Compact Acquisition System Research Articles

Multiplexed Surface Electrode Arrays Based on Metal Oxide Thin-Film Electronics for High-Resolution Cortical Mapping.

Electrode grids are used in neuroscience research and clinical practice to record electrical activity from the surface of the brain. However, existing passive electrocorticography (ECoG) technologies are unable to offer both high spatial resolution and wide cortical coverage, while ensuring a compact acquisition system. The electrode count and density are restricted by the fact that each electrode must be individually wired. This work presents an active micro-electrocorticography (µECoG) implant that tackles this limitation by incorporating metal oxide thin-film transistors (TFTs) into a flexible electrode array, allowing to address multiple electrodes through a single shared readout line. By combining the array with an incremental-ΔΣ readout integrated circuit (ROIC), the system is capable of recording from up to 256 electrodes virtually simultaneously, thanks to the implemented 16:1 time-division multiplexing scheme, offering lower noise levels than existing active µECoG arrays. Invivo validation is demonstrated acutely in mice by recording spontaneous activity and somatosensory evoked potentials over a cortical surface of ≈8×8mm2 . The proposed neural interface overcomes the wiring bottleneck limiting ECoG arrays, holding promise as a powerful tool for improved mapping of the cerebral cortex and as an enabling technology for future brain-machine interfaces.

Underwater Single-Photon Lidar Equipped with High-Sampling-Rate Multi-Channel Data Acquisition System

Lidar has emerged as an important technology for the high-precision three-dimensional remote sensing of the ocean. While oceanic lidar has been widely deployed on various platforms, its underwater deployment is relatively limited, despite its significance in deep-sea exploration and obstacle avoidance for underwater platforms. Underwater lidar systems must meet stringent requirements for high performance, miniaturization, and high integration. Single-photon lidar, by elevating the detection sensitivity to the single-photon level, enables high-performance detection under the condition of a low-pulse-energy laser and a small-aperture telescope, making it a stronger candidate for underwater lidar applications. However, this imposes demanding requirements for the data acquisition system utilized in single-photon lidar systems. In this work, a self-developed multi-channel acquisition system (MCAS) with a high-resolution and real-time histogram statistics capability was developed. By utilizing field-programmable gate array (FPGA) technology, a method that combines coarse counters with multi-phase clock interpolation achieved an impressive resolution of 0.5 ns and enabled a time of flight duration of 1.5 μs. To address counting instability, a dual-counter structure was adopted in the coarse counter, and real-time histogram statistics were achieved in the data acquisition system through a state machine. Furthermore, the non-uniform phase shift of the clock was analyzed, and a correction algorithm based on code density statistics was proposed to mitigate the periodic modulation of the backscattered signal, with the effectiveness of the algorithm demonstrated through experimental results. The robustness and stability of the MCAS were validated through an underwater experiment. Ultimately, the development of this compact acquisition system enables the implementation of underwater single-photon lidar systems, which will play a crucial role in underwater target imaging, obstacle avoidance in underwater platforms, and deep-sea marine environment monitoring.

Development of a Compact Acquisition System for Touch Location on a Conformable Monoport Distributed Sensor

A compact acquisition system developed for a flexible large area monoport tactile surface is presented in this paper. This sensor requires a single port connection and avoids complicated matrix acquisition system and multiplexing. The tactile surface is based on a coplanar transmission line printedd on a large area flexible substrate. Touching the waveguide generates a reflected signal. A harmonic analysis of this reflected signal at the line input port allows locating the touch event. A compact and low complexity acquisition system has been developed in order to demonstrate the principle and evaluate the feasibility of its integration on the sensor. Theoretical background, design and measurements on the overall sensor are exposed. The acquisition circuit imperfections have been demonstrated experimentally and correction methods have been proposed and implemented. Results are presented, and to assess the precision of the compact acquisition system, they are compared to reference measurements made with a Vector Network Analyzer

First operation and performance of a 200 lt double phase LAr LEM-TPC with a 40 × 76 cm2 readout

In this paper we describe the design, construction, and operation of afirst large area double-phase liquid argon Large Electron MultiplierTime Projection Chamber (LAr LEM-TPC). The detector has a maximumdrift length of 60 cm and the readout consists of a 40 × 76 cm2 LEM and 2D projective anode to multiply and collectdrifting charges. Scintillation light is detected by means ofcryogenic PMTs positioned below the cathode. To record both chargeand light signals, we have developed a compact acquisition system,which is scalable up to ton-scale detectors with thousands of chargereadout channels. The acquisition system, as well as the design andthe performance of custom-made charge sensitive preamplifiers, aredescribed. The complete experimental setup has been operated for afirst time during a period of four weeks at CERN in the cryostat ofthe ArDM experiment, which was equipped with liquid and gas argonpurification systems. The detector, exposed to cosmic rays, recordedevents with a single-channel signal-to-noise ratio in excess of 30 forminimum ionising particles. Cosmic muon tracks and theirδ-rays were used to assess the performance of the detector, andto estimate the liquid argon purity and the gain at differentamplification fields.

A VLSI chip set for digital radiology with energy selection

We present a compact acquisition system for digital radiology, based on GaAs detectors. The system is based on a custom VLSI circuit set, with analog and digital functions for the acquisition of radiological images in a wide range of applications. The circuit architectures and the operating principles are presented. We use a broad spectrum X-ray tube and try to exploit the full physical information contained in the incident radiation by means of both single photon counting and energy measurement of each photon.