- Lensless Microscope Made for Telemedicine
LOS ANGELES, April 27, 2010 — Aydogan Ozcan, whose invention of a novel lensless imaging technology for telemedicine could radically transform global health care, has now taken his work a step further. The University of California, Los Angeles engineer has created a miniature microscope, the world's smallest and lightest for telemedicine applications.
The microscope, unveiled in a paper published online in the journal Lab on a Chip, builds on imaging technology known as LUCAS (Lensless Ultrawide-field Cell Monitoring Array platform based on Shadow imaging), which was developed by Ozcan, who is an assistant professor of electrical engineering at the UCLA Henry Samueli School of Engineering and Applied Science as well as a researcher at UCLA's California NanoSystems Institute.
Instead of using a lens to magnify objects, LUCAS generates holographic images of microparticles or cells by employing an LED to illuminate the objects and a digital sensor array to capture their images. The technology can be used to image blood samples or other fluids, even in Third World countries.
The prototype for a lensless microscope developed at UCLA has the approximate diameter of a US quarter. The microscope only weighs 46 g, about as much as a large chicken egg. (Image: Ozcan Research Group at UCLA)
"This is a very capable and yet cost-effective microscope, shrunk into a very small package," Ozcan said. "Our goal with this project was to develop a device that can be used to improve health outcomes in resource-limited settings."
The lensless microscope, in addition to being far more compact and lightweight than conventional microscopes, also obviates the need for a trained technician to analyze the images produced. Instead, images are analyzed by computer so that results are available instantaneously.
Weighing 46 grams — approximately as much as a large chicken egg — the microscope is a self-contained imaging device. The only external attachments necessary are a USB connection to a smartphone, PDA or computer, which supplies the microscope with power and allows images to be uploaded for conversion into results and then sent to a hospital.
Samples are loaded using a small chip that can be filled with saliva or a blood smear for health monitoring. With blood smears, the lensless microscope can accurately identify cells and particles, including red blood cells, white blood cells and platelets. The technology has the potential to help monitor diseases such as malaria, HIV and tuberculosis in areas where there are great distances between people in need of health care and the facilities capable of providing it, according to Ozcan. The device can even be used to test water quality in the field following a disaster such as hurricane or earthquake.
Using a couple of inexpensive add-on parts, the lensless microscope also can be converted into a differential interference contrast (DIC) microscope, also known as a Nomarski microscope. DIC microscopes are used to gain information on the density of a sample, giving the appearance of a 3-D image by putting lines and edges in stark contrast. The additional parts for conversion to a DIC microscope cost approximately $1 to $2.
A number of design elements lead Ozcan to believe his lensless microscope will be a useful medical tool in resource-limited settings, such as some countries in Africa. Two key requirements for such settings are ease of use and durability. The microscope requires minimal training; because of the device’s large field of view, samples do not need to be scanned or perfectly aligned in the microscope. And operating the microscope is as simple as filling a chip with a sample and sliding the chip into a slot on the side of the microscope. Because of its large aperture, the lensless microscope is also resistant to problems caused by debris clogging the light source. In addition, there are few moving parts, making the microscope fairly robust.
The lensless microscope also is an example of a type of technology known as telemedicine. In resource-limited settings, tools that are portable enough to do medical tests in the field are vital. Tools such as the lensless microscope could be digitally integrated as part of a telemedicine network that connects various mobile health care providers to a central lab or hospital, filling gaps in physical infrastructure with mobile tools. The transmission connections for such networks already exist in cellular networks, which have penetrated even the most remote corners of the globe.
"Making things user-friendly is what I love about being an engineer," Ozcan said. "It is very rewarding to create something that to the end-user is very simple, when in reality years of research and work went into the technology and product development."
The California NanoSystems Institute (CNSI) at UCLA is an integrated research center operating jointly at UCLA and UC Santa Barbara whose mission is to foster interdisciplinary collaborations for discoveries in nanosystems and nanotechnology; to train the next generation of scientists, educators and technology leaders; and to facilitate partnerships with industry, fueling economic development and the social well-being of California, the U.S. and the world.
The CNSI was established in 2000 with $100 million from the state of California and an additional $250 million in federal research grants and industry funding. At the institute, scientists in the areas of biology, chemistry, biochemistry, physics, mathematics, computational science and engineering measure, modify and manipulate the building blocks of the world — atoms and molecules. These scientists benefit from an integrated laboratory culture that enables them to conduct dynamic research at the nanoscale, leading to significant breakthroughs in the areas of health, energy, the environment and information technology.
For more information, visit: cnsi.ucla.edu
- The optical recording of the object wave formed by the resulting interference pattern of two mutually coherent component light beams. In the holographic process, a coherent beam first is split into two component beams, one of which irradiates the object, the second of which irradiates a recording medium. The diffraction or scattering of the first wave by the object forms the object wave that proceeds to and interferes with the second coherent beam, or reference wave at the medium. The resulting...
- An instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the near end. The objective forms a real aerial image of the object in the focal plane of the eyepiece where it is observed by the eye. The overall magnifying power is equal to the linear magnification of the objective multiplied by the magnifying power of the eyepiece. The eyepiece can be replaced by a film to photograph the primary image, or a positive or negative relay...
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