A Comparison of a Novel Stretchable Smart Patch for Measuring Runner's Step Rates with Existing Measuring Technologies.

A novel wearable smart patch can monitor various aspects of physical activity, including the dynamics of running, but like any new device developed for such applications, it must first be tested for validity. Here, we compare the step rate while running in place as measured by this smart patch to the corresponding values obtained utilizing ''gold standard'' MEMS accelerometers in combination with bilateral force plates equipped with HBM load cells, as well as the values provided by a three-dimensional motion capture system and the Garmin Dynamics Running Pod. The 15 healthy, physically active volunteers (age = 23 ± 3 years; body mass = 74 ± 17 kg, height = 176 ± 10 cm) completed three consecutive 20-s bouts of running in place, starting at low, followed by medium, and finally at high intensity, all self-chosen. Our major findings are that the rates of running in place provided by all four systems were valid, with the notable exception of the fast step rate as measured by the Garmin Running Pod. The lowest mean bias and LoA for these measurements at all rates were associated consistently with the smart patch.

Cloth-based microfluidic devices integrated onto the patch as wearable colorimetric sensors for simultaneous sweat analysis.

Introduction: In this work, a flexible, and wearable point-of-care (POC) device integrated on a pain relief patch as wearable colorimetric sensors have been developed for sweat analysis, such as lactic acid, sodium ions, and pH simultaneously. Herein, the patch has still functioned as pain relief, while it allows for sweat monitoring during exercise, and in daily activities. Methods: It was constructed on cotton cloth using wax printing technology (batik stamp) as cloth-based microfluidic devices (CMDs). Here, it uses micro volumes of samples to perform the reaction in the sensing zones, where the sensitive reagents are immobilized so that it can collect and analyze the sweat (lactic acid, sodium ions, and pH) as the model for sweat analytes. The colorimetric analysis was conducted via a smartphone camera by using a free app (Color Grab) for a color image analysis that uses for quantitative analysis or naked eye for semi-qualitative analysis. Results: The ∆RGB value of the CMDS shows the excellent linear correlation vs analytes concentration, where the coefficient of correlations was found for lactic acid (R2 = 0.994), sodium ion (R2 = 0.998), and pH (R2 = 0.994). The ∆RGB value shows the appropriate color value for the linear correlation of the analyte target concentrations in the sweat samples. Here, the limit of detection (LOD) was found at 45.73 µg/mL for lactic acid and 56.46 µg/mL for sodium ions. The reproducibility was found at 0.79% and 0.89%, for lactic acid and sodium ions respectively. Conclusion: It was applied for sweat analysis during exercise, and the results show in agreement with the standard methods used in a clinical laboratory.

Self-powered smart patch promotes skin nerve regeneration and sensation restoration by delivering biological-electrical signals in program.

Skin wound is always accompanied with nerve destruction. Due to the limited clinical treatment option, loss of skin sensation with unsatisfactory nerve regeneration is remained to be a challenge for wound therapy. Endogenous mesenchymal stem cells (MSCs) based in situ regeneration, of which, MSCs recruited by chemokines and directed for neuronal differentiation by biological and electrical signals have been thought a novel strategy with potential to accelerate the nerve regeneration and sensory functions recovery. However, most current therapeutic systems usually deliver the chemokines, biological and electrical signals separately and statically, resulting in limited nerve regeneration and sensory functions recovery. Moreover, most of the devices for providing electrical signals need external energy input and complicated practice, leading to poor compliance in patients. To address these issues, we propose a self-powered smart patch (PRG-G-C) to provide chemokine and biological-electrical cues in program. PRG-G-C was composed of a flexible piezoelectric generator to supply electrical stimulation and a conductive gel, which served as the reservoir of chemokine and neural directing exosomes as well as the electrode to transfer electric cue. PRG-G-C was shown to efficiently accelerate rapid nerve regeneration and sensation restoration at the wound site within 23 days. This study demonstrates a proof-to-concept in organizing chemokine, neural directing biological-electrical heterogeneous cues within a self-powered smart patch for accelarating nerve regeneration and sensation restoration, possessing great potential in neural repair applications.

Lasered Graphene Microheaters Modified with Phase-Change Composites: New Approach to Smart Patch Drug Delivery.

The combination of paraffin wax and O,O'-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol was used as a phase-change material (PCM) for the controlled delivery of curcumin. The PCM was combined with a graphene-based heater derived from the laser scribing of polyimide film. This assembly provides a new approach to a smart patch through which release can be electronically controlled, allowing repetitive dosing. Rather than relying on passive diffusion, delivery is induced and terminated through the controlled heating of the PCM with transfer only occurring when the PCM transitions from solid to liquid. The material properties of the device and release characteristics of the strategy under repetitive dosing are critically assessed. The delivery yield of curcumin was found to be 3.5 µg (4.5 µg/cm2) per 3 min thermal cycle.

Flexible, Wearable and Fully-printed Smart Patch for pH and Hydration Sensing in Wounds.

Wound healing is a complex and dynamic regeneration process, wherein the physical and chemical parameters are continuously changing. Its management and monitoring can provide immense benefits, especially for bed-ridden patients. This work reports a low-cost, flexible, and fully printed on-skin patch sensor to measure the change in pH and fluid content in a wound. Such a bendable sensor can also be easily incorporated in a wound dressing. The sensor consists of different electrodes printed on polydimethylsiloxane (PDMS) substrate for pH and moisture sensing. The fabricated sensor patch has a sensitivity of 7.1 ohm/pH for wound pH levels. The hydration sensor results showed that moisture levels on a semi-porous surface can be quantified through resistance change.

Improving Dyspnoea Symptom Control of Patients in Palliative Care Using a Smart Patch-A Proof of Concept Study.

The world of healthcare constantly aims to improve the lives of people while nurturing their health and comfort. Digital health and wearable technologies are aimed at making this possible. However, there are numerous factors that need to be addressed such as aging, disabilities, and health hazards. These factors are intensified in palliative care (PC) patients and limited hospital capacities make it challenging for health care providers (HCP) to handle the crisis. One of the most common symptoms reported by PC patients with severe conditions is dyspnoea. Monitoring devices with sufficient comfort could improve symptom control of patients with dyspnoea in PC. In this article, we discuss the proof-of-concept study to investigate a smart patch (SP), which monitors the pulmonary parameters: (a) breathing rate (BR) and inspiration to expiration ratio (I:E); markers for distress: (b) heart rate (HR) and heart rate variability (HRV), and (c) transmits real-time data securely to an adaptable user interface, primarily geared for palliative HCP but scalable to specific needs. The concept is verified by measuring and analyzing physiological signals from different electrode positions on the chest and comparing the results achieved with the gold standard Task Force Monitor (TFM).

Wearable and Flexible Ozone Generating System for Treatment of Infected Dermal Wounds.

Wound-associated infections are a significant and rising health concern throughout the world owing to aging population, prevalence of diabetes, and obesity. In addition, the rapid increase of life-threatening antibiotic resistant infections has resulted in challenging wound complications with limited choices of effective therapeutics. Recently, topical ozone therapy has shown to be a promising alternative approach for treatment of non-healing and infected wounds by providing strong antibacterial properties while stimulating the local tissue repair and regeneration. However, utilization of ozone as a treatment for infected wounds has been challenging thus far due to the need for large equipment usable only in contained, clinical settings. This work reports on the development of a portable topical ozone therapy system comprised of a flexible and disposable semipermeable dressing connected to a portable and reusable ozone-generating unit via a flexible tube. The dressing consists of a multilayered structure with gradient porosities to achieve uniform ozone distribution. The effective bactericidal properties of the ozone delivery platform were confirmed with two of the most commonly pathogenic bacteria found in wound infections, Pseudomonas aeruginosa and Staphylococcus epidermidis. Furthermore, cytotoxicity tests with human fibroblasts cells indicated no adverse effects on human cells.

Stress measurement in surgeons and residents using a smart patch.

BACKGROUND: Stress may negatively affect surgeons' performance during surgical procedures, jeopardizing patient safety. For measuring stress, complex methods are used that cannot record stress real time. This study reports stress measurements in surgeons and residents using a novel patch sensor to identify activities and risk factors of stress. METHODS: In this explorative study, surgeons and residents wore the HealthPatch™ during all daily activities for 2-3 days. The patch recorded heart rate variability (HRV), and real time stress percentage using a validated algorithm of heart rate (HR) and HRV. The patch was compared with self perceived stress reporting using STAI. RESULTS: A significant increase in HRV and stress percentage was shown in twenty surgeons and residents during surgery in comparison with other activities. Consultants showed lower stress levels while operating compared to fellows and residents. Stress according to the patch did not correlate with STAI outcome. CONCLUSIONS: Continuous stress monitoring using a wearable sensor patch reveals relevant data on actual stress of surgeons and residents. Stress was highest performing an operation, particularly in fellows and residents.