Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

CUHK Faculty of Engineering develops novel imaging approach

21.11.2019

Bringing faster 3D imaging for biomedical researches

The research result has been published in the journal Optics Letters recently.


The researchers prepared two-photon microscopy images of a pollen grain by using (a) traditional point-scanning and (b) the new compressive imaging approach. The point-scanning imaging time was 2.2 seconds while the compressive imaging time required only 0.55 seconds.

Credit: The Chinese University of Hong Kong

Activities of neurons are generally completed on a time scale of 10 milliseconds, which makes it hard for conventional microscopes to observe these phenomena directly. This new compressive sensing two-photon microscopy can be applied to 3D imaging of the nerve distribution of living things or to monitoring activities from hundreds of neurons simultaneously.

New multi-focus laser scanning method to break the scanning speed limit of two-photon microscope

Two-photon microscopy works by delivering ultrafast pulses of infrared laser light to the sample, where it interacts with fluorescent labels to create an image. It is extensively used for biological researches because of its ability to produce high-resolution 3D images up to a depth of one millimeter in a living tissue. These advantages, however, come with a limited imaging speed of the two-photon microscopy because of the weak fluorescent signal.

To speed up scanning, the research team developed a multi-focus laser illumination method that uses a digital micromirror device (DMD). The research solves the problem of conventional DMD being unusable to work with ultrafast laser, enabling them to be integrated and used in beam shaping, pulse shaping, and two-photon imaging.

The DMD generates 30 points of focused laser light on randomly selected locations within a specimen. The position and intensity of each point of light are controlled by a binary hologram that is projected onto the device. During each measurement, the DMD reflashes the hologram to change the position of each focus and records the intensity of the two-photon fluorescence with a single-pixel detector. Although, in many ways, the DMD multi-focus scanning is more flexible and faster than traditional mechanical scanning, the speed is still limited by the DMD's refresh rate.

Combining the compressive sensing algorithm to further improve the imaging speed

The researchers further increased the imaging speed in this research by combining multi-focus scanning with compressive sensing. This approach enables image acquisition with fewer measurements. This is because it carries out image measurement and compression in a single step and then uses an algorithm to rebuild the images from the measurement results. For two-photon microscopy, it can reduce the number of measurements by between 70% and 90%.

After conducting a simulation experiment to demonstrate the new method's performance and parameters, the researchers tested it with two-photon imaging experiments. These experiments demonstrated the technique's ability to produce high-quality 3D images with high imaging speeds from any field of view. For example, they were able to acquire 3D images from a pollen grain, in just 0.55 seconds. The same images acquired with traditional point scanning took 2.2 seconds.

Prof. Shih-Chi Chen said, "This method achieved a three to five times enhancement in imaging speed without sacrificing the resolution. We believe this novel approach will lead to new discoveries in biology and medicine, such as optogenetics. The team is now working to further improve the speed of the reconstruction algorithm and image quality. We also plan to use the DMD together with other advanced imaging techniques, which allows imaging in deeper tissues."

###

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

Media Contact

Angela Wan
angelawan@cuhk.edu.hk
852-394-33916

http://www.cuhk.edu.hk 

Angela Wan | EurekAlert!

Further reports about: 3D images algorithm laser light two-photon microscopy

More articles from Life Sciences:

nachricht Structual color barcode micromotors for multiplex biosensing
21.01.2020 | Science China Press

nachricht Cyanobacteria in water and on land identified as source of methane
21.01.2020 | Forschungsverbund Berlin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A new look at 'strange metals'

For years, a new synthesis method has been developed at TU Wien (Vienna) to unlock the secrets of "strange metals". Now a breakthrough has been achieved. The results have been published in "Science".

Superconductors allow electrical current to flow without any resistance - but only below a certain critical temperature. Many materials have to be cooled down...

Im Focus: Programmable nests for cells

KIT researchers develop novel composites of DNA, silica particles, and carbon nanotubes -- Properties can be tailored to various applications

Using DNA, smallest silica particles, and carbon nanotubes, researchers of Karlsruhe Institute of Technology (KIT) developed novel programmable materials....

Im Focus: Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time

Styrofoam or copper - both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives - from computer processors, where it is important to dissipate heat as...

Im Focus: Fraunhofer IAF establishes an application laboratory for quantum sensors

In order to advance the transfer of research developments from the field of quantum sensor technology into industrial applications, an application laboratory is being established at Fraunhofer IAF. This will enable interested companies and especially regional SMEs and start-ups to evaluate the innovation potential of quantum sensors for their specific requirements. Both the state of Baden-Württemberg and the Fraunhofer-Gesellschaft are supporting the four-year project with one million euros each.

The application laboratory is being set up as part of the Fraunhofer lighthouse project »QMag«, short for quantum magnetometry. In this project, researchers...

Im Focus: How Cells Assemble Their Skeleton

Researchers study the formation of microtubules

Microtubules, filamentous structures within the cell, are required for many important processes, including cell division and intracellular transport. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

A new look at 'strange metals'

21.01.2020 | Materials Sciences

Body's natural signal carriers can help melanoma spread

21.01.2020 | Health and Medicine

Structual color barcode micromotors for multiplex biosensing

21.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>