SPADnet gets funded

Sept. 22, 2010
A new collaborative research project has been formed to develop a new generation of smart, CMOS-based large-area networked image sensors for photon-starved biomedical applications.

Lausanne, Switzerland--A new collaborative research project has been formed to develop a new generation of smart, CMOS-based large-area networked image sensors for photon-starved biomedical applications. Called "Fully Networked Digital Components for Photon-starved Biomedical Imaging Systems" and nicknamed SPADnet (a SPAD is a single-photon avalanche diode), the project is being funded by the European Union within the Information and Communication Technologies (ICT) Theme of its Seventh Research Framework Programme (FP7).

Launched on July 1st, 2010, SPADnet is being coordinated by the Ecole Polytechnique Federale de Lausanne (EPFL) and includes seven leading European experts in image sensors, medical imaging, and photonics. SPADnet was granted 3,700,000 EUR of funding over a 42 month period. The SPADnet consortium met on July 16th, 2010 in Budapest for its general kick-off meeting.

Targeting single-shot rare events

In addition to the large-area CMOS-based networked image sensors, SPADnet will develop ring-assembly modules for positron-emission-tomography (PET) imaging and carry out performance tests in a PET evaluation system. While suited to applications offering repetitive measurement techniques, existing sensors are not well adapted to single-shot, rare events that often occur in diagnostic tools based on specific radiation detection, PET, single-photon-emission computed tomography (SPECT), gamma cameras, and other minimally invasive point-of-care tools. In addition, the relatively small field of view of existing sensors is a limiting factor.

SPADnet's prime objective is to develop a scalable photonic component for large format, rare-event imaging. The core of the component will be a SPAD array implemented in CMOS. Large formats will be achieved by tessellating several tens of dies in abutment style using innovative packaging techniques based on through-silicon vias (TSVs).

Spatial oversampling reduces dead time

The ability to stamp the time and position of each photon impingement in a burst event offers a second key advance. The concept of spatial oversampling is introduced, where a single measurement is partitioned into a myriad of submeasurements occurring simultaneously. In space oversampling, many SPADs will detect the same event independently, thus reducing the dead time on average by a factor of the number of detectors involved. The decomposition of the large-format imager to a network of independent arrays is key to managing massive data streams. In conventional photomultiplier tubes (PMTs) or silicon photomultipliers (SiPMs), the sensitive device produces a stream of analog electrical pulses, whereas the photonic component proposed in this project will generate streams of precomputed digital data.

The current state of the art for interchip data exchange will be the basis for efficient data communication in a true network communication style. Data packets will be routed in the network and will be handled on demand. For example, coincidence-mapping engines can be used in this context as snoopers on the data bus, thus considerably simplifying systems such as PET.

Follow us on Twitter

Subscribe now to Laser Focus World magazine; It’s free!

About the Author

John Wallace | Senior Technical Editor (1998-2022)

John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.

Sponsored Recommendations

Request a quote: Micro 3D Printed Part or microArch micro-precision 3D printers

April 11, 2024
See the results for yourself! We'll print a benchmark part so that you can assess our quality. Just send us your file and we'll get to work.

Request a free Micro 3D Printed sample part

April 11, 2024
The best way to understand the part quality we can achieve is by seeing it first-hand. Request a free 3D printed high-precision sample part.

How to Tune Servo Systems: The Basics

April 10, 2024
Learn how to tune a servo system using frequency-based tools to meet system specifications by watching our webinar!

Precision Motion Control for Sample Manipulation in Ultra-High Resolution Tomography

April 10, 2024
Learn the critical items that designers and engineers must consider when attempting to achieve reliable ultra-high resolution tomography results here!

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!