Featured Research

from universities, journals, and other organizations

Overcoming light scattering: New optical system sees deeper inside tissue

Date:
July 2, 2014
Source:
The Optical Society
Summary:
Optical imaging could become even more valuable if researchers could find a way for light to penetrate all the way through the body's tissues. Currently, passing through a fraction of an inch of skin is enough to scatter the light and scramble the image. Now researchers have developed a single-pixel optical system based on compressive sensing that can overcome the fundamental limitations imposed by this scattering.

Researchers placed an image of the Cheshire Cat behind a layer of material that hides the object. A standard multi-pixel camera cannot see the cat because the material in front scatters the light (left). However, by using a single-pixel optical system based on compressive sensing, the researchers could overcome the imaging limitations traditionally imposed by scattering to recover fine details about the hidden object (right).
Credit: Optics Express

Optical imaging methods are rapidly becoming essential tools in biomedical science because they're noninvasive, fast, cost-efficient and pose no health risks since they don't use ionizing radiation. These methods could become even more valuable if researchers could find a way for optical light to penetrate all the way through the body's tissues. With today's technology, even passing through a fraction of an inch of skin is enough to scatter the light and scramble the image. Now a team of researchers from Spain's Jaume I University (UJI) and the University of Valčncia has developed a single-pixel optical system based on compressive sensing that can overcome the fundamental limitations imposed by this scattering.

Related Articles


The work was published today in The Optical Society's (OSA) open-access journal Optics Express.

"In the diagnostic realm within the past few years, we've witnessed the way optical imaging has helped clinicians detect and evaluate suspicious lesions," said Jesús Lancis, the paper's co-author and a researcher in the Photonics Research Group at UJI. "The elephant in the room, however, is the question of the short penetration depth of light within tissue compared to ultrasound or x-ray technologies. Current knowledge is insufficient for early detection of small lesions located deeper than a millimeter beneath the surface of the mucosa."

"Our goal is to see deeper inside tissue," he added.

To achieve this, the team used an off-the-shelf digital micromirror array from a commercial video projector to create a set of microstructured light patterns that are sequentially superimposed onto a sample. They then measure the transmitted energy with a photodetector that can sense the presence or absence of light, but has no spatial resolution. Then they apply a signal processing technique called compressive sensing, which is used to compress large data files as they are measured. This allows them to reconstruct the image.

One of the most surprising aspects of the team's work is that they use essentially a single-pixel sensor to capture the images. While most people think that more pixels result in better image quality, there are some cases where this isn't true, Lancis said. In low-light imaging, for instance, it's better to integrate all available light into a single sensor. If the light is split into millions of pixels, each sensor receives a tiny fraction of light, creating noise and destroying the image.

"Something similar happens when you try to transmit images through scattering media," Lancis said. "When we use a conventional digital camera to get an image, we only see the familiar noisy pattern known as 'speckle.' In compressive imaging, since we aren't using pixelated sensors, it should be less sensitive to light scrambling and enable transmission of images through scattering."

Also notable, the team's technique could operate through dynamic scattering. "Most scattering media of interest, like biological tissue, are dynamic in the sense that the scatter centers continuously change their positions with time -- meaning that the speckle patterns are 'in motion.' This is ideal for some applications because monitoring the changes of the speckle can reveal information about the sample, but the drawback is that it's a major nuisance to transmit or get images," Lancis pointed out. "Our technique, however, requires no calibration of the medium, and its fluctuations during the sensing stage don't limit imaging ability."

What's ahead for the team? "Our next goal is to break the barriers of light penetration depth inside a scattering medium with the state-of-the-art megapixel-programmable spatial light modulators used in consumer electronics," Lancis says. To do this, they'll need to demonstrate that their technique works even when the sample is embedded inside the tissue.


Story Source:

The above story is based on materials provided by The Optical Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Enrique Tajahuerce, Vicente Durán, Pere Clemente, Esther Irles, Fernando Soldevila, Pedro Andrés, Jesús Lancis. Image transmission through dynamic scattering media by single-pixel photodetection. Optics Express, 2014; 22 (14): 16945 DOI: 10.1364/OE.22.016945

Cite This Page:

The Optical Society. "Overcoming light scattering: New optical system sees deeper inside tissue." ScienceDaily. ScienceDaily, 2 July 2014. <www.sciencedaily.com/releases/2014/07/140702111031.htm>.
The Optical Society. (2014, July 2). Overcoming light scattering: New optical system sees deeper inside tissue. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2014/07/140702111031.htm
The Optical Society. "Overcoming light scattering: New optical system sees deeper inside tissue." ScienceDaily. www.sciencedaily.com/releases/2014/07/140702111031.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) — Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) — What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) — A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins