Tutorials and Short Courses

Sunday, September 22, 8:30 - 12:30
701A

Piezoelectric effect is the ability of certain dielectric materials with non-centre symmetries to generate an electric charge in response to applied mechanical stress (direct piezoelectric effect), or to generate mechanical strain/displacement under applied electric field (converse piezoelectric effect). Piezoelectric materials are essential parts of the electronics and electrical equipment used for consumer and industrial applications, such as ultrasonic piezoelectric transducers for medical imaging and non-destructive evaluation, sensors, actuators, transformers and resonators. Some of the devices use the converse piezoelectric effect, such as actuator or injector, some use the direct piezoelectric effect, such as sensor or hydrophone, while most of the electromechanical devices take the advantage of both direct and converse piezoelectric effects, for example, the ultrasound transducers and surface acoustic wave (SAW)/bulk acoustic wave (BAW) sensors. Generally used piezoelectric materials include bulk ceramics, single crystals, thin films, textured ceramics, polymers and composites.

This short course comprises two main parts. The first part will focus on the fundamentals of ferroelectricity, including piezoelectricity, covering: the defining properties of ferroelectric materials; the origin of spontaneous polarisation in both the classical static and lattice dynamics models; the Curie-Weiss law; simple crystal chemical models of electrostriction and piezoelectricity.

The second part will highlight the application-oriented figure-of-merit of piezoelectric materials from a material perspective, discussing the material fabrication, sample preparation, poling techniques, material property characterizations, and assessing material behavior under specific conditions mimicking the real application scenarios.

Sunday, September 22, 8:30 - 12:30
701B

This short course explores the interaction of Analog Front End (AFE) electronics with passive transducers, advances to the integration of the AFE with in-probe electronics, and finally considers the implications on ultrasound system design.

This course starts by considering the electronics within a typical AFE. A basic electronics primer is provided including Characteristic Impedance, Impedance Matching, Cable Selection then Analog and Switched Mode Transmit Circuits, Transmit/Receive Switches and Multiplexers, Receiver AFE, Amplification including Noise Factor and Noise Figure, Filtering and Analog to Digital Convertors (ADC).

Sunday, September 22, 8:30 - 12:30
701C

MEMS and acoustic wave (SAW, BAW, and LambWave) devices are based on similar technology and physical background, but they have been developing in different communities for a long time. In this short course, the lecturer, who has been deeply involved in developing both MEMS and acoustic wave device technologies, presents and discusses the following MEMS-related design and implementation techniques for the ultrasonics community:

 1. Overview of Piezoelectric Micro Acoustic devices enabled by MEMS techniques
2. Microfabrication techniques for Microacoustic and MEMS devices Wafer-level packaging and integration techniques
3. Design techniques for RF MEMS/microacoustic devices based on piezoelectric multilayer stack
4. Packaging technologies for RF MEMS devices
5. Outlooks and Future Directions

Sunday, September 22, 14:00 - 15:45
Room: 701A

This Short Course covers the physics and properties of recently invented XBARs – resonators suitable for the development of 3.5 GHz – 8 GHz filters for application in 5G mobile phones. Recently Murata announced the production of such filters exploiting XBARs. This device exploits the fundamental shear mode resonance in the λ/2-thick piezoelectric membrane, strongly coupled to the lateral electric field in a properly selected cut of lithium niobate (LN). The physics of XBARs will be discussed in detail as well as the advantages of these resonators and the ladder filters exploiting them. Simple admittance formulas, modeling of XBARs, loss mechanisms, suppression of parasitic modes, etc. as well as recent experimental results are presented.  The way to increase device robustness and the power handling levels are discussed. The recently proposed bi-layered, 3-layered, etc. structures with the periodically inversed polarity of piezo-layers potentially allow to XBARs go to the 20 GHz - 28 GHz range with a low level of losses in wide-band filters.  Other devices exploiting the Lamb modes in thin LN layers, such as YBARs, are briefly presented. Very fast development of this class of devices continues.

Sunday, September 22, 14:00 - 18:00
Room: 701B

This tutorial will discuss the fundamentals that affect the piezoelectric response and the quality factors of piezoelectric materials for ultrasound transducers.  The origin of the piezoelectric effect in AlN, PVDF, PbZr_0.52Ti_0.48O₃ (PZT) and various piezoelectric single crystals will be discussed.  Optimization of materials for both bulk and thin film transducers will be covered.

Sunday, September 22, 14:00 - 15:45
Room: 701C

(Al,Sc)N thin films are key enablers of many piezoMEMS technologies and devices. This tutorial will focus on aspects of the materials science of (Al,Sc)N and closely-related chemistries that are most relevant to piezoMEMS applications; it targets both MEMS experts interested in a deeper understanding of the materials they use and materials experts curious about bringing their expertise to the MEMS world.

The tutorial will start with a quick overview of the basics of piezoMEMS and the relationships between device behavior and intrinsic materials parameters. This introduction will be followed by a discussion of how film chemistry can tune materials properties, as guided by both computational studies and experimental results, followed by discussions of growth and integration considerations. Most of the tutorial will focus on sputtered films (DC, HiPIMS, and RF), but we will also discuss the challenges and opportunities associated with other growth and integration techniques. We will wrap up with piezoMEMS-relevant opportunities enabled by the now well-known ferroelectricity of (Al,Sc)N. Questions and audience engagement are highly encouraged.

Sunday, September 22, 16:15 - 18:00
Room: 701A

Recent development of acoustic metamaterials opens a door to an unprecedented large design space for acoustic properties such as negative bulk modulus, negative density, and refractive index. These novel concepts pave the way for the design of a new class of acoustic materials and devices with great promise for diverse applications, such as broadband noise insulation, sub-wavelength imaging and acoustic cloak from sonar detection. This tutorial will focus on the current advancement of acoustic metasurfaces with promise to provide novel functions such as passive phase shifters for phase modulation as well as tunable amplitude modulation. For example, I will present our recent exploration of architectured meta structures for acoustic waves enabled by advanced design and micro/nanofabrication techniques.  I will also discuss the concept of acoustic subwavelength imaging system based on wave vector conversion. The combination of resonator arrays that enhance the waves with specific wave vectors, and binary phase gratings that add or subtract wave vectors by first-order diffraction, establishes a one-to-one relationship between the subwavelength and propagating wave components.

Sunday, September 22, 16:15 - 18:00
Room: 701C

In this tutorial I will present architectures based on piezoMEMS technology to demonstrate stress-optical modulation and tuning of silicon nitride and silicon photonic integrated circuits. We will define fundamental performance metrics and compare various monolithic and heterogeneous optomechanical systems. In the second part of the course, I will introduce new applications enabled by optomechanics including acousto-optic modulators, inertial sensors, magnetic-free optical isolators, and fast tunable lasers for LIDAR and microcombs. I will then close with a discussion of applications of ultrasonic piezoMEMS technology and frequency control not only of photons (flying qubits) but also color centers in diamond and silicon carbide (atom-like defects).

Sunday, September 22, 8:30 - 12:30
701D

The propagation of ultrasonic waves through materials is essentially governed by its elastic and anelastic properties. Following the basics of interatomic forces and elasticity, ultrasonic velocities in single crystals and polycrystalline materials are discussed, providing means for materials characterization using ultrasonic velocity measurements. The third-order elastic constants in polycrystalline materials describe the acoustoelastic constants which form the basis for the evaluation of elastic stresses in materials. Stresses lead to anisotropic velocities and so do textures. It is discussed how these can be separated. The anisotropy of the constituents of the microstructure of a material leads to ultrasonic scattering and therefore to attenuation of the propagating waves, whereas the anelasticity in lattice structure leads to internal friction. In turn, the measurement of the scattered ultrasound can be used to characterize the microstructure. These effects are discussed with various examples. Fatigue and creep manifest themselves in the elastic constants and in the nonlinear β- and other parameters responsible for the generation of harmonics, which can be exploited for nondestructive materials characterization. Finally, the phase velocity and the attenuation of ultrasonic waves are frequency dependent due to their interaction with internal degrees of freedom in the propagation media, for example by dislocation motions in metals which couple to elastic stresses. In causal and linear systems, the velocity and the attenuation are not independent of each other. This interdependence is known as the Kramers-Kronig relations. Applications of these relations will be presented. In summary, the course emphasizes the principles forming the basis for NDMC using ultrasonics.

Sunday, September 22, 8:30 - 10:15
Room: 701E

The dielectric response in any material lies deeply entangled to its structure at different length scales. The entities which respond to an applied electric field are of different nature and size: atomic vibrations, dipoles, polar fluctuations, polar clusters, domain walls, domains... Because the dielectric response is a way to measure the ability of a material to store charges, it is vital to identify the relevant actors when an electromagnetic field is applied. Using different spectroscopic methods one can study the dynamic response of all of them, or, selecting the frequency range, focus on a specific type.

Sunday, September 22, 8:30 - 10:15
Room: 701F

Ferroelectric domain gratings with sub-µm periods are imperative for realization of paradigm-shifting nonlinear optical devices, such as nonlinear optical interactions involving counter-propagating photons. These optical interactions have no counter-part in the world and cannot be achieved using the available nonlinear optical materials and currently available periodic poling technology. Despite the great
potential of these nonlinear processes for classical, as well as quantum optical applications, their usage is sparsely spread due to the challenging implementation of the required nano-domain structures. In this talk, I will review our work in sub- µm domain-structuring techniques for KTP isomorphs. I will present a qualitative leap in periodic poling techniques that allows us to demonstrate devices and frequency conversion schemes that were deemed unfeasible just a few years ago; and has allowed us to fabricate bulk (1mm thick) domain structures with feature sizes down to 200 nm. The technological breakthrough comes from implementing coercive-field gratings in the material via ion exchange. We will discuss the influence of the ion-exchanged grating properties on the domain formation. Our studies reveal that the formation of sub-µm domains is governed by the depth, shape, and critical ion-concentration of the ion-exchanged volume, independent of the poling period. The above findings are of importance in further scaling the coercive field engineering technique to smaller poling periods and larger aperture domain-engineered devices.

Sunday, September 22, 10:45 - 12:30
Room: 701E

Multi-piezo material, a new concept material combining strong piezoluminescence and piezoelectricity, can emit light with unprecedented sensitivity and stability when subjected to mechanical stimuli. Piezoluminescence, also called elasticoluminescence, is a form of mechanoluminescence (ML) during elastic deformation, which has attracted considerable attention because it can be repeatedly used for mechano-optical conversion [1-5]. Elastic ML offers the advantages of wireless detection and nondestructive analysis. It is a promising candidate for various applications, such as stress sensing, and damage diagnosis, particularly for dynamic visualization of stress distribution in industrial plants, buildings, and living organisms.

Sunday, September 22, 10:45 - 12:30
Room: 701F

Crystallographic texturing of ferroelectric ceramics allows exploitation of property anisotropy and application of domain engineering, potentially offering a means of achieving significantly enhanced piezoelectric properties. Templated grain growth (TGG) has been proved to be a very effective approach to fabricate high-quality textured piezoelectric ceramics. Here fundamental basis for texture development in piezoelectric ceramics will be outlined from aspects of TGG-related theories and texture analysis, and processings to induce grain orientations will be surveyed with emphases on template selection & synthesis, template alignment techniques, and relationships among densification and texture development.

Sunday, September 22, 14:00 - 15:45
Room: 701D

Topolgical structures in ferroelectric systems have recently drawn immense attention. For example, topological configurations such as skyrmions, flux closure domains, or nanoscale bubble domains have led to emergent properties including chirality, negative capacitance, and giant electromechanical response. These topological defects are often observed at the nanoscale. The above attributes make polar topologies promising candidates for various low-energy, high-density device applications. Critically, understanding the nanoscale domain configurations of ferroelectric topological defects is essential for gaining insight into their fundamental characteristics and potential applications. Piezoresponse Force Microscopy (PFM) is one of the powerful techniques for investigating their electromechanical properties at the nanoscale. 

This tutorial provides a comprehensive overview of PFM to effectively utilize this powerful technique for characterizing topological defects and exploring their novel properties and related phenomena. It begins with an introduction to the underlying physics of piezoelectric/ferroelectric materials and ferroelectric topologies, as well as the working principles of PFM. Subsequently, vector PFM, and switching spectroscopy PFM (SS-PFM) are explained, with discussion of how to interpret and analyze PFM results. Finally, the applications of PFM to the study of nanoscale topological defects will be discussed in detail. 

Sunday, September 22, 14:00 - 15:45
Room: 701F

Synthesis and processing of ferroelectric thin films are introduced. Processing includes not only physical processes including sputtering and evaporation methods, but also chemical processes including chemical solution deposition and hydrothermal methods. The importance of phase transition between the paraelectric and ferroelectric phases is
also discussed.

Sunday, September 22, 16:15 - 18:00
Room: 701D

A strong interest in complex polarization textures has recently emerged, paving the way for a new era in ferroelectrics and pushing the second century of ferroelectrics into previously unimagined directions. Recent advances in this field include the discovery of highly complex polarization textures, non-Ising and chiral domain walls, bubble domains, labyrinth patterns, vortices, or polar skyrmions. New developments in this field focus on low-dimensional polar topological structures with unknown physical properties, and the first experimental methods with the potential to measure the associated local symmetry violations are emerging. In this context, two-photon microscopy based on second-harmonic generation (SHG) microscopy with polarimetry analysis has emerged as a suitable method to probe local symmetry and complex polarization textures.

Sunday, September 22, 16:15 - 18:00
Room: 701F

Ferroelectric properties were initially discovered in perovskite-structured materials over a century ago. However, it was only in the last two decades that these properties were confirmed in fluorite-structured doped HfO 2 and wurtzite-structured AlN films, respectively[1][2]. The ferroelectricity in doped HfO 2 or ZrO 2 has been attributed to a previously unknown non-centrosymmetric orthorhombic Pca2 1 phase, while it relates to the hexagonal P6 3 mc phase in wurtzite-structured ferroelectrics. In addition to different dopants in HfO 2 , it was found that a certain dopant content, oxygen vacancies, surface and bulk effects, and quenching are beneficial for the formation of the polar phase. All effects indicate that strain and stress contribute to the ferroelectric phase formation. Similarly, strain and bond ionicity are discussed for doped AlN, GaN, and ZnO to influence the properties
strongly[3,12].

Sunday, September 22, 8:30 - 10:15
Room: 701G

Characterization of random processes by Power Spectral Density;
Phase noise and its influence on the signal spectrum (carrier collapse effect, Schawlow-Townes formula);

Phase and amplitude noise measurement techniques: (i) phase bridge, (ii) dual-channel readout with cross-correlation, (iii) microwave interferometry.

Phase and amplitude fluctuations in microwave oscillators;
Oscillator phase noise suppression techniques;
Oscillator phase noise measurement techniques;
Phase noise performance of cryogenic microwave oscillators;
Microwave signals with pure phase and amplitude modulation; applications to precision noise measurements.

Sunday, September 22, 10:45 - 12:30
Room: 701G

This tutorial focuses on the role of electronics in time and frequency metrology. It shows why a proper design of the electronic apparatus is a key aspect of an application: a new experiment, instrument or facility. After a brief comparison of off-the-shelf commercial versus custom solutions, the tutorial will show how to develop a custom high-performance and flexible apparatus. High performance is provided by low noise components, while flexibility is guaranteed by digital devices, in particular by Field Programmable Gate Arrays (FPGAs). Practical examples among vapor cell clocks, coherent fiber links and timescale generation in realtime are then provided for clarifying the advantages of this approach.

Sunday, September 22, 14:00 - 15:45
Room: 701G

Coordinated Universal Time (UTC) is the reference for timekeeping all over the world and it provides traceability to the second of the International System of Units (SI). UTC is realized by an average of all the atomic clocks kept by the National Metrology Institutes, or Observatories, around the world. Its accuracy is ensured by Primary and Secondary Frequency Standards that realize the definition of the SI second at the best level of accuracy reaching 10^-16 in relative value for the primary standards based on caesium atoms, and 10^-18 for secondary frequency standards based on optical radiations.

Sunday, September 22, 16:15 - 18:00
Room: 701G

GNSS and Two-Way Satellite Time and Frequency Transfer (GNSSTT and TWSTFT) are considered to be the most accurate means of long-baseline time transfer, and the main components in the international time scale comparison. For its high accuracy and reasonable cost, GPSTT is now used for many commercial and industrial applications such as communications networks and power grids. In this tutorial, we will give the overview, principles, and operational techniques of GNSS and TWSTFT, further discuss their calibration implementation, current developments, and the potential usages especially for TWSTFT.

Sunday, September 22, 8:30 - 10:15
Room: 701H

Microwave atomic clocks are everywhere in society.  They range from chip-scale models that can fit into hand-held electronics, to “hardened” units that are flown in space, to laboratory units that reach state of the art levels of precision and accuracy.  The term “microwave” corresponds to the wavelength of the radiation used to stimulate the internal atomic transition that forms the basis of the clock.  Atomic clock technology grew out of experiments in the 1930’s to investigate and characterize internal atomic structure.  It was quickly realized that energy levels of certain internal atomic states, and so the frequency of electromagnetic radiation used to make transitions between them, are exquisitely stable and immune to external perturbations and so might be used as a reference for a frequency standard.  The first atomic clocks were based on techniques used in these scientific investigations.  Due to the intervening 80+ years of development, microwave atomic clocks enjoy a high degree of sophistication and technical maturity that enables their wide range of applications.

Sunday, September 22, 10:45 - 12:30
Room: 701H

The versatile quantum states of atoms that have connections to different physical quantities can be used for metrology applications with the best fundamental accuracy and precision, such as measurements of time, magnetic field, electric field, acceleration, and rotation. Comparing different techniques of atomic metrology, the vapor-cell-based approaches have the best technological maturity owning to the fact that atoms are physically confined inside glass containers without complicated atom trapping mechanisms. In this tutorial, I will start with reviewing the fundamental principles of atomic metrology for different types of sensing application. I will discuss the significantly relevant atomic physics of alkali-vapor cells. I will talk about pros and cons of the vapor-cell sensing technologies and their state of the art. Then I will illustrate the innovative vapor-cell techniques that I developed in my research career for quasi-DC atomic electrometry, pure optical magnetic gradiometry, and vapor-cell active atomic clock as some examples of advanced vapor-cell-based atomic metrology. 

Sunday, September 22, 14:00 - 15:45
Room: 701H

Over the past 20 years optical frequency combs have been a powerful and enabling technology in the context of time and frequency measurement. Their main claim to fame has been their central in the development of optical atomic clocks and the realization of clock comparisons to support redefinition of the SI second and tests of fundamental physics. Optical frequency combs, based on modelocked lasers, combine ultrafast optical techniques and laser phase stabilization to permit coherent harmonic synthesis of atomic references across hundreds of terahertz in the optical domain. Photo-mixing and nonlinear frequency conversion of the laser pulse train can be used to extend the synthesis range all the way to the XUV, to the MID IR, and down to the electronic domain, allowing for the realization of broadband synthesis across much of the electro-magnetic spectrum. The unique capabilities of optical frequency combs: low phase noise, low timing-jitter, spatial coherence, broad optical bandwidth, frequency resolution, efficient frequency conversion have led to a plethora of applications beyond atomic clocks. In my tutorial I will discuss how optical frequency comb sources are used for both precision optical and microwave synthesis and metrology and discuss their function and performance in the context of various time/frequency applications.

Sunday, September 22, 16:15 - 18:00
Room: 701H

Optical atomic clocks have now reached a level of precision and accuracy that holds immense promise
for applications such as the redefinition of the second and sub-centimeter resolution geopotential
measurements. Notably, many field-deployable optical atomic clocks are progressing rapidly, driven by
the ultimate goal of bringing this groundbreaking technology out of the lab and into real-world
applications. In this tutorial, we will focus on neutral atom-based optical frequency standards. I will
explain the principles behind optical atomic clocks and describe the experimental techniques required to
achieve optical clocks with systematic uncertainties at the 1E-18 level and below. I will also discuss
various sources of systematic uncertainty and how they have been characterized. Finally, we will explore
how we can overcome these limitations to enhance performance and discuss potential future
applications.

Sunday, September 22, 8:30 - 12:30
702

Piezoelectric MEMS based acoustic wave resonators have been the backbone for low loss, high-rejection and compact RF filters over the past 30 years.  This course will provide an overview on basic principles of piezoelectric theory and acoustic wave propagation, material selection, underlying bulk acoustic wave resonator design, and measurement techniques for the design of RF bulk acoustic wave (BAW) filters. 

Sunday, September 22, 8:30 - 12:30
703

Acoustic tweezers, a cutting-edge technology at the intersection of acoustics, microfluidics, and biomedical engineering, have emerged as a powerful tool for the precise manipulation and sorting of microscale objects. This tutorial provides a comprehensive overview of the design, fabrication, and diverse applications of acoustic tweezers. The tutorial begins by introducing the fundamental principles of acoustic tweezers, highlighting the underlying physics of acoustic wave propagation and the generation of acoustic radiation forces. It explores various design strategies for creating acoustic tweezer devices, including transducer configurations, materials selection, and system designs.

Sunday, September 22, 14:00 - 18:00
Room: 702

Nonlinearity in the context of ultrasonic waves has gained increasing attention in recent years for various reasons. In micro-acoustic devices for mobile communication, nonlinear effects can lead to signal corruption and require countermeasures, especially in view of tightening linearity requirements by new standards like 5G. In the field of non-destructive evaluation, nonlinearity is a desired effect, as it provides a better chance to detect, with the help of ultrasound, defects and pre-fatigue at an earlier stage as compared to the linear regime. Nonlinear effects have to be well understood for their efficient use or design of countermeasures.

Sunday, September 22, 14:00 - 18:00
Room: 703

To optimize your ultrasound imaging device and corresponding imaging algorithms, it is important to have a good understanding of the propagation of acoustic wave fields in heterogeneous media and in particular the underlying physical mechanisms and mathematical formulations. This course is about the fundamentals of acoustic wave theory and imaging and inversion. 

Sunday, September 22, 8:30 - 12:30
Room: 500

The functional performance of ferroelectric materials often relies on the interactions between polarization and external stimuli, which are intimately related to the dynamical responses of domains and domain walls. Molecular Dynamics (MD) is an ideal computational tool for investigating dynamical processes on large length and time scales, while providing atomistic details with femtosecond time resolution. At the very heart of MD simulations is the force field, which accurately describes the interatomic interactions within the material of interest. However, the application of MD to new material systems is often hindered by the limited availability and accuracy of classical force fields, as developing a force field is a tedious process due to the many-body nature of the potential energy. This situation has been greatly improved thanks to the emergence of machine learning force fields (MLFFs), which offer an attractive solution to the accuracy-efficiency dilemma by combining the strengths of first-principles methods like Density Functional Theory (DFT) and classical MD.

Sunday, September 22, 14:00 - 18:00
Room: 500

In this short course, we present machine learning, signal processing algorithms, and high-performance computational system design for ultrasonic imaging, machine learning and data analysis applications. Several case studies will be presented including detecting defects in critical components in nuclear power plants, microstructure characterization and flaw detection in large-grained materials using order statistics and deep neural network architectures, massive ultrasonic data compression using wavelet packet transformation optimized by convolutional autoencoders, and software-defined ultrasonic system design for communications through solid structures.

Sunday, September 22, 8:30 - 12:30
501

Nowadays, GPUs (Graphics Processing Units) serve as workhorses for processing massive amount of data and to accelerate general-purpose scientific and engineering computing.

The main goal of the training is to get familiar with the GPU/parallel programming and apply it to ultrasound signal processing. The short-course is going to be practically oriented with a 25/75 split between the lectures and exercises. We are planning to leverage a common knowledge of the basic ultrasound processing methods and show how to translate them into working parallel algorithms.

The workshop will target both low-level Nvidia CUDA GPU programming and high-level Python tools. This blend of development tools enables fast prototyping of new processing methods and later migration to a high-performance native GPU implementation.

During the exercises, the Participants will implement and test their algorithms on ready to use RF datasets, as well as have an opportunity to run them on an ultrasound research system equipped with GPU.

Sunday, September 22, 8:30 - 12:30
507

Super-resolution ultrasound imaging has the capacity to distinguish and map structures that are smaller than the classical limit, typically a fraction of the wavelength. For ultrasound imaging, this means exploring features, such as blood vessels, in the micrometric range deep inside tissue. At the end of this course, students should be able to understand and reproduce super-resolution ultrasound imaging experiments, from data acquisition to image reconstruction, and apply such knowledge in their specific fields. 

Sunday, September 22, 14:00 - 18:00
701E

This short course gives an introduction to therapeutic use of ultrasound that is currently transitioning from research studies to clinical practice. The ultrasound induced bio-effects useful for therapy will be reviewed along with the generation of ultrasound. Mainly the absorption of ultrasound waves in soft biological tissues leading to heat creation will be described as well as the concept of the equivalent time at 43°C. The second half of the course will cover mechanical effects of ultrasound, and will discuss non-thermal therapy approaches, including lithotripsy, histotripsy, non-thermal ablation and targeted drug delivery. The potential of therapeutic methods using ultrasound currently in preclinical evaluation and clinical practice will be discussed together with the future directions and potential impact of therapeutic ultrasound. The course will emphasize technological issues and system architecture constraints, and will cover the current therapy ultrasound systems and their use in clinical practice. Examples of the results of the clinical studies will be reviewed. 

Sunday, September 22, 14:00 - 18:00
Room: 501

Ultrasound has become the most commonly performed medical imaging procedure in the world because it provides real-time imaging with high clinical value while being portable, non-ionizing and inexpensive. This course will provide an introductory survey of ultrasound imaging focused on the design, fabrication, and testing of medical ultrasound transducers.  Starting from an overview of the basic types of phased-array transducers (linear, convex, sector), we will show how the probe’s design is derived from its target application.  We will describe how engineering tools, like equivalent-circuit, finite-element, and acoustic field models, can be used to predict transducer performance accurately, and then to optimize the design.  A discussion of the structure of an ultrasound probe will lead to a survey of the different types of materials used in probes and their critical properties.  Typical fabrication processes will be reviewed and common problems in probe manufacturing will be summarized.  Methods for evaluating completed transducers will be described.  The course will include recent developments in probe technology, including single crystal piezoelectrics, cMUT transducers, catheters, 2D arrays, and electronics in probes, and will address some of the performance advantages and fabrication difficulties associated with them.

Sunday, September 22, 14:00 - 18:00
Room: 507

This short course is based on a recent review article (https://ieeexplore.ieee.org/abstract/document/9913943) and will present basic principles of hydrophone measurements, including mechanisms of action for various hydrophone designs, sensitivity and directivity calibration procedures, practical considerations for performing measurements, signal processing methods to correct for both frequency-dependent sensitivity and spatial averaging across the hydrophone sensitive element, uncertainty in hydrophone measurements, special considerations for high-intensity therapeutic ultrasound, and advice for choosing an appropriate hydrophone for a particular measurement task. Recommendations will be made for information to be included in hydrophone measurement reporting.  The instructors are world-leading hydrophone experts who are active in the development of International Electrotechnical Commission standards on hydrophones and collectively have authored over 40 articles concerning hydrophone methodology in peer-reviewed journals.

Sunday, September 22, 14:00 - 18:00
Room: 506

This short course will provide an overview of the basic techniques of Doppler blood flow imaging used in the industry, followed by the limitations of these conventional approaches to imaging low-velocity blood flow. The course will then cover how low-velocity flow detection has been greatly improved with the advent of new microvascular Doppler flow imaging modes found on a number of commercial imaging systems. The second part of the course will cover how the introduction of microbubbles solves a key limitation of even these new microvascular Doppler modes to allow visualization of relative variations in microvascular flow. However, ultrasound contrast has had limited clinical application, in part due to a lack of quantification. Finally, traditional and new efforts to quantify microvascular hemodynamics using microbubbles, particularly nonlinear ULM approaches, will be presented.  The course will also provide some hands-on processing of Doppler and microbubble signals.