Biomedical subjects

Theofanis A Maniatis

Publications and source records attributed to Theofanis A Maniatis.

4 recordsLinked to original sources

PubMed2005

Telematics enabled virtual simulation system for radiation treatment planning.

In this paper, GALENOS, a Telematics Enabled Virtual Simulation System for Radiation Treatment Planning (RTP) is described. The design architecture of GALENOS is in accordance with the dual aim of virtual simulation of RTP, i.e. to allow (a) delineation of target volume and critical organs, and (b) placement of irradiation fields. An important feature of GALENOS is the possibility for on-line tele-collaboration between health care professionals under a secure framework. The advantages of GALENOS include elimination of patient transfers between departments and health care institutions as well as availability of patient data at sites different than those of his/her physical presence.

Computer Simulation↗

PubMed2005

Investigating the enhancement of three-dimensional diffraction tomography by using multiple illumination planes.

The three dimensional (3-D) extension of the two well-known diffraction tomography algorithms, namely, direct Fourier interpolation (DFI) and filtered backpropagation (FBP), are presented and the problem of the data needed for a full 3-D reconstruction is investigated. These algorithms can be used efficiently to solve the inverse scattering problem for weak scatterers in the frequency domain under the first-order Born and Rytov approximations. Previous attempts of 3-D reconstruction with plane-wave illumination have used data obtained with the incident direction restricted at the xy plane. However, we show that this restriction results in the omission of the contribution of certain spatial frequencies near the omegaz axis for the final reconstruction. The effect of this omission is studied by comparing the results of reconstruction with and without data obtained from other incident directions that fill the spatial frequency domain. We conclude that the use of data obtained for incident direction in only the xy plane is sufficient to achieve a satisfactory quality of reconstruction for a class of objects presenting smooth variation along the z axis, while abrupt variations along the z axis cannot be imaged. This result should be taken into account in the process of designing the acquisition geometry of a tomography scanner.

Algorithms↗

PubMed2003

Secure environment for real-time tele-collaboration on virtual simulation of radiation treatment planning.

A secure framework is described for real-time tele-collaboration on Virtual Simulation procedure of Radiation Treatment Planning. An integrated approach is followed clustering the security issues faced by the system into organizational issues, security issues over the LAN and security issues over the LAN-to-LAN connection. The design and the implementation of the security services are performed according to the identified security requirements, along with the need for real time communication between the collaborating health care professionals. A detailed description of the implementation is given, presenting a solution, which can directly be tailored to other tele-collaboration services in the field of health care. The pilot study of the proposed security components proves the feasibility of the secure environment, and the consistency with the high performance demands of the application.

Computer Graphics↗

PubMed2002

Real-time collaborative environment for radiation treatment planning virtual simulation.

A virtual simulation (VS) system is a software system that enables the delineation of anatomical structures, and the placement of irradiation fields for the purpose of radiation treatment planning, making use of patient's tomographic data, instead of the real patient. Since patient's tomographic data can be communicated between distinct radiotherapy departments, collaborative work on VS, connecting remote health care professionals, becomes feasible. In this paper, an environment enabling real-time collaboration on VS is presented. The environment architecture is based on both offline and online communication of data under a secure framework and can be directly integrated into the infrastructure of a radiotherapy department. The online collaboration relies on the simultaneous execution of all actions at both collaborating sites, and prerequisites the offline communication of the data set on which the collaboration will be performed. Analytical description of the custom-made layered service, which supports the offline communication is given, along with a detailed presentation of the secure management of messages, which enables the real-time collaboration. The technical evaluation of the environment highlights the effectiveness of the proposed methodology, since real-time secure collaboration on VS is achieved.

Computer Graphics↗