Tag Archives: smartphone-based diagnostics

Smart Wound Dressing

Smart Wound Dressing Emits Light When Dressing Needs to Come Off

The human skin provides a natural barrier to pathogens and serves as the first line of defense against harmful microbes. When the skin’s integrity is broken via cuts, sores, or other wounds, the site of broken skin potentially becomes an entryway for a systemic infection. Hence, good wound care is crucial from developing sepsis, or widespread infection that can lead to multi-organ failure, particularly in people with chronic diseases, e.g. diabetes, rheumatoid arthritis, or those who are immunocompromised, e.g. receiving chemotherapy, immunotherapy, battling active HIV infection.

Good wound care technique is largely dependent on the specific characteristics of the wound: nature of wound, size, amount of exudate, illness that can exacerbate wound, etc. However, one thing clinicians agree on is that the wound should be kept covered until a temporary barrier, like a scab, forms to prevent infection. Checking on status of wound healing may require frequent dressing changes, which can be detrimental to proper healing. As a result, Swiss scientists collectively from University Hospital Zurich, Centre Suisse d’Electronique et de Microtechnique (CSEM), EMPA, and ETH Zurich developed a type of smart wound dressing called Flusitex—short for fluorescence sensing integrated into medical textiles.

Flusitex works by monitoring the pH (acidity or alkalinity) of the wound. When normal healing is progressing well, pH jumps to 8 before resting around 5 or 6. If the wound’s healing trajectory deviates from standard healing protocols, or the wound becomes chronic, pH may oscillate between 7 and 8. Integrated into the smart wound dressing are pyranine and benzalkonium chloride molecules. Pyranine is a pH-sensitive fluorescent dye, which enable the dressing to fluoresce when a UV light is shined on the bandage at an internal pH of 7.5—an indication the chronic wound is on the verge of healing—which alerts clinicians to leave the dressing alone. Benzalkonium chloride, an antiseptic, is particularly known for killing Staphylococus aureas bacteria, which are commensal on the human skin and may cause opportunistic infections if allowed to enter the wound bed.

To make Flusitex more accessible and user-friendly, scientists are exploring ways to allow an app and camera from a smartphone to interpret fluorescing pH changes on the smart wound dressing so that users can monitor wound healing progress from home.

Rapid HIV Test

Viral Load Can Be Detected with New Rapid HIV Test

Scientists at Imperial College London, together with DNA Electronics, have developed a rapid HIV test using a USB drive that can detect HIV viral load in 20 minutes. Only a drop of blood is needed for the USB stick—similar to diabetics checking glucose levels with a fingerstick—which is then inserted into a desktop or portable notebook, where it communicates with an app, feeding data to the software, and the user can read the results in less than 30 minutes. The viral load, if any, is detected through the presence of the virus genetic material, RNA; if present, amount is also indicated in the results. Using blood samples of 991 participants, results were 95 percent accurate compared with the traditional method, which takes at least a couple of days to process results.

According to the World Health Organization (WHO), approximately 37 million people worldwide are living with HIV/AIDS, of which 2 million are children. Majority of the population infected with the virus reside in sub-Saharan Africa. Moreover, 18.2 million are on antiretroviral therapy (ART) to keep viral count down. With the rapid HIV test, HIV levels can be easily tracked at home for ART recipients to determine medication efficacy. If drug resistance occurs, regular home monitoring can detect it sooner than later and a new treatment regimen can be implemented. Also, in developing regions where access to technology is limited, the USB stick technique can easily test for HIV using a portable device, and implement treatment to help staunch transmission, as in the case of mother to child via birth or breastfeeding.

The rapid HIV test using a USB drive with a litmus medium that detects change in pH as evidence of RNA material of the virus is still in its beginning phase and will be a long time before we see it used in homes. However, scientists have high hopes for its use and are concomitantly developing the device to detect hepatitis virus as well.

Smartphone Microscope

Identifying Parasitic Worms Made Easy with New Smartphone Microscope

According to the World Health Organization (WHO), 1.5 billion people, or 24 percent of the world’s population, sustain infections caused by parasitic worms, in which sub-Saharan Africa is known to be affected the greatest with river blindness and lymphatic filariasis. Both are testable and treatable with medications as long as the patient is also not infected with the Loa loa worm, in which the medication can cause death. To prevent such complications, scientists at University of California Berkeley have developed CellScope Loa, a smartphone microscope that detects the presence of Loa parasites within two minutes with a drop of blood.

CellScope Loa consists of a 3D-printed plastic base, where the smartphone slides in, and outfitted with LED lights, USB port, gears, and microcontrollers, with a Bluetooth-enabled controller board. Using Bluetooth as the interface, an app designed for the smartphone microscope channels the base and creates a video as the blood sample is analyzed in front of the phone’s camera. An algorithm then sorts through the video footage, detects the parasites, and displays the worm count on the screen.

River blindness is transmitted by the bites of blackflies and caused blindness in 50 percent of the afflicted males in West Africa, according to the WHO. Lymphatic filariasis is spread by mosquitoes and causes a disease called elephantiasis which is characterized by massive swelling of the arms, legs, and genitals. An antiparasitic drug called ivermectin is effective in treating both conditions but only when a large Loa count is absent. Otherwise, the medication can cause severe or fatal brain damage.

Traditional method of detecting Loa worms in the bloodstream is to transport the sample back to a laboratory and manually count the worms under a microscope. With CellScope Loa, the need to transport and set the sample into a smear is ruled out, saving time and resources.

A trial run of CellScope Loa was performed in Cameroon, and the accuracy of detecting parasitic worms through the smartphone microscope was equivalent to that of traditional methods.

Smartphone Plug-In Accessory

Smartphone Plug-In Accessory Aims to Diagnose HIV and Syphilis in 15 Minutes

A team of researchers from Columbia University have developed a smartphone plug-in accessory to identify HIV and syphilis markers in 15 minutes with a drop of finger-prick blood, reducing the cost of the conventional-run test from an upwards of $18,000 to $34.

Typically, such tests are performed by means of a biochemical process called enzyme-linked immunosorbent assay (ELISA), which utilizes expensive equipment and test results may not be available up to a few weeks. The smartphone accessory can pick up HIV antibodies and both treponemal-specific antibodies for syphilis and non-treponemal antibodies for an active syphilis infection in 15 minutes. Using the audio jack as its power source and a method to transmit data, the device consists of microfluidic disposable cassettes that contain reagents to detect the three antibodies from a drop of blood. Employing the physical principle of vacuum pressure, a thumb is pressed down to initiate the negative-pressure activated sequence that floods the test chamber with test reagents from a prefilled cassette.

A field test was implemented in Rwanda among 96 subjects, of which 97 percent recommended the test due to its speedy performance, simple test procedure, and the dongle’s ability to test for multiple diseases. The scientists noted the test’s tendency to procure false-positive results and recognize the need to fine-tune the method.

In developing and underdeveloped nations, the smartphone plug-in accessory can prove to be a boon in identifying HIV and syphilis infections in pregnant women since they can be transmitted to fetuses. Early detection is key to prevent permanent harm to the unborn child. The appeal of such a contraption is potentially high even in developed nations like the United States where the escalating cost of health care has no ceiling.