LENSFREE TELEMEDICINE MICROSCOPY ON A WIRELESS PHONE

SAIEE Africa Research Journal, 2012

Optical microscopy is widely accepted as one of the gold standards in disease diagnosis. However, factors such as cost and the need for a trained eye limit the prevalence of such equipment, particularly in resource-limited areas such as rural clinics. Lensless microscopy, which is based on principles of digital holography, has illustrated the possibility of using simple and cheap optical components combined with software algorithms to implement microscope platforms. We present a digital in-line holographic microscope (DIHM) platform to be used with image processing and classification algorithms to provide a low cost, portable and automated microscope. Initial results show that the images obtained using the DIHM platform are similar to those obtained using a conventional bright field microscope. Applications of this work are targeted towards the implementation of a full blood count, which could provide resource-limited areas with improved healthcare facilities and diagnosis times.

2012

Abstract Within the last few years, cellphone subscriptions have widely spread and now cover even the remotest parts of the planet. Adequate access to healthcare, however, is not widely available, especially in developing countries. We propose a new approach to converting cellphones into low-cost scientific devices for microscopy. Cellphone microscopes have the potential to revolutionize health-related screening and analysis for a variety of applications, including blood and water tests.

2008

We report the development of a simple commercial digital holographic microscope. The hologram is recorded using a CCD sensor and numerically reconstructed to provide quantitative analysis of the object. The laser source is coupled via fibre optics and the opto-mechanical setup is flexible and customizable for either the reflection or transmission mode. The user-friendly software allows live reconstruction, simultaneously providing both the amplitude and phase images. System performance is improved with phase unwrapping and interferometric comparison. Additional features include various image enhancements, cross-sectional and line profiling, measurement and data analysis tools for quantitative 3D imaging and surface topography measurement. The performance of the product is tested on different micro devices, glass and silicon surfaces.

Lecture Notes in Networks and Systems

Mobile microscopy is a newly formed field that emerged from a combination of optical microscopy capabilities and spread, functionality, and everincreasing computing resources of mobile devices. Despite the idea of creating a system that would successfully merge a microscope, numerous computer vision methods, and a mobile device is regularly examined, the resulting implementations still require the presence of a qualified operator to control specimen digitization. In this paper, we address the task of surpassing this constraint and present a "smart" mobile microscope concept aimed at automatic digitization of the most valuable visual information about the specimen. We perform this through combining automated microscope setup control and classic techniques such as autofocusing, in-focus filtering, and focus-stacking-adapted and optimized as parts of a mobile cross-platform library.

PLoS ONE, 2009

Light microscopy provides a simple, cost-effective, and vital method for the diagnosis and screening of hematologic and infectious diseases. In many regions of the world, however, the required equipment is either unavailable or insufficiently portable, and operators may not possess adequate training to make full use of the images obtained. Counterintuitively, these same regions are often well served by mobile phone networks, suggesting the possibility of leveraging portable, camera-enabled mobile phones for diagnostic imaging and telemedicine. Toward this end we have built a mobile phonemounted light microscope and demonstrated its potential for clinical use by imaging P. falciparum-infected and sickle red blood cells in brightfield and M. tuberculosis-infected sputum samples in fluorescence with LED excitation. In all cases resolution exceeded that necessary to detect blood cell and microorganism morphology, and with the tuberculosis samples we took further advantage of the digitized images to demonstrate automated bacillus counting via image analysis software. We expect such a telemedicine system for global healthcare via mobile phone -offering inexpensive brightfield and fluorescence microscopy integrated with automated image analysis -to provide an important tool for disease diagnosis and screening, particularly in the developing world and rural areas where laboratory facilities are scarce but mobile phone infrastructure is extensive.

SPIE Newsroom, 2007

The use of digital optics to compensate for aberrations simplifies the digital holographic microscope while increasing the accuracy and resolution of full-field phase measurements.

Applied Optics, 2008

Digital holographic microscopy enables a quantitative phase contrast metrology that is suitable for the investigation of reflective surfaces as well as for the marker-free analysis of living cells. The digital holographic feature of (subsequent) numerical focus adjustment makes possible applications for multifocus imaging. An overview of digital holographic microscopy methods is described. Applications of digital holographic microscopy are demonstrated by results obtained from livings cells and engineered surfaces.

Optics in the Life Sciences, 2011

In this paper we report the development of two attachments to a commercial cell phone that transform the phone's integrated lens and image sensor into a 3506 microscope and visible-light spectrometer. The microscope is capable of transmission and polarized microscopy modes and is shown to have 1.5 micron resolution and a usable field-of-view of *1506150 mm with no image processing, and approximately 3506350 mm when post-processing is applied. The spectrometer has a 300 nm bandwidth with a limiting spectral resolution of close to 5 nm. We show applications of the devices to medically relevant problems. In the case of the microscope, we image both stained and unstained blood-smears showing the ability to acquire images of similar quality to commercial microscope platforms, thus allowing diagnosis of clinical pathologies. With the spectrometer we demonstrate acquisition of a white-light transmission spectrum through diffuse tissue as well as the acquisition of a fluorescence spectrum. We also envision the devices to have immediate relevance in the educational field.

Analytical Cellular Pathology, 2012

The recent revolution in digital technologies and information processing methods present important opportunities to transform the way optical imaging is performed, particularly toward improving the throughput of microscopes while at the same time reducing their relative cost and complexity. Lensfree computational microscopy is rapidly emerging toward this end, and by discarding lenses and other bulky optical components of conventional imaging systems, and relying on digital computation instead, it can achieve both reflection and transmission mode microscopy over a large field-of-view within compact, cost-effective and mechanically robust architectures. Such high throughput and miniaturized imaging devices can provide a complementary toolset for telemedicine applications and point-of-care diagnostics by facilitating complex and critical tasks such as cytometry and microscopic analysis of e.g., blood smears, Pap tests and tissue samples. In this article, the basics of these lensfree m...

PROCEEDINGS OF THE III INTERNATIONAL CONFERENCE ON ADVANCED TECHNOLOGIES IN MATERIALS SCIENCE, MECHANICAL AND AUTOMATION ENGINEERING: MIP: Engineering-III – 2021, 2021

One of the most widely used biological and medical instruments are the microscopes. Many new modalities have been developed by constant advancement in the field of microscopy, but their relative sizes and their complexity, and their costs often hinder the usefulness of these instruments in the wider general community and many field environments. In this research, we used a 3D printer and the smartphone camera to design and construct a microscopic prototype to create a relatively low-cost, solid structure and to get pictures that are economically viable and are necessary for recording, analysis, education, and publication to acquire and distribute digital photomicrographs. The two-dimensional program, computer-aided design (Auto CAD) and the three-dimensional program (3D MAX) for 3D printed parts have been used to model and print the necessary components for the microscope prototype. The optical elements include a smartphone camera, an eyepiece, and an objective lens. The use of a traditional eyepiece facilitates device two-way compatibility of smartphones and software with a conventional microscope. The prototype microscope examined several specimens of animal tissue such as skin, follicle hair, and connective tissue. The photos were really accurate, clear, and magnified enough to see the tiny details of the biological cells and tissues. The resulting magnification was comparable to 10x of conventional microscope.

Imaging & Microscopy, 2006

Digital Holographic Microscopes (DHM) enables strictly noninvasive visualisation of unstained transparent and partially reflective specimens, in real time, by providing simultaneously amplitude and phase changes of a light wave transmitted or reflected. They are used for characterisation of samples at the nanometer scale, for quality control on production line, and for dynamical analysis of biological specimen and micro systems. more than 15 reconstructions per second for 512 x 512 pixels holograms with a standard personal computer.

Ingeniería y Competitividad, 2017

The principles and some applications of the digital lensless holographic microscopy (DLHM) to study the microworld are shown in this paper. The recording and reconstruction processes of the DLHM are analyzed to study its lateral resolution power. The effect of the spatial coherence in the study of a section of the head of a Drosophila melanogaster fly are presented. DLHM is applied to study dwynamic and static colloidal systems as a proof of the capability of achieving micrometer spatial lateral resolution without the use of lenses

Lab on a Chip, 2009

We present a lensfree digital microscopy platform implemented on a cell-phone. It operates based on digital in-line holography and provides a compact and lightweight alternative to conventional microscopes, such that the cell-phone is modified with an inexpensive attachment weighing only ~38 grams. This lensfree cell-phone microscope captures holographic images of the objects which are then rapidly processed by a custom-developed reconstruction algorithm to provide microscopic images of the sample. This mechanically-robust cellphone microscope achieves a numerical aperture of ~0.1-0.2 over an imaging field-of-view (FOV) of ~24 mm 2 and may provide a cost-effective and field-portable diagnostics tool for telemedicine applications.

Optical microscopy is reached a new level in terms of resolution, 3-D imaging capability, flexibility of imaging different samples which increase imaging complexity and the cost.. Though established labs can afford high-end microscopes, it remains a concern in rural areas where clinics and patients cannot afford much. Semi-portable microscopy based on inline holographic setup is demonstrated where depth information as 3rd dimension can also be accessed. This setup contains only light emitting diode (LED), pinhole and charge coupled device (CCD) camera. Since laser source gives rise to speckle noise and it is also cost constraint for developing a low cost microscopy, thus it is replaced with incoherent LED source. This setup is also known as 'lensless holography' because there is no use of lens for imaging. In conventional inline holographic setup the sample is placed closed to the pinhole which will restrict field of view (FOV) and diffraction signature of one particle (cell) will overlap with other. To avoid overlap of diffraction signatures and to increase FOV sample was placed close to CCD sensor. To test the working of microscopy agarose microbeads were used. Optimization algorithm is used for reconstruction of object field from recorded hologram.. Thus both amplitude as well as the phase images of the microbeads is reconstructed. Instead of using microscopic objective to focus sample, autofocus algorithm is used to calculate the focused plane.

PLOS ONE

Miniaturized imaging devices have pushed the boundaries of point-of-care imaging, but existing mobile-phone-based imaging systems do not exploit the full potential of smart phones. This work demonstrates the use of simple imaging configurations to deliver superior image quality and the ability to handle a wide range of biological samples. Results presented in this work are from analysis of fluorescent beads under fluorescence imaging, as well as helminth eggs and freshwater mussel larvae under white light imaging. To demonstrate versatility of the systems, real time analysis and post-processing results of the sample count and sample size are presented in both still images and videos of flowing samples.