P.J. Hicks

An integrated multi-element array transducer for ultrasound imaging

Abstract Much progress has been made towards integrating the electronic circuitry associated with either linear or phased ultrasonic array scanning into the hand-held case of the transducer. The number of wires required to connect the transducer back to the display system has been dramatically reduced and the path length between transducer elements and the driver circuits kept to a few millimetres. To achieve this new construction, polymer transducer arrays have been fabricated and the pulse-control circuitry has been integrated onto custom-designed silicon chips.

A novel position‐sensitive detector using an image‐sensing integrated circuit

A novel position‐sensitive detector has been developed which consists of an array of electron‐sensing electrodes and a corresponding array of amplifiers and counters all integrated onto a single silicon chip. The integrated circuit is coupled with a microchannel plate electron multiplier so that it counts individual charged particles or photons. The detector array is capable of being extended by abutting individual detector chips side by side in the form of a hybrid circuit. The detector is currently in use on both electron‐energy‐loss and photoelectron spectrometers.

An integrated array transducer receiver for ultrasound imaging

At Eurosensors VII the authors described an integrated ultrasonic array transducer that featured integrated transmit circuitry. The present paper describes integrated receiving circuitry that the authors have gone on the develop. The motivation for the receiver is the same as for the transmitter: (a) the entire receiver circuitry, along with the transmit circuitry, to be part of a hand-held transducer; (b) a small number of wires to connect the scanner to the base unit. The transducer in question is a one-dimensional polyvinylidene polymer array with a centre frequency of 20 MHz. Novel receiver design concepts have been developed to enable the wide bandwidth to be accommodated.

A programmable multi-channel CMOS pulser chip to drive ultrasonic array transducers

A 16-channel programmable pulse generator ASIC has designed in 1.5¿m CMOS technology. By employing novel design techniques time delays with 1nS time resolution have been achieved with a dynamic range of 219. Currently the chip is being used to drive ultrasonic transducer arrays.

Development of a new type of self-scanned electron image sensing integrated circuit

The object of this research was to design and fabricate a linear array of electron sensing electrodes coupled to detection and read-out circuitry in the form of amplifiers and counters integrated onto a single CMOS chip. The chip replaces existing position-sensitive detection systems in electron spectrometers.

A new generation of integrated multichannel single‐particle detectors (invited)

Monolithic integrated circuit (IC) detectors have been developed which consist of an array of electron sensing anodes and a corresponding array of amplifiers and counters all integrated onto a single chip. The anodes are fabricated on the surface of the chip over a thick dielectric film. The IC is mounted with a microchannel plate multiplier so that it counts individual charged particles and photons. The detector chip is so designed that it can be used in hybrid configurations. The active anode area can, therefore, be arbitrarily extended by abutting individual detector chips side by side, under the control of a customizing gate‐array chip. Quad‐detector chip sets are currently in use.

An integrated multichannel charged-particle sensing system

Abstract A novel hybrid circuit featuring application-specific integrated circuits (ASICs) has been developed which, when fitted with microchannel plate electron multipliers, can be used for position-sensitive detection of charged particles, ultraviolet radiation and X-rays. The integrated circuit consists of an array of charge-sensing electrodes with a corresponding array of amplifiers and counters all integrated on a single chip and giving parallel detection. This has significant advantages over existing position-sensitive detection systems. The system is now in place in a number of laboratories around the world and has been used in a variety of applications. Examples of data obtained with the aid of the detector are presented.

A ‘when and where’ charged-particle sensing system

Abstract A prototype, eight-channel, integrated circuit is described which uses a 32-phase clock to record the arrival time of incident particles. The chip architecture is such that data can be acquired continuously to a pulse-pair resolution of 1 ns and up to a peak input frequency approaching 500 MHz per channel. The device incorporates cache memory and write only if data (WOID) techniques to maximize the throughput of the chip. A feedback circuit has been implemented in the delay line to ensure that the chip is immune to both temperature and voltage variations.

High Frequency Integrated Ultrasound Arrays

There is increasing interest in the use of ultrasound imaging techniques at frequencies in excess of 20 MHz. Examples may be found in both medicine and industry. This places a great demand on the imaging systems employed, particularly if the aim is to produce real time images using multi-element arrays. The Ultrasound Research Group at UMIST have been working along these lines for a number of years and this paper represents a report on work in progress covering beam plotting experiments to investigate the characteristics of the transmitted ultrasound field. We also report on preliminary results from the receive system which is based on phased array techniques.

A multi-channel accumulator

A multi-channel accumulator is described, which provides reduced data acquisition times compared with existing multi-channel scalers and multi-detector systems. The instrument has been implemented using a single application-specific integrated circuit and a memory array, so that it may be mounted as a single-card plug-in for a system controller. Tests indicate that the instrument will accumulate data from the detector at rates corresponding to up to 25.6 million pulses per second. This represents a fivefold improvement over the previous best reported count rate. The application of the accumulator in a high resolution electron energy-loss spectrometer is considered although the specification is sufficiently general to allow its use in other experimental apparatus.