Tag Archives: Antony Orth

In-body fibre optic imaging to go 3D

26 April 2019:

An advanced new method has been developed by CNBP researchers that may open the door to 3D microscopy in hard-to-reach areas of the human body.

It sees the successful miniaturization of a 3D imaging technique called ‘light field imaging’, taken to extreme new levels, making in-body application possible.

It could find significant application in diagnostic procedures called optical biopsies, where suspicious tissue is investigated during medical endoscopic procedures.

Reported in the journal ‘Science Advances’, project lead of the innovative imaging approach is Dr Antony Orth, Research Fellow at the RMIT University node of the CNBP (pictured).

The paper can be accessed below or read the media release here.

Journal: Science Advances.

Publication title: Optical fiber bundles: Ultra-slim light field imaging probes.

Authors: A. Orth, M. Ploschner, E. R. Wilson, I.S. Maksymov and B. C. Gibson.

Abstract: Optical fiber bundle microendoscopes are widely used for visualizing hard-to-reach areas of the human body. These ultrathin devices often forgo tunable focusing optics because of size constraints and are therefore limited to two-dimensional (2D) imaging modalities. Ideally, microendoscopes would record 3D information for accurate clinical and biological interpretation, without bulky optomechanical parts. Here, we demonstrate that the optical fiber bundles commonly used in microendoscopy are inherently sensitive to depth information. We use the mode structure within fiber bundle cores to extract the spatio-angular description of captured light rays—the light field—enabling digital refocusing, stereo visualization, and surface and depth mapping of microscopic scenes at the distal fiber tip. Our work opens a route for minimally invasive clinical microendoscopy using standard bare fiber bundle probes. Unlike coherent 3D multimode fiber imaging techniques, our incoherent approach is single shot and resilient to fiber bending, making it attractive for clinical adoption.

Below – Modal structure in optical fiber bundles captures light field information. Credit Antony Orth, RMIT University.

Fluorescence microscopy gets the BAMM treatment!

7 June 2018:

A novel technique developed by researchers at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) will help shine new light on biological questions by improving the quality and quantity of information that can be extracted in fluorescence microscopy.

The technique, ‘bleaching-assisted multichannel microscopy’ (BAMM) takes a current long-standing weakness of fluorescence microscopy – photobleaching – and turns it into a strength that improves imaging output by up to three times, with no additional hardware required.

Reported in the journal ‘Biomedical Optics Express’ (lead author Dr Antony Orth, CNBP Research Fellow at RMIT University), BAMM will help researchers gain biological insights into the intricate processes taking place within living cells. This includes the interplay between proteins and molecules which have the potential to impact a wide range of health areas from fertility, to pain, to heart disease and more.

Publication authors: Antony Orth, Richik N. Ghosh, Emma R. Wilson, Timothy Doughney, Hannah Brown, Philipp Reineck, Jeremy G. Thompson, and Brant C. Gibson.

Read more about this innovative technique from our media release or access the publication online.

Below – This figure shows the information-rich cellular images made possible by using the newly reported BAMM technique. The ‘Original’ image shows cells containing multiple fluorescent targets, all having similar colours. This results in a monochrome image. With BAMM, photobleaching rates are colour coded red, green and blue for visualisation, so that each fluorescently labelled structure can be identified even though the fluorophore’s native colour information was never used.

CNBP input into major exhibition

11 May 2018:

The launch of a ground-breaking and unconventional permanent exhibition at Scienceworks titled ‘Beyond Perception: Seeing the Unseen’ had more than a touch of CNBP involvement with RMIT based researchers  A/Prof Brant Gibson and Dr Tony Orth involved in providing information, content and ideas to the exhibition over a 12-18 month planning and implementation period.

The exhibition, reflecting the latest and greatest stories from science and technology, provides interactive, large-scale experiences that reveals the invisible fields and forces that surround us, such as gravitational waves, invisible light, sound and aerodynamics. It also demonstrates current research which is continuing to uncover these amazing and tantalizing worlds.

“The areas where we contributed were around the use of the visible part of the electromagnetic spectrum for optical microscopy applications,” says A/Prof Brant Gibson.

“We looked at the the fact that the diffraction limit of a microscope has now been ‘broken’ with the development of superresolution microscopy such as STED or PALM.”

“It was an absolute pleasure to be involved in this type of activity that takes science out to the broader community,” says A/Prof Gibson.

“The exhibition provides an opportunity for people to immerse themselves and to deeply engage with the exhibition using sound, light and waves in ways which are radically different to other exhibitions I’ve seen.”

Information on the exhibition and how to visit can be found online.

Below – a quote from A/Prof Gibson forms part of an exhibition display.

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.

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.