Phased Array Ultrasound Transducer Research Articles

Pipeline for Planning and Execution of Transcranial Ultrasound Neuromodulation Experiments in Humans.

Transcranial ultrasound stimulation (TUS) is an emerging non-invasive neuromodulation technique capable of manipulating both cortical and subcortical structures with high precision. Conducting experiments involving humans necessitates careful planning of acoustic and thermal simulations. This planning is essential to adjust for bone interference with the ultrasound beam's shape and trajectory and to ensure TUS parameters meet safety requirements. T1- and T2-weighted, along with zero-time echo (ZTE) magnetic resonance imaging (MRI) scans with 1 mm isotropic resolution, are acquired (alternatively computed tomography x-ray (CT) scans) for skull reconstruction and simulations. Target and trajectory mapping are performed using a neuronavigational platform. SimNIBS is used for the initial segmentation of the skull, skin, and brain tissues. Simulation of TUS is carried over with the BabelBrain tool, which uses the ZTE scan to produce synthetic CT images of the skull to be converted into acoustic properties. We use a phased array ultrasound transducer with electrical steering capabilities. Z-steering is adjusted to ensure that the target depth is reached. Other transducer configurations are also supported in the planning tool. Thermal simulations are run to ensure temperature and mechanical index requirements are within the acoustic guidelines for TUS in human subjects as recommended by the FDA. During TUS delivery sessions, a mechanical arm assists in the movement of the transducer to the required location using a frameless stereotactic localization system.

A Novel Concept of Transperineal Focused Ultrasound Transducer for Prostate Cancer Local Deep Hyperthermia Treatments

Design, embodiment, and experimental study of a novel concept of extracorporeal phased array ultrasound transducer for prostate cancer regional deep hyperthermia treatments using a transperineal acoustic window is presented. An optimized design of hyperthermia applicator was derived from a modelling software where acoustic and thermal fields were computed based on anatomical data. Performance tests have been experimentally conducted on gel phantoms and tissues, under 3T MRI guidance using PRFS thermometry. Feedback controlled hyperthermia (ΔT = 5 °C during 20min) was performed on two ex vivo lamb carcasses with prostate mimicking pelvic tissue, to demonstrate capability of spatio-temporal temperature control and to assess potential risks and side effects. Our optimization approach yielded a therapeutic ultrasound transducer consisting of 192 elements of variable shape and surface, pseudo randomly distributed on 6 columns, using a frequency of 700 kHz. Radius of curvature was 140 mm and active water circulation was included for cooling. The measured focusing capabilities covered a volume of 24 × 50 × 60 mm3. Acoustic coupling of excellent quality was achieved. No interference was detected between sonication and MR acquisitions. On ex vivo experiments the target temperature elevation of 5 °C was reached after 5 min and maintained during another 15 min with the predictive temperature controller showing 0.2 °C accuracy. No significant temperature rise was observed on skin and bonny structures. Reported results represent a promising step toward the implementation of transperineal ultrasound hyperthermia in a pilot study of reirradiation in prostate cancer patients.

20-MHz phased array ultrasound transducer for in vivo ultrasound imaging of small animals

In vivo ultrasound imaging with phased array transducers is of great importance for both clinical application and biomedical research. In this work, relaxor ferroelectric PMN-0.28PT single crystal with very high piezoelectric constant d33 ≥ 2000 pC/N and electromechanical coupling coefficient k33 ∼ 0.92 is used to fabricate high-frequency phased array transducers. A 128-element 20-MHz phased array transducer is successfully fabricated, and the optimized performance of −6 dB average bandwidth of ∼ 84 % and insertion loss of −43 dB are achieved. The axial and lateral imaging resolutions of the transducer are determined to be 81 µm and 243 µm, respectively. With Verasonics image platform, in vivo fisheye images are acquired, demonstrating the potential application of our developed high-frequency phased array transducer for biomedical research on small animals.

Collaborative Robotic Wire + Arc Additive Manufacture and Sensor-Enabled In-Process Ultrasonic Non-Destructive Evaluation.

The demand for cost-efficient manufacturing of complex metal components has driven research for metal Additive Manufacturing (AM) such as Wire + Arc Additive Manufacturing (WAAM). WAAM enables automated, time- and material-efficient manufacturing of metal parts. To strengthen these benefits, the demand for robotically deployed in-process Non-Destructive Evaluation (NDE) has risen, aiming to replace current manually deployed inspection techniques after completion of the part. This work presents a synchronized multi-robot WAAM and NDE cell aiming to achieve (1) defect detection in-process, (2) enable possible in-process repair and (3) prevent costly scrappage or rework of completed defective builds. The deployment of the NDE during a deposition process is achieved through real-time position control of robots based on sensor input. A novel high-temperature capable, dry-coupled phased array ultrasound transducer (PAUT) roller-probe device is used for the NDE inspection. The dry-coupled sensor is tailored for coupling with an as-built high-temperature WAAM surface at an applied force and speed. The demonstration of the novel ultrasound in-process defect detection approach, presented in this paper, was performed on a titanium WAAM straight sample containing an intentionally embedded tungsten tube reflectors with an internal diameter of 1.0 mm. The ultrasound data were acquired after a pre-specified layer, in-process, employing the Full Matrix Capture (FMC) technique for subsequent post-processing using the adaptive Total Focusing Method (TFM) imaging algorithm assisted by a surface reconstruction algorithm based on the Synthetic Aperture Focusing Technique (SAFT). The presented results show a sufficient signal-to-noise ratio. Therefore, a potential for early defect detection is achieved, directly strengthening the benefits of the AM process by enabling a possible in-process repair.

Novel Phased Array Piezoelectric Micromachined Ultrasound Transducers (pMUTs) for Medical Imaging

Two kinds of 128 channels pMUT-based phased array ultrasound transducers are described in this paper, one with a high frequency of around 6 MHz and another with a low frequency of around 1.5 MHz. The active area of the transducer is around 25 mm long and 10 mm wide. There are in total 6270 pMUT elements in the reported arrays. For the transducer with a center frequency of 6 MHz, each pMUT has a membrane diameter of 85 μm and the pitch between every two channels is 200 μm. The transducer benefits from a high transmission and receive sensitivity of 44 kPa / V / Channel @ 3 cm and 204 mV / MPa, respectively. For the transducer with a center frequency of 1.5 MHz, each pMUT has a membrane diameter of 160 μm and the pitch between every two elements is 214 μm. The proposed transducer obtained a transmit and receive sensitivity of 430 Pa / V / Channel @ 3 cm and 190 mV / MPa, respectively. The transducer has a -3dB and -6dB bandwidth of 118% and 184%, respectively. The bandwidth is higher than any previously reported transducer in any technology, such as bulk-PZT, pMUT, or capacitive MUT (cMUT). The functionality of the transducer arrays is confirmed by obtaining B-mode images in water medium.

Focused ultrasound for functional neurosurgery.

Brain lesioning is a fundamental technique in the functional neurosurgery world. It has been investigated for decades and presented promising results long before novel pharmacological agents were introduced to treat movement disorders, psychiatric disorders, pain, and epilepsy. Ablative procedures were replaced by effective drugs during the 1950s and by Deep Brain Stimulation (DBS) in the 1990s as a reversible neuromodulation technique. In the last decade, however, the popularity of brain lesioning has increased again with the introduction of magnetic resonance-guided focused ultrasound (MRgFUS). In this review, we will cover the current and emerging role of MRgFUS in functional neurosurgery. Literature review from PubMed and compilation. Investigated since 1930, MRgFUS is a technology enabling targeted energy delivery at the convergence of mechanical sound waves. Based on technological advancements in phased array ultrasound transducers, algorithms accounting for skull penetration by sound waves, and MR imaging for targeting and thermometry, MRgFUS is capable of brain lesioning with sub-millimeter precision and can be used in a variety of clinical indications. MRgFUS is a promising technology evolving as a dominant tool in different functional neurosurgery procedures in movement disorders, psychiatric disorders, epilepsy, among others.

Transcranial MR-Guided Histotripsy System.

Histotripsy has been previously shown to treat a wide range of locations through excised human skulls in vitro. In this article, a transcranial magnetic resonance (MR)-guided histotripsy (tcMRgHt) system was developed, characterized, and tested in the in vivo pig brain through an excised human skull. A 700-kHz, 128-element MR-compatible phased-array ultrasound transducer with a focal depth of 15 cm was designed and fabricated in-house. Support structures were also constructed to facilitate transcranial treatment. The tcMRgHt array was acoustically characterized with a peak negative pressure up to 137 MPa in free field, 72 MPa through an excised human skull with aberration correction, and 48.4 MPa without aberration correction. The electronic focal steering range through the skull was 33.5 mm laterally and 50 mm axially, where a peak negative pressure above the 26-MPa cavitation intrinsic threshold can be achieved. The MR compatibility of the tcMRgHt system was assessed quantitatively using SNR, B0 field map, and B1 field map in a clinical 3T magnetic resonance imaging (MRI) scanner. Transcranial treatment using electronic focal steering was validated in red blood cell phantoms and in vivo pig brain through an excised human skull. In two pigs, targeted cerebral tissue was successfully treated through the human skull as confirmed by MRI. Excessive bleeding or edema was not observed in the peri-target zones by the time of pig euthanasia. These results demonstrated the feasibility of using this preclinical tcMRgHt system for in vivo transcranial treatment in a swine model.

Miniaturized phased-array ultrasound and photoacoustic endoscopic imaging system

Visualization and detection of early-stage gynecological malignancies represents a challenge for imaging due to limiting factors including tissue accessibility, device ease of use, and accuracy of imaging modalities. In this work, we introduce a miniaturized phased-array ultrasound and photoacoustic endoscopic probe which is capable of providing structural, functional, and molecular data for the characterization of gynecologic disease. The proposed probe consists of a 64-element ultrasound phased-array transducer coupled to a fiber-optic light delivery system for co-registered ultrasound and photoacoustic imaging. The fabricated US and PA imaging endoscope’s diameter is 7.5 mm, allowing for potential passage through the cervical canal and thus an intimate contact with gynecological tissues such as the cervical canal and uterus. The developed endoscopic probe was tested and characterized in a set of tissue-mimicking phantoms. US and PA resolutions were measured experimentally using 200 μm diameter wires, resulting in apparent axial and lateral diameters of 289 μm and 299 μm for US, and 308 μm and 378 μm for PA, respectively. The probe’s abilities to operate in both discrete and integrated illumination/acquisition were tested in gelatin phantoms with embedded optical absorbers with the results demonstrating the ability to acquire volumetric dual-modal US and PA images.

Prototyping of a High Frequency Phased Array Ultrasound Transducer on a Piezoelectric Thick Film

A process including virtual prototyping of a high frequency phased array ultrasound transducer on a piezoelectric thick film using a finite element method (FEM) is shown. Generated FEM models were based on PMN-PT (Pb(Mg1/3Nb2/3)O3-PbTiO3) thick films, made by sol-gel technique, with the thickness vibrational mode resonant frequency of each film being close to 28.5MHz. Ultrasound transducers with such characteristics, due to their size and high frequency, are suitable for use in small medical diagnostic tools intended for use in delicate and sensitive areas (for example in ophthalmology and dermatology). With respect to their size, the transducers should retain very good focusing, beam steering and other advantages that phased array layout offers. To ensure an optimal performance of the phased array ultrasound transducer on such a piezoelectric thick film, several electrode patterns were used and tested in FEM simulations with the end goal of getting best performance from the PMN-PT thick films. A 64-element configuration was shown to be a promising technological solution for ophthalmological ultrasound diagnostics.

Acoustic Field of Phased-Array Ultrasound Transducer with the Focus/Foci Shifting

High-intensity focused ultrasound (HIFU) is becoming popular in the treatment of solid tumors because of its non-invasiveness with few complications. The acoustic field is of importance in evaluating the safe focus shifting distance and determining the treatment plan. The propagation of finite-amplitude acoustic wave from a 331-element HIFU phased-array with focus steering along and transverse to the transducer axis and 4-foci shifting on the focal plane was simulated using the angular spectrum approach (ASA) with a marching second-order operator-splitting scheme. In addition, the acoustic field produced by a truncated asymmetric transesophageal HIFU annular array was also simulated, and the effects of driving frequency and the number of concentric rings were investigated. Because of the nonlinear effects, the peak negative pressure is lower than that of peak positive pressure at the main lobe but has a larger beam size. However, the peak positive and negative pressures at the grating lobe are quite similar. The effects of the focus shifting distances on the main and grating lobe (both acoustic pressure and − 6 dB beam size) were evaluated. With the focus shifting axially away from the transducer surface, the main lobe has decreased acoustic pressure by ~ 1.9 fold and increased beam size by ~ 4.5 fold while the grating lobe has the increased acoustic pressure by ~ 1.8 fold. The focus shifting laterally leads to the reduced pressure at the main lobe by ~ 1.4 fold but the slight decrease at the grating lobe by ~ 1.1 fold. In comparison, the shifting of multi-foci has similar influences on the main lobe but increases the pressure at the grating lobe. Driving frequency of annular array is found to have greater influences on the peak pressure and beam size. Our algorithm can simulate the acoustic field of phased-array in arbitrary shape and optimize the transducer design, and the focus shifting distance and strategy should be selected appropriately for the safe HIFU exposure.

Which ultrasound transducer type is best for diagnosing pneumothorax?

BackgroundAn accurate physical examination is essential in the care of critically ill and injured patients. However, to diagnose or exclude a pneumothorax, chest auscultation is unreliable compared to lung ultrasonography. In the dynamic prehospital environment, it is desirable to have the best possible ultrasound transducer readily available. The objective is to assess the difference between a linear-array, curved-array, and phased-array ultrasound transducer in the assessment for pneumothorax and to determine which is best.MethodsIn this double-blinded, cross-sectional, observational study, 15 observers, experienced in lung ultrasonography, each assessed 66 blinded ultrasound video clips of either normal ventilation or pneumothorax that were recorded with three types of ultrasound transducers. The clips were recorded in 11 adult patients that underwent thoracoscopic lung surgery immediately before and after the surgeon opened the thorax. The diagnostic accuracy of the three transducers, elapsed time until a diagnosis was made, and the perceived image quality was recorded.ResultsIn total, 15 observers assessed 990 ultrasound video clips. The overall sensitivity and specificity were 98.2% and 97.2%, relatively. No significant difference was found in the diagnostic performance between transducers. A diagnosis was made slightly faster in the linear-array transducer clips, compared to the phased-array transducer (p = .031). For the linear-, curved-, and phased-array transducer, the image quality was rated at a median (interquartile range [IQR]) of 4 (IQR 3–4), 3 (IQR 2–4), and 2 (IQR 1–2), relatively. Between the transducers, the difference in image quality was significant (p < .0001).ConclusionsThere was no difference in diagnostic performance of the three transducers. Based on image quality, the linear-array transducer might be preferred for (prehospital) lung ultrasonography for the diagnosis of pneumothorax.

Towards using a focussed phased array of millimetre length scale elements for ultrasound imaging

Sparse phased array ultrasound transducers with millimetre length scale elements have previously been proposed for generating hyperthermia but not for imaging. Numerical simulation with a pseudospectral solver was used to investigate: (a) how the position of the maximum pressure in the focal region changed with element diameter and frequency; (b) how the size and position of the focal region changed with focal distance under steering; and (c) the imaging performance of 15 element random arrays. These analyses were performed for both piston-like and non piston-like millimetre diameter elements since previous work has shown a shift in the distance to the maximum pressure in the focal region with the latter. The results for these elements were compared with elements where the diameter was <λ/2. The distance from the array to the position of maximum pressure in the focal region diverged from the value with element diameter <λ/2; values for piston-like elements increased positively whilst values for non piston-like elements increased negatively. With distances expressed in λ, no difference was found for arrays at 1 MHz and 2.5 MHz. For piston-like elements, but not for non piston-like elements, two peaks were found in the focal region which were in-line with the direction of propagation for a focus on the central axis but which rotated to become parallel with the direction of propagation when steering exceeded 20°. The size and position of the focal region under steering was similar for the non piston-like elements and elements with diameter <λ/2. Little difference was found in image quality or the size of the point spread function (PSF) between images at 2.5 MHz with piston-like and non piston-like behaviour for steering angles less than 20° when compared with a linear array of similar size. These results suggest that imaging with random arrays of millimetre length scale elements is possible.

Development of an MRI-Compatible High-Intensity Focused Ultrasound Phased Array Transducer Dedicated for Breast Tumor Treatment.

High-intensity focused ultrasound (HIFU) under magnetic resonance imaging (MRI) guidance can achieve a noninvasive and precise ablation of the solid tumor. In the study, an MRI-compatible 1-MHz 16-channel ring-shaped transducer was developed to minimize the burn risk of breast skin and perform volumetric ablation for short treatment time. The measured electroacoustic conversion efficiency of the transducer was 50.90% ± 5. The transducer could produce a point and a quasi-hollow-cylinder lesion in a thermal-sensitive phantom or an ex vivo pork by tuning the phase of each element. It may achieve volumetric ablation of 1.5 cm3 when the point lesion is located inside the hollow lesion. Ex vivo ablation experiments showed that the transducer could cause a coagulative necrosis in the pork from the surrounded subcutaneous fat by 5 mm without fat damage. The temperature and region of the pork ablation were quantified by MRI technique. There was no MRI interference from HIFU and vice versa while both systems operated concurrently.

MR-Guided Focused Ultrasound

Since the middle of the 20th century and in order to treat neurological diseases, clinicians have proposed the use of ultrasound, instead of skin incision or trepanation, when performing intracranial thermocoagulation. However, focusing ultrasound intracranially with high precision was technically difficult until recent technological developments. Specifically, advancements in ultrasound phased-array transducers have eliminated the need for a craniotomy, and progress in magnetic resonance (MR) imaging has allowed the real-time measurement of intracranial temperature. Both of the above have enabled the use of MR-guided focused ultrasound as a treatment for refractory essential tremor. Studies focusing on the long-term effects of this treatment are under way. Given that it is less invasive than previous methods, this procedure could be indicated for the treatment of other neurological diseases, including Parkinson's disease, brain tumors, dystonia, and epilepsy.

Ultrasonic Neuromodulation: Evidence from Neuron to Animal Model

Neurostimulation is among the fundamental ways of neuroscience to probe the neural mechanisms from molecular to behavioral levels. The cutting-edge discovery of ultrasound as a non-invasive neurostimulation tool, has made possible for the effective amelioration of multiple functional brain diseases such as Parkinson disease, epilepsy and major depression. In this study, we highlight the up-to-date research on the application of the ultrasonic radiation force in the stimulation of isolated neuron, mice and monkeys with the underlying mechanism and the challenges of ultrasonic neuromodulation discussed. A high-frequency neurostimulation chip based on surface acoustic waves (SAWs) was designed and fabricated for the stimulation of isolated neuron. The responses of HEK cells, and neuron under the stimulation of the chip were recorded by the Ca2+ imaging and patch clamp. Confocal imaging of fluo-4-AM fluorescence was conducted on the neuron cells with the neurostimulation chip. The whole-cell voltage clamp was used to record the changes in membrane current in response to stimulation with the chip. Portable and wearable systems incorporating high voltage waveform generator (0.5-5MHz) were designed for free-moving small animal studies. In addition, a wearable 256-element 2D dual-curvature focused ultrasound phased-array transducer and MRI compatible ultrasonic neuromodulation system were developed for primate studies. Rhesus monkeys were trained to perform perceptual tasks with and without intermittent ultrasonic stimulation to specific cerebral cortex. In vivo single or multiple neuron electrode recording and eye tracking were conducted during task performance, allowing an evaluation of the direct linkage between physiology and behavior. Time-lapsed series of confocal images were obtained from neuron cells loaded with fluo-4-AM. Ca2+ transients were triggered in response to the stimulation by the high-frequency neurostimulation chip indicated by the increase in fluo-4 fluorescence intensity. Alterations in the membrane currents in response to high-frequency neurostimulation were recorded for HEK cells and neuron, respectively. Electromyography and local field potential signals were successfully recorded, demonstrating that the ultrasound neuromodulation can induce neuronal activity and evoke motor behaviors of animals. These results manifested that the interaction between ultrasonic radiation force and the protein of cell membranes may lead to the opening of mechanosensitive ion channels, thus triggering effective neuromodulation at both cellular and behavioral levels.

Development of a 20-MHz wide-bandwidth PMN-PT single crystal phased-array ultrasound transducer

In this study, a 20-MHz 64-element phased-array ultrasound transducer with a one-wavelength pitch is developed using a PMN-30%PT single crystal and double-matching layer scheme. High piezoelectric (d33>1000pC/N) and electromechanical coupling (k33>0.8) properties of the single crystal with an optimized fabrication process involving the photolithography technique have been demonstrated to be suitable for wide-bandwidth (⩾70%) and high-sensitivity (insertion loss ⩽30dB) phased-array transducer application. A −6dBbandwidth of 91% and an insertion loss of 29dBfor the 20-MHz 64-element phased-array transducer were achieved. This result shows that the bandwidth is improved comparing with the investigated high-frequency (⩾20MHz) ultrasound transducers using piezoelectric ceramic and single crystal materials. It shows that this phased-array transducer has potential to improve the resolution of biomedical imaging, theoretically. Based on the hypothesis of resolution improvement, this phased-array transducer is capable for small animal (i.e. mouse and zebrafish) studies.

A simple uniformity test for ultrasound phased arrays

PurposeIt is difficult to test phased array ultrasound transducers for non functioning elements. We aimed to modify a widely performed test to improve its ease and effectiveness for these arrays. MethodsA paperclip was slowly moved along the transducer array, with the scanner operating in M-mode, imaging at a fundamental frequency with automatic gain and grey scale adjustment disabled. Non-functioning elements are identified by a dark vertical line in the image. The test was repeated several times for each transducer, looking for consistency of results. 2 transducers, with faults already shown by electronic transducer testing, were used to validate the method. 23 transducers in clinical use were tested. ResultsThe results of the modified test on the 2 faulty transducers agreed closely with electronic transducer testing results. The test indicated faults in 5 of the 23 transducers in clinical use: 3 with a single failed element and 2 with non-uniform sensitivity. 1 transducer with non-uniform sensitivity had undergone lens repair; the new lens was visibly non-uniform in thickness and further testing showed a reduction in depth of penetration and a loss of elevational focus in comparison with a new transducer. ConclusionsThe modified test is capable of detecting non-functioning elements. Further work is required to provide a better understanding of more subtle faults.

Detecting failed elements on phased array ultrasound transducers using the Edinburgh Pipe Phantom.

Imaging faults with ultrasound transducers are common. Failed elements on linear and curvilinear array transducers can usually be detected with a simple image uniformity or 'paperclip' test. However, this method is less effective for phased array transducers, commonly used in cardiac imaging. The aim of this study was to assess whether the presence of failed elements could be detected through measurement of the resolution integral (R) using the Edinburgh Pipe Phantom. A 128-element paediatric phased array transducer was studied. Failed elements were simulated using layered polyvinyl chloride (PVC) tape as an attenuator and measurements of resolution integral were carried out for several widths of attenuator. All widths of attenuator greater than 0.5 mm resulted in a significant reduction in resolution integral and low contrast penetration measurements compared to baseline (p < 0.05). Measurements of resolution integral and low contrast penetration both have the potential to be used as straightforward and inexpensive tests to detect failed elements on phased array transducers. Particularly encouraging is the result for low contrast penetration as this is a quick and simple measurement to make and can be performed with many different test objects, thus enabling 'in-the-field' checks.

Quantitative shear-wave optical coherence elastography with a programmable phased array ultrasound as the wave source.

The purpose of this study is to implement a beam-steering ultrasound as the wave source for shear-wave optical coherence elastography (SW-OCE) to achieve an extended range of elastic imaging of the tissue sample. We introduce a linear phased array ultrasound transducer (LPAUT) as the remote and programmable wave source and a phase-sensitive optical coherence tomography (OCT) as the sensitive shear-wave detector. The LPAUT is programmed to launch acoustic radiation force impulses (ARFI) focused at desired locations within the range of OCT imaging, upon which the elasticity map of the entire OCT B-scan cross section is recovered by spatial compounding of the elastic maps derived from each launch of AFRIs. We also propose a directional filter to separate the shear-wave propagation at different directions in order to reduce the effect of tissue heterogeneity on the shear-wave propagation within tissue. The feasibility of this proposed approach is then demonstrated by determining the stiffness of tissue-mimicking phantoms with agarose concentrations of 0.5% and 1% and also by imaging the Young's modulus of retinal and choroidal tissues within a porcine eye ball ex vivo. The approach opens up opportunities to combine medical ultrasound imaging and SW-OCE for high-resolution localized quantitative assessment of tissue biomechanical property.

High-Curie-temperature relaxor piezoelectric single crystals for 1.5D ultrasound phased-array applications

In this letter, a 2.5MHz 320-element 1.5D active matrix phased-array ultrasound transducer was designed and fabricated using high-temperature relaxor-based piezoelectric ternary Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) single crystals. The experiment and finite element analysis with the PZFlex package software were developed to design and optimize the 1.5D transducer. The FEM results show that the −6dB fractional bandwidth is up to 83% using two λ/3.75 matching layers. A 64×5 active element PIN–PMN–PT single-crystal phased array was fabricated and tested. The measured center frequency and −6dB fractional bandwidth were 2.5MHz and 71%, respectively. Elevation beam profiles were obtained using a hydrophone, which showed that the measured −6dB slice thickness was approximately 3mm throughout the entire range of field of interest. The PIN–PMN–PT single crystal with over 30 degree usage temperature and higher Ec field should satisfy the demands of advanced high-density ultrasound transducer applications.