We present a 72 × 60, angle-sensitive single photon avalanche diode (A-SPAD) array for lens-less 3D fluorescence lifetime imaging. An A-SPAD pixel consists of (1) a SPAD to provide precise photon arrival time where a time-resolved operation is utilized to avoid stimulus-induced saturation, and (2) integrated diffraction gratings on top of the SPAD to extract incident angles of the incoming ligh...

Single molecule localisation microscopy (SMLM) has become an essential part of the super-resolution toolbox for probing cellular structure and function. The rapid evolution of these techniques has outstripped detector development and faster, more sensitive cameras are required to further improve localisation certainty. Single-photon avalanche photodiode (SPAD) array cameras offer single-photon ...

In many approaches to recommendation diversification, a recommender scores items for relevance and then re-ranks them to balance relevance with diversity. In intent-aware diversification, diversity is formulated in terms of coverage of aspects, where aspects are either explicit such as movie genres or implicit such as the latent factors found during matrix factorization. Typically, the same set...

BACKGROUND The aim of extracorporeal albumin dialysis (ECAD) is to reduce endogenous toxins accumulating in liver failure. To date, ECAD is conducted mainly with the Molecular Adsorbents Recirculating System (MARS). However, single-pass albumin dialysis (SPAD) has been proposed as an alternative. The aim of this study was to compare the two devices with a prospective, single-centre, non-inferio...

SPAD-based solid state CMOS image sensors utilising analogue integrators have attained deep sub-electron read noise (DSERN) permitting single photon counting (SPC) imaging. A new method is proposed to determine the read noise in DSERN image sensors by evaluating the peak separation and width (PSW) of single photon peaks in a photon counting histogram (PCH). The technique is used to identify and...

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...