Modeling and Characterization of Pre-Charged Collapse-Mode CMUTs

Recently, the applications of ultrasound transducers expanded from high-end diagnostic tools to point of care diagnostic devices and wireless power receivers for implantable devices. These new applications additionally require that the transducer technology must comply to biocompatibility and manufacturing scalability. In this respect,...

Energy Efficient High Voltage Driver for High Frequency Ultrasound Medical Applications

Noninvasive brain stimulation plays an essential role in diagnosing and treating diseases of the brain. This stimulation can affect disease-related changes in brain activation, inhibition, or connectivity. Ultrasound neuromodulation is a rapidly growing field of noninvasive brain stimulation. In a form of acoustic pressure waves, ultrasound can...

A High-Frequency Beamforming Channel for Ultrasound Stimulation and Ultrasonic Powering

New non-imaging ultrasound applications, such as ultrasound stimulation and ultrasonic power transfer, need sub-millimeter volumetric spatial resolution, electronically control of the focal spot location, high ultrasound intensity, and a tiny form factor. Satisfying these requirements demands a high-frequency phased array ultrasound transducer....

A Tiled Ultrasound Matrix Transducer for Volumetric Imaging of the Carotid Artery

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 matrix transducer should be interfaced with an application-specific integrated circuit (ASIC) for...

Time-efficient low power time/phase-reversal beamforming for the tracking of ultrasound implantable devices

Ultrasound (US) has recently gained attention for powering and communication with implantable devices due to its short wavelength and low attenuation. However, beam mis-alignments cause a sharp decrease in the amount of transferred power and quality of communication. This work investigates a telemetry protocol that relies on the difference in...

Maximization of Transmitted Acoustic Intensity from Silicon Integrated Piezoelectric Ultrasound Transducers

2D phased array ultrasonic transducers realized through the combination of bulk piezoelectric ceramics and complementary metal-oxide-semiconductor (CMOS) integrated circuits (IC) are enabling a new range of wearable ultrasound therapeutic applications. Traditional therapeutic ultrasound transducers have an air backing layer to maximize...

Automated Characterization of Matrix Transducer Arrays using the Verasonics Imaging System

Over the past decades, ultrasound imaging has made considerable progress based on the advancement of imaging systems as well as transducer technology. With the need for advanced transducer arrays with complex designs and technical requirements, there is also a need for suitable tools to characterize such transducers. However, despite the...

The long-term reliability of pre-charged CMUTs for the powering of deep implanted devices

Recently, focused ultrasound has been proposed to power deeply implanted medical devices. Almost exclusively, lead zirconate titanate (PZT) transducers are used to convert acoustic energy into electrical energy. Unfortunately, these lead containing devices cannot be hermetically encapsulated since that would block the ultrasound. We propose the...

Experimental Investigation of the Effect of Subdicing on an Ultrasound Matrix Transducer

Over the past decades, real-time three-dimensional (3D) medical ultrasound has attracted much attention since it enables clinicians to diagnose more accurately. This calls for ultrasound matrix transducers with a large number of elements, which can be interfaced with an application-specific integrated circuit (ASIC) for data reduction. An...

Real-Time Coded Excitation Imaging Using a CMUT-based Side Looking Array for Intravascular Ultrasound

Intravascular ultrasound (IVUS) is a well-established diagnostic method that provides images of the vessel wall and atherosclerotic plaques. We investigate the potential for phased-array IVUS utilizing coded excitation (CE) for improving the penetration depth and image signal-to-noise ratio (SNR). It is realized on a new experimental...

An Integrated 2D Ultrasound Phased Array Transmitter in CMOS with Pixel Pitch-Matched Beamforming

Emerging non-imaging ultrasound applications, such as ultrasonic wireless power delivery to implantable devices and ultrasound neuromodulation, require wearable form factors, millisecond-range pulse durations and focal spot diameters approaching 100 μm with electronic control of its three-dimensional location. None of these are compatible...

Ultrasound Energy Transfer using Charged CMUTs

Implantable medical devices (IMDs) such as cardiac pacemakers, cochlear implants, and neurostimulators improve millions of people’s lives every day. Over the years, IMDs have significantly improved in function, increased in lifetime, and decreased in size. However, further miniaturisation is limited by the batteries used to power these devices,...

Silicon photonic micro-ring resonators to sense strain and ultrasound

We demonstrated that photonic micro-ring resonators can be used in micro-machined ultrasound microphones. This might cause a breakthrough in array transducers for ultrasonography; first because optical multiplexing allows array interrogation via one optical fiber and second because the silicon-on-insulator technology allows cost-effective...