Early identification of acute exacerbations of COPD facilitates better care. This study was designed to validate a short questionnaire (Exascore) developed to help patients, relatives and carers to ...diagnose acute exacerbations.
We first addressed content validity that allowed the elaboration of two questionnaires, one assessing the current status and the other stable status (transition). The second step tested their construction validity, reproducibility and concomitant validity among 126 COPD patients aged 64.4±9.9 years. They included 56 presenting with an exacerbation and 70 in stable state, of whom 57 completed the questionnaire a second time after 7 days. The diagnosis of exacerbation and assessment of severity (gold standard) were established by the treating respiratory physician and confirmed by two independent experts.
Factorial analyses established a "current status" questionnaire comprising 8 items and 2 dimensions. Cronbach's alpha coefficients were satisfactory, 0.867 for "respiratory impact", 0.886 for "psychosocial impact" and 0.886 for the total score. Concomitant validity and reproducibility were also adequate. The transition questionnaire did not obtain convincing psychometric results.
The "current status" Exascore questionnaire satisfies psychometric quality criteria while being usable in clinical practice. It helps in diagnosing acute exacerbations and assessing their intensity. Further studies will need to test the adequacy of proposed thresholds, the factorial structure of the score in healthcare professionals and patients' relatives, and its predictive power.
Upgrading the beam telescopes at the DESY II Test Beam Facility Augustin, H.; Diener, R.; Dittmeier, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2022, Letnik:
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The DESY II Test Beam Facility is a key infrastructure for modern high energy physics detector development, providing particles with a small momentum spread in a range from 1 to 6GeV to user groups ...e.g. from the LHC experiments and Belle II as well as generic detector R&D. Beam telescopes are provided in all three test beam areas as precise tracking reference without time stamping, with triggered readout and a readout time of > 115 μs . If the highest available rates are used, multiple particles are traversing the telescopes within one readout frame, thus creating ambiguities that cannot be resolved without additional timing layers. Several upgrades are currently investigated and tested: Firstly, a fast monolithic pixel sensor, the TelePix, to provide precise track timing and triggering on a region of interest is proposed to overcome this limitation. The TelePix is a 180nm HV-CMOS sensor that has been developed jointly by DESY, KIT and the University of Heidelberg and designed at KIT. In this publication, the performance evaluation is presented: The difference between two amplifier designs is evaluated. A high hit detection efficiency of above 99.9% combined with a time resolution of below 4ns at negligible pixel noise rates is determined. Finally, the digital hit output to provide region of interest triggering is evaluated and shows a short absolute delay with respect to a traditional trigger scintillator as well as an excellent time resolution. Secondly, a fast LGAD plane has been proposed to provide a time resolution of a few 10 ps, which is foreseen to drastically improve the timing performance of the telescope. Time resolutions of below 70 ps have been determined in collaboration with the University of California, Santa Barbara.
The requirements of the ultra thin pixel detectors for the Mu3e experiment at PSI can be achieved by the HVCMOS technology, which allows the design of fast monolithic detectors. The latest nearly ...full size prototype, MuPix8, has a size of about 1 × 2 cm2. The pixel readout circuitry was fully redesigned in comparison to the previous MuPix versions. MuPix8’s readout electronics implement a new concept with two comparators and two different operation modes. One mode uses two threshold voltages for time walk correction, the other is a ramp-ADC. First tests show a detection efficiency of 99.6% for 4 GeV electrons.
•Large area (1 × 2 cm2) HVCMOS sensor chip with efficiency greater than 99.6%.•New readout electronics with two comparators for each pixel for timewalk correction.•Readout modes: two threshold voltages mode and ADC threshold voltage mode.•Scan logic with pixel groups for a fast search for hits.
High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) based on a 180 nm HV-CMOS process have been proposed to realize thin, fast and highly integrated pixel sensors. The MuPix7 prototype, fabricated ...in the commercial AMS H18 process, features a fully integrated on-chip readout, i.e. hit-digitization, zero suppression and data serialization. MuPix7 is the first fully monolithic HV-CMOS pixel sensor that has been tested for the use in high irradiation environments like HL-LHC. We present results from laboratory and test beam measurements of MuPix7 prototypes irradiated with neutrons (up to 5.0 × 1015 neq/cm2) and 24 GeV protons (up to 7.8 × 1015 protons/cm2) and compare the performance with non-irradiated sensors. At sensor temperatures of about 8 °C efficiencies of ≥90% at noise rates below 40 Hz per pixel are measured for fluences of up to 1.5 × 1015 neq/cm2. A time resolution better than 22 ns, expressed as Gaussian σ, is measured for all tested settings and sensors, even at the highest irradiation fluences. The data transmission at 1.25 Gbit/s and the on-chip PLL remain fully functional.
The Mu3e experiment is searching for the charged lepton flavour violating decay \( \mu^+\rightarrow e^+ e^- e^+ \), aiming for an ultimate sensitivity of one in \(10^{16}\) decays. In an environment ...of up to \(10^9\) muon decays per second the detector needs to provide precise vertex, time and momentum information to suppress accidental and physics background. The detector consists of cylindrical layers of \(50\, \mu\text{m}\) thin High Voltage Monolithic Active Pixel Sensors (HV-MAPS) placed in a \(1\,\text{T}\) magnetic field. The measurement of the trajectories of the decay particles allows for a precise vertex and momentum reconstruction. Additional layers of fast scintillating fibre and tile detectors provide sub-nanosecond time resolution. The MuPix8 chip is the first large scale prototype, proving the scalability of the HV-MAPS technology. It is produced in the AMS aH18 \(180\, \text{nm}\) HV-CMOS process. It consists of three sub-matrices, each providing an untriggered datastream of more than \(10\,\text{MHits}/\text{s}\). The latest results from laboratory and testbeam characterisation are presented, showing an excellent performance with efficiencies \(>99.6\,\text{\%}\) and a time resolution better than \(10\, \text{ns}\) achieved with time walk correction.
The DESY II Test Beam Facility is a key infrastructure for modern high energy physics detector development, providing particles with a small momentum spread in a range from 1 to 6 GeV to user groups ...e.g. from the LHC experiments and Belle II as well as generic detector R&D. Beam telescopes are provided in all three test beam areas as precise tracking reference without time stamping, with triggered readout and a readout time of > 115 \(\mu\)s. If the highest available rates are used, multiple particles are traversing the telescopes within one readout frame, thus creating ambiguities that cannot be resolved without additional timing layers. Several upgrades are currently investigated and tested: Firstly, a fast monolithic pixel sensor, the TelePix, to provide precise track timing and triggering on a region of interest is proposed to overcome this limitation. The TelePix is a 180 nm HV-CMOS sensor that has been developed jointly by DESY, KIT and the University of Heidelberg and designed at KIT. In this publication, the performance evaluation is presented: The difference between two amplifier designs is evaluated. A high hit detection efficiency of above 99.9 % combined with a time resolution of below 4 ns at negligible pixel noise rates is determined. Finally, the digital hit output to provide region of interest triggering is evaluated and shows a short absolute delay with respect to a traditional trigger scintillator as well as an excellent time resolution. Secondly, a fast LGAD plane has been proposed to provide a time resolution of a few 10 ps, which is foreseen to drastically improve the timing performance of the telescope. Time resolutions of below 70 ps have been determined in collaboration with the University of California, Santa Barbara.
High Voltage Monolithic Active Pixel Sensors (HV-MAPS) are based on a commercial High Voltage CMOS process and collect charge by drift inside a reversely biased diode. HV-MAPS represent a promising ...technology for future pixel tracking detectors. Two recent developments are presented. The MuPix has a continuous readout and is being developed for the Mu3e experiment whereas the ATLASPix is being developed for LHC applications with a triggered readout. Both variants have a fully monolithic design including state machines, clock circuitries and serial drivers. Several prototypes and design variants were characterised in the lab and in testbeam campaigns to measure efficiencies, noise, time resolution and radiation tolerance. Results from recent MuPix and ATLASPix prototypes are presented and prospects for future improvements are discussed.
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