Texas Instruments (Norway)

In human exhaled breath, more than 3000 volatile organic compounds (VOCs) are found, which are directly or indirectly related to internal biochemical processes in the body. Electronic noses (E-noses) could play a potential role in screening/analyzing various respiratory and systemic diseases by studying breath signatures. An E-nose integrates a sensor array and an artificial neural network that responds to specific patterns of VOCs, and thus can act as a non-invasive technology for disease monitoring. The gold standard blood glucose monitoring test for diabetes diagnostics is invasive and highly uncomfortable. This contributes to the massive need for technologies which are non-invasive and can be used as an alternative to blood measurements for glucose detection. While lung cancer is one of the deadliest cancers with the highest death rate and an extremely high yearly global burden, the conventional diagnosis means, such as sputum cytology, chest radiography, or computed tomography, do not support wide-range population screening. A few standard non-invasive techniques, such as mass spectrometry and gas chromatography, are expensive, non-portable, and require skilled personnel for operation and are again not suitable for large-scale screening. Breath contains markers for both diabetes and lung cancer along with markers for several diseases and thus, a non-invasive technique such as the E-nose would greatly improve analysis procedures over existing invasive methods. This review shows the state-of-the-art technologies for VOC detection and machine learning approaches for two clinical models: diabetes and lung cancer detection.

This paper presents a multilevel inverter topology suitable for the generation of dodecagonal space vectors instead of hexagonal space vectors as in the case of conventional schemes. This feature eliminates all the 6n ± 1 (n = odd ) harmonics from the phase voltages and currents in the entire modulation range with an increase in the linear modulation range. The topology is realized by flying capacitor-based three-level inverters feeding from two ends of an open-end winding induction motor with asymmetric dc links. The flying capacitor voltages are tightly controlled throughout the modulation range using redundant switching states for any load power factor. A simple and fast carrier-based space-vector pulsewidth modulation (PWM) scheme is also proposed for the topology which utilizes only the sampled amplitudes of the reference wave for the PWM timing computation.

Context The adoption of camera trapping in place of traditional wildlife survey methods has become common despite inherent flaws in equipment and a dearth of research to test their fit for purpose. Overwhelmingly, the development of commercial camera traps has been driven by the needs of North American hunters. Camera-trap models and features are influenced by these market forces that drive the changes in designs as new technologies develop. This focus on recreation, rather than research has often frustrated wildlife professionals as the equipment has rarely met minimum standards for scientific application. Aims We investigated the demand for white-flash camera traps around the world to highlight the demand for such camera traps in wildlife research to the manufacturing industry. We also compiled the camera-trap specifications required by scientists through the world in an effort to influence and improve the quality of camera traps for research. Methods We carried out an internet-based survey of biologists, zoologists, conservationists and other wildlife researchers by using a questionnaire to gather baseline market data on camera-trap use and demand. We also conducted an informal survey of scientists via email and in person, asking for their preferences and features of an ultimate camera-trap design. Key result Infrared camera traps are widely used and more so than white-flash camera traps, although the demand for white flash remains significant. Cost, speed, size, ease of use, versatility and the range of settings were the key features identified in a good camera trap. Conclusions The present paper describes and discusses the desired features and specifications as defined by over 150 scientists using camera traps around the world. Data gathered also provide some insight into the market demand for camera traps by biologists, zoologists, conservationists and other wildlife researchers around the world. These design features are discussed under the guise of the ultimate camera trap for wildlife research, with the disclaimer that no such camera trap currently exists. Implications The information provided in the paper has and will be a useful guide to future camera-trap designs, although it is unlikely that all of the features required will ever be produced in a cheap camera trap.

Abstract The rapid and label-free diagnosis of malignancies in ex vivo breast biopsy tissues has significant utility in pathology laboratories and operating rooms. We report a MEMS-based platform integrated with microchips that performs phenotyping of breast biopsy tissues using electrothermal sensing. The microchip, fabricated on a silicon substrate, incorporates a platinum microheater, interdigitated electrodes (IDEs), and resistance temperature detectors (RTDs) as on-chip sensing elements. The microchips are integrated onto the platform using a slide-fit contact enabling quick replacement for biological measurements. The bulk resistivity ( ρ B ), surface resistivity ( ρ S ), and thermal conductivity ( k ) of deparaffinized and formalin-fixed paired tumor and adjacent normal breast biopsy samples from N = 8 patients were measured. For formalin-fixed samples, the mean ρ B for tumors showed a statistically significant fold change of 4.42 ( P = 0.014) when the tissue was heated from 25 °C to 37 °C compared to the adjacent normal tissue, which showed a fold change of 3.47. The mean ρ S measurements also showed a similar trend. The mean k of the formalin-fixed tumor tissues was 0.309 ± 0.02 W m −1 K −1 compared to a significantly higher k of 0.563 ± 0.028 W m −1 K −1 for the adjacent normal tissues. A similar trend was observed in ρ B , ρ S , and k for the deparaffinized tissue samples. An analysis of a combination of ρ B , ρ S , and k using Fisher’s combined probability test and linear regression suggests the advantage of using all three parameters simultaneously for distinguishing tumors from adjacent normal tissues with higher statistical significance.

In this study, analysis of extending the linear modulation range of a zero common‐mode voltage (CMV) operated n ‐level inverter by allowing reduced CMV switching is presented. A new hybrid seven‐level inverter topology with a single DC supply is also presented in this study and inverter operation for zero and reduced CMV is analysed. Each phase of the inverter is realised by cascading two three‐level flying capacitor inverters with a half‐bridge module in between. Proposed inverter topology is operated with zero CMV for modulation index <86% and is operated with a CMV magnitude of V dc /18 to extend the modulation range up to 96%. Experimental results are presented for zero CMV operation and for reduced common voltage operation to extend the linear modulation range. A capacitor voltage balancing algorithm is designed utilising the pole voltage redundancies of the inverter, which works for every sampling instant to correct the capacitor voltage irrespective of load power factor and modulation index. The capacitor voltage balancing algorithm is tested for different modulation indices and for various transient conditions, to validate the proposed topology.

In this paper, a current error space vector (CESV)-based hysteresis current controller for a multilevel 12-sided voltage space vector-based inverter-fed induction motor (IM) drive is proposed. The proposed controller gives a nearly constant switching frequency operation throughout different speeds in the linear modulation region. It achieves the elimination of 6n ±1, n = odd harmonics from the phase voltages and currents in the entire modulation range, with an increase in the linear modulation range. It also exhibits fast dynamic behavior under different transient conditions and has a simple controller implementation. Nearly constant switching frequency is obtained by matching the steady-state CESV boundaries of the proposed controller with that of a constant switching frequency SVPWM-based drive. In the proposed controller, the CESV reference boundaries are computed online, using the switching dwell time and voltage error vector of each applied vector. These quantities are calculated from estimated sampled reference phase voltages. Vector change is decided by projecting the actual current error along the computed hysteresis space vector boundary of the presently applied vector. The estimated reference phase voltages are found from the stator current error ripple and the parameters of the IM.

This study presents a 17‐level inverter‐based induction motor drive for high‐resolution multilevel voltage space‐vector (SV) generation. The proposed topology consists of a three‐level inverter and a seven‐level inverter connected to an open‐end winding induction machine. The two inverters are powered by two unequal DC supplies, resulting in a low component count, with just 12 switches and three floating capacitors per phase. The voltage SVs applied by the two inverters are chosen to eliminate circulating power flow and prevent DC bus overcharging. In addition, the switching states of both inverters are chosen in order to keep voltages of all floating capacitors well‐controlled. Since the capacitors voltages are controlled using the phase currents, additional pre‐charging circuitry is not required. A modulation scheme using level‐shifted carriers has also been developed, which can be used with both V/f control and d–q control. The high‐voltage inverter has a low effective switching frequency and the low‐voltage inverter has a high effective switching frequency, reducing the switching loss. The included results of steady‐state and transient testing of an experimental prototype demonstrate that the proposed scheme is suited for industrial drives and traction applications.

Abstract Micromolding technology is widely used for the fabrication of polymer microneedles for transdermal and intradermal drug delivery applications. Geometric features of microneedles in molding are solely determined by geometry of the master mold template. Fabrication of master mold template usually involves costly and cumbersome technologies due to small feature sizes typical of microneedles. In this research, a novel molding platform is designed that is fabricated using low‐cost and simple techniques with flexibility of producing large number of microneedle geometries. The proposed molding platform eliminates need for developing multiple mold templates for fabrication of various geometries of polymer microneedles. Utility of this molding platform is demonstrated in polylactic acid‐based solid thermoplastic microneedles and polyacrylic acid‐based dissolvable microneedles with various aspect ratio settings. Various microneedles fabricated at heights differing with resolution of as low as 100 µm are successfully achieved using specified settings in the molding platform. The suitability of fabricated microneedles for drug delivery applications is evaluated by in vitro and in vivo testing.

This work demonstrates a BLE compatible battery-less Wireless Sensor Mote, powered by an RF Energy Harvesting (RFEH) Chip. The chip integrates Energy Harvesting and Power conditioning circuits. RF-Energy is harvested from UHF RFID receiver (i.e, 865–868 MHz) and is stored in an external capacitor bank. This energy is utilized to run a microcontroller + radio SoC, wherein data from a sensor (analog temperature sensor) is read and broadcasted as BLE advertisement packets. An android app was developed to process and display the sensor value. The designed chip harvests at power level of −12 dBm and above. Whereas the complete system works at a power level of −8dbm. The maximum BLE packet transmission interval at the specified power level is about 30 minutes. To the best of our knowledge, this is the first work to demonstrate BLE broadcast with RF Harvesting.

The grid-tied inverter synchronizes with the network on the basis of the instantaneous voltage phase angle. This angle is computed by the so-called synchronization algorithms. During grid disturbances, it is estimated with a certain accuracy, which varies for different disturbances and depends on the choice of algorithm. The tests presented here determine how to make an optimal selection of the synchronization algorithm. The research methods used are modeling, simulation and analysis of the results obtained. One of the most important outcomes is the determination of the root-mean-square sync error and its dynamics denotation. The research conclusions should be of particular interest to designers of distributed energy systems with a large number of inverter energy sources. © 2020 Polish Academy of Sciences. All rights reserved.

Abstract In the recent days, for the traction and electric vehicle (EV) applications, multiphase machines with pole phase modulation (PPM) technique have been proposed. The smoother operation during pole changeovers as well as steady‐state operations is a significant constraint while adopting the PPM‐based multiphase induction motor (PPMIM) drives for EV and traction applications. So, in this paper, the PPMIM dynamic model and associated vector control are proposed for attaining a smoother operation of the machine. The machine modelling equations and transformation matrices are implemented in an arbitrary reference frame by considering the different pole phase combinations. Based on the modelling equations, the indirect field‐oriented control (IFOC) is proposed for PPMIM drives by reflecting the associated changes in parameters for different pole phase modes. In the IFOC, for regulating the d ‐axis and q‐ axis current components, single PI control loops have been implemented for all pole‐phase combinations. The proposed IFOC scheme is robust and applicable for adopting any type of pulse width modulation. The experimental, as well as simulation results, are given to illustrate the potentiality of the proposed dynamic model and IFOC. The PPMIM machine performance during the steady state as well as pole changeovers in different pole phase modes are analyzed and associated. Simulation and experimental results are presented.

Abstract This paper describes a quadcopter manipulator system, an aerial robot with an extended workspace, its controller design, and experimental validation. The aerial robot is based on a quadcopter with a three degree of freedom robotic arm connected to the base of the vehicle. The work aims to create a stable airborne robot with a robotic arm that can work above and below the airframe, regardless of where the arm is attached. Integrating a robotic arm into an underactuated, unstable system like a quadcopter can enhance the vehicle's functionality while increasing instability. To execute a mission with accuracy and reliability during a real‐time task, the system must overcome the inter‐coupling effects and external disturbances. This work presents a novel design for a robust adaptive feedback linearization controller with a model reference adaptive controller and hardware implementation of the quadcopter manipulator system with plant uncertainties. The closed‐loop stability of the aerial robot and the tracking error convergence with the robust controller is analyzed using Lyapunov stability analysis. The quadcopter manipulator system is custom developed in the lab with an off‐the‐shelf quadcopter and a 3D‐printed robotic arm. The robotic system architecture is implemented using a Jetson Nano companion computer for autonomous onboard flight. Experiments were conducted on quadcopter manipulator system to evaluate the autonomous aerial robot's stability and trajectory tracking with the proposed controller.

A 2.4 GHz low power, Internet-of-Things (IoT) based system for neonatal health-care application is presented. The system includes an ultra-low power receiver compatible with a wearable device with interface-connectivity to the sensors and a controller. A novel design of a "wake-up" receiver architecture is presented, where an LC oscillator and a ring oscillator combination provides a desired ultra-low power solution. The proposed receiver front-end consists of a gm-boosting current-reuse based low noise amplifier (LNA) and a transmission-gate based passive switching mixer. The prototype is designed in a 65-nm CMOS technology. The simulation results show a gain of 14.9 dB while consuming 75μW from a 0.75 V supply. The LNA gain is 16 dB with a noise figure of 5.7 dB and IIP3 of 18.16 dBm.

The inverted pendulum is a popular model for describing bipedal dynamic walking. The operating point of the walker can be specified by the combination of initial mid-stance velocity (v0) and step angle (φm) chosen for a given walk. In this paper, using basic mechanics, a framework of physical constraints that limit the choice of operating points is proposed. The constraint lines thus obtained delimit the allowable region of operation of the walker in the v0-φm plane. A given average forward velocity vx,avg can be achieved by several combinations of v0 and φm. Only one of these combinations results in the minimum mechanical power consumption and can be considered the optimum operating point for the given vx,avg. This paper proposes a method for obtaining this optimal operating point based on tangency of the power and velocity contours. Putting together all such operating points for various vx,avg, a family of optimum operating points, called the optimal locus, is obtained. For the energy loss and internal energy models chosen, the optimal locus obtained has a largely constant step angle with increasing speed but tapers off at non-dimensional speeds close to unity.

Indoor Localisation has been an interesting and significant area of research in the recent times because of its diverse applications. There is always a trade-off between the number of devices used and the accuracy obtained for any indoor localisation system. In our work we make use of WiFi access points, a smart phone with inertial sensors and a server. Since RSSI value is not very much reliable, we go with a hybrid approach where fingerprinted RSSI values of different access points are used to initialise the position using Maximum Likelihood estimate and thereafter the inertial sensors takes over the localisation. After certain distance is travelled, the error accumulated is corrected by access points' RSSI values. The proposed simple hybrid system <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> yields an accuracy of minimum 2m consistently, with only 3 access points in the indoor space. Hence, the system is overall better than most of the indoor localisation systems present.

Abstract The histopathological diagnosis of cancer is the current gold standard to differentiate normal from cancerous tissues. We propose a portable platform prototype to characterize the tissue's thermal and optical properties, and their inter‐dependencies to potentially aid the pathologist in making an informed decision. The measurements were performed on 10 samples from five subjects, where the cancerous and adjacent normal were extracted from the same patient. It was observed that thermal conductivity (k) and reduced‐scattering‐coefficient ( μ' s ) for both the cancerous and normal tissues reduced with the rise in tissue temperature. Comparing cancerous and adjacent normal tissue, the difference in k and μ' s (at 940 nm) were statistically significant (p = 7.94e‐3), while combining k and μ' s achieved the highest statistical significance (6.74e‐4). These preliminary results promise and support testing on a large number of samples for rapidly differentiating cancerous from adjacent normal tissues.

ABSTRACT In this article, a Field Programmable Gate Array (FPGA)‐based hardware accelerator for 3D electromagnetic extraction, using Method of Moments (MoM) is presented. As the number of nets or ports in a system increases, leading to a corresponding increase in the number of right‐hand‐side (RHS) vectors, the computational cost for multiple matrix‐vector products presents a time bottleneck in a linear‐complexity fast solver framework. In this work, an FPGA‐based hardware implementation is proposed toward a two‐level parallelization scheme: (i) matrix level parallelization for single RHS and (ii) pipelining for multiple‐RHS. The method is applied to accelerate electrostatic parasitic capacitance extraction of multiple nets in a Ball Grid Array (BGA) package. The acceleration is shown to be linearly scalable with FPGA resources and speed‐ups over 10× against equivalent software implementation on a 2.4 GHz Intel Core i5 processor is achieved using a Virtex‐6 XC6VLX240T FPGA on Xilinx's ML605 board with the implemented design operating at 200 MHz clock frequency. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:776–783, 2016

We propose efficient encoding and decoding hardware architectures for (n, k), t-error correcting Bose-Chaudhuri-Hocquenghem (BCH) product codes in the frequency domain. Using the properties of conjugate classes over a finite field, we reduce the algorithmic complexity of the encoder, leading to a significant reduction in the hardware complexity. A low latency (2t+2) decoder for the above encoder is also designed. For a particular case of n=15 and t=2, the architectures were implemented on a Kintex 7 KC-705 FPGA kit, giving high throughputs of 22.5 Gbps and 5.6 Gbps at 100 MHz for the encoder and decoder respectively.

Photon emission by single molecules is a random event with a well-defined distribution. This calls for event-based detection in single-molecule localization microscopy. The detector has the advantage of providing a temporal change in photons and emission characteristics within a single blinking period (typically, ∼ 30 ms ) of a single molecule. This information can be used to better localize single molecules within a user-defined collection time (shorter than average blinking time) of the event detector. The events collected over every short interval of time / collection time (∼ 3 ms ) give rise to several independent temporal photon distributions ( tPSFs ) of a single molecule. The experiment showed that single molecules intermittently emit photons. So, capturing events over a shorter period / collection time than the entire blinking period gives rise to several realizations of the temporal PSFs ( tPSFs ) of a single molecule. Specifically, this translates to a sparse collection of active pixels per frame on the detector chip (image plane). Ideally, multiple realizations of single-molecule tPSF give several position estimates of the single-molecules, leading to multiple tPSF centroids. Fitting these centroid points by a circle provides an approximate position (circle center) and geometric localization precision (determined by the FWHM of the Gaussian) of a single molecule. Since the single-molecule estimate (position and localization precision) is directly driven by the data (photon detection events on the detector pixels) and the recorded tPSF , the estimated value is purely experimental rather than theoretical (Thomson’s formula). Moreover, the temporal nature of the event camera and tPSF substantially reduces noise and background in a low-noise environment. The method is tested on three different test samples (1) Scattered Cy3 dye molecules on a coverslip, (2) Mitochondrial network in a cell, and (3) Dendra2HA transfected live NIH3T3 cells (Influenza-A model). A super-resolution map is constructed and analyzed based on the detection of events (temporal change in the number of photons). Experimental results on transfected NIH3T3 cells show a localization precision of ∼ 10 nm , which is ∼ 6 fold better than standard SMLM. Moreover, imaging HA clustering in a cellular environment reveals a spatio-temporal PArticle Resolution (PAR) (2.3 l p × τ ) of 14.11 par where 1 par = 10 −11 meter . second . However, brighter probes (such as Cy3) are capable of ∼ 3.16 par . Cluster analysis of HA molecules shows &gt; 81% colocalization with standard SMLM, indicating the consistency of the proposed eventSMLM technique. The single-molecule imaging on live cells reveals temporal dynamics (migration, association, and dissociation) of HA clusters for the first time over 60 minutes. With the availability of event-based detection and high temporal resolution, we envision the emergence of a new kind of microscopy that is capable of high spatio-temporal particle resolution in the sub-10 par regime.

By exploiting the subblock structure of a tensor product code, we provide an upper bound on the maximum correctable burst length of tensor product codes used with interleavers designed based on only the minimum distance and the maximum correctable burst length of its component codes, without taking the specific code geometry and soft decoding into consideration. We provide necessary and sufficient conditions for an interleaver to achieve this upper bound. Further, for two cases of the tensor product codes, we design optimal intracodeword interleavers that satisfy the proposed conditions.