31 research outputs found
Breast cancer "tailored follow-up" in Italian oncology units: a web-based survey
urpose: Breast cancer follow-up procedures after primary treatment are still a controversial issue. Aim of this study was to investigate, through a web-based survey, surveillance methodologies selected by Italian oncologists in everyday clinical practice. Methods: Referents of Italian medical oncology units were invited to participate to the study via e-mail through the SurveyMonkey website. Participants were asked how, in their institution, exams of disease staging and follow-up are planned in asymptomatic women and if surveillance continues beyond the 5th year. Results: Between February and May 2013, 125 out of 233 (53.6%) invited referents of Italian medical oncology units agreed to participate in the survey. Ninety-seven (77.6%) referents state that modalities of breast cancer follow-up are planned according to the risk of disease progression at diagnosis and only 12 (9.6%) oncology units apply the minimal follow-up procedures according to international guidelines. Minimal follow-up is never applied in high risk asymptomatic women. Ninety-eight (78.4%) oncology units continue follow-up in all patients beyond 5 years. Conclusions: Our survey shows that 90.4% of participating Italian oncology units declare they do not apply the minimal breast cancer follow-up procedures after primary treatment in asymptomatic women, as suggested by national and international guidelines. Interestingly, about 80.0% of interviewed referents performs the so called "tailored follow-up", high intensity for high risk, low intensity for low risk patients. There is an urgent need of randomized clinical trials able to determine the effectiveness of risk-based follow-up modalities, their ideal frequency and persistence in time
CMOS integrated pixel array for low-level radiation detection using "time compression" parametric amplification
In this work, theoretical modeling and simulations of a 'time compression' parametric amplification pixel array to be used in CMOS imaging for low-level or near IR radiation are presented. The implementation in the higher resistivity substrate process used for smart-power devices, namely the 30 V thin-film 1.0 µm SIMOX-CMOS based on Silicon-on-Insulator technology, enables isolated separation of photoactive and readout circuitry areas when integrated on the same chip. The method presented shows that very high readout current peaks can be generated which are much higher than the mean value of the photocurrent induced. Thus, the parametrically amplified readout signals can be detected by a low-noise peak-detector circuit. The 500x500 µm2 area pixels with internal parametrically controllable amplification and increased pixel fill-in factor (>90%) present higher detection volume due to enlarged deep-depletion region depth caused by a low resistivity substrate. Moreover, the X-Y addressing and the inverse exponential dependence of the parametric amplification on the incoming radiant flux for each pixel provide separately controllable single-pixel internal amplification which improves the intra-scene high dynamic range demands
Double modified internal gate (MIG) pixel for fluorescence imaging applications
In this work we present a double modified internal gate (MIG) pixel structure, fabricated in a slightly modified 0.35µm CMOS process, to be effectively used in, e.g. low-level irradiance fluorescent imaging applications. The pixel structure enables a non-destructive readout, which facilitates a constant monitoring of the molecule fluorescence process. The readout isbased on signal averaging and up-the-ramp sampling current differential readout, which drastically reduces the amount of noise in the pixel output signal. The modified internal gates enable extremely low dark-current and very low-noise operation
Development of a solid-state position sensitive neutron detector prototype based on  6Li-glass scintillator and digital SiPM arrays
Photomultiplier tubes (PMT) have been used extensively as the photodetector of choice in scintillation baseddetectors for cold and thermal neutrons. However, the limitations of PMT based scintillation neutron detectorssuch as their sensitivity to magnetic fields or their high operating voltages (> 1 kV) have triggered the search foralternative photodetectors for these applications. Silicon photomultipliers (SiPM) operate in the single photonregime, have lower operating voltages (∼20–70 V) than PMTs and are insusceptible to magnetic field. Additionalfeatures of the SiPMs like their low production cost, compactness and higher readout rates make them apotential candidate to replace the photodetector part in these developments. Therefore, we are developing ascintillation neutron detector based on SiPM technology. The detector prototype with an active detection area of13 cm × 13 cm is aimed to be used in the future at the TREFF instrument of the Heinz Maier-Leibnitz Zentrum (MLZ)in Garching, Germany, for neutron reflectometry experiments. In this paper, we report the detector concept, itsdevelopment and the simulation results for design optimization
Single-Pixel Near-Infrared 3D Image Reconstruction in Outdoor Conditions
In the last decade, the vision systems have improved their capabilities to capture 3D images in bad weather scenarios. Currently, there exist several techniques for image acquisition in foggy or rainy scenarios that use infrared (IR) sensors. Due to the reduced light scattering at the IR spectra it is possible to discriminate the objects in a scene compared with the images obtained in the visible spectrum. Therefore, in this work, we proposed 3D image generation in foggy conditions using the single-pixel imaging (SPI) active illumination approach in combination with the Time-of-Flight technique (ToF) at 1550 nm wavelength. For the generation of 3D images, we make use of space-filling projection with compressed sensing (CS-SRCNN) and depth information based on ToF. To evaluate the performance, the vision system included a designed test chamber to simulate different fog and background illumination environments and calculate the parameters related to image quality
Photodetection Characterization of SiPM Technologies for their Application in Scintillator based Neutron Detectors
Lateral drift-field photodiode for low noise, high-speed, large photoactive-area CMOS imaging applications
In this work a theoretical concept and simulations are presented for a novel lateraldrift-field photodetector pixel to be fabricated in a 0.35 mm CMOS process. The proposed pixel consists of a specially designed n-well with a non-uniform lateral doping profile that follows a square-root spatial dependence. ''Buried'' MOS capacitor-based collection gate, a transfer-gate, and an n-type MOSFET source/drain n+ floating-diffusion serve to realize a non-destructive readout. The pixel readou tis performed using an in-pixel source-follower pixel buffer configuration followed by an output amplifier featuring correlated double-sampling. The concentration gradient formed in the n-well employs a single extra implantation step in the 0.35 mm CMOS process mentioned and requires only a single extra mask. It generates an electrostatic potential gradient, i.e. alateral drift-field, in the photoactive area of the pixel which enables high charge transfer speed and low image-lag. According to the simulation results presented, charge transfer times of less than 3 ns are to be expected
SPAD detector for long-distance 3D ranging with sub-nanosecond TDC
We report on the design and characterization of a smart pixel for long-distance ranging, comprising a high performances Single-Photon detector and sub-nanosecond Timeto-Digital Conversion (TDC), in 0.35 μm CMOS technology