sources
PubMed2005

Immersive visualization training of radiotherapy treatment.

External radiation beam treatment of cancer tumours involves delivery of invisible radiation beams through the body where internal structures can not be seen. Beam targeting of patient anatomy has to very accurate to achieve the desired therapeutic result. Good understanding of radiotherapy treatment (RT) concepts is essential to training. This paper presents a virtual environment simulator developed by the authors for training and education of intensity modulated radiotherapy (IMRT) treatment of cancer. This simulator employs immersive visualization to provide a high fidelity spatial awareness of the complex relationships between tumour, organs at risk, treatment beam and radiation dose. All these visualization are provided by a 3D virtual environment based on the patient in a RT treatment room. Immersive visualization using this simulator is being used to train radiation oncologist and radiation physicists about radiotherapy treatment.

Computer Simulation↗
PubMed2005

A dynamic friction model for haptic simulation of needle insertion.

This paper describes a new friction model, termed the brush model, suitable for haptic simulations of needle insertion in virtual environments. A novel two-layer surface contact model is presented that provides real-time rendering of friction forces at haptic refresh rates. A significant modification to the brush model is also presented, leading to a new friction model, termed the fixed bristle brush model. Simulation results show that the two models can accurately reflect the experimentally observed friction characteristics. This paper presents a simulation of friction during needle insertion; results agree with the experimental observations.

Computer Simulation↗
PubMed2003

Discovery of genes with highly restricted expression patterns in the Drosophila wing disc using DNA oligonucleotide microarrays.

The Drosophila wing disc is divided along the proximal-distal axis into regions giving rise to the body wall (proximal), wing hinge (central) and wing blade (distal). We applied DNA microarray analysis to discover genes with potential roles in the development of these regions. We identified a set of 94 transcripts enriched (two fold or greater) in the body wall and 56 transcripts enriched in the wing/hinge region. Transcripts that are known to have highly restricted expression patterns, such as pannier, twist and Bar-H1 (body wall) and knot, nubbin and Distal-less (wing/hinge), showed strong differential expression on the arrays. In situ hybridization for 50 previously uncharacterized genes similarly revealed that transcript enrichment identified by the array analysis was consistent with the observed spatial expression. There was a broad spectrum of patterns, in some cases suggesting that the genes could be targets of known signaling pathways. We show that three of these genes respond to wingless signaling. We also discovered genes likely to play specific roles in tracheal and myoblast cell types, as these cells are part of the body wall fragment. In summary, the identification of genes with restricted expression patterns using whole genome profiling suggests that many genes with potential roles in wing disc development remain to be characterized.

Animals↗