In-shoe sensor system with an embedded user interface and wearable leg unit

In-shoe sensor systems are of great interest to monitor foot health, sports activities and rehabilitation strategies. Among the potential users are people with diabetes, a large part of the population for which monitoring foot pressure and temperature is critical to avoid ulceration, and even amputation. Despite all these reasons the use of foot monitoring devices is still uncommon compared to other accessories such as fitness tracking devices. This work describes the development of an instrumented insole for monitoring pressure, temperature and humidity taking advantage of widely available wearable components. This is made possible by additionally developing a shield board for time-division multiplexing of the pressure signals and an embedded user interface which is stored in the microcontroller's memory and uploaded to a smartphone at start-up via Bluetooth Low Energy. The user interface runs on a smartphone to provide both real time monitoring and averages of sensor data. The system is described in detail and validated by monitoring pressure patterns during stance, by testing response to temperature variations and observing patterns in individuals with pes planus posture.info:eu-repo/semantics/publishedVersio

A Review of Wearable Sensor Systems to Monitor Plantar Loading in the Assessment of Diabetic Foot Ulcers

Diabetes is highly prevalent throughout the world and imposes a high economic cost on countries at all income levels. Foot ulceration is one devastating consequence of diabetes, which can lead to amputation and mortality. Clinical assessment of diabetic foot ulcer (DFU) is currently subjective and limited, impeding effective diagnosis, treatment and prevention. Studies have shown that pressure and shear stress at the plantar surface of the foot plays an important role in the development of DFUs. Quantification of these could provide an improved means of assessment of the risk of developing DFUs. However, commercially-available sensing technology can only measure plantar pressures, neglecting shear stresses and thus limiting their clinical utility. Research into new sensor systems which can measure both plantar pressure and shear stresses are thus critical. Our aim in this paper is to provide the reader with an overview of recent advances in plantar pressure and stress sensing and offer insights into future needs in this critical area of healthcare. Firstly, we use current clinical understanding as the basis to define requirements for wearable sensor systems capable of assessing DFU. Secondly, we review the fundamental sensing technologies employed in this field and investigate the capabilities of the resultant wearable systems, including both commercial and research-grade equipment. Finally, we discuss research trends, ongoing challenges and future opportunities for improved sensing technologies to monitor plantar loading in the diabetic foot

Palmilha sensorial para o diagnóstico de apoio desequilibrado na face plantar do pé

Esta dissertação de mestrado tem como objetivo final completar o curso de Engenharia de Eletromecânica. O tema desenvolvido neste projeto é uma palmilha sensorial que auxilie no diagnóstico médico de testes em baropodometria e contribuir na prevenção de desenvolvimento de úlceras. Usando uma palmilha preparada com sensores, será possível detetar em que pontos o pé exerce demasiada pressão e assim entender a possibilidade de formação ou desenvolvimento de úlceras. Um dispositivo deste tipo tem uma grande utilidade, por exemplo, em pacientes diabéticos que podem sofrer de amputações no pé, devido a úlceras que aparecem devido a desenvolverem neuropatia. A palmilha sensorial não é só destinada para pacientes diabéticos, mas também atletas, ou pessoas normais que necessitem de analisar o pé para ver se tem o pé chato. O princípio de funcionamento terá sensores de pressão que irão captar a pressão que o pé faz na palmilha. O sensor fica então encarregue de traduzir essa energia da pressão em energia elétrica. O sinal vai sofrer de uma amplificação e filtração, para conversão de um sinal analógico para um sinal digital, que tem o fim de ser apresentado num displayThe following master’s thesis is the final objective of the Electromechanical course. In this project, a sensorial insole will be developed that will support the diagnosis of baropodometric tests. These tests have the concept of using an insole that measures the pressure on certain points, in a way that avoids the formation or growth of ulcers. A device of this kind has a great need in patients that may suffer foot amputations, like diabetic. Ulcers appear specially in diabetic patients due to neuropathy origin. This sensorial insole is not only intended for diabetic patients, but also athletes, or normal people that need to analyse the foot to check for flat foot. The operation principle will have pressure sensors that will capture the pressure the foot does on the insole. The sensor will then have to transform this pressure energy into electric energy. The signal should then be amplified and filtered, so a conversion from an analogical sign to a digital sign, so it can be displayed on a screen

Graphene Biosensors for Diabetic Foot Ulcer Monitoring

The prevalence of Diabetes Mellitus (DM) in the twenty-first century has increased drastically, consequently, the incidence of DM-related complications has increased as well. According to the International Diabetes Federation (IDF) in 2021, globally one in every ten adults aged from 20 to 79 years had DM. Approximately 15-34% of individuals with DM are likely to develop a Diabetic Foot Ulcer (DFU) throughout their lifetime. Unmonitored and in- fected DFU can lead to non-traumatic lower extremity amputation and worst-case cause morbidity. Therefore, it is of great importance to develop effective, rapid production, bio- compatible, low-cost, flexible, wearable, sustainable sensors to monitor objectively the ulcer healing state. This dissertation aims to meet this need through the development of tempera- ture and pH laser-induced graphene (LIG) sensors on paper, that could be included in smart bandages and medical wound dressings. During this dissertation, LIG on paper fabrication parameters were studied to obtain the most reproducible, durable, and good electrical per- formance. The production condition of the LIG used for the development of the sensors had an average sheet resistance value of 24.9Ω/ with 1.2 Ω/ of standard deviation. The ther- moresistive sensor developed is characterized by a negative temperature coefficient with a highly linear response, and a sensitivity of 0.71 %℃−1 from 26℃ to 40℃, a suitable interval for its application. The electrochemical cell produced works as a potentiometric pH sensor. Its working electrode (WE) was electropolymerized with polyaniline (PANI) a pH-sensitive bio- compatible electrolyte. The sensor demonstrated a Nernstian behavior with a sensitivity of 53.0 / and 2.3 / of standard deviation on the interval from 2 pH to 9 pH.A prevalência da Diabetes Mellitus (DM) no século XXI aumentou drasticamente, con- sequentemente, a incidência de complicações relacionadas com a DM também aumentou. Segundo a Federação Internacional de Diabetes em 2021, globalmente um em cada dez adultos com idades compreendidas entre os 20 e os 79 anos tem DM. Aproximadamente 15- 34% dos indivíduos com DM são suscetíveis de desenvolver uma úlcera do pé diabético (DFU) durante toda a sua vida. A DFU não monitorizada e infetada pode levar a uma amputa- ção não traumática das extremidades inferiores e causar morbilidade no pior dos casos. Por conseguinte, é de grande importância desenvolver sensores eficazes, de produção rápida, biocompatíveis, de baixo custo, flexíveis, viáveis e sustentáveis para monitorizar objetivamen- te o estado de cicatrização da úlcera. Esta tese visa responder a esta necessidade através do desenvolvimento de sensores de temperatura e pH induzidos por laser (LIG) em papel, que poderiam ser incluídos em ligaduras inteligentes e curativos médicos de feridas. Durante esta dissertação, foram estudados parâmetros de fabrico de LIG em papel para obter o mais re- produtível, durável, e bom desempenho elétrico. O valor da resistência da folha média da condição de produção utilizada para o desenvolvimento foi de 24.9 Ω/ com um desvio padrão de 1.2 Ω/. O sensor termoresistivo desenvolvido é caracterizado por um coeficiente de temperatura negativa com uma resposta altamente linear, e uma sensibilidade de 0.71 %℃−1 entre os 26℃ e 40℃, um intervalo adequado para a sua aplicação. A célula ele- troquímica produzida funciona como um sensor de pH potenciométrico. O seu elétrodo de trabalho (WE) foi electropolimerizado com polianilina (PANI) um eletrólito biocompatível sensível ao pH. O sensor demonstrou um comportamento Nernstiano com uma sensibilidade de 53.0 / e desvio padrão de 2.3/ no intervalo de 2 a 9 pH

Development of Solution Blow Spun Nanofibers as Electrical and Whole Cell Biosensing Interfaces

Infectious pathogens place a huge burden on the US economy with more than $120 billion spent annually for direct and indirect costs for the treatment of infectious diseases. Rapid detection schemes continue to evolve in order to meet the demand of early diagnosis. In chronic wound infections, bacterial load is capable of impeding the healing process. Additionally, bacterial virulence production works coherently with bacterial load to produce toxins and molecules that prolongs the healing cycle. This work examines the use of nonwoven polymeric conductive and non-conductive nanofiber mats as synthetic biosensor scaffolds, drug delivery and biosensor interface constructs. A custom-made nanofiber platform was built to produce solution blow spun nanofibers of various polymer loading. Antimicrobial nanofiber mats were made with the use of an in-situ silver chemical reduction method. Ceria nanoparticles were incorporated to provide an additional antioxidative property. Conductivity properties were examined by using silver and multi-walled carbon nanotubes (MWCNT) as a filler material. SBS parameters were adjusted to analyze electrical conductivity properties. Nanofiber mats were used to detect bacteria concentrations in vitro. Protein adhesion to conductive nanofibers was studied using fluorescent antibodies and BCA assay. Anti-rabbit and streptavidin Alexa Flour 594 was used to examine the adsorption properties of SBS nanofiber mats. Enhancements were made to further improve interface design for specificity. SBS nanofiber electrodes were fabricated to serve as scaffold and detection site for spike protein detection. Bacteria virulence production was examined by the detection of pyocyanin and quorum sensing molecules. The opportunistic pathogen, Pseudomonas aeruginosa is a nosocomial iii pathogen found in immunocompromised patients with such as those with chronic wounds and cystic fibrosis. Pyocyanin is one of four quorum sensing molecules that the pathogen produces which can be detected electrochemically due to its inherent redox-active activity. SBS has been used to develop a sensing scheme to detect pyocyanin. This work also examines the use of a synthetic biosensor with a LasR based system capable of detecting homoserine lactone produced by P. aeruginosa and other common gram-negative pathogens. Genetic modifications were made to biosensor in order to replace a green, fluorescent reporter with a chromoprotein based reporter system for visual readout. Additionally, work related to community service and outreach regarding the encouragement of middle school students to pursue Science, Technology, Engineering and Math (STEM) was conducted. Results from outreach program showed an increase in the STEM interest among a group of middle school students. There was a general trend with STEM career knowledge, STEM self-efficacy and the level of interest in STEM careers and activities. Military research was also done with the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) to develop several assays for the detection of several highly infectious viruses and bacteria. Due to confidentiality, the work cannot be published in this manuscript