Chronic Wounds Point-of-care system for monitoring moisture, temperature, pH, Interleukin-6 and Uric Acid levels

慢性伤口是指那些需要三个月以上才能愈合或在及时治疗后没有改善的伤口，更有可能被细菌感染或定居。目前，处理慢性伤口最普遍的方法是目测评估和诊断性敷料，这对医疗保健部门有重大的财务影响。慢性伤口影响着美国570万人，每年花费200亿美元。(Brown，Ashley，&Koh，2018)(Tran，等人，2022)目前市场上已有一些用于非侵入性伤口监测的压力、化学和光学传感器。然而，一个能够检测水分、温度、pH和化学生物标志物的微型系统需要有一个更完整的伤口监测系统。(Tran，et al.，2022)伤口温度持续升高至少1.11摄氏度可能是由感染或新陈代谢变化引起的，因此必须经常监测组织温度和水分水平，以决定何时更换绷带或移除坏死组织。(Tran，等人，2022)(Brown，Ashley，&Koh，2018)慢性伤口的PH值在7.18到8.90之间，这导致了一个温和的基础环境，促进了细菌的定植。仅测量PH值不足以监测感染，但当与尿酸(UA)和白介素6(IL-6)等其他生物标志物相结合时，它们可能有助于及早发现感染和炎症阶段的程度。(Brown，Ashley，&Koh，2018)。(Pusta，Tertis，Cristea，&Mirel，2022)。这个项目的目的是开发一种灵活的可穿戴系统，包括廉价的无线温度、水分和pH传感器以及用于测量IL-6和UA水平的电化学生物传感器。这种护理点(POC)系统将作为一种多功能的原位设备，可以诊断伤口参数并调节伤口部位的感染，从而有可能加强现有的治疗选择。该装置的结构将包括具有集成电子设备的外部柔性纺织基板，顶部具有印刷温度、湿度和电化学生物传感器的(一次性)活性层，然后是与伤口接触的一层吸收材料。由于具有高导电性、高导热性、高载流子迁移率、功能性和生物相容性等特点，液相剥离石墨烯将成为温度和电化学生物传感器的主要活性材料。(Davies，Tzalichuk，Wiper，&Walton，2016)对于温度传感器，将通过将石墨烯或石墨烯/温度敏感聚合物墨水印刷到传感器阵列(热敏电阻)中来利用石墨烯的热导率。(伊斯梅尔，伊德里斯和阿卜杜拉，2022)(严，王，和李，2015)(Servati，Zou，Wang，Ko和Servati，2017)。将研究一种最佳的包埋方法、生物相容的底物材料(即聚乳酸(Plaa)、纤维素和壳聚糖)以及对运动和应变信号敏感性的校正方法。对于湿度传感器，将考虑由导电材料(即石墨烯、银和氯化银)制成的电极。(McColl，MacDouga，Watret和Connolly，2009)当通过便携式电表将小电流输送到这些电极时，传感器电极上的阻抗将允许检测到湿度水平。作为另一种选择，离子导电聚合物电极(即PEDOT：PSS，PPy，PANI)将被印刷，当与富离子渗出物接触时，将改变其离子电子传导机制，外推到阻抗变化。(Tessarolo等人，2021年)为了检测化学生物标志物和监测pH值水平，将分别研究喷墨打印EnFET(酶场效应晶体管设备)和ISFET(离子选择场效应晶体管)。

Chronic wounds are those that take longer than three months to heal or do not show improvements after prompt treatment, being more likely to become infected or colonised by bacteria. Currently, the most prevalent methods for managing chronic wounds are visual assessment and diagnostic dressing, which have significant financial impacts on the healthcare sector. Chronic wounds impact 5.7 million people in the US and cost $20 billion annually. (Brown , Ashley, & Koh, 2018) (Tran, et al., 2022) A few of the pressure, chemical, and optical sensors that have been explored for non-invasive wound monitoring are currently on the market. However, a microsystem that can detect moisture, temperature, pH, and chemical biomarkers is required to have a more complete wound monitoring system. (Tran, et al., 2022) Continuous temperature increases of at least 1.11 degree C at the wound may be caused by infections or changes in metabolism, hence it is essential to frequently monitor the tissue temperature and moisture level to decide when to change the bandage or remove necrotic tissue. (Tran, et al., 2022) (Brown , Ashley, & Koh, 2018) Chronic wounds have a pH between 7.18 and 8.90, which results in a mildly basic environment that promotes bacterial colonisation. pH measurements alone are insufficient for infection monitoring, but when combined with additional biomarkers such uric acid (UA) and interleukin-6 (IL-6), they may be useful for detecting infections early on and the extent of the inflammatory phase. (Brown , Ashley, & Koh, 2018). (Pusta , Tertis, Cristea, & Mirel, 2022).The purpose of this project is to develop a flexible wearable system that includes inexpensive wireless temperature, moisture, and pH sensors as well as electrochemical biosensors for measuring, IL-6, and UA levels. This point-of-care (POC) system would act as a multifunctional in situ device that can diagnose wound parameters and regulate the infection at the wound site offering the potential to enhance available treatment options. The structure of the device would include an outer flexible textile substrate with integrated electronics, an (disposable) active layer on top with printed temperature, moisture, and electrochemical biosensors, and then a layer of absorbent material that would encounter the wound. Owing to its high electrical and thermal conductivity, high carrier mobility, functionality, and biocompatibility, liquid-phase exfoliated graphene will be addressed as the primary active material for temperature and electrochemical biosensors. (Davies, Tzalenchuk, Wiper, & Walton, 2016) For the temperature sensors the thermal conductivity of graphene will be exploited by printing graphene or graphene/temperature-sensitive polymers inks into sensor arrays (thermistors). (Ismail, Idris, & Abdullah, 2022) (Yan, Wang, & Lee, 2015) (Servati, Zou, Wang, Ko, & Servati, 2017). An optimal encapsulation method, biocompatible substrate material (i.e., polylactic acid (PLAA), cellulose, and chitosan) and correction method for signal susceptibility to motion and strain will be investigated. For the moisture sensor, electrodes made of conductive materials (i.e., graphene, Ag, and AgCl) will be taken into consideration. (McColl, MacDougal, Watret, and Connolly, 2009) When a small current is delivered to these electrodes by a portable metre, the electrical impedance across the sensor electrodes will allow the moisture level to be detected. As an alternative, ion-conductive polymeric electrodes (i.e., PEDOT: PSS, PPy, PANI) will be printed that, when in contact with the ion-rich exudate, will modify their ionic electronic conduction mechanism, extrapolating into impedance changes. (Tessarolo, et al., 2021) To detect chemical biomarkers and monitor pH levels, inkjet-printed EnFET (enzyme field-effect transistor devices) and ISFET (ion-selective field-effect transistor) will be investigated respectively.