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Algorithms for estimating cardiac output (CO) from the arterial blood pressure wave have been observed to be inaccurate during changes in vascular tone. Many such algorithms are based on the Windkessel model of the circulation. We investigated the optimal analytical approaches and assumptions that make up each algorithm during changes in vascular tone. Several analytical approaches and assumptions...
Advances in robotic surgery especially in minimally-invasive surgery (MIS) has increased the need for translating computer-vision algorithms in endoscopic imagery to support surgical decisions. While methods for stereo reconstruction have been extensively investigated for man-made environments, such an extensive and detailed study on the pros and cons of stereo reconstruction for endoscopic images...
Visually stimulated brain-computer interfacing detects which target on a screen a user is gazing at; however, this is also accomplished by tracking gaze points with a camera. These two approaches have been independently investigated and sometimes doubts about BCI with visual stimuli are raised in terms of usability compared to eye tracking interfaces (ETI). This paper answers this question by investigating...
Successful brain-computer interfaces (BCIs) swiftly and accurately communicate the user's intention to a computer. Typically, information transfer rate (ITR) is used to measure the performance of a BCI. We propose a multi-step process to speed up detection and classification of the user's intent and maximize ITR. Users randomly looked at 4 frequency options on the interface in two sessions, one without...
An approach to the generation of super-resolution (SR) images from fundoscopy images is proposed that is based on the 3D registration of the original fundoscopy images. The proposed approach utilizes a simple 3D registration method to enable the application of conventional SR techniques which, otherwise, employ 2D image registration. Qualitative and quantitative comparative evaluation shows that the...
Previously, a static and adjustable image overlay systems were proposed for aiding needle interventions. The system was either fixed to a scanner or mounted over a large articulated counterbalanced arm. Certain drawbacks associated with these systems limited the clinical translation. In order to minimize these limitations, we present the mobile image overlay system with the objective of reduced system...
Kinect has been increasingly applied in rehabilitation as a motion capture device. However, the inherent limitations significantly hinder its further development in this important area. Although a number of Kinect fusion approaches have been proposed, only a few of them was actually considered for rehabilitation. In this paper, we propose to fuse information from multiple Kinects to achieve this....
Ensuring robustness of myocontrol algorithms for prosthetic devices is an important challenge. Robustness needs to be maintained under nonstationarities, e.g. due to electrode shifts after donning and doffing, sweating, additional weight or varying arm positions. Such nonstationary behavior changes the signal distributions — a scenario often referred to as covariate shift. This circumstance causes...
Traditional metrics for evaluating the severity of psoriasis are highly subjective, which complicates efforts to identify effective treatments in clinical trials. We propose a method for the objective measurement of the psoriasis severity parameter of erythema (redness). This procedure is standardized for different camera systems and lighting environments through the usage of a color card with predetermined...
The role of analogue-to-digital converter (ADC) boards in ac primary electrical metrology is steadily increasing. Most measurement methods, and the corresponding implementations, dedicated to measurements of electrical impedance and power often do not rely on ADCs absolute accuracy, but rather on their time and temperature stability, frequency response and mismatch among channels. The summary discusses...
A portable error simulator for evaluating voltage transformer test set(VTTS) using a voltage divider consisting the serial combination of the resistor and capacitor was developed. The error simulator was applied to the calibration of several type commercial current-comparator-based VTTS and covered the ratio error and phase error range up to ±10 % and ±15 crad, respectively. From the calculated and...
This paper describes the principle, structure and the self-calibration method of a new type of current comparator which is designed and constructed by NIM. This current comparator is based on “shield guiding structure”, and its ratio is from 0.1∶1 to 1∶1.
The surveying technique of close-range Photogrammetry is based on an approach of representation of the image forming mechanism of photography and extract spatial information through computation on photos. This research used the fundamentals of close-range Photogrammetry and is applied to model leaves, measure the geometric model of leaf length and width and compare with the conventional measurement...
We present the comparison of results from the generation and the measurement of direct currents in the pA range, performed with traceable state-of-the-art methods at highest accuracy. The currents were generated with the capacitor charging method, and measured with the first prototype of a novel picoammeter developed at PTB. The results confirm the agreement between both methods and the linearity...
Localization and tracking of players is crucial for monitoring both indoor and outdoor sports activities. The effects of the environment pose a major challenge for an accurate position estimation. In this paper, we present a novel solution based on the received signal strength indication (RSSI) feature provided by off-the-shelf wireless networks. Trilateration is used for estimating the position of...
Resistive dividers for wideband power analyzers have been designed. They have been built with identical resistors connected in series and parallel in a quasi-coaxial structure. Simulations on the PSpice models, the methods developed for their calibration and the preliminary experiments show that the accuracy for frequency up to 20 kHz can be better than 30 parts in 106 for the ratio and 20 µrad for...
In this paper, a novel foreground calibration technique is presented for current-steering DACs. Each current source is in parallel with a CAL DAC injecting a small correction current that corrects the mismatch and tracks the temperature variations. High matching accuracy is not only achieved at the calibration temperature, but also maintained across a wide operating temperature range from −40 °C to...
A capacitor-resistor combined bank to calibrate both the capacitance ratio and dissipation factor of the commercial capacitance and tan δ measuring bridge is fabricated. The fabricated portable working standards as a secondary standard for ratio calibration are realized by connecting the double shielded capacitors in parallel employing the substitution and build-up technique, whereas, the standards...
This paper describes how to using the calibration method to verify a NFC RF Conformance Test Tool without the traditional test case running and script checking to choose a most accurate test tool.
A reference system for on-site calibration and validation of revenue metering systems is realized. The system consists of a three-phase power meter and high-accuracy current and voltage transformers (CTs and VTs). Measurements can be made up to 150 kV (system voltage) and line currents up to 5000 A. The power meter, the CTs, and the VTs were all calibrated. Based on the excellent results of the calibration...
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