Mobile Phone Based Clinical Microscopy for Global Health Applications

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 phone-mounted 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

A Smartphone-Based Tool for Rapid, Portable, and Automated Wide-Field Retinal Imaging.

Purpose:High-quality, wide-field retinal imaging is a valuable method for screening preventable, vision-threatening diseases of the retina. Smartphone-based retinal cameras hold promise for increasing access to retinal imaging, but variable image quality and restricted field of view can limit their utility. We developed and clinically tested a smartphone-based system that addresses these challenges with automation-assisted imaging. Methods:The system was designed to improve smartphone retinal imaging by combining automated fixation guidance, photomontage, and multicolored illumination with optimized optics, user-tested ergonomics, and touch-screen interface. System performance was evaluated from images of ophthalmic patients taken by nonophthalmic personnel. Two masked ophthalmologists evaluated images for abnormalities and disease severity. Results:The system automatically generated 100° retinal photomontages from five overlapping images in under 1 minute at full resolution (52.3 pixels per retinal degree) fully on-phone, revealing numerous retinal abnormalities. Feasibility of the system for diabetic retinopathy (DR) screening using the retinal photomontages was performed in 71 diabetics by masked graders. DR grade matched perfectly with dilated clinical examination in 55.1% of eyes and within 1 severity level for 85.2% of eyes. For referral-warranted DR, average sensitivity was 93.3% and specificity 56.8%. Conclusions:Automation-assisted imaging produced high-quality, wide-field retinal images that demonstrate the potential of smartphone-based retinal cameras to be used for retinal disease screening. Translational Relevance:Enhancement of smartphone-based retinal imaging through automation and software intelligence holds great promise for increasing the accessibility of retinal screening

Tattoo-associated lacrimal gland enlargement and sarcoidosis

Purpose: To describe a case of tattoo-associated sarcoidosis presenting with cutaneous findings of tattoo granulomas and ophthalmic manifestation of isolated bilateral lacrimal gland enlargement. Observations: A 35-year-old female presented with bilateral upper eyelid swelling for over a year. She reported no associated episodes of ocular pain or visual decline since onset of eyelid edema. On examination, the lacrimal glands were firm and enlarged bilaterally. Slit-lamp examination demonstrated no evidence of active or prior ocular inflammation. Further systemic examination revealed multiple raised papules within a 4-year-old chest/shoulder tattoo. Histopathology from a lacrimal gland biopsy showed non-caseating granulomas consistent with sarcoidosis. Conclusions and importance: The authors report a rare case of a 35-year-old presenting with isolated dacryoadenitis and tattoo granulomas found to be a tattoo-associated sarcoidosis. Although uveitis is a commonly described ocular manifestation in tattoo-associated sarcoidosis, few reports have described lacrimal gland enlargement as a presenting ophthalmic feature in tattoo-associated sarcoidosis

Fluorescence mobile phone microscopy images of tuberculosis in sputum.

<p>(a) Fluorescence image of Auramine O-stained TB sputum sample. (b) Enlarged view of two tuberculosis bacilli from red-outlined area in (a). (c) Automated counting of fluorescently-labeled tuberculosis bacilli; counted bacilli are numbered and set to red in the image. Scale bars in (a) and (c) are 10 µm, scale bar in (b) is 1 µm.</p

Mobile phone microscopy images of diseased blood smears.

<p>(a) Thick smear of Giemsa-stained malaria-infected blood. (b) Thin smear of Giemsa-stained malaria-infected blood. (c) Sickle-cell anaemia blood smear. White arrows point to two sickled red blood cells. Scale bars are 10 µm.</p

Mobile phone microscopy layout schematic, prototype, and sample images.

<p>(a) Mobile phone microscopy optical layout for fluorescence imaging. The same apparatus was used for brightfield imaging, with the filters and LED removed. Components only required for fluorescence imaging are indicated by “fluo.” Not to scale. (b) A current prototype, with filters and LED installed, capable of fluorescence imaging. The objective is not visible because it is contained within the optical tubing, and the sample is mounted adjacent to the metallic focusing knob. (c) Brightfield image of 6 µm fluorescent beads. (d) Fluorescent images of beads shown in (c). The field-of-view projected onto the camera phone CMOS is outlined. Scales bars are 10 µm.</p

Smartphone-based Anterior Segment Imaging: A Comparative Diagnostic Accuracy Study of a Potential Tool for Blindness Prevalence Surveys.

PURPOSE: To determine if smartphone photography could be a useful adjunct to blindness prevalence surveys by providing an accurate diagnosis of corneal opacity. METHODS: A total of 174 patients with infectious keratitis who had undergone corneal culturing over the past 5&nbsp;years were enrolled in a diagnostic accuracy study at an eye hospital in South India. Both eyes had an ophthalmologist-performed slit lamp examination, followed by anterior segment photography with a handheld digital single lens reflex (SLR) camera and a smartphone camera coupled to an external attachment that provided magnification and illumination. The diagnostic accuracy of photography was assessed relative to slit lamp examination. RESULTS: In total, 90 of 174 enrolled participants had a corneal opacity in the cultured eye and no opacity in the contralateral eye, and did not have a penetrating keratoplasty or missing photographs. Relative to slit lamp examination, the sensitivity of corneal opacity diagnosis was 68% (95%CI 58-77%) using the smartphones default settings and 59% (95%CI 49-69%) using the SLR, and the specificity was 97% (95%CI 93-100%) for the smartphone and 97% (95%CI 92-100%) for the SLR. The sensitivity of smartphone-based corneal opacity diagnosis was higher for larger scars (81% for opacities 2 mm in diameter or larger), more visually significant scars (100% for eyes with visual acuity worse than 20/400), and more recent scars (85% for eyes cultured in the past 12&nbsp;months). CONCLUSION: The diagnostic performance of a smartphone coupled to an external attachment, while somewhat variable, demonstrated high specificity and high sensitivity for all but the smallest opacities