620 Results Found

The opacity of conventional ultrasound transducers can impede the miniaturization and workflow of current photoacoustic systems. In particular, optical-resolution photoacoustic microscopy (OR-PAM) requires the coaxial alignment of optical illuminatio...

An inverse Class-E power amplifier was designed for an ultrasound transducer. The proposed inverse Class-E power amplifier can be useful because of the low series inductance values used in the output matching network that helps to reduce signal disto...

This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etc...

This study aimed to develop an optimal methodology for the design of a miniaturized, 1–3 piezoelectric composite focused ultrasound transducer. Miniaturized focused ultrasound (FUS) devices, generally guided through catheters, have received con...

An acoustic matching layer is an essential component of an ultrasound transducer to achieve maximum ultrasound transmission efficiency. Here, we develop a flexible printed circuit board (FPCB) with a composite structure consisting of multiple polyimi...

Many applications of ultrasound for sensing, actuation and imaging require miniaturized and low power transducers and transducer arrays integrated with electronic systems. Piezoelectric micromachined ultrasound transducers (PMUTs), diaphragm-like thi...

Intravascular ultrasound (IVUS) is a valuable imaging modality for the diagnosis of atherosclerosis. It provides useful clinical information, such as lumen size, vessel wall thickness, and plaque composition, by providing a cross-sectional vascular i...

Ultrasound transducer devices have their own frequency ranges, depending on the applications and specifications, due to penetration depth, sensitivity, and image resolution. For imaging applications, in particular, the transducer devices are preferab...

Robotic prostheses and powered exoskeletons are novel assistive robotic devices for modern medicine. Muscle activity sensing plays an important role in controlling assistive robotics devices. Most devices measure the surface electromyography (sEMG) s...

This paper presents the design and fabrication process of a spherical-omnidirectional ultrasound transducer for underwater sensor network applications. The transducer is based on the vibration of two hemispheres with a thickness of 1 mm and an outer...

High frame rate three-dimensional (3D) ultrasound imaging would offer excellent possibilities for the accurate assessment of carotid artery diseases. This calls for a matrix transducer with a large aperture and a vast number of elements. Such a matri...

The superharmonic imaging of tissue has the potential for high spatial and contrast resolutions, compared to the fundamental and second harmonic imaging. For this technique, the spectral bandwidth of an ultrasound transducer is divided for transmissi...

A dual-frequency ultrasound transducer (DFUT) is usually preferred for its numerous advantageous applications, especially in biomedical imaging and sensing. However, most of DFUTs are based on the combination of fundamental and harmonic operations, o...

Argus II retinal prosthesis is the US Food and Drug Administration (FDA) approved medical device intended to restore sight to a patient’s blind secondary to retinal degeneration (i.e., retinitis pigmentosa). However, Argus II and most reported...

The present study illustrates the design, fabrication, and evaluation of a novel multifocal point (MFP) transducer based on polyvinylidene fluoride (PVDF) film for high-frequency ultrasound application. The fabricated MFP surface was press-focused us...

Piezoelectric 1-3 composite materials have become extensively utilized in diagnostic ultrasound transducers owing to their high electromechanical coupling coefficient, low acoustic impedance, and low dielectric loss. In this study, Sm-doped PMN-PT ce...

During dynamic ultrasound assessments, unintended transducer movement over the skin needs to be prevented as it may bias the results. The present study investigated the validity of two methods quantifying transducer motion. An ultrasound transducer w...

Plane-wave ultrasound imaging (PWUS) has become an important method of ultrasound imaging in recent years as its frame rate has exceeded 10,000 frames per second, allowing ultrasound to be used for two-dimensional shear wave detection and functional...

This paper describes the fabrication of 1-3 piezoelectric composites by using PZT5-A pure piezoelectric ceramics and the preparation of a high-frequency single-directional planar underwater ultrasound transducer by using the developed composites. Fir...

Focused ultrasound is a promising therapeutic technique, as it involves the focusing of an ultrasonic beam with sufficient acoustic energy into a target brain region with high precision. Low-intensity ultrasound transmission by a single-element trans...

A new multiwavelength visible-range-supported opto–ultrasound instrument using a light-emitting diode and ultrasound transducer was developed in order to produce multiwavelength visible light with minimized color aberration errors, and detect u...

Dual-frequency ultrasounds have demonstrated significant potential in augmenting thermal ablation efficiency for tumor treatment. Ensuring proper impedance matching between the dual-frequency transducer and the power amplifier system is imperative fo...

Medical ultrasound and other devices that require transducer arrays are difficult to manufacture, particularly for high frequency devices (>30 MHz). To enable focusing and beam steering, it is necessary to reduce the center-to-center element spaci...

The objective of this article is to review the recent advancement in piezoelectric micromachined ultrasound transducer (PMUT) technology and the associated piezoelectric materials, device fabrication and characterization, as well as applications. PMU...

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicrosco...

In most commercial single-element intravascular ultrasound (IVUS) transducers, with 20 MHz to 40 MHz center frequencies, a conductive adhesive is used to bond a micro-sized cable for the signal line to the surface of the transducer aperture (<1 mm...

Pancreatic cancer with less than 10% 3-year survival rate is one of deadliest cancer types and greatly benefits from enhanced radiotherapy. Organ motion monitoring helps spare the normal tissue from high radiation and, in turn, enables the dose escal...

In high frequency ultrasound imaging (HFUI), the quality of focusing is deeply related to the length of the depth of field (DOF). In this paper, a phase-inversion technique implemented by a dual-element transducer is proposed to enlarge the DOF. The...

The dual-bias high-voltage circuit of a transmit amplifier for immersion ultrasound transducer applications is proposed to enhance the therapeutic effect of human HeLa cells. High-voltage output signals generated from a transmit amplifier are typical...

Complete blockage of a coronary artery, called chronic total occlusion (CTO), frequently occurs due to atherosclerosis. To reopen the obstructed blood vessels with a stent, guidewire crossing is performed with the help of angiography that can provide...

This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively...

This review paper discusses the advances of the gravimetric detection devices based on capacitive micromachined ultrasound transducers structure. Principles of gravimetric operation and device modeling are reviewed through the presentation of an anal...

This paper presents a fully addressable 8 × 8 two-dimensional (2D) rigid piezoelectric micromachined ultrasonic transducer (PMUT) array. The PMUTs were fabricated on a standard silicon wafer, resulting in a low-cost solution for ultrasound imag...

Energy harvesting using the piezoelectric material in the development of compact vibration energy harvesters can be used as a backup power source for wireless sensors or to fully replace the use of fossil-resource-wasting batteries and accumulators t...

In diagnostic ultrasound imaging applications, preamplifiers are used as first-stage analog front-end amplifiers for ultrasound transducers because they can amplify weak acoustic signals generated directly by ultrasound transducers. For emerging diag...

This article reports the fine-tuning of the optical resonance wavelength (ORW) of surface-micromachined optical ultrasound transducer (SMOUT) arrays to enable ultrasound data readout with non-tunable interrogation light sources for photoacoustic comp...

In general, it is difficult to visualize internal ocular structure and detect a lesion such as a cataract or glaucoma using the current ultrasound brightness-mode (B-mode) imaging. This is because the internal structure of the eye is rich in moisture...

As a well-known medical imaging methodology, intravascular ultrasound (IVUS) imaging plays a critical role in diagnosis, treatment guidance and post-treatment assessment of coronary artery diseases. By cannulating a miniature ultrasound transducer mo...

In ultrasound systems, a protection circuit must be used to protect the receiver electronics from the high-voltage pulses generated by the transmitter and to minimize the signal loss and distortion of the low-voltage echoes generated by the transduce...

An aluminum nitride (AlN) piezoelectric micromachined ultrasound transducer (PMUT) array was proposed and fabricated for non-invasive radial artery stiffness monitoring, which could be employed in human vascular health monitoring applications. Using...

High-frequency ultrasound transducers offer higher spatial resolution than low-frequency ultrasound transducers; however, their maximum sensitivity are lower. Matching circuits are commonly utilized to increase the amplitude of high-frequency ultraso...

This paper presents a fibered-epitaxial lead zirconate titanate (PZT) thin film with intermediate features between the monocrystalline and polycrystalline thin films for piezoelectric micromachined ultrasound transducer (pMUT). The grain boundaries c...

Transcranial focused ultrasound has been studied for non-invasive and localized treatment of many brain diseases. The biggest challenge for focusing ultrasound onto the brain is the skull, which attenuates ultrasound and changes its propagation direc...

Medical ultrasound is an imaging technique that utilizes ultrasonic signals as information carriers, and has wide applications such as seeing internal body structures, finding a source of a disease, and examining pregnant women. The most commonly use...

The medical ultrasound transducer is a principal component in ultrasound systems, as it significantly influences system performance. The high-voltage power amplifier (HVPA) is the key ultrasound transmitter component and interfaces with the medical u...

Bulk piezoelectric ultrasound transducers on integrated circuits offer unique properties for therapeutic applications of ultrasound neuromodulation. However, current implementations of such transducers are not optimized for the high transmit efficien...

Beauty treatment for skin requires a high-intensity focused ultrasound (HIFU) transducer to generate coagulative necrosis in a small focal volume (e.g., 1 mm3) placed at a shallow depth (3–4.5 mm from the skin surface). For this, it is desirable to m...

Photoacoustic imaging (PAI) is drawing extensive attention and gaining rapid development as an emerging biomedical imaging technology because of its high spatial resolution, large imaging depth, and rich optical contrast. PAI has great potential appl...

Hyperechoic vertical artifacts are an essential feature of lung ultrasound (LUS) arising from various pathological states. Those that meet the criteria for B-lines have the most significant diagnostic value and should be differentiated from other hyp...

The purpose of this study was to determine the observer agreement in assessing the enhancement pattern of suspicious breast lesions with contrast-enhanced ultrasound (CEUS) using high and low frequency transducers. Methods: This prospective study inc...