A major problem for optical biomedical imaging methods, e.g. near-infrared optical tomography (NIROT), using time resolved SPAD sensors is a slow acquisition time, resulting in motion artefacts and decreased patient comfort. We present a new SPAD sensor module optimised for the NIROT application. Dynamic TDC reallocation is employed to reduce the die area occupied by timing circuitry whilst als...

In this paper we present a two-photon fluorescence lifetime imaging microscopy (FLIM) system based on a two-dimensional single photon avalanche diode (SPAD) array fabricated in CMOS [1] [2]. To the best of our knowledge, this is the first demonstration of two-photon FLIM based on a CMOS detector. The sensor reported here exhibits picosecond accuracy, operates at room temperature, and requires n...

Nitrogen (N) management is critical in optimizing potato yield and quality and reducing environmental pollution. Six N rates from 34 to 270 kg ha , and different timing of N application were used in a 3-year field experiment to contrast SPAD-502 chlorophyll meter and QuickBird satellite imagery data against the conventional petiole sampling technique for assessing canopy N status. Overall treat...

This paper reports on the first implementation of a single-photon avalanche diode (SPAD) in standard silicon on insulator (SOI) complementary metal-oxide-semiconductor (CMOS) technology. The SPAD is realized in a circular shape, and it is based on a P(+)/N-well junction along with a P-well guard-ring structure formed by lateral diffusion of two closely spaced N-well regions. The SPAD electric-f...

Chlorophyll meters are widely used to guide nitrogen (N) management by monitoring leaf N status in agricultural systems, but the effects of environmental factors and leaf characteristics on leaf N estimations are still unclear. In the present study, we estimated the relationships among SPAD readings, chlorophyll content and leaf N content per leaf area for seven species grown in multiple enviro...

Different surface organelles contribute to specific interactions of a pathogen with host tissues or infectious partners. Multiple pilus gene clusters potentially encoding different surface structures have been identified in several gram-positive bacterial genomes sequenced to date, including actinomycetales, clostridia, corynebacteria, and streptococci. Corynebacterium diphtheriae has been show...

A single-photon avalanche diode (SPAD) with enhanced near-infrared (NIR) sensitivity has been developed, based on 0.18 μm CMOS technology, for use in future automotive light detection and ranging (LIDAR) systems. The newly proposed SPAD operating in Geiger mode achieves a high NIR photon detection efficiency (PDE) without compromising the fill factor (FF) and a low breakdown voltage of approxim...

Single-photon avalanche diode (SPAD) is a promising photosensor because of its high sensitivity to optical signals in weak illuminance environment. Recently, it has drawn much attention from researchers in visible light communications (VLC). However, existing literature only deals with the simplified channel model, which only considers the effects of Poisson noise introduced by SPAD, but neglec...

BACKGROUND Quantitative structure-activity relationships (QSAR) analysis of peptides is helpful for designing various types of drugs such as kinase inhibitor or antigen. Capturing various properties of peptides is essential for analyzing two-dimensional QSAR. A descriptor of peptides is an important element for capturing properties. The atom pair holographic (APH) code is designed for the descr...

O clorofilômetro (SPAD-502) é amplamente utilizado para estimar teores de clorofila, mas a falta de uniformidade na distribuição dos cloroplastos pode afetar sua precisão. Os objetivos deste estudo foram avaliar o efeito da fluência de fótons (F = irradiância x tempo de iluminação) em folhas com teores diferentes de clorofila e determinar o efeito da relação clorofila a/b nos valores do SPAD em...