Integrated Multiplex Sensing Bandage for In Situ Monitoring of Early Infected Wounds

PALM-T2: A colorimetric paper sensor for detecting heterocyclic amine/carbonyl, lactate, moisture, trimethylamine and tryptophan derivatives in wound infections

Conventional bacteria detection from wound infections requires costly or time-consuming methods that require either trained personnel, tedious sample preparation, or complex instrumentation. Hence, it is crucial to develop simple and inexpensive methods that enable accurate, point-of-care assessment of wound infections. Herein, we developed a Paper sensor to detect metabolites, i.e. heterocyclic Amine/Carbonyl, Lactate, Moisture, Trimethylamine and Tryptophan derivatives (termed PALM-T2), released from prevalent wound bacterial species. PALM-T2 consists of five sensing zones that are connected via a sampling arm. Each sensing zone contains a colorimetric sensor that generates unique colour response to certain bacteria metabolites. Images of PALM-T2 were captured using a smartphone and ImageJ was used to analyze colour changes in each sensing zones, eventually revealing the type and concentration of prevalent wound bacterial species. Simulated wound fluid and ex-vivo pig skin 'wound' models were used to demonstrate PALM-T2's performance in simultaneous detection of multiple bacteria metabolites within 30 min. The PALM-T2 sensor displays a great potential for point-of-care detection of bacteria at 105 CFU/mL, the lowest concentration observed from an infected wound.

A Fully Integrated Wearable Biomimetic Microfluidic Wound Tracker for In Situ Dynamic Monitoring of Wound Exudate Oxygen

Wearable wound exudate sensors hold great promise for providing dynamic measurements of valuable biomarkers. However, no existing sensors are able to achieve the fully integrated, skin-on, and dynamic detection of raw wound exudate oxygen (O2), which is closely related to wound conditions and also essential for wound healing. Here, we report a fully integrated wearable biomimetic microfluidic wound tracker, capable of skin-on biomimetic microfluidic wound exudate sampling, dynamic monitoring of wound exudate O2 in addition to wound exudate uric acid, lactate, pH, and temperature, and wireless control through the seamless integration of specially designed microfluidic, sensing, and electronic modules. We test the performance of the device in both bacterium-inoculated and uninoculated wounds using mouse models. We further assess its potential for wound management in the healing process of infected diabetic mouse wounds through controlled experiments related to local hyperbaric O2 treatment.

Recent Progress in Antibacterial Surfaces for Implant Catheters

Catheter-related infections (CRIs) caused by hospital-acquired microbial infections lead to the failure of treatment and the increase of mortality and morbidity. Surface modifications of the implant catheters have been demonstrated to be effective approaches to improve and largely reduce the bacterial colonization and related complications. In this work, we focus on the last 5-year progress in the surface modifications of biomedical catheters to prevent CRIs. Their antibacterial strategies used for surface modifications are further divided into 5 classifications through the antimicrobial mechanisms, including active surfaces, passive surfaces, active and passive combination surfaces, stimulus-type response surfaces, and other types. Each feature and the latest advances in these abovementioned antibacterial surfaces of implant catheters are highlighted. Finally, these confronting challenges and future prospects are discussed for the antibacterial modifications of implant catheters.

Vertical Graphene-Based Multiparametric Sensing Array for Integration of Smart Catheter to Electrochemically Monitor Peritoneal Dialysis

Renal failure is typical chronic kidney disease that required peritoneal dialysis as the primary treatment, but current catheter devices lack functionality to monitor changes in chemical analytes during peritoneal dialysis. Fabrication of miniatured sensing modules with good electrochemical performance in tiny catheter devices is the key to realize the smart monitoring of peritoneal dialysis. In this work, a vertical graphene-based multiparametric sensing array (VG-MSA) is developed to continuously measure fluctuations of various analyte concentrations for peritoneal dialysis monitoring. Vertical graphene (VG) electrode with good electrochemical properties serves as the core module in VG-MSA, allowing the development of miniatured sensing modules with sufficient electrochemical performance. The VG-MSA enables sensitive and multiplexed measurement of dialysate components like metabolites (reactive oxygen species, uric acid, and glucose) and ions (K+, Ca2+, and H+). The VG-MSA is demonstrated to effectively detect biochemical signals in peritoneal dialysate in vivo on rat models. The VG-MSA catheter can be inserted into abdominal cavity, allowing full contact with dialysate for in situ, real-time, and continuous collection of biochemical information during peritoneal dialysis. The VG-MSA catheter device offers a valuable tool for monitoring dialysis quality and facilitating treatment adjustments, potentially as a promising platform for high-quality therapy of renal failure.

Laser-Induced Graphene Electrodes for Flexible pH Sensors

In the growing field of personalized medicine, non-invasive wearable devices and sensors are valuable diagnostic tools for the real-time monitoring of physiological and biokinetic signals. Among all the possible multiple (bio)-entities, pH is important in defining health-related biological information, since its variations or alterations can be considered the cause or the effect of disease and disfunction within a biological system. In this work, an innovative (bio)-electrochemical flexible pH sensor was proposed by realizing three electrodes (working, reference, and counter) directly on a polyimide (Kapton) sheet through the implementation of CO2 laser writing, which locally converts the polymeric sheet into a laser-induced graphene material (LIG electrodes), preserving inherent mechanical flexibility of Kapton. A uniform distribution of nanostructured PEDOT:PSS was deposited via ultrasonic spray coating onto an LIG working electrode as the active material for pH sensing. With a pH-sensitive PEDOT coating, this flexible sensor showed good sensitivity defined through a linear Nernstian slope of (75.6 ± 9.1) mV/pH, across a pH range from 1 to 7. We demonstrated the capability to use this flexible pH sensor during dynamic experiments, and thus concluded that this device was suitable to guarantee an immediate response and good repeatability by measuring the same OCP values in correspondence with the same pH applied.

A Scoping Review of 'Smart' Dressings for Diagnosing Surgical Site Infection: A Focus on Arthroplasty

Early diagnosis and treatment of surgical wound infection can be challenging. This is especially relevant in the management of periprosthetic joint infection: early detection is key to success and reducing morbidity, mortality and resource use. 'Smart' dressings have been developed to detect parameters suggestive of infection. This scoping review investigates the current status of the field, limited to devices tested in animal models and/or humans, with a focus on their application to arthroplasty. The literature was searched using MEDLINE/PubMed and Embase databases from 2000 to 2023. Original articles assessing external sensing methods for the detection of wound infection in animal models or human participants were included. Sixteen articles were eligible. The results were broadly divided by sensing method: colorimetric, electrochemical and fluorescence/photothermal responses. Six of the devices detected more than one parameter (multimodal), while the rest were unimodal. The most common parameters examined were temperature and pH. Most 'smart' dressings focused on diagnosing infection in chronic wounds, and none were tested in humans with wound infections. There is limited late-stage research into using dressing sensors to diagnose wound infection in post-surgical patients. Future research should explore this to enable inpatient and remote outpatient monitoring of post-operative wounds to detect wound infection.

Self-powered biosensing sutures for real-time wound monitoring

Effective wound management has the potential to reduce both the duration and cost of wound healing. However, traditional methods often rely on direct observation or complex and expensive biological testing to monitor and evaluate the invasive damage caused by wound healing, which can be time-consuming. Biosensors offer the advantage of precise and real-time monitoring, but existing devices are not suitable for integration with sensitive wound tissue due to their external dimensions. Here, we have designed a self-powered biosensing suture (SPBS) based on biofuel cells to accurately monitor glucose concentration at the wound site and promote wound healing. The anode of the SPBS consists of carbon nanotubes-modified carbon fibers, tetrathiafulvalene (TTF), and glucose oxidase (GOx), while the cathode is composed of Ag2O and carbon nanotubes modified nanotubes modified carbon fibers. It was observed that SPBS exhibited excellent physical and chemical stability in vitro. Regardless of different bending degrees or pH values, the maximum power density of SPBS remained above 92%, which is conducive to long-term dynamic evaluation. Furthermore, the voltage generated by SPBS reflects blood glucose concentration, and measurements at wound sites are consistent with those obtained using a commercially available blood glucose meter. SPBS achieves the healing effect of traditional medical sutures after complete healing within 14 days. It offers valuable insights for intelligent devices dedicated to real-time wound monitoring.

Advances in Multifunctional Electronic Catheters for Precise and Intelligent Diagnosis and Therapy in Minimally Invasive Surgery

The advent of catheter-based minimally invasive surgical instruments has provided an effective means of diagnosing and treating human disease. However, conventional medical catheter devices are limited in functionalities, hindering their ability to gather tissue information or perform precise treatment during surgery. Recently, electronic catheters have integrated various sensing and therapeutic technologies through micro/nanoelectronics, expanding their capabilities. As micro/nanoelectronic devices become more miniaturized, flexible, and stable, electronic surgical catheters are evolving from simple tools to multiplexed sensing and theranostics for surgical applications. The review on multifunctional electronic surgical catheters is lacking and thus is not conducive to the reader's comprehensive understanding of the development trend in this field. This review covers the advances in multifunctional electronic catheters for precise and intelligent diagnosis and therapy in minimally invasive surgery. It starts with the summary of clinical minimally invasive surgical instruments, followed by the background of current clinical catheter devices for sensing and therapeutic applications. Next, intelligent electronic catheters with integrated electronic components are reviewed in terms of electronic catheters for diagnosis, therapy, and multifunctional applications. It highlights the present status and development potential of catheter-based minimally invasive surgical devices, while also illustrating several significant challenges that remain to be overcome.

A highly stretchable smart dressing for wound infection monitoring and treatment

Smart dressings integrated with bioelectronics have attracted considerable attention and become promising solutions for skin wound management. However, due to the mechanical distinction between human body and the interface of electronics, previous smart dressings often suffered obvious degradation in electrical performance when attached to the soft and curvilinear wound sites. Here, we report a stretchable dressing integrated with temperature and pH sensor for wound status monitoring, as well as an electrically controlled drug delivery system for infection treatment. The wound dressing was featured with the deployment of liquid metal for seamless connection between rigid electrical components and gold particle-based electrodes, achieving a stretchable soft-hard interface. Stretching tests showed that both the sensing system and drug delivery system exhibited good stretchability and long-term stable conductivity with the resistance change rate less than 6 % under 50 % strain. Animal experiments demonstrated that the smart dressing was capable of detecting bacterial infection via the biomarkers of temperature and pH value and the infection factors of wound were significantly improved with therapy through electrically controlled antibiotics releasing. This proof-of-concept prototype has potential to significantly improve management of the wound, especially those with dynamic strain.

MXene/TPU Hybrid Fabrics Enable Smart Wound Management and Thermoresponsive Drug Delivery

Thermoresponsive wound dressings with real-time monitoring and on-demand drug delivery have gained significant attention recently. However, such smart systems with stable temperature adjustment and drug release control are still lacking. Here, a novel smart fabric is designed for wound management with thermoresponsive drug delivery and simultaneously temperature monitoring. The triple layers of the fabrics are composed of the drug-loaded thermoresponsive nanofiber film, the MXene-optimized joule heating film, and the FPCB control chip. The precise and stable temperature stimulation can be easily achieved by applying a low voltage (0-4 V) to the heating film, achieving the temperature control ranging from 25 to 130 °C. And the temperature of the wound region can be monitored and adjusted in real time, demonstrating an accurate and low-voltage joule heating capability. Based on that, the drug-loaded film achieved precise thermoresponsive drug release and obtained significant antibacterial effects in vitro. The in vivo experiments also proved the hybrid fabric system with a notable antibacterial effect and accelerated wound healing process (about 30% faster than the conventional gauze group).

Next-generation of smart dressings: Integrating multiplexed sensors and theranostic functions

Non-healing wounds represent a significant burden for healthcare systems and society, giving rise to severe economic and human issues. Currently, the use of dressings and visual assessment represent the primary and standard care for wounds. Conventional dressings, like cotton gauze, provide only passive physical protection. Besides, they end up paradoxically hampering the wound-healing process by producing tissue damage and pain when removed during routine check-ups. In response to these limitations, researchers, engineers, and technologists are developing innovative dressings that incorporate advanced diagnostic and therapeutic functionalities, coined as "smart dressings". Now, the maturation of smart dressing is bringing them closer to real-life applications, leading to an exciting new generation of these devices. The next generation of smart dressings is capable of monitoring in real-time multiple biomarkers while including pro-healing capabilities in a single platform. Such multiplexed and theranostic smart dressings are expected to offer a timely biomarker-directed diagnosis of non-healing wounds while enabling rapid, automated, and personalized treatments of infection and chronicity. Herein, we provide an insightful overview of these advantageous devices, delving into the diverse spectrum of possible engineering strategies. This encompasses the use of electrochemical and optical platforms with diverse multiplexing architectures, such as multi-zone sensing arrays and multi-layered devices. Open or closed-loop theranostic mechanisms using various stimuli-responsive materials that could be internally or externally controlled are also included. Finally, a critical discussion on the main challenges and future directions of smart dressings is also offered.

Point-of-care detection devices for wound care and monitoring

Healthcare resources are heavily burdened by infections that impede the wound-healing process. A wide range of advanced technologies have been developed for detecting and quantifying infection biomarkers. Finding a timely, accurate, non-invasive diagnostic alternative that does not require a high level of training is a critical step toward arresting common clinical patterns of wound health decline. There is growing interest in the development of innovative diagnostics utilizing a variety of emerging technologies, and new biomarkers have been investigated as potential indicators of wound infection. In this review, we summarize diagnostics available for wound infection, including those used in clinics and still under development.

Ingenious fabrication of bamboo leaf-like ferric vanadate intertwined multi-walled carbon nanotubes nanocomposite as a sensitive sensor for determination of uric acid in fetal bovine serum

A novel nanocomposite material, ferric vanadate intertwined multi-walled carbon nanotubes (FeV/MWCNTs), has been designed which was drop-coated onto a glassy carbon electrode (GCE). The constructed sensor was used for the sensitive determination of uric acid (UA) in fetal bovine serum (FBS) and human serum (HS). A series of characterization and electrochemical tests showed that the ultrasound-assisted assembly of FeV with MWCNTs not only overcame the disadvantages of low conductivity and easy (unwanted) aggregation, but also avoided the decrease in effective surface area due to the severe aggregation of each individual raw material. The fabricated FeV/MWCNTs nanocomposites exhibited higher conductivity, larger effective surface area, and better electrocatalytic activity. In addition, under optimized conditions, the developed electrochemical sensor FeV/MWCNTs/GCE has a lower limit of detection (LOD, 0.05 µM; Ep = 0.268 V vs. Ag/AgCl) and wider linear range (0.20-100 µM), which can satisfy the criteria of trace UA detection. The results of UA determination in FBS (recovery = 95.5-103%; RSD ≤ 3.1%) and HS (recovery = 95.5-103%; RSD ≤ 4.3%) further validated the feasibility of FeV/MWCNTs-based electrochemical sensors for the determination of UA in biological fluids.

Current status and progress in research on dressing management for diabetic foot ulcer

Diabetic foot ulcer (DFU) is a major complication of diabetes and is associated with a high risk of lower limb amputation and mortality. During their lifetime, 19%-34% of patients with diabetes can develop DFU. It is estimated that 61% of DFU become infected and 15% of those with DFU require amputation. Furthermore, developing a DFU increases the risk of mortality by 50%-68% at 5 years, higher than some cancers. Current standard management of DFU includes surgical debridement, the use of topical dressings and wound decompression, vascular assessment, and glycemic control. Among these methods, local treatment with dressings builds a protective physical barrier, maintains a moist environment, and drains the exudate from DFU wounds. This review summarizes the development, pathophysiology, and healing mechanisms of DFU. The latest research progress and the main application of dressings in laboratory and clinical stage are also summarized. The dressings discussed in this review include traditional dressings (gauze, oil yarn, traditional Chinese medicine, and others), basic dressings (hydrogel, hydrocolloid, sponge, foam, film agents, and others), bacteriostatic dressings, composite dressings (collagen, nanomaterials, chitosan dressings, and others), bioactive dressings (scaffold dressings with stem cells, decellularized wound matrix, autologous platelet enrichment plasma, and others), and dressings that use modern technology (3D bioprinting, photothermal effects, bioelectric dressings, microneedle dressings, smart bandages, orthopedic prosthetics and regenerative medicine). The dressing management challenges and limitations are also summarized. The purpose of this review is to help readers understand the pathogenesis and healing mechanism of DFU, help physicians select dressings correctly, provide an updated overview of the potential of biomaterials and devices and their application in DFU management, and provide ideas for further exploration and development of dressings. Proper use of dressings can promote DFU healing, reduce the cost of treating DFU, and reduce patient pain.

Integrated Multiplex Sensing Clear Aligner for In Situ Monitoring of Dental Enamel Demineralization

Clear aligners have become one of the most important tools in orthodontic treatment. However, over a lengthy period of orthodontic treatment, enamel demineralization or even dental caries could be susceptible for occurrence. Therefore, early diagnosis of enamel demineralization has been widely investigated. Nevertheless, for reasons including bulky monitoring equipment and complexity of operation, few techniques reported to date possessed clinical utility. The combination of flexible electronics and electrochemical sensing technology presented a promising strategy. Herein, an integrated multiplex sensing clear aligner (IMSCA) system, including a clear aligner with a multiplex sensor array patch, was developed for in situ monitoring of Ca²⁺, pH, and PO₄^3- in the oral environment to provide a foundation for early diagnosis of enamel demineralization. The IMSCA exhibited a broad linear response range, great selectivity, temporal stability, reproducibility, and biological safety. Results of enamel demineralization simulating experiments and human permanent tooth demineralization experiments validate the capability of the IMSCA to indicate the occurrence of enamel demineralization. All results ultimately point to the promising clinical utility of the IMSCA, which facilitates the quantitative characterization of enamel demineralization in complex oral environments. This study provides a novel strategy in the early diagnosis of enamel demineralization.

Masticatory system-inspired microneedle theranostic platform for intelligent and precise diabetic management

Integrated systems for diabetic theranostics present advanced technology to regulate diabetes yet still have critical challenges in terms of accuracy, long-term monitoring, and minimal invasiveness. Inspired by the feature and functions of animal masticatory system, we presented a biomimetic microneedle theranostic platform (MNTP) for intelligent and precise management of diabetes. The MNTP was supported by a miniatured circuit, which used microneedle arrays for on-demand skin penetration, enabling interstitial fluid exudation for simultaneous detection of glucose and physiological ions, and subcutaneous insulin delivery. Interstitial fluid exudation enabled sensing in oxygen-rich environment via the incorporated epidermal sensor functionalized with hybrid carbon nanomaterials. This feature addressed the biosafety issues due to implanted electrodes and the "oxygen-deficit" issues in vivo. The MNTP was demonstrated to accurately detect glucose and ions and deliver insulin to regulate hyperglycemia. The biomimetic and intelligent features of the MNTP endowed it as a highly advanced system for diabetes therapy.

A Bifunctional Fully Integrated Wearable Tracker for Epidermal Sweat and Wound Exudate Multiple Biomarkers Monitoring

Fully integrated wearable electronics that combine the extraordinary feature of incessant and on-body operation with the distinctive external equipment-free trait are the ultimate goal of modern wearables. Epidermal sweat and wound exudate, as two noninvasively accessible biofluids on/surrounding the skin, reflect underlying health conditions. However, the design of universal wearable sensors with the bifunctional capability to monitor both epidermal secretions is still a challenge. Here, a single bifunctional fully integrated wearable tracker for wirelessly, simultaneously, and dynamically in situ measuring multiple epidermal sweat or wound exudate biomarkers is propos. Considering the electrolytes (e.g., Na⁺ , K⁺ , and H⁺ ) and metabolites (e.g., uric acid (UA)) levels in sweat or wound exudate may correlate with health or wound conditions, the dynamic and skin-on tracking of the biomarkers of Na⁺ , K⁺ , pH, and UA levels in sweat under subjects' exercise and in wound exudate during subjects' wound healing are performed through the seamless integration of microfluidic, sensing, and electronic modules. Its applicability is evaluated for noninvasive hyperuricemia management in hyperuricemia/healthy subjects through a purine-rich intake test and for wound management in subjects' infected wounds through a control medical treatment.

Smartphone-Based Multiplexed Biosensing Tools for Health Monitoring

Many emerging technologies have the potential to improve health care by providing more personalized approaches or early diagnostic methods. In this review, we cover smartphone-based multiplexed sensors as affordable and portable sensing platforms for point-of-care devices. Multiplexing has been gaining attention recently for clinical diagnosis considering certain diseases require analysis of complex biological networks instead of single-marker analysis. Smartphones offer tremendous possibilities for on-site detection analysis due to their portability, high accessibility, fast sample processing, and robust imaging capabilities. Straightforward digital analysis and convenient user interfaces support networked health care systems and individualized health monitoring. Detailed biomarker profiling provides fast and accurate analysis for disease diagnosis for limited sample volume collection. Here, multiplexed smartphone-based assays with optical and electrochemical components are covered. Possible wireless or wired communication actuators and portable and wearable sensing integration for various sensing applications are discussed. The crucial features and the weaknesses of these devices are critically evaluated.

A compact, low-cost, and binary sensing (BiSense) platform for noise-free and self-validated impedimetric detection of COVID-19 infected patients

Electrochemical immuno-biosensors are one of the most promising approaches for accurate, rapid, and quantitative detection of protein biomarkers. The two-working electrode strip is employed for creating a self-supporting system, as a tool for self-validating the acquired results for added reliability. However, the realization of multiplex electrochemical point-of-care testing (ME-POCT) requires advancement in portable, rapid reading, easy-to-use, and low-cost multichannel potentiostat readers. The combined multiplex biosensor strips and multichannel readers allow for suppressing the possible complex matrix effect or ultra-sensitive detection of different protein biomarkers. Herein, a handheld binary-sensing (BiSense) bi-potentiostat was developed to perform electrochemical impedance spectroscopy (EIS)-based signal acquisition from a custom-designed dual-working-electrode immuno-biosensor. BiSense employs a commercially available microcontroller and out-of-shelf components, offering the cheapest yet accurate and reliable time-domain impedance analyzer. A specific electrical board design was developed and customized for impedance signal analysis of SARS-CoV-2 nucleocapsid (N)-protein biosensor in spiked samples and alpha variant clinical nasopharyngeal (NP) swab samples. BiSense showed limit-of-detection (LoD) down to 56 fg/mL for working electrode 1 (WE1) and 68 fg/mL for WE2 and reported with a dynamic detection range of 1 pg/mL to 10 ng/mL for detection of N-protein in spiked samples. The dual biosensing of N-protein in this work was used as a self-validation of the biosensor. The low-cost (∼USD$40) BiSense bi-potentiostat combined with the immuno-biosensors successfully detected COVID-19 infected patients in less than 10 min, with the BiSense reading period shorter than 1.5 min, demonstrating its potential for the realization of ME-POCTs for rapid and hand-held diagnosis of infections.

A review of current advancements for wound healing: Biomaterial applications and medical devices

Wound healing is a complex process that is critical in restoring the skin's barrier function. This process can be interrupted by numerous diseases resulting in chronic wounds that represent a major medical burden. Such wounds fail to follow the stages of healing and are often complicated by a pro‐inflammatory milieu attributed to increased proteinases, hypoxia, and bacterial accumulation. The comprehensive treatment of chronic wounds is still regarded as a significant unmet medical need due to the complex symptoms caused by the metabolic disorder of the wound microenvironment. As a result, several advanced medical devices, such as wound dressings, wearable wound monitors, negative pressure wound therapy devices, and surgical sutures, have been developed to correct the chronic wound environment and achieve skin tissue regeneration. Most medical devices encompass a wide range of products containing natural (e.g., chitosan, keratin, casein, collagen, hyaluronic acid, alginate, and silk fibroin) and synthetic (e.g., polyvinyl alcohol, polyethylene glycol, poly[lactic‐co‐glycolic acid], polycaprolactone, polylactic acid) polymers, as well as bioactive molecules (e.g., chemical drugs, silver, growth factors, stem cells, and plant compounds). This review addresses these medical devices with a focus on biomaterials and applications, aiming to deliver a critical theoretical reference for further research on chronic wound healing.

Determination of Transdermal Rate of Metallic Microneedle Array through an Impedance Measurements-Based Numerical Check Screening Algorithm

Microneedle systems have been widely used in health monitoring, painless drug delivery, and medical cosmetology. Although many studies on microneedle materials, structures, and applications have been conducted, the applications of microneedles often suffered from issues of inconsistent penetration rates due to the complication of skin-microneedle interface. In this study, we demonstrated a methodology of determination of transdermal rate of metallic microneedle array through impedance measurements-based numerical check screening algorithm. Metallic sheet microneedle array sensors with different sizes were fabricated to evaluate different transdermal rates. In vitro sensing of hydrogen peroxide confirmed the effect of transdermal rate on the sensing outcomes. An FEM simulation model of a microneedle array revealed the monotonous relation between the transdermal state and test current. Accordingly, two methods were primely derived to calculate the transdermal rate from the test current. First, an exact logic method provided the number of unpenetrated tips per sheet, but it required more rigorous testing results. Second, a fuzzy logic method provided an approximate transdermal rate on adjacent areas, being more applicable and robust to errors. Real-time transdermal rate estimation may be essential for improving the performance of microneedle systems, and this study provides various fundaments toward that goal.

Intelligent Wearable Sensors Interconnected with Advanced Wound Dressing Bandages for Contactless Chronic Skin Monitoring: Artificial Intelligence for Predicting Tissue Regeneration

Toward the adoption of artificial intelligence-enabled wearable sensors interconnected with intelligent medical objects, this contactless multi-intelligent wearable technology provides a solution for healthcare to monitor hard-to-heal wounds and create optimal efficiencies for clinical professionals by minimizing the risk of disease infection. This article addressed a flexible artificial intelligence-guiding (FLEX-AI) wearable sensor that can be operated with a deep artificial neural network (deep ANN) algorithm for chronic wound monitoring via short-range communication toward a seamless, MXENE-attached, radio frequency-tuned, and wound dressing-integrated (SMART-WD) bandage. Based on a supervised training set of on-contact pH-responsive voltage output, the confusion matrix for healing-stage recognition from this deep ANN machine learning revealed an accuracy of 94.6% for the contactless measurement. The core analytical design of these smart bandages integrated wound dressing of poly(vinyl acrylic) gel@PANI/Cu₂O NPs for instigating pH-responsive current during the wound healing process. Effectively, a chip-free bandage tag was fabricated with a capacitive Mxene/PTFE electret and adhesive acrylic inductance to match the resonance frequency generated by the intelligent wearable antenna. Under zero-current electrochemical potential, the wound dressing attained a slope of -76 mV/pH. With the higher activation voltage applied toward the wound dressing electrodes, cuprous ions intercalated more into the hybrid PVA gel/PANI shell, resulting in an exponential increase of the two-terminal current response. The healing phase diagram was classified into regimes of fast-curing, slow-curing, and no-curing for skin disease treatment with corticosteroids. Ultimately, the near-field sensing technology offers adequate information for guiding treatment decisions as well as drug effectiveness for wound care.

A Review of Recent Advances in Flexible Wearable Sensors for Wound Detection Based on Optical and Electrical Sensing

Chronic wounds that are difficult to heal can cause persistent physical pain and significant medical costs for millions of patients each year. However, traditional wound care methods based on passive bandages cannot accurately assess the wound and may cause secondary damage during frequent replacement. With advances in materials science and smart sensing technology, flexible wearable sensors for wound condition assessment have been developed that can accurately detect physiological markers in wounds and provide the necessary information for treatment decisions. The sensors can implement the sensing of biochemical markers and physical parameters that can reflect the infection and healing process of the wound, as well as transmit vital physiological information to the mobile device through optical or electrical signals. Most reviews focused on the applicability of flexible composites in the wound environment or drug delivery devices. This paper summarizes typical biochemical markers and physical parameters in wounds and their physiological significance, reviews recent advances in flexible wearable sensors for wound detection based on optical and electrical sensing principles in the last 5 years, and discusses the challenges faced and future development. This paper provides a comprehensive overview for researchers in the development of flexible wearable sensors for wound detection.