Ultrasound Sensor Research Articles

DESIGN AND BUILD OF AUTOMATIC WASTAFEL USING ULTRASOUND HC-SR04 SENSOR BASED ON ARDUINO

The lack of public concern for washing hands during the Covid-19 pandemic, the authors designed an automatic sink using an arduino-based HC-SR04 ultrasound sensor to attract the public's interest. By making automatic sink technology using the HC-SR04 ultrasound sensor based on Arduino for use in hand washing by the community. This study uses experimental research that examines the effect of automatic washbasin with people's behavior in washing hands. By testing the use of water in 20 seconds, 43 people can use it in one day, and soap can be used by 6 people in one day in 5 seconds. The automatic sink using the HC-SR04 ultrasound sensor based arduino can be used with a distance that is made less than 15cm designed to be practical and sterile because it is used that does not touch faucets or soap. The conclusion of the study is that if there is an object that approaches the ultrasound sensor within a distance of less than 15cm, the water pump will be active for 20 seconds or the soap pump for 5 seconds will automatically come out. And it will run out if used for 934 seconds in 1 liter gallon or 46 people a day and the use of soap for 5 seconds will run out approximately 6 people in one day.

Inspection of transverse flaws for railways using phased array ultrasonic technique

AbstractRail monitoring is an important activity which aims to preserve the safety and availability of railways. According to statistics, the primary cause of railway accidents is due to transverse defects that occur in the rail head. These special defects develop generally in a plane orthogonal to the rail running direction. The detection of these defects is a priority to increase the safety of rail transportation. Rail control monitoring techniques mostly rely on infrared thermography, eddy currents, air-coupled acoustic sensors, and ultrasounds. The present research studies the rail diagnosis by means of a non-contact device. The focus is on ultrasonic based methods where excitation is generated by thermal elastic coupling following laser irradiation of the rail head. For the reception of echoes, a special ultrasound sensor was used. In order to sense defects, phased array elements, which use multiple transducers and electronic time delays, are used to increase and to focalise the signal intensity. Flaws that have a moderate extension are better detected by the proposed method than with laser irradiation consisting of a single spot.

Real-Time Determination of Total Solids in UASB Reactors Using a Single Emitter Ultrasonic Sensor

The lack of proper sludge withdrawal routines has been one of the main causes of solids washout and consequent deterioration of effluent quality from up-flow anaerobic sludge blanket (UASB) reactors treating sewage in developing countries. The establishment of an adequate sludge withdrawal routine depends on the knowledge of the sludge mass inside the reactor, but for this, it is necessary to continuously monitor the solid’s profile along the height of the digestion compartment of such reactors. Knowing the sludge concentration at the highest point of this compartment, immediately before the passage of the liquid to the settling compartment, allows the definition of more robust strategies for sludge discharge, in order to not exceed the retention capacity (storage) of solids in the reactor. To couple with that, a low-cost ultrasound sensor was developed and tested with the aim of monitoring total solids concentration inside UASB reactors. Bench and demo-scale tests were performed to validate the developed technology. Results have shown that the sensor can provide real-time values of total solids inside the reactor with 0.1% accuracy up to 1% total solids content.

Photoacoustic Mouse Brain Imaging Using an Optical Fabry-Pérot Interferometric Ultrasound Sensor.

Photoacoustic (PA, or optoacoustic, OA) mesoscopy is a powerful tool for mouse cerebral imaging, which offers high resolution three-dimensional (3D) images with optical absorption contrast inside the optically turbid brain. The image quality of a PA mesoscope relies on the ultrasonic transducer which detects the PA signals. An all-optical ultrasound sensor based on a Fabry-Pérot (FP) polymer cavity has the following advantages: broadband frequency response, wide angular coverage and small footprint. Here, we present 3D PA mesoscope for mouse brain imaging using such an optical sensor. A heating laser was used to stabilize the sensor’s cavity length during the imaging process. To acquire data for a 3D angiogram of the mouse brain, the sensor was mounted on a translation stage and raster scanned. 3D images of the mouse brain vasculature were reconstructed which showed cerebrovascular structure up to a depth of 8 mm with high quality. Imaging segmentation and dual wavelength imaging were performed to demonstrate the potential of the system in preclinical brain research.

Home Monitoring System for Comprehensive Geriatric Assessment in Patient's Dwelling: System Design and UX Evaluation.

Population aging threatens the sustainability of welfare systems since it is not accompanied by an extended healthy and independent period in the last years of life. The Comprehensive Geriatric Assessment (CGA) has been shown to be efficient in maintaining the healthy period at the end of the life. Frailty monitoring is typically carried out for an average period of 6 months in clinical settings, while more regular monitoring could prevent the transition to disability. We present the design process of a system for frailty home monitoring based on an adapted CGA and the rationale behind its User eXperience (UX) design. The resulting home monitoring system consists of two devices based on ultrasound sensors, a weight scale, and a mobile application for managing the devices, administering CGA-related questionnaires, and providing alerts. Older users may encounter barriers in their usage of technology. For this reason, usability and acceptability are critical for health monitoring systems addressed to geriatric patients. In the design of our system, we have followed a user-centered process, involving geriatricians and older frail patients by means of co-creation methods. In the iterative process of design and usability testing, we have identified the most effective way of conducting the home-based CGA, not just by replicating the dialogue between the physician and the patient, but by adapting the design to the possibilities and limitations of mobile health for this segment of users. The usability evaluation, carried out with 14 older adults, has proved the feasibility of users older than 70 effectively using our monitoring system, additionally showing an intention over 80% for using the system. It has also provided some insights and recommendations for the design of mobile health systems for older users.

Novel Nanoelectromechanical System Pressure Biosensing Method for Early Detection of Cholesterol Accumulation in Blood Vessels

High cholesterol could be dangerous, along with the deposits of other substances, such as fat, on the walls of the arteries. These plaques can reduce blood flow through the arteries, which in turn can cause complications such as chest pain, blood clots, and heart attack. Hence, there is a need for an efficient way to measure the concentration of cholesterol in blood vessels with great accuracy to predict its risk on health. The present study aims to measure the concentration of cholesterol and track it accurately in the blood vessels using an ultrasound pressure sensor, which detects the concentration of cholesterol and produces a pressure field around its surface that is directly proportional to the concentration. This field can be tracked by ultrasound. In this study, the experiments conducted involved the insertion of aluminum nanoparticles, which represent a pressure sensor coated with a massless piezoelectric aluminum nitride nanoplate, into simulated blood vessels containing different concentrations that mimic human blood. The sensitivity of the blood vessels was monitored at different time periods. Moreover, an experimental setup was constructed to validate the possibility of using existing ultrasound medical imaging technologies in tracking the proposed nano biosensors. The setup involves prototyping a medical phantom with a specific acoustic characteristic for simulating human tissues. Various clinical scenarios have been imitated and the possibility of tracking these novel micro electromechanical pressure biosensors has been discussed.

Imaging radar for automated driving functions

AbstractThis work presents the implementation of a synthetic aperture radar (SAR) at 77 GHz, for automotive applications. This implementation is unique in the sense that it is a radar-only solution for most use-cases. The set-up consists of two radar sensors, one to calculate the ego trajectory and the second for SAR measurements. Thus the need for expensive GNSS-based dead reckoning systems, which are in any case not accurate enough to fulfill the requirements for SAR, is eliminated. The results presented here have been obtained from a SAR implementation which is able to deliver processed images in a matter of seconds from the point where the targets were measured. This has been accomplished using radar sensors which will be commercially available in the near future. Hence the results are easily reproducible since the deployed radars are not special research prototypes. The successful widespread use of SAR in the automotive industry will be a large step forward toward developing automated parking functions which will be far superior to today's systems based on ultrasound sensors and radar (short range) beam-forming algorithms. The same short-range radar can be used for SAR, and the ultrasound sensors can thus be completely omitted from the vehicle.

The prototype for measuring the height and monitoring of river water quality based on the Internet of Things

Abstract. Technology continues to develop from year to year which aims to simplify human work or automation of a system. The concept of measuring the water level is automatically applied to the river in front of the Tanggulangin tourism market, which aims to make it easier for residents to check the river water level in real time via the internet network. By utilizing the DS18B20 sensor to find out the temperature which has 97.85% accuracy and the HC-SR04 ultrasonic distance sensor which has 100% accuracy at a distance of less than 20 CM to find out the water level based on changes in the distance value on the sensor as an indication of the rise and fall of river water. From the sensor, the sensor is controlled with the Arduino UNO and NodeMCU microcontroller board to make the system work automatically, as well as the use of the MIT App Inventor to create android applications and to support the internet of things system. From the results of this research, it is obtained: (1). In the HC-SR04 ultrasound sensor test, the stability of the measurement value is very good, seen from the standard deviation value. (2). In testing the DS18B20 temperature sensor with a standard thermometer ratio has a difference of 0.7 ° C accuracy with an accuracy of 97.85% so that it can be used as a measurement tool. (3). On the TDS sensor, the standard deviation can be between 130-141 ppm which indicates this tool can function properly. (4). On the LCD, it can work properly and is ready to use in a system that functions to display information carried out by the microcontroller. (5). For pH sensors, this sensor can measure the degree of acidity / basicity of water between 1-10 pH.

Obstacles and Areas Detection Based on Pulse Width Modulation Method for Electric Wheelchair Safety Using Ultrasound Sensors

People with disabilities find it difficult to operate wheelchairs especially those with disabilities who do not have hands and feet or are disabled. The aim of this research is to improve safety control for electric wheelchairs by detecting obstacles and detecting areas that minimize collisions against obstacles. The contribution of this research is the use of the HC-SR04 ultrasound sensors to avoid a wheelchair colliding with an obstacle using the Pulse Width Modulation (PWM) method which is set based on the distance of the obstacle and the detection of free areas and corridor areas using the PWM method which is adjusted based on following the wall. The HC-SR04 ultrasound sensor is used as input and is processed on the Arduino nanomicrocontroller series to produce a value of PWM. Measuring the HC-SR04 ultrasound sensor against obstacles obtained the largest deviation of 0.72 and average 148,6 cm at a distance of 150 cm and the smallest deviation at a distance of less than 50 cm and the wheelchair can move at slow, medium and fast speeds with the measurement results on Duty Cycles of 71%, 82% and 94%. The results showed that the final distance of the wheelchair against obstacles was less than 50 cm and the wheelchair moved at a distance of 34 - 53 cm following the wall. The results of this study can control motor speed based on obstacles that can be implemented in electric wheelchairs to improve safety and ease of operation for people with disabilities.

Interferometric optical fiber sensor for optoacoustic endomicroscopy

Optical fiber sensors can offer robust and miniaturized detection of wideband ultrasound, yielding high sensitivity and immunity to electromagnetic interference. However, the lack of cost-effective manufacturing methods prevents the disseminated use of these sensors in biomedical applications. In this study, we developed and optimized a simple method to create optical cavities with high-quality mirrors for acoustic sensing based on micro-manipulation of UV-curable optical adhesives and electroless chemical silver deposition. This approach enables the manufacturing of ultrasound sensors based on Fabry-Pérot interferometers on optical fiber tips with minimal production costs. Characterization and high-resolution optoacoustic imaging experiments show that the manufacturing process yielded a fiber sensor with a small NEP ( ) over a broad detection bandwidth (25 MHz), generally outperforming conventional piezoelectric based transducers. We discuss how the new manufacturing process leads to a high-performance acoustic detector that, due to low cost, can be used as a disposable sensor.

Sensitive, small, broadband and scalable optomechanical ultrasound sensor in silicon photonics

Ultrasonography1 and photoacoustic2,3 (optoacoustic) tomography have recently seen great advances in hardware and algorithms. However, current high-end systems still use a matrix of piezoelectric sensor elements, and new applications require sensors with high sensitivity, broadband detection, small size and scalability to a fine-pitch matrix. This work demonstrates an ultrasound sensor in silicon photonic technology with extreme sensitivity owing to an innovative optomechanical waveguide. This waveguide has a tiny 15 nm air gap between two movable parts, which we fabricated using new CMOS-compatible processing. The 20 μm small sensor has a noise equivalent pressure below 1.3 mPa Hz−1/2 in the measured range of 3–30 MHz, dominated by acoustomechanical noise. This is two orders of magnitude better than for piezoelectric elements of an identical size4. The demonstrated sensor matrix with on-chip photonic multiplexing5–7 offers the prospect of miniaturized catheters that have sensor matrices interrogated using just a few optical fibres, unlike piezoelectric sensors that typically use an electrical connection for each element. An optical ultrasound sensor based on a CMOS-compatible split-rib waveguide is demonstrated, offering high sensitivity, broadband detection (measured 3–30 MHz), small size (20 μm) and scalability to a fine-pitch matrix.

Biomedical Photoacoustic Imaging With Unknown Spatially Distributed Ultrasound Sensor Array.

With the growth of interest in different medical study on biological function, non-invasive photoacoustic imaging of biological tissue attracts the interests for researchers. To eliminate the limited angle effect of photoacoustic imaging based on ultrasound linear array, spatially distributed ultrasound sensor array is applied. The accurate sensor array position determines the quality of the imaging results. In this study, we proposed three methods based on photoacoustic and ultrasound signals to enhance the imaging quality using a 256-element full-ring array. Groups of photoacoustic and ultrasound signals are used to regress the position of each element sensor. In phantom study and mouse brain study, photoacoustic imaging results can both yield details clearly with average error rate of less than 1% (50 [Formula: see text]). The performance of our three methods have proved that they can be potentially applied to other ultrasound-based medical imaging studies with unknown distributed positions of sensor array to enhance the imaging quality. The proposed methods can contribute to precise biomedical imaging with unknown distributed positions of sensor array in different application scenarios.

A Theoretical/Numerical Study on Ultrasound Wave Coupling From Structure to Remotely Bonded Fiber Bragg Grating Ultrasound Sensor

Abstract Recently published experimental works on remotely bonded fiber Bragg grating (FBG) ultrasound (US) sensors show that they display some unique characteristics that are not observed with directly bonded FBG sensors. These studies suggest that the bonding of the optical fiber strongly influences how the ultrasound waves are coupled from the structure to the FBG sensor. In this paper, the analytical model of the structure-adhesive-optical fiber section, treated as an ultrasound coupler, is derived and analyzed to explain the observed experimental phenomena. The resulting dispersion curve shows that the ultrasound coupler possesses a cutoff frequency, above which a dispersive longitudinal mode exists. The low propagation speed of the dispersive longitudinal mode leads to multiple resonances at and above the cutoff frequency. To characterize the resonant characteristics of the ultrasound coupler, a semi-analytical model is implemented and the scattering parameters (S-parameters) are introduced for broadband time-frequency analysis. The simulation was able to reproduce the experiment observations reported by other researchers. Furthuremore, the behaviors of the remotely bonded FBG sensors can be explained based on its resonant characteristics.

Ultrasonic Time-of-Flight Computed Tomography for Investigation of Batch Crystallisation Processes.

Crystallisation is a crucial step in many industrial processes. Many sensors are being investigated for monitoring such processes to enhance the efficiency of them. Ultrasound techniques have been used for particle sizing characterization of liquid suspensions, in crystallisation process. An ultrasound tomography system with an array of ultrasound sensors can provide spatial information inside the process when compared to single-measurement systems. In this study, the batch crystallisation experiments have been conducted in a lab-scale reactor in calcium carbonate crystallisation. Real-time ultrasound tomographic imaging is done via a contactless ultrasound tomography sensor array. The effect of the injection rate and the stirring speed was considered as two control parameters in these crystallisation functions. Transmission mode ultrasound tomography comprises 32 piezoelectric transducers with central frequency of 40 kHz has been used. The process-based experimental investigation shows the capability of the proposed ultrasound tomography system for crystallisation process monitoring. Information on process dynamics, as well as process malfunction, can be obtained via the ultrasound tomography system.

DESIGN OF BALL COLLECTING ROBOT

A concept of four-wheeled mobile service robot capable of collecting balls from the Tennis court is proposed in this article. The robot is capable of manoeuvring on its own in an autonomous way and also it can be operated wirelessly. The robot is built using the Arduino Uno R3 microcontroller board along with sensors like LiDAR, ultrasound sensor, optical encoders, infrared sensor, camera for vision system. Sensor fusion can be implemented for localization of the robot while detection of the tennis ball can be attained by learning based object detection algorithm using OpenCV. A* algorithm is proposed for the navigation of the robot towards the object. Wireless operation of the robot can be achieved with the Bluetooth technology using the Android application via a smartphone. The article is an overview and information.

Highly sensitive and miniature microfiber-based ultrasound sensor for photoacoustic tomography

Highly sensitive and miniature microfiber-based ultrasound sensor for photoacoustic tomography

Flexible fiber-laser ultrasound sensor for multiscale photoacoustic imaging

Photoacoustic imaging (PAI) is a noninvasive biomedical imaging technology capable of multiscale imaging of biological samples from organs down to cells. Multiscale PAI requires different ultrasound transducers that are flat or focused because the current widely-used piezoelectric transducers are rigid and lack the flexibility to tune their spatial ultrasound responses. Inspired by the rapidly-developing flexible photonics, we exploited the inherent flexibility and low-loss features of optical fibers to develop a flexible fiber-laser ultrasound sensor (FUS) for multiscale PAI. By simply bending the fiber laser from straight to curved geometry, the spatial ultrasound response of the FUS can be tuned for both wide-view optical-resolution photoacoustic microscopy at optical diffraction-limited depth (~1 mm) and photoacoustic computed tomography at optical dissipation-limited depth of several centimeters. A radio-frequency demodulation was employed to get the readout of the beat frequency variation of two orthogonal polarization modes in the FUS output, which ensures low-noise and stable ultrasound detection. Compared to traditional piezoelectrical transducers with fixed ultrasound responses once manufactured, the flexible FUS provides the freedom to design multiscale PAI modalities including wearable microscope, intravascular endoscopy, and portable tomography system, which is attractive to fundamental biological/medical studies and clinical applications.

Internet of Things Assisted Monitoring Using Ultrasound-Based Gesture Recognition Contactless System

In the last decade, we have seen an increase in the use of digital technologies in our daily lives, including advanced systems such as mobile applications, smart digital kiosks for intelligent retailing, touch screens for ordering food, or simple implementations such as the ticket machines in the butchers. However, from the perspective of interaction design, those sensing systems suffer from several constraints and limitations such as, low usability and poor hygiene. For example, the elderly or the disabled normally have huge difficulties when interacting with these types of digital systems. Moreover, the recent SARS-CoV-2 pandemic has made us rethink the way we interact with the digital devices. Hence, in this paper, we present a novel solution for digital interaction through a contactless model. This system can provide human gesture recognition and therefore it can be integrated into others to achieve contactless control. We have implemented a prototype based on cost efficient sensors to validate the idea’s feasibility. Moreover, a sequence of real world experiments has also been conducted to evaluate its performance. This system is composed with 1) a 3d printed grid of ultrasound sensors to capture the distance information from a human body; 2) software to analyse the data for gesture predictions. This analysis results will be transformed into control commands to interact with the attached system. The experimental results have shown that the proposed system is capable of providing a contactless Human Computer Interaction (HCI), and also has a great opportunity to replace existing touching interaction manner with a remote control scheme.

Factors affecting morphological and electrical properties of Barium Titanate: A brief review

Abstract Lead Zirconate Titanate has been extensively used to make ultrasound transducers, sensors, and actuators as well as high-value ceramic capacitors for a very long time. The main disadvantage of Lead Zirconate Titanate is its toxic nature due to the presence of Lead, which has been banned in most of the nations around the globe. In search of Lead-free materials as a suitable replacement to Lead Zirconate Titanate, Barium Titanate is a very strong candidate. It can be used as an electrical insulator in its purest form. Doped Barium Titanate is a promising tunable material with enhanced ferroelectric and piezoelectric properties which can be a good alternative to Lead Zirconate Titanate. Properties of Barium Titanate are found to change with preparation routes, doping, and other factors. Variation in dielectric constant and high permittivity makes Barium Titanate a useful material for many applications in modern electronic devices. In this paper, analysis has been done on the changes that occur in the properties of Barium Titanate with different factors like crystallographic orientation, grain size, texturing, doping concentration, and sintering process. The piezoelectric property makes Barium Titanate useful for many applications like semiconductors, positive temperature-coefficient resistors, transducers, and ceramics. From the perspective of future applications, materials possessing good fracture toughness improved piezoelectric and dielectric properties, and higher temperature stability is needed. Therefore, it is concluded that the properties of Barium Titanate are enhanced when doped with suitable materials like Mn, Ce, Ti, Fe, Zr, etc. and by adopting different preparation routes like the sol–gel method, hydrothermal method, chemical alloying method, co-precipitation method, and polymeric precursor method.

Pyroelectric ultrasound sensor model: directional response

Ultrasound is typically measured using phase-sensitive piezoelectric sensors. Interest in phase-insensitive sensors has grown recently, with proposed applications including ultrasound attenuation tomography of the breast and acoustic power measurement. One advantage of phase-insensitive detectors, in contrast to conventional phase-sensitive detectors, is that they do not suffer from a narrow directional response at high frequencies due to phase cancellation. A numerical model of a phase-insensitive pyroelectric ultrasound sensor is presented. The model consists of three coupled components run in sequence: acoustic, thermal, and electrical. The acoustic simulation models the propagation and absorption of the incident ultrasound wave. The absorbed acoustic power density is used as a heat source in the thermal simulation of the time-evolution of the temperature in the sensor. Both the acoustic and thermal simulations are performed using the k-Wave MATLAB toolbox with an assumption that shear waves are not supported in the medium. The final component of the model is a pyroelectric circuit model which outputs the sensor response based on the temperature change in the sensor. The modelled pyroelectric sensor response and directional dependence are compared to empirical data.