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.
Flow cytometer plays a key role in cell sorting and analysis. For a higher detection precision, sheath flow is adopted to avoid the turbulent or vortex effect when the cell flowing through a capillary tube during the cell counting in many commercial cytometers. This method works well when the low flow velocity is relatively low. However, in order to have a higher analysis efficiency for clinical laboratories,...
We have previously proposed the use of acoustic microbubble delivery in blood vessels to improve the efficacy of acoustic targeted drug therapy. The technical requirement is the detailed visualization of the blood vessel network for navigation around a target such as a tumor. For this purpose, we have used three-dimensional (3D) Doppler-mode volumes to obtain the blood vessel structure. However, since...
To facilitate the development and application of ultrasound shear wave elastography (SWE) in arteries, it is necessary to understand the nature of shear waves (SWs) propagating in pressurized anisotropic tubes embedded in softer surrounding tissues and blood. Phantom models are widely used to study SWE in tubular settings mimicking arterial geometry without yet considering anisotropy. To investigate...
Pulmonary embolism (PE) is the third-leading cause of death from cardiovascular disease. Currently, PE is treated via catheter-delivered, ultrasound-enhanced thrombolysis using side-fired, low-intensity ultrasound energy (0.5 W/cm2) at ∼2 MHz to reduce the required dose of thrombolytic drugs because of the enhanced drug penetration into the clot. However, several clinical studies have shown that the...
Sub-diffraction imaging, also known as ultrasound localization microscopy, is a novel method that can overcome the fundamental diffraction limit by localizing spatially isolated microbubbles. This method requires the use of a low concentration of microbubbles to ensure that they are spatially isolated. For in vivo microvascular imaging, especially for cancer tissue with high microvascular density,...
Phase-change contrast agents (PCCAs) provide advantages over conventional microbubble contrast agents, including increased circulation time and the ability to extravasate from leaky tumor vasculature. Additionally, PCCAs can be vaporized into echogenic microbubbles for diagnostic ultrasound imaging. Previous studies have demonstrated that the vaporization threshold of PCCAs is higher in vivo than...
Focused ultrasound (FUS) combined with microbubbles (MBs) has been shown to locally and temporarily open the blood-brain barrier (BBB). However, concurrent opening BBB (long pulse) and mapping the location of BBB opening (short pulse) by pulsed-wave excitation always conflicts. Previously proposed passive cavitation imaging in brain suffered from degraded axial resolution because of long driving pulse...
Flow cytometer plays an important role in cell sorting and analysis. Traditional flow cytometers adopt hydrodynamic focusing method which works well when the low flow velocity is relatively low. However, in order to have a higher analysis efficiency for clinical laboratories, a higher flow velocity is preferred, which sometimes will lead to cells siltation when using sheath flow. In this paper, an...
Persistent occlusion following venous thrombosis is associated with an increased risk of post-thrombotic syndrome. Venous recanalization may prevent this complication. Ultrasonic histotripsy has been shown to fractionate thrombus through a cavitation cloud generated by an external transducer and restore the flow [1]. In this study, we aimed at demonstrating that thrombotrispy can be performed with...
The role of angiogenesis in cancer has spurred the development of new methods for imaging vasculature. One such method is acoustic angiography, a dual-frequency superharmonic contrast imaging technique. Custom transducers are necessary for the ultra-wide bandwidth required for this technique, but the current single-element designs present several limitations for translation to clinical use, such as...
In this study, we investigated the transmission and irradiation of aerial ultrasonic waves (frequency: 20 kHz) without attenuation. We proposed a method in which sound waves are transmitted by using a rigid tube to irradiate an object without attenuation. In this report, We transmitted and irradiated high-intensity aerial focused ultrasonic waves with a straight rigid acrylic tube. The results showed...
We have previously proposed the use of acoustic microbubble delivery in blood vessels to improve the efficacy of acoustic targeted drug therapy. The technical requirement is the detailed visualization of the blood vessel network (BVN) for navigation around a target such as a tumor. To obtain the accurate shape of BVN for this purpose, we have experienced a problem of expansion and deficiency in 3D...
In vivo measurement of the mechanical properties of thin-walled soft tissues (e.g., mitral valve, artery and bladder) and in situ mechanical characterization of thin-walled artificial soft biomaterials in service are of great challenge. Those thin-walled structures are usually pre-stressed to achieve and/or improve their functional performance, which further complicate the inverse analysis to identify...
Recently, it has been developed a sound source capable of irradiating aerial ultrasonic waves of very high intensity, and researches on applied technologies utilizing the ultrasonic power have been actively conducted. In these applied technologies, it is necessary to irradiate sound waves to the object under optimum conditions. However, this technique has a problem that optimum sound wave irradiation...
Ultrasound contrast enhanced super resolution imaging has recently attracted extensive attention due to its extraordinary resolution. Vessels that were detected in small animals with ultrafast plane wave imaging sequences were about ten fold smaller than the resolution predicted by a the classical diffraction limit. However the imaging depth in small animals is shallow. To translate this technology...
High channel count, large area ultrasound arrays at fine pitch require close integration of transducer elements and ASIC electronics. Composites of single crystal material and non-conducting epoxy filler can be used to increase bandwidth. Direct bonding of the composite to the ASIC leads to acoustic mismatch and excessive ringing. A collimated connection block (i.e. an interposer) between the array...
Clinical implementation of super-resolution (SR) ultrasound imaging requires accurate single microbubble detection, and would benefit greatly from automation in order to minimize time requirements and user dependence. We present a machine learning based post-processing tool for the application of SR ultrasound imaging, where we utilize superpixelation and support vector machines (SVMs) for foreground...
Contrast enhanced ultrasound imaging shows great potential for visualising lymphatic vessels and identifying sentinel lymph nodes. However current approaches still have artefacts reducing the lymphatic vessel contrast against background tissue [A. Sever, Clinical Radiology, 2012]. Pulse inversion (PI) detects nonlinear echoes from microbubbles but also from tissue due to nonlinear propagation of ultrasound...
Design, and optimization of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research areas all faces the problem of scaling up from laboratory results to industrial purposes. A traditional ultrasonic reactor usually has several issues, such as low effectiveness as well as complex and unstable system performance,...
Design and optmiziation of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research projects all faces the problem of scaling up laboratory results for industrial use. A traditional ultrasonic reactor usually has several issues, such as low effectiveness and complex and unstable system performance, which all...
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.