Design and development af a lightweight low-cost sensor unit for the parallel measurement of particles, gaseous air pollutants, atmospheric pressure, temperature and humidity

<p>There are frequent measurement tasks, where lightweight low-cost sensor units are of interest for the parallel measurement of several environmental parameters. Moreover, often measurements of environmental parameters are necessary not only at one specific point, but distributed over a large area or at different altidudes. In this case it makes sense to utilize lightweight low-cost sensor units. Because of the low price the can be produced in many exemplares und used at several places in parallel.</p> <p>The Laboratory for Environmental Measurement Techniques (UMT) at the Duesseldorf University of Applied Sciences (HSD) has developed such electronic units with following features:</p> <ul> <li>They can measure particulate matter PM10, PM2.5, PM1, PNC and size distribution using particulate sensors of different brands, e.g. Alphasense sensors R2 or N3 or Sensirion SDS 30.</li> <li>Additionally they have analog interfaces so that they can be equipped with sensor units for gaseous pollutants, e.g, Alphasense sensors for SO<sub>2</sub>, NO<sub>2</sub>, Ozone and many other gases like CO<sub>2</sub> using Sensirion sensors.</li> <li>In parallel atmospheric pressure, temperature and humidity can be measured by additional dedicated sensors.</li> <li>The sensor units are equipped with a SD card memory and optionally with I<sup>2</sup>C or RS232 interface.</li> <li>Additionally the data can be transmitted in a wireless way to a server on 433 MHz, 868 MHz, 2.4 GHz ISM-band or via LTE or IRIDIUM.</li> <li>The main electronic unit is of lightweight design. Therefore the low-cost sensor units can be used easily on mobile platformes like drones or bicycles.</li> <li>The sensor unit has a low power consumption, so it can be operated independently for days or weeks, depending on the battery capacity.</li> <li>A GPS module enables a timestamp for the data and gives position and altitude.</li> </ul> <p>Several fully installed measurement units have been tested by UMT groundbased at industrial and heavily polluted urban sites in Germany. Moreover, such a unit has been operated on a measurement drone for taking vertical and horizontal pollutant profiles. It is planned to use these sensor units also at volcanic sites in a mobile and stationary way. The low-cost sensor units have been intercompared with certified air pollution measurement systems to assure the data quality.</p>

Optical computation of a spin glass dynamics with tunable complexity

Spin glasses (SGs) are paradigmatic models for physical, computer science, biological, and social systems. The problem of studying the dynamics for SG models is nondetermistic polynomial-time (NP) hard; that is, no algorithm solves it in polynomial time. Here we implement the optical simulation of an SG, exploiting the N segments of a wavefront-shaping device to play the role of the spin variables, combining the interference downstream of a scattering material to implement the random couplings between the spins (the Jij matrix) and measuring the light intensity on a number P of targets to retrieve the energy of the system. By implementing a plain Metropolis algorithm, we are able to simulate the spin model dynamics, while the degree of complexity of the potential energy landscape and the region of phase diagram explored are user defined, acting on the ratio P/N=α. We study experimentally, numerically, and analytically this Hopfield-like system displaying a paramagnetic, ferromagnetic, and SG phase, and we demonstrate that the transition temperature Tg to the glassy phase from the paramagnetic phase grows with α. We demonstrate the computational advantage of the optical SG where interaction terms are realized simultaneously when the independent light rays interfere on the detector’s surface. This inherently parallel measurement of the energy provides a speedup with respect to purely in silico simulations scaling with N.

Reliability and Agreement of Three Devices for Measuring Implant Stability Quotient in the Animal Ex Vivo Model

Resonance frequency analysis (RFA) is the most extended method for measuring implant stability. The implant stability quotient (ISQ) is the measure obtained by different RFA devices; however, inter- and intra-rater reliability and agreement of these instruments remain unknown. Thirty implants were placed in three different pig mandibles. ISQ was measured parallel and perpendicular (lingual) to the peg axis with Osstell® Beacon, Penguin® and MegaISQ® by two different investigators and furthermore, one performed a test-retest. Intraclass correlation coefficient was calculated to assess the intra- and inter-rater reliability. Pearson correlation coefficient was used to assess the agreement. Intraclass correlation coefficients ranged from 0.20 to 0.65 for the Osstell® Beacon; 0.57 to 0.86 for the Penguin®; and −0.01 to 0.60 for the MegaISQ®. The highest ISQ values were obtained using Penguin® (66.3) in a parallel measurement; the lowest, using the MegaISQ® (60.1) in a parallel measurement. The highest correlation values with the other devices were obtained by MegaISQ® in a parallel measurement. Osstell® Beacon and MegaISQ® showed lower reliability than Penguin®. Osstell® had good agreement for measuring ISQ both in parallel and perpendicular, and MegaISQ® had the best agreement for measuring ISQ in parallel.

Diagnostic performance of Oncuria™, a urinalysis test for bladder cancer

Background Due to insufficient accuracy, urine-based assays currently have a limited role in the management of patients with bladder cancer. The identification of multiplex molecular signatures associated with disease has the potential to address this deficiency and to assist with accurate, non-invasive diagnosis and monitoring. Methods To evaluate the performance of Oncuria™, a multiplex immunoassay for bladder detection in voided urine samples. The test was evaluated in a multi-institutional cohort of 362 prospectively collected subjects presenting for bladder cancer evaluation. The parallel measurement of 10 biomarkers (A1AT, APOE, ANG, CA9, IL8, MMP9, MMP10, PAI1, SDC1 and VEGFA) was performed in an independent clinical laboratory. The ability of the test to identify patients harboring bladder cancer was assessed. Bladder cancer status was confirmed by cystoscopy and tissue biopsy. The association of biomarkers and demographic factors was evaluated using linear discriminant analysis (LDA) and predictive models were derived using supervised learning and cross-validation analyses. Diagnostic performance was assessed using ROC curves. Results The combination of the 10 biomarkers provided an AUROC 0.93 [95% CI 0.87–0.98], outperforming any single biomarker. The addition of demographic data (age, sex, and race) into a hybrid signature improved the diagnostic performance AUROC 0.95 [95% CI 0.90–1.00]. The hybrid signature achieved an overall sensitivity of 0.93, specificity of 0.93, PPV of 0.65 and NPV of 0.99 for bladder cancer classification. Sensitivity values of the diagnostic panel for high-grade bladder cancer, low-grade bladder cancer, MIBC and NMIBC were 0.94, 0.89, 0.97 and 0.93, respectively. Conclusions Urinary levels of a biomarker panel enabled the accurate discrimination of bladder cancer patients and controls. The multiplex Oncuria™ test can achieve the efficient and accurate detection and monitoring of bladder cancer in a non-invasive patient setting.

Diagnostic Performance of Oncuria™, a Urinalysis Test for Bladder Cancer

Background: Due to insufficient accuracy, urine-based assays currently have a limited role in the management of patients with bladder cancer. The identification of multiplex molecular signatures associated with disease has the potential to address this deficiency and to assist with accurate, non-invasive diagnosis and monitoring. Methods: To evaluate the performance of Oncuria™, a multiplex immunoassay for bladder detection in voided urine samples. The test was evaluated in a multi-institutional cohort of 362 prospectively collected subjects presenting for bladder cancer evaluation. The parallel measurement of 10 biomarkers (A1AT, APOE, ANG, CA9, IL8, MMP9, MMP10, PAI1, SDC1 and VEGFA) was performed in an independent clinical laboratory. The ability of the test to identify patients harboring bladder cancer was assessed. Bladder cancer status was confirmed by cystoscopy and tissue biopsy. The association of biomarkers and demographic factors was evaluated using linear discriminant analysis (LDA) and predictive models were derived using supervised learning and cross-validation analyses. Diagnostic performance was assessed using ROC curves.Results: The combination of the 10 biomarkers provided an AUROC 0.93 [95% CI: 0.87 – 0.98], outperforming any single biomarker. The addition of demographic data (age, sex, and race) into a hybrid signature improved the diagnostic performance AUROC 0.95 [95% CI: 0.90 – 1.00]. The hybrid signature achieved an overall sensitivity of 0.93, specificity of 0.93, PPV of 0.65 and NPV of 0.99 for bladder cancer classification. Sensitivity values of the diagnostic panel for high-grade bladder cancer, low-grade bladder cancer, MIBC and NMIBC were 0.94, 0.89, 0.97 and 0.93, respectively. Conclusions: Urinary levels of a biomarker panel enabled the accurate discrimination of bladder cancer patients and controls. The multiplex Oncuria™ test can achieve the efficient and accurate detection and monitoring of bladder cancer in a non-invasive patient setting.

Energy balance closure and advective fluxes at ADVEX sites

When measuring the energy balance at the earth’s surface using the Eddy covariance technique, the obtained budgets seldom produce a closed energy balance. The measurements often miss some of the energy fluxes. A possible reason is the neglect of non-turbulent surface fluxes of latent heat and sensible heat, i.e. advective fluxes of these quantities. We present estimates of advective latent and sensible heat fluxes for three different sites across Europe based on the ADVEX dataset. The obtained horizontal and vertical advective fluxes were site-specific and characterized by large scatter. In relative terms, the data indicated that the sensible heat budget was less affected by advection than the latent heat budget during nighttime; this is because vertical turbulent latent heat fluxes were very small or close to zero during the night. The results further showed that the additional energy gain by sensible heat advection might have triggered enhanced evaporation for two sites during nighttime. Accounting for advective fluxes improved the energy balance closure for one of the three ADVEX sites. However, the energy balance closure of the other two sites did not improve overall. A comparison with energy balance residuals (energy missed by the measurements without accounting for advection) indicated a large influence of systematic errors. An inspection of the energy balance for the sloped site of the ADVEX dataset underlined the necessity of slope-parallel measurement of radiation.

First-Step PPG Signal Analysis for Evaluation of Stress Induced during Scanning in the Open-Air MRI Device

The paper describes first-step experiments with parallel measurement of cardiovascular parameters using a photoplethysmographic optical sensor and standard portable blood pressure monitors in different situations of body relaxation and stimulation. Changes in the human cardiovascular system are mainly manifested by differences in the Oliva–Roztocil index, the instantaneous heart rate, and variations in blood pressure. In the auxiliary experiments, different physiological and psychological stimuli were applied to test whether relaxation and activation phases produce different measured parameters suitable for further statistical analysis and processing. The principal investigation is aimed at analysis of vibration and acoustic noise impact on a physiological and psychological state of a person lying inside the low-field open-air magnetic resonance imager (MRI). The obtained results will be used to analyze, quantify, and suppress a possible stress factor that has an impact on the speech signal recorded during scanning in the MRI device in the research aimed at 3D modeling of the human vocal tract.

Simulation and disturbance estimation of speed-controlled mechatronic drive systems

In the field of modern production systems, the process-parallel measurement of time-varying process forces and torques for high-level process monitoring is becoming increasingly important. Commonly utilized methods are based on additional sensors placed close to the working area. Unfortunately, this often leads to a higher complexity and additional costs due to the necessity of external hardware. An alternative approach is to evaluate the already available machine-internal signals of the subordinate drive systems. The process forces act on the load side of the machine axes in the form of disturbance forces and influence the drive-internal signals such as motor current or motor speed. To extract these disturbances, additional superimposed forces (e.g. friction and acceleration forces) and the influence of the feedback control as well as the mechanical system must be considered. Therefore, in the present paper, the application of various observer-based approaches for the estimation of load side disturbances on speed- controlled mechatronic drive systems will be examined. The investigations are performed on a simulation model of a speed-controlled machine axis. After an introduction, three different disturbance observers will be presented. Subsequently, the paper describes the structure of the simulation model including its parameterization based on test rig measurements. Afterwards, the performance of the disturbance observers will be investigated and compared taking selected influencing factors like changing controller and inertia parameters into account. The paper closes with a summary and an outlook.

Prozesskontrolle auch bei tiefen Bohrungen/Process control even for deep boreholes – Development of a mechatronic tool system for BTA deep hole drilling for compensation of straightness deviation

Obwohl mit Tiefbohrverfahren in der Regel Bohrungen mit deutlich höherer Qualität als mit konventionellen Bohrverfahren hergestellt werden können, stellt der Mittenverlauf von Tiefbohrungen mit zunehmender Bohrungstiefe ein Qualitätsproblem dar. Die Prozesskontrolle im industriellen Einsatz wird zurzeit manuell und sehr zeitaufwendig durch den Maschinenbediener mithilfe eines mobilen Ultraschallsystems durchgeführt. Um eine einheitliche Qualität der Bauteile sicherzustellen und Kosten einzusparen, wird ein mechatronisches System zur Kompensation des Mittenverlaufs entwickelt.   Even though deep hole drilling methods can produce boreholes of higher quality than conventional drilling methods, the straightness deviation of the bore hole represents a quality problem, particularly with increasing drilling depth. Process control in industrial applications is currently performed manually and very time-consuming by the machine operator using a mobile ultrasonic system. In order to ensure a high quality of the components and to save costs, a mechatronic system for process-parallel measurement and influencing of the straightness deviation is being developed.

FAST AND COST EFFICIENT MEASURING OF GEOMETRY AND TEMPERATURE FOR OPEN-DIE FORGING

In open-die forging it is state of the art to use simulation tools for creating forging plans and setpoint values for the forging press and the automated part manipulator. These forging plans define required positions and forces. Therefore, the process can be fully automated. However, even small variations of not considered influence parameters lead to different forging results and thus to a discontinuous process. Influencing factors are, e.g. material parameter deviations, uncertainties in force measurements or variations in the part temperature due to varying environmental conditions. This paper presents an approach for a fully automatic open-die forging process with respect to actual conditions, based on a parallel measurement of the workpiece geometry and temperature and a “process-real-time” adaptation on the controller system. The focus of this work is the development of a measuring strategy and an according sensor setup for the combined temperature and geometry measurement of the workpiece. In addition, the structure, the characteristic features of the components and the beam path of the sensors scanning units are shown. Furthermore, first experimental results for the alignment of the beam path are presented. In the outline, the setup and calibration strategy of the measurement system are stated.