The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, we describe a 920 MHz band long range wireless SAW passive tag system (WSPTS) for vibration monitoring, which achieves more than 10m reading distance. For the purpose of structural health monitoring (SHM) of aging infrastructures (e.g. bridge, building, and so forth), passive wireless sensor systems are an attractive option because they are operated battery-less and almost maintenance...
Many structural health monitoring techniques rely on the full field analysis related to stress guided waves propagation. Such techniques can be quite slow as in general the acquisition of the full wave field and its processing, aimed at extracting damage related information, are time consuming processes. Therefore, strategies to reduce the acquisition time and improve the damage detection and quantification...
The drilling process is generally costly and time consuming and prone to serious hazards. Cost-efficiency and enhanced safety measures are vital for any drilling operation. Recent studies indicate that poor reliability in the drilling process resulted in as much as 30% loss of production time. Improved sensor technology with process automation can improve process performance and safety. During drilling...
Focused ultrasound can effectively treat tumors by thermal ablation, but treatment times associated with mechanical or electronic scanning of single foci can be prohibitively long. Maximizing the energy efficiency of focused ultrasound ablation may decrease treatment time while also decreasing sensitivity to perfusion. One proposed approach [Mast et al., US Patent 9132287, 2015] creates multiple foci...
Photoacoustic (PA) imaging has been proposed for cancer treatment monitoring. Tumor oxygen saturation (sO2) should in principle be related to vascular parameters such as blood flow. In this work, in-vivo PA estimates of sO2 were compared to power Doppler (pD) measures of vascularity hours after the administration of microbubbles (MB), radiation therapy (XRT), individually or combined (MB-XRT).
Sulphate attack is considered one of the most aggressive causes of concrete degradation. Ettringite triggers expansion mechanisms that have harmful effects on the Portland cement matrix, causing micro-cracking and, consequently, a reduction in the stiffness and strength of concrete. Portland cement composites are very dispersive and heterogeneous materials that makes very challenging to do non-invasive...
Corrosion of metal alloys is very common in the industrial field, and failure to monitor the seriousness of corrosion can cause serious consequences. Compared with other Non-Destructive Testing methods, the method of ultrasonic surface wave testing has a lot of advantages including portability, efficiency, and un-contamination etc. This makes it a very promising method to evaluate or monitor chemical...
Most chemotherapeutics (CTs) are delivered systemically, causing nausea, hair loss, fatigue and a compromised immune system. Biocompatible in situ forming implants (ISFIs) are drug delivery vehicles which are injected as a liquid before solidifying in tissues and ultimately breaking down. By dissolving CTs in an ISFI solution, they can be injected directly to the tumour site and released in a controllable...
Stillbirth is when a baby is born without signs of life after 28 weeks of gestation. It is estimated that 2.6 million stillbirths occurred in 2015 [Lawn et al. 2016]. Today, the fetus is examined at regular hospital checks during pregnancy, but no checks are done between these hospital visits. These antenatal tests are not always effective to prevent stillbirth [O'Neill et al. 2012]. More frequent...
Pulse Wave Velocity (PWV), a surrogate marker of arterial stiffness, is associated with cardiovascular mortality and vascular atherosclerotic burden. The Bramwell-Hill equation links PWV with arterial compliance. Pulse wave imaging (PWI) is a noninvasive technique developed by our group for tracking the propagation of pulse waves along the arterial wall at high spatial and temporal resolution. It...
Ultrasound velocity in soft biological tissues is defined by the molecular composition of the tissues [1]. Water is the main molecular component of soft tissues and muscle water content is typically over 70%. Ultrasound velocity in muscle is a linear function of the water content [2]. Since the muscle is the main water reservoir of human body, measurements of ultrasound velocity in muscle may serve...
Detection of focused ultrasound (FUS)-stimulated microbubble activity (i.e. acoustic cavitation) is a key methodology for monitoring and guidance of FUS therapies that harness the bioeffects of acoustic cavitation. The intensity and location of secondary acoustic emissions emitted by microbubbles can be passively detected and imaged using diagnostic imaging arrays. In turn, ultrasound-guided FUS (USgFUS)...
Off-line ultrasonic non-destructive testing (NDT) is used to inspect defects in thermal power plants. However, for new-generation thermal power plants, off-line NDT is not sufficient and long-term monitoring at high temperature is desired. In the previous study, ultrasonic transducers made by CaBi4Ti4O15 (CBT)/Pb(Zr, Ti)O3 (PZT) were investigated and maximum operation temperature was estimated as...
Ultrasound offers measurements of parameters encountered in harsh environments such as steam generators, heat exchangers and nuclear reactor primary and secondary systems. But there is a lack of piezo-materials tolerant of high temperatures and nuclear irradiation. Another issue is that transducers are needed that can be left in place on curved surfaces such as pipes and valves. The transducers should...
Uterine fibroids are noncancerous growths that develop in or just outside a woman's uterus. For treatment of these, high intensity focused ultrasound (HIFU) surgery is gaining more and more popularity. Presently, two representative types of HIFU treatment are used: magnetic resonance guided and ultrasound (US) guided HIFU treatment depending on the method to monitor the treatment. This work is about...
A real-time ultrasound (US) coagulation monitoring for coagulation based on acoustic radiation force is described. US imaging to facilitate HIFU has advantages with respect to portability, cost effectiveness and spatiotemporal resolution. Localized motion imaging (LMI) is one of the techniques based on US to detect a change of tissue mechanical properties caused by its thermal coagulation. To achieve...
Recently, the diffraction-limit of resolution for ultrasound imaging has been bypassed in-vivo with the localization of microbubbles [Errico et al, Nature 2015]. However, ultrasound therapy remains bound to the half-wavelength limit, imposing a compromise between the therapeutic precision and its penetration. Exploiting threshold phenomena, such as vaporization or cavitation, could provide a solution...
Tumor hypoxia has been shown to decrease the sensitivity of solid tumors to radiation. Systemic efforts to increase tumor oxygenation levels immediately prior to therapy, however, have largely proven unsuccessful. The objective of this work was to determine the utility of oxygen-filled, ultrasound sensitive microbubbles for locally delivering oxygen and sensitizing tissue to radiation in a breast...
It is highly desirable to monitor microwave ablation (MWA) treatments noninvasively for substantially improving the clinical implementation of MWA procedures and progress toward full clinical uses worldwide. This in vivo study explored the feasibility of using ultrasonic Nakagami imaging to evaluate the thermal lesions in liver and kidney in a porcine model for the purpose of monitoring MWA.
Focused ultrasound (FUS) with circulating microbubbles creates transient and reversible permeabilization of vasculatures which provides an essential means to deliver therapeutics and imaging agents, for instance across the BBB. We have previously shown that 3D color Doppler and photoacoustic imaging can monitor BBB disruption (BBBD) in mice. Here we study how changes in NPs size, concentration and...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.