Skin patch technologies could enable clinical laboratories to monitor patients’ vitals and report to medical professionals in real time
Pathologists and clinical laboratory leaders have read many Dark Daily ebriefings on the development of skin patches over the years that do everything from monitoring fatigue in the military to being a complete lab-on-skin technology. Now, researchers at the University of California San Diego (UCSD) have developed a wearable patch that can monitor cardiovascular signals and other various biochemical levels in the body simultaneously.
The researchers believe there is enormous potential for such a patch in helping patients monitor conditions such as hypertension or diabetes. They also foresee a scenario where the patch could be used in settings where vitals must be constantly monitored. They hope to develop future versions of the patch that can detect more biomarkers within the body.
“This type of wearable would be very helpful for people with underlying medical conditions to monitor their own health on a regular basis,” Lu Yin, a PhD student and co-first author of the study, told New Atlas. “It would also serve as a great tool for remote patient monitoring, especially during the COVID-19 pandemic when people are minimizing in-person visits to the clinic,” she added.
Combining Precision Medicine with Telehealth and the Internet of Things
About the size of a postage stamp and consisting of stretchy polymers that conform to the skin, the UCSD patch monitors blood pressure and contains sensors that measure different biochemical levels in the body, such as:
The sensors are carefully arranged on the patch to eliminate interference between the signals, noted a UCSD press release.
In their published research, the UCSD researchers wrote of their new skin patch monitoring device, “Intertwined with concepts of telehealth, the internet of medical things, and precision medicine, wearable sensors offer features to actively and remotely monitor physiological parameters. Wearable sensors can generate data continuously without causing any discomfort or interruptions to daily activity, thus enhancing the self-monitoring compliance of the wearer, and improving the quality of patient care.” (Photo copyright: University of California San Diego.)
“Each sensor provides a separate picture of a physical or chemical change. Integrating them all in one wearable patch allows us to stitch those different pictures together to get a more comprehensive overview of what’s going on in our bodies,” said Sheng Xu, PhD, Principle Investigator, Xu Research Group at UCSD, Assistant Professor in the Department of NanoEngineering Department, and a co-first author of the study, in the press release.
The UCSD researchers developed their skin patch to monitor specific biomarkers that can affect blood pressure.
“Let’s say you are monitoring your blood pressure and you see spikes during the day and think that something is wrong,” co-first author Juliane Sempionatto, PhD, a postdoctoral researcher at California Institute of Technology (Caltech) and co-first author of the study, told New Atlas. “But a biomarker reading could tell you if those spikes were due to an intake of alcohol or caffeine. This combination of sensors can give you that type of information,” she added.
The blood pressure sensor sits near the center of the patch and consists of a set of small transducers welded to the patch via a conductive link. Voltage applied to the transducers send ultrasound waves through the body which bounce off arteries and create echoes that are detected by the sensor and converted into an accurate blood pressure reading.
The chemical sensor releases the drug pilocarpine into the skin to induce sweat and then measures the chemicals contained in the sweat to provide readings of certain biochemical levels.
The glucose sensor located in the patch emits a mild electrical current to the body that stimulates the release of interstitial fluid and then reads the glucose level in that fluid.
“The novelty here is that we take completely different sensors and merge them together on a single small platform as small as a stamp,” Joseph Wang, D.Sc, SAIC Endowed Chair, Distinguished Professor of NanoEngineering, Director of the Center for Wearable Sensors at UCSD, and co-author of the study told New Atlas. “We can collect so much information with this one wearable and do so in a non-invasive way, without causing discomfort or interruptions to daily activity.” (Photo copyright: University of Southern California San Diego.)
Skin Patch Measurements Closely Match Those of Traditional Devices
Test subjects wore the patch on their neck while performing various combinations of the following tasks:
exercising on a stationary bicycle,
eating a high-sugar meal,
drinking an alcoholic beverage, and
drinking a caffeinated beverage.
The results of the measurements taken from the patch closely matched measurements collected by traditional monitoring devices such as a:
For now, the patch must be connected to an external power source which transmits the reading to a counter-top machine, but the researchers hope to create a wireless version in the future.
“There are opportunities to monitor other biomarkers associated with various diseases,” Sempionatto said in the UCSD press release. “We are looking to add more clinical value to this device.”
Other Similar Skin Patch Monitoring Technologies
Though an important breakthrough, the UCSD’s device is not the first skin patch monitor to be developed.
Multiple research and clinical studies are underway that hope to prove the accuracy and safety of wearable devices at detecting and monitoring certain health conditions. It’s a worthy goal.
Skin patches, such as the one created at UCSD, could enable clinical laboratories to provide value-added service to medical professionals and patients alike. Medical labs could potentially monitor skin patch readings in real-time and notify physicians and patients of changes in biomarkers that require attention.
Further, as this technology is developed, it will likely find a ready market with the latest generation of consumers who are more willing than previous generations to buy their own diagnostic tests for home use. These “next-generation” healthcare consumers have demonstrated their willingness to use Apple watches, Fitbits, and similar wearable devices to monitor their condition during exercise and other health metrics.
Pathologists and clinical laboratory managers should not overlook the potential for robust consumer demand to accelerate development and market adoption of such skin patches.
Painless technology could one day replace some phlebotomy blood draws as the go-to specimen-collection method for clinical laboratory testing and health monitoring
Clinical laboratories have long sought a non-invasive way to do useful medical laboratory testing without the need for either a venipuncture or a needle stick. Now engineers at the McKelvey School of Engineering at Washington University in St. Louis in Missouri have developed a disposable microneedle patch that one day could be a painless alternative to some blood draws for diagnostics tests and health monitoring.
The technology uses an easy-to-administer low-cost patch that can be applied to the skin like an adhesive bandage. The patch is virtually painless because the microneedles are too small to reach nerve receptors. Another unique aspect to this innovative approach to collecting a specimen for diagnostic testing is that the Washington University in St. Louis (WashU) research team designed the microneedle patch to include plasmonic-fluor. These are ultrabright gold nanolabels that light up target protein biomarkers and can make the biomarkers up to 1,400 times brighter at low concentrations, compared to traditional fluorescent labels.
The patch, states a WashU news release, “… can be applied to the skin, capture a biomarker of interest and, thanks to its unprecedented sensitivity, allow clinicians to detect its presence.”
The technology is low cost, easy for clinicians or patients themselves to use, and could eliminate the need for a trip to patient service center where a phlebotomist would draw blood for clinical laboratory testing, the news release states.
“We have created a platform technology that anyone can use. And they can use it to find their own biomarker of interest,” study leader Srikanth Singamaneni, PhD (above), Lilyan and E. Lisle Hughes Professor in the Department of Mechanical Engineering and Materials Sciences at Washington University in St. Louis, said in the WashU news release. Singamaneni and his colleagues are developing a new specimen collection method that might someday be widely used by clinical laboratories. (Photo copyright: Washington University in St. Louis.)
“We used the microneedle patch in mice for minimally invasive evaluation of the efficiency of a cocaine vaccine, for longitudinal monitoring of the levels of inflammatory biomarkers, and for efficient sampling of the calvarial periosteum [a skull membrane]—a challenging site for biomarker detection—and the quantification of its levels of the matricellular protein periostin, which cannot be accurately inferred from blood or other systemic biofluids,” the researchers wrote. “Microneedle patches for the minimally invasive collection and analysis of biomarkers in interstitial fluid might facilitate point-of-care diagnostics and longitudinal monitoring.”
Mark Prausnitz, PhD, Regents’ Professor, J. Erskine Love Jr. Chair in Chemical and Biomolecular Engineering, and Director of the Center for Drug Design, Development, and Delivery at Georgia Tech, told WIRED, “Blood is a tiny fraction of the fluid in our body. Other fluids should have something useful—it’s just hard to get those fluids.”
“Previously, concentrations of a biomarker had to be on the order of a few micrograms per milliliter of fluid,” said Zheyu (Ryan) Wang, a PhD candidate in Srikanth Singamaneni’s lab at McKelvey School of Engineering and a lead author of the paper, in the WashU news release. By using plasmonic-fluor, researchers were able to detect biomarkers on the order of picograms per milliliter—one millionth of the concentration.
“That’s orders of magnitude more sensitive,” Wang said.
Unlike blood, dermal interstitial fluid often does not contain high enough concentrations of biomarkers to be easily detectable. To overcome this hurdle, the Washington University in St. Louis research team developed a microneedle patch with plasmonic-fluor—ultrabright gold nanolabels (above)—which lit up target protein biomarkers, making them roughly 1,400 times brighter at low concentrations than when using traditional fluorescent labels commonly used in many medical laboratory tests. (Photo copyright: Washington University in St. Louis.)
Can Microneedles Be Used as a Diagnostic Tool?
As reported in WIRED, the polystyrene patch developed by Srikanth Singamaneni’s lab at McKelvey School of Engineering removes interstitial fluid from the skin and turns the needles into “biomarker traps” by coating them with antibodies known to bind to specific proteins, such as Interleukin 6 (IL-6). Once the microneedles are mixed with plasmonic-fluor, the patch will glow if the IL-6 biomarkers are present.
The development of such a highly sensitive biomarker-detection method means skin becomes a potential pathway for using microneedles to diagnose conditions, such as myocardial infarction or to measure COVID-19 antibodies in vaccinated persons.
“Now we can actually use this tool to understand what’s going on with interstitial fluid, and how we’re going to be able to use it to answer healthcare-related or medical problems,” Maral Mousavi, PhD, Assistant Professor of Biomedical Engineering, Viterbi School of Engineering at the University of Southern California, told WIRED. “I think it has the potential to be that kind of a game changer.”
Because the WashU study is a proof-of-concept in mice, it may be many years before this technology finds its way to clinical application. Many skin biomarkers will need to be verified for direct links to disease before microneedle patches will be of practical use to clinicians for diagnostics. However, microneedle patch technology has already proven viable for the collection of blood.
In 2017, Massachusetts-based Seventh Sense Biosystems (7SBio) received 510(k) clearance for a new microneedle blood collection device. Called TAP, the device is placed on the upper arm and blood collection starts with a press of a button. The process takes two to three minutes.
Initially, the FDA clearance permitted only healthcare workers to use the device “to collect capillary blood for hemoglobin A1c (HbA1c) testing, which is routinely used to monitor blood sugar levels in diabetic or pre-diabetic patients,” a Flagship Pioneering news release noted.
Then, in 2019, the FDA extended its authorization “to include blood collection by laypersons. Regulators are also allowing the device to be used ‘at-home’ for wellness testing,” a 7SBio news release stated. This opened the door for a microneedle device to be used for home care blood collection.
“No one likes getting blood drawn, but blood is the single-most important source of medical information in healthcare today, with about 90% of all diagnostic information coming from blood and its components,” Howard Weisman, former CEO of 7SBio and current CEO of PaxMedica, a clinical-stage biopharmaceutical company, said in the Flagship Pioneering news release. “TAP has the potential to transform blood collection from an inconvenient, stressful, and painful experience to one people can do themselves anywhere, making health monitoring much easier for both healthcare professionals and patients.”
As microneedle technology continues to evolve, clinical laboratories should expect patches to be used in a growing number of drug delivery systems and diagnostic tests. But further research will be needed to determine whether interstitial fluid can provide an alternate pathway for diagnosing disease.
Similar health monitoring devices have been popular with chronic disease patients and physicians who treat them; this technology may give clinical laboratories a new diagnostic tool
There is an ever-increasing number of companies working to develop lab testing technologies that would be used outside of the traditional clinical laboratory. One such example is Nutromics, an Australia-based medical technology company which recently announced it has raised US $14 million to fund its new lab-on-a-patch platform, according to a company press release.
Nutromics’ lab-on-a-patch device “uses DNA sensor technology to track multiple targets in the human body, including disease biomarkers and hard-to-dose drugs,” according to MobiHealthNews. Notably, Nutromics’ technology uses interstitial fluid as the sample source.
Nutromics raised $4 million last year to support a manufacturing facility and an initial human clinical trial of its “continuous molecular monitoring (CMM) platform technology that is able to track multiple targets in the human body via a single wearable sensor. The platform provides real-time, continuous molecular-level insights for remote patient monitoring and hospital-at-home systems,” MobiHealthNews reported.
“We are aiming to cause a paradigm shift in diagnostic healthcare by essentially developing a lab-on-a-patch. A lack of timely and continuous diagnostic insights can strongly impact outcomes when dealing with critical disease states. With this strategic industry and VC (venture capital) investment in us, we see more confidence in our technology and hope to accelerate our growth,” said entrepreneur and chemical engineer Peter Vranes (above), co-founder and CEO of Nutromics, in a press release. Clinical laboratory leaders have watched similar biometric monitoring devices come to fruition. (Photo copyright: Nutromics.)
.
How Nutromics’ Lab-on-a-Patch Works
“Our technology is, in fact, two technologies coming together—a marker and needle. What that does is give us access to fluid under your skin called interstitial fluid. If you’re going to measure something continuously, that’s a really good fluid [to measure],” Vranes told Outcomes Rocket.
Vranes calls the system’s aptamer-based sensor platform technology the “jewel in the crown.” An aptamer is a short sequence of artificial DNA or RNA that binds a specific target molecule. Nutromics’ aptamer sensor, Vranes said, enables targeting of analytes, unlike continuous glucose monitors (CGMs).
“[CGMs] are limited to metabolites—things that are already in the body like glucose and lactate. We’re not limited to those. We can do a whole range of different targets. And what that gives us is a ‘blue ocean’ opportunity to go in and solve problems in areas that other technologies just can’t solve,” Vranes said.
Nutromics plans to develop multiple aptamer-based sensors that measure a variety of analytes in interstitial fluid, Medtech Insight noted.
Nutromics’ wearable DNA sensor lab-on-a-patch technology (above) enables monitoring of multiple targets, including disease biomarkers and some medications, MobiHealthNews explained. The wearable patch contains microneedles that painlessly access interstitial fluid under the skin. Collected data is wirelessly transmitted to a software application and integrates with consumer health software and provider platforms, according to Nutromics. Medical laboratories could have a role in collecting this data and adding it other test results from patients using the wearable patch. (Photo copyright: Nutromics.)
Initial Launch Will Include Antibiotic Monitoring
Nutromics expects to initially launch therapeutic monitoring of vancomycin, a glycopeptide antibiotic medication used to treat various bacterial infections. The company says 60% of doses for this prescription antibiotic are not within therapeutic range.
“Interstitial fluid originates in the blood and then leaks out of capillaries to bring nutrients to cells in the body’s tissues. Because interstitial fluid is in direct communication with the cells, it should have information about the tissues themselves beyond what can be measured from testing the blood,” said Mark Prausnitz, PhD, Regents Professor and J. Erskine Love Jr. Chair, Georgia Tech School of Chemical and Biomolecular Engineering, in a 2020 news release announcing results of human trials of microneedle-based ISF sampling.
“We sampled interstitial fluid from 21 human participants and identified clinically relevant and sometimes distinct biomarkers in interstitial fluid when compared to companion plasma samples based on mass spectrometry analysis,” the scientists wrote.
Clinical laboratory leaders and pathologists will find it useful to monitor the development of diagnostics for use outside the lab. Nutromics is an example of a company developing wearable health technology that painlessly gathers data for lab tests to be conducted in point-of-care and near-patient settings.
Wearable microneedle sensors that track multiple biomarkers in interstitial fluid are finding their way into chronic disease monitoring and sample collecting for clinical laboratory testing
Wearable devices that replace finger sticks and blood draws for monitoring biomarkers of chronic diseases such as diabetes are the holy grail of non-invasive (or at least minimally invasive) technologies that collect specimens for clinical laboratory testing.
Now, in their quest for alternatives to invasive phlebotomy blood draws, engineers at University of California San Diego’s (UCSD) Center for Wearable Sensors have added their own wearable device to the mix. The scientists developed a “lab-on-the-skin” multi-tasking microneedle sensor that monitors multiple biomarkers simultaneously, according to a UCSD news release.
“This is like a complete lab on the skin,” said Joseph Wang, PhD (above), Distinguished Professor of Nanoengineering at UC San Diego and Director of UCSD’s Center of Wearable Sensors, in a news release. “It is capable of continuously measuring multiple biomarkers at the same time, allowing users to monitor their health and wellness as they perform their daily activities.” UC San Diego’s microneedle patch for monitoring biomarkers of disease certainly would be popular with patients who must regularly undergo painful blood draws for clinical laboratory testing. (Photo copyright: UC San Diego.)
Advantage of Monitoring Multiple Biomarkers in Real Time
While current glucose monitors on the market only measure glucose, the UCSD wearable device also monitors alcohol and lactate, providing other additional information to diabetics when engaged in activities that affect those biomarkers.
For example, UCSD’s microneedle sensor allows diabetics to monitor their glucose level when drinking alcohol, which can lower glucose levels. Additionally, monitoring lactate while exercising also could be beneficial since physical activity influences the body’s ability to regulate glucose.
“With our wearable, people can see the interplay between their glucose spikes or dips with their diet, exercise, and drinking of alcoholic beverages. That could add to their quality of life as well,” said Farshad Tehrani, a nanoengineering PhD graduate researcher in Wang’s lab at UCSD and one of the co-first authors of the study, in the news release.
UC San Diego’s wearable microneedle patch (above) is about the size of a stack of six quarters and simultaneously monitors glucose, alcohol, and lactate levels continuously. It affixes to the skin through a patch of microneedles each about one-fifth the width of a human hair. The microneedles barely penetrate the surface of the skin to sample biomolecules in the interstitial fluid and are not painful. The quarter-sized patch is worn on the upper arm and transmits its data to a smartphone app. The microneedle patch is disposable, and the reusable electronic case is rechargeable using an off-the-shelf wireless charging pad. (Photo copyright: Laboratory for Nanobioelectronics/UC San Diego.)
Other Microneedle Wearable Monitoring Patches
The quest for a painless alternative to in-patient blood draws for many clinical laboratory tests has been ongoing worldwide for years.
In “Researchers Develop ‘Smart’ Microneedle Adhesive Bandage System for Monitoring Sodium, Glucose, pH, and More,” Dark Daily reported on a proof-of-concept study conducted by scientists from Israel and China who developed a “smart” microneedle adhesive bandage that measures and monitors in real time three critical biomarkers that currently require invasive blood draws for medical laboratory tests commonly performed on patients in hospitals.
While further research and validation of studies are needed before UC San Diego’s wearable microneedle sensor patch can be deployed to monitor chronic diseases, it is in good company. Diabetics and other suffers of similar chronic diseases can look forward to a future where they can monitor their health conditions in real time without the need for invasive blood draws and clinical laboratory testing.
MIT’s deep learning artificial intelligence algorithm demonstrates how similar new technologies and smartphones can be combined to give dermatologists and dermatopathologists valuable new ways to diagnose skin cancer from digital images
According to an MIT press release, “The paper describes the development of an SPL [Suspicious Pigmented Lesion] analysis system using DCNNs [Deep Convolutional Neural Networks] to more quickly and efficiently identify skin lesions that require more investigation, screenings that can be done during routine primary care visits, or even by the patients themselves. The system utilized DCNNs to optimize the identification and classification of SPLs in wide-field images.”
The MIT scientists believe their AI analysis system could aid dermatologists, dermatopathologists, and clinical laboratories detect melanoma, a deadly form of skin cancer, in its early stages using smartphones at the point-of-care.
“Our research suggests that systems leveraging computer vision and deep neural networks, quantifying such common signs, can achieve comparable accuracy to expert dermatologists,” said Luis Soenksen, PhD (above), Venture Builder in Artificial Intelligence and Healthcare at MIT and first author of the study in an MIT press release. “We hope our research revitalizes the desire to deliver more efficient dermatological screenings in primary care settings to drive adequate referrals.” The MIT study demonstrates that dermatologists, dermatopathologists, and clinical laboratories can benefit from using common technologies like smartphones in the diagnosis of disease. (Photo copyright: Wyss Institute Harvard University.)
Improving Melanoma Treatment and Patient Outcomes
Melanoma develops when pigment-producing cells called melanocytes start to grow out of control. The cancer has traditionally been diagnosed through visual inspection of SPLs by physicians in medical settings. Early-stage identification of SPLs can drastically improve the prognosis for patients and significantly reduce treatment costs. It is common to biopsy many lesions to ensure that every case of melanoma can be diagnosed as early as possible, thus contributing to better patient outcomes.
“Early detection of SPLs can save lives. However, the current capacity of medical systems to provide comprehensive skin screenings at scale are still lacking,” said Luis Soenksen, PhD, Venture Builder in Artificial Intelligence and Healthcare at MIT and first author of the study in the MIT press release.
The researchers trained their AI system by using 20,388 wide-field images from 133 patients at the Gregorio Marañón General University Hospital in Madrid, as well as publicly available images. The collected photographs were taken with a variety of ordinary smartphone cameras that are easily obtainable by consumers.
They taught the deep learning algorithm to examine various features of skin lesions such as size, circularity, and intensity. Dermatologists working with the researchers also visually classified the lesions for comparison.
When the algorithm is “shown” a wide-field image like that above taken with a smartphone, it uses deep convolutional neural networks to analyze individual pigmented lesions and screen for early-stage melanoma. The algorithm then marks suspicious images as either yellow (meaning further inspection should be considered) or red (indicating that further inspection and/or referral to a dermatologist is required). Using this tool, dermatopathologists may be able to diagnose skin cancer and excise it in-office long before it becomes deadly. (Photo copyright: MIT.)
“Our system achieved more than 90.3% sensitivity (95% confidence interval, 90 to 90.6) and 89.9% specificity (89.6 to 90.2%) in distinguishing SPLs from nonsuspicious lesions, skin, and complex backgrounds, avoiding the need for cumbersome individual lesion imaging,” the MIT researchers noted in their Science Translational Medicine paper.
In addition, the algorithm agreed with the consensus of experienced dermatologists 88% of the time and concurred with the opinions of individual dermatologists 86% of the time, Medgadget reported.
Modern Imaging Technologies Will Advance Diagnosis of Disease
According to the American Cancer Society, about 106,110 new cases of melanoma will be diagnosed in the United States in 2021. Approximately 7,180 people are expected to die of the disease this year. Melanoma is less common than other types of skin cancer but more dangerous as it’s more likely to spread to other parts of the body if not detected and treated early.
More research is needed to substantiate the effectiveness and accuracy of this new tool before it could be used in clinical settings. However, the early research looks promising and smartphone camera technology is constantly improving. Higher resolutions would further advance development of this type of diagnostic tool.
In addition, MIT’s algorithm enables in situ examination and possible diagnosis of cancer. Therefore, a smartphone so equipped could enable a dermatologist to diagnose and excise cancerous tissue in a single visit, without the need for biopsies to be sent to a dermatopathologist.
Currently, dermatologists refer a lot of skin biopsies to dermapathologists and anatomic pathology laboratories. An accurate diagnostic tool that uses modern smartphones to characterize suspicious skin lesions could become quite popular with dermatologists and affect the flow of referrals to medical laboratories.
