PMUT and CMUT Devices for Biomedical Applications: A Review

Piezoelectric Micromachined Ultrasonic Transducers (PMUT) and Capacitive Micromachined Ultrasonic Transducers (CMUT) have seen great developments in recent years, both in terms of performance and scope of applications within the biomedical ultrasound domain. This paper presents a review of the state-of-the-art of PMUT and CMUT technologies,...

Hybrid neuroelectronics: towards a solution-centric way of thinking about complex problems in neurostimulation tools

Responsive neuromodulation is increasingly being used to treat patients with neuropsychiatric diseases. Yet, inefficient bridges between traditional and new materials and technological innovations impede advancements in neurostimulation tools. Signaling in the brain is accomplished predominantly by ion flux rather than the movement of electrons....

Low-cost shaping of electrical stimulation waveforms for bioelectronic medicine with improved efficiency and selectivity

Electrical stimulation is proven to be an effective way of neuromodulation in bioelectronic medicine (e.g. cochlear implants, deep brain stimulators, etc.), delivering localized treatment by the means of electrical pulses. To increase the stimulation efficiency and neural-type selectivity, there is an increasing interest to employ non...

A 2D Ultrasound Phased-Array Transmitter ASIC for High-Frequency US Stimulation and Powering

Ultrasound (US) neuromodulation and ultrasonic power transfer to implanted devices demand novel ultrasound transmitters capable of steering focused ultrasound waves in 3D with high spatial resolution and US pressure, while having a miniaturized form factor. Meeting these requirements needs a 2D array of ultrasound transducers directly...

An Energy-Efficient High-Voltage Pulser for High-Frequency Ultrasound Medical Applications

Emerging ultrasound (US) biomedical applications, from battery-powered US imaging to US neuromodulation, demand wearable form factor and power-efficient US transmitters. Fulfilling these specifications demands a high-frequency and power-efficient 2D US phased-array transmitter directly integrated with the ASIC. In such systems, pulsers are the...

Multichannel current-mode stimulator with channel-specific regulated power supply

Developing neuroprosthetic bioelectronic devices requires wirelessly-powered implantable stimulator systems with hundreds to thousands of output channels. Power efficiency optimization is crucial for scaling up the number of output channels. Current-mode electrical stimulation is favored for safety but is power-inefficient in conventional...

Energy efficiency of pulse shaping in electrical stimulation: the interdependence of biophysical effects and circuit design losses

Power efficiency in electrical stimulator circuits is crucial for developing large-scale multichannel applications like bidirectional brain-computer interfaces and neuroprosthetic devices. Many state-of-the-art papers have suggested that some non-rectangular pulse shapes are more energy-efficient for exciting neural excitation than the...

Pre-Filtering of Stimuli for Improved Energy Efficiency in Electrical Neural Stimulation

This work proposes a guideline for designing more energy-efficient electrical stimulators by analyzing the frequency spectrum of the stimuli. It is shown that the natural low-pass characteristic of the neuron’s membrane limits the energy transfer efficiency from the stimulator to the cell. Thus, to improve the transfer efficiency, it is proposed...

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 Parasitic Resistance Extraction Tool Leveraged by Image Processing

Most academic and commercial tri-dimensional (3D) parasitic resistance extraction EDA/CAD tools rely on finite element methods (FEM) and are mainly suited to digital circuitry. In analog and mixed-signal (AMS) circuits, such as power converters and radio-frequency analog front-ends, the layout structures used for the metal interconnections...

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...

Stent with Piezoelectric Transducers for High Spatial Resolution Ultrasound Neuromodulation- a Finite Element Analysis

Deep brain stimulation is currently the only technique used in the clinical setting to modulate the neural activity of deep brain nuclei. Recently, low-intensity transcranial focused ultrasound (LIFU) has been shown to reversibly modulate brain activity through a transcranial pathway. Transcranial LIFU requires a low-frequency ultrasound of...

Application of a sub-0.1-mm³ implantable mote for in vivo real-time wireless temperature sensing

There has been increasing interest in wireless, miniaturized implantable medical devices for in vivo and in situ physiological monitoring. Here, we present such an implant that uses a conventional ultrasound imager for wireless powering and data communication and acts as a probe for real-time temperature sensing, including the monitoring of...

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...