1,720,996 research outputs found
Optical eye tracking system for non-invasive and automatic monitoring of eye position and movements in radiotherapy treatments of ocular tumors
No full textA noninvasive eye tracking system based on infrared 3-D video-oculographic techniques is proposed for the automatic monitoring of eye position and orientation in external beam radiotherapy of ocular tumors. The presented method can be applied for the real-time estimation of lesion position and tumor-beam misalignments, allowing automatic patient setup and eye movement gated treatments. A prototypal eye tracker was developed and tested on five subjects, achieving gaze estimation errors of 0.5° and eye monitoring frequencies of 125 Hz. The proposed application can potentially improve quality and efficacy of ocular radiotherapy treatments, currently based on invasive, qualitative, and manual control procedure
DEVICE FOR MONITORING POSITION AND MOVEMENTS OF AN EYE, PARTICULARLY SUITABLE FOR OCULAR RADIOTHERAPY
No full textThe present invention is about a device for non-invasive monitoring of an eye position and ocular movements of a patient, comprising:
- a housing body (2) having at least one through opening (2a);
- a plurality of light sources (3) housed in said housing body (2);
- a plurality of sensor means (4) housed in said housing body (2);
- deflector means (6) for invisible radiation (RL) supplied, in use, by said plurality of light sources (3) and reflected by said eye (O) under examination;
- support means (8) that can be adjusted for said housing body (2);
- at least one program data processing and control unit (9). The support means (8) can be adjusted in such a way that the through opening (2a) of the housing body (2) can be placed at the eye (O) under examination so that the invisible radiation hits the eye (O) frontally.
The program data processing and control unit (9) is designed to calculate instant-by-instant the position and orientation of a suitable three-dimensional reference system integral with the eye with respect to a predetermined three-dimensional reference system
Within-breath specific gas volume variations (ΔSVg) assessed by four-dimensional computed tomography (4D-CT) in lung tumor patients
No full textTime-consistent parametrization from dynamic optical surface detection for respiratory motion recovery in radiation oncology
No full textA novel CT-based contrast enhancement technique for markerless lung tumor tracking in X-ray projection images
No full textDispositivo per il monitoraggio della posizione e dei movimenti dell’occhio, particolarmente adatto per la radioterapia oculare
No full textEye Tracking System for Set-Up Control and Motion Monitoring in Ocular Proton Therapy: A Proof of Concept
No full textMulti-dimensional respiratory motion tracking from markerless optical surface imaging based on deformable mesh registration
No full textImproving the Contrast of Proton and Carbon Radiography by Using CT Prior Knowledge
No full textPurpose: To enhance the quality of proton/carbon radiography for real time tumor tracking using CT prior knowledge. Methods: A method for contrast enhancement was applied to particle radiographies (230 MeV proton, 330 MeV proton, 500MeV/n Carbon) virtually generated by means of Monte Carlo simulations. CT data volumes from 6 lung patients, with different lesion size, were processed and analyzed. The tumor region (generally the PTV) and low density voxels were segmented out to generate a new processed CT. A Digital Reconstructed Radiography (DRR) was computed from this processed CT volume. After equalizing the histogram between 0 and 1 of both particle radiography and DRR, the two images were subtracted thus obtaining a high signal around the tumor region. Contrast to Noise Ratio (CNR) was used as a metric to measure the enhancement. A normalized cross-correlation based algorithm was implemented to automatically detect the GTV area. The estimated center of mass (CM) of the GTV was compared to projection contours drawn by physicians. Results: CNR figures showed improvement up to 6 times when comparing the enhanced contrast image vs. the original particle radiography. The 2D distance between the real and the automatically estimated CM of the GTV was 2,12±0,62 mm (median±quartile). Conclusions: The advantage of using proton or carbon radiography to detect soft tissue during patient set up and radiation delivery can be further on improved by using prior knowledge derived from the planning CT. The method we propose is able to significantly enhance the contrast of the tumor region with acceptable computational time for real time applications. Further analysis is required to study the benefit of such a methodology to track the lesion over time during treatment. The authors declare that no conflicts of interest exist
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