Tag Archives: Antony Orth

Extending depth of field of MOF imaging probes

2 March 2018:

A fully computational method for extending the depth of field of multicore optical fibers (MOF) imagers has been demonstrated by CNBP researchers in a new paper published in the journal ‘Optics Express’. The work shows that the depth of field can be more than doubled for certain spatial frequencies. Lead author on the publication is CNBP Research Fellow Dr Antony Orth from RMIT University.

Journal: Optics Express.

Publication title: Extended depth of field imaging through multicore optical fibers.

Authors: Antony Orth, Martin Ploschner, Ivan S. Maksymov, and Brant C. Gibson.

Abstract: Compact microendoscopes use multicore optical fibers (MOFs) to visualize hard-to-reach regions of the body. These devices typically have a large numerical aperture (NA) and are fixed-focus, leading to blurry images from a shallow depth of field with little focus control. In this work, we demonstrate a method to digitally adjust the collection aperture and therefore extend the depth of field of lensless MOF imaging probes. We show that the depth of field can be more than doubled for certain spatial frequencies, and observe a resolution enhancement of up to 78% at a distance of 50μm from the MOF facet. Our technique enables imaging of complex 3D objects at a comparable working distance to lensed MOFs, but without the requirement of lenses, scan units or transmission matrix calibration. Our approach is implemented in post processing and may be used to improve contrast in any microendoscopic probe utilizing a MOF and incoherent light.

Turn your phone into a microscope

20 February 2018:

Australian researchers from the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) have developed a 3D printable ‘clip-on’ that can turn any smartphone into a fully functional microscope.

“We’ve designed a simple mobile phone microscope that takes advantage of the integrated illumination available with nearly all smartphone cameras,” explains lead developer and CNBP Research Fellow at RMIT University, Dr Antony Orth.

You can read more about this exciting innovation at the leading technology web site Gizmodo.

 

 

Add-on clip turns smartphone into fully operational microscope

19 February 2018:

Australian researchers from the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) have developed a 3D printable ‘clip-on’ that can turn any smartphone into a fully functional microscope.

Reported in the research journal ‘Scientific Reports’, the smartphone microscope is powerful enough to visualise specimens as small as 1/200th of a millimetre, including microscopic organisms, animal and plant cells, blood cells, cell nuclei and more.

The clip-on technology is unique in that it requires no external power or light source to work yet offers high-powered microscopic performance in a robust and mobile handheld package.

And the researchers are making the technology freely available, sharing the 3D printing files publicly so anyone – from scientists to the scientifically curious – can turn their own smartphones into microscopes.

Lead developer and CNBP Research Fellow at RMIT University, Dr Antony Orth (pictured), believes the technology has immense potential as a scientific tool, one that is ideal for use in remote areas and for field-work where larger standalone microscopes are unavailable or impractical.

“We’ve designed a simple mobile phone microscope that takes advantage of the integrated illumination available with nearly all smartphone cameras,” says Dr Orth.

The clip-on has been engineered with internal illumination tunnels that guide light from the camera flash to illuminate the sample from behind. This overcomes issues seen with other microscopy-enabled mobile phone devices says Dr Orth.

“Almost all other phone-based microscopes use externally powered light sources while there’s a perfectly good flash on the phone itself,” he explains. “External LEDs and power sources can make these other systems surprisingly complex, bulky and difficult to assemble.”

“The beauty of our design is that the microscope is useable after one simple assembly step and requires no additional illumination optics, reducing significantly the cost and complexity of assembly. The clip-on is also able to be 3D printed making the device accessible to anyone with basic 3D printing capabilities.”

A further advantage noted by Dr Orth is that the clip-on enables both bright-field and dark-field microscopy techniques to be undertaken. Bright-field microscopy is where a specimen is observed on a bright background. Conversely, dark-field shows the specimen illuminated on a dark background.

“The added dark-field functionality lets us observe samples that are nearly invisible under conventional bright-field operation such as cells in media,” he says. “Having both capabilities in such a small device is extremely beneficial and increases the range of activity that the microscope can be successfully used for.”

Dr Orth believes the potential applications for the smartphone microscope are enormous.

“Our mobile microscope can be used as an inexpensive and portable tool for all types of on-site or remote area monitoring.”

“Water quality, blood samples, environmental observation, early disease detection and diagnosis—these are all areas where our technology can be easily used to good effect.”

Dr Orth sees significant benefit in developing countries for the device.

“Powerful microscopes can be few and far between in some regions,” says Dr Orth. “They’re often only found in larger population centres and not in remote or smaller communities. Yet their use in these areas can be essential—for determining water quality for drinking, through to analysing blood samples for parasites, or for disease diagnosis including malaria.”

To ensure that this technology can be utilised the world over, the files for the 3D printing of the microscope clip-on are being made freely available. They are available for download at the CNBP web site – http://cnbp.org.au/online-tools.

“Ideally, a phone microscope should take advantage of the integrated flash found in nearly every modern mobile, avoiding the need for external lighting and power. It should also be as compact and easy to assemble as possible. It is this design philosophy that inspired us in the development of this add-on clip,” says Dr Orth.

The new phone microscope has already been tested by Dr Orth and his CNBP colleagues in a number of areas, successfully visualizing samples ranging from cell culture, to zooplankton to live cattle semen in support of livestock fertility testing.

Below: Cells being viewed by an add-on clip that turns a smartphone into a fully operational microscope.

Enhancement of the NV quantum yield

3 July 2017:

Researchers from CNBP’s RMIT University node (lead author CNBP PhD student Marco Capelli pictured), have had a paper published in the journal ‘Nanoscale’.

The researchers report an enhancement of the nitrogen-vacancy (NV) quantum yield by up to 7% in bulk diamond caused by an external magnetic field.

The paper is accessible online.

Journal: Nanoscale.

Publication title: Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield .

Authors: M. Capelli, P. Reineck, D. W. M. Lau, A. Orth, J. Jeske, M. W. Doherty, T. Ohshima, A. D. Greentree and B. C. Gibson.

Abstract: The nitrogen-vacancy (NV) centre in diamond is a unique optical defect that is used in many applications today and methods to enhance its fluorescence brightness are highly sought after. We observed experimentally an enhancement of the NV quantum yield by up to 7% in bulk diamond caused by an external magnetic field relative to the field-free case. This observation is rationalised phenomenologically in terms of a magnetic field dependence of the NV excited state triplet-to-singlet transition rate. The theoretical model is in good qualitative agreement with the experimental results at low excitation intensities. Our results significantly contribute to our fundamental understanding of the photophysical properties of the NV defect in diamond.

Neurophotonics Summer School

21 June 2017:

This years Neurophotonics Summer School held in Quebec, Canada, June 11-21, was attended by three CNBP members – Vicky Staikopoulos (University of Adelaide, pictured), Antony Orth (RMIT University) and Varun Sreenivasan (UNSW).

The school focuses on teaching physics and biology and how they can merge, and runs for 10 days and includes 14 lectures from world class speakers and 10 workshops that teach the latest technology in the bio-imaging of the central nervous system.

For the last 4 days of the summer school, students are given a project to participate in for direct hands-on experience which is then presented on the last day,  with prizes awarded for the top 3 presentations.

This year, equal second prize was given to Vicky Staikopoulos for her work on Digital Holographic Microscopy in red blood cells.

 

Microscopy meet ‘big data’

22 March 2017:

Cell Systems has published an invited preview article authored by CNBP Research Fellow Dr Antony Orth along with collaborators from Harvard University and Massachussetts General Hospital.

The commentary article discusses how data-driven methods are poised to shake-up how we approach bio-microscopy. Microscopy-based assays can be made more informative and more predictive when paired with a library of reference images. The preview puts new results in this field into context and suggests further avenues of research.

The article is accessible online although a subscription is required.

 

Dictionary-enhanced imaging cytometry

22 February 2017:

A new paper by CNBP researcher Tony Orth (lead author pictured) describes how to use large image sets to perform cell classification and imaging performance. The work combines years of hardware development on a high throughput microlens microscope together with large scale image processing.

The authors on the paper found that they could get a computer to accurately identify white blood cells types purely from a reference set of images (or dictionary), without resorting to time-consuming manual classification by trained staff.

Moreover, the authors demonstrated that because white blood cells come in a limited number of shapes and sizes, even a very poor quality noisy image of a white blood cell can be effectively enhanced by looking for similar images in the dictionary set.

This has potential applications for low-light level imaging. Working with a small amount of light is detrimental in terms of image quality but gentle on cells. The author’s dictionary-based method provides a way to partially recover image quality for dose-limited imaging.

The paper is accessible online.

Dictionary-enhanced imaging cytometry. Antony Orth, Diane Schaak and Ethan Schonbrun. Scientific Reports 7, Article number: 43148 (2017).

Science ‘Experience Day’ at RMIT

18 January 2017:

Researchers at CNBP’s RMIT University node were busy doing light-based demonstrations on Wednesday Jan 18th, as part of the ‘RMIT University Experience Day’ program, whereby students from years 10, 11 and 12 get to engage in hands-on workshops and explore life on campus while experiencing the differing aspects of University discipline areas.

As part of the ‘experience’ activity, over seventy high school students (predominantly in Year 10) visited the CNBP researchers in their physics laboratories. While there, students were given an overview of biophotonic science as well as laboratory research, and shown the exciting things that can be done with light including 3D scanning, fluorescence microscopy and more.

Below – CNBP researcher Philipp Reineck talks and demonstrates photonics to students.

 

 

 

Best paper award at SPIE Photonics West

Antony_Orth_web18 March 2016:

Congratulations to CNBP Research Fellow Antony Orth who has won a Hitachi Hi-Tech award for a paper presented at the recent SPIE Photonics West BIOS 2016 conference (High-Speed Biomedical Imaging and Spectroscopy: Toward Big Data Instrumentation and Management).

There were six awards distributed to authors who presented at the conference, with Antony’s talk titled “Gigapixel microscopy with microlens arrays.”

Awarded participants had to be both the primary author and presenter of an accepted abstract to be eligible. Qualifying papers and presentations were then evaluated by the awards committee.

Well done on your award Antony!