Rapid prototyping of a temperature, humidity, and pressure monitor electronic layer for Pressure Ulcer wound patch

Abstract Pressure ulcer is a result of relieving pressure from skin or underlying tissues, causing localized injuries. In this study, a prototype of an electronic monitoring layer that can be placed on top of the wound patch is designed. The electronic layer is comprised of four force-sensitive pressure sensors, and an integrated temperature and humidity sensor to monitor the activities surrounding the wound site. In the simulated wound bed experiments, the results indicated that the utilization of the Bosch BME280 I2C module, when placed on top of a gauze pad, can deliver accurate and real-time monitoring of the temperature and humidity values. Furthermore, the force-sensitive resistors (FSR) installed can be utilized to detect external pressure beyond the set allowable force applied of 32 mmHg or 700g. Therefore, the electronic layer assembled from commercially available sensors can be used to monitor temperature and humidity while being able to detect externally applied pressure in real-time. However, improvements in the size and flexibility of the electronic layer are necessary to reduce the discomfort that patients suffering from pressure ulcers will experience.

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Electromechanical Response of Conductive Porous Structure

Journal of Nanomaterials ◽

10.1155/2015/868405 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6

Author(s):

Hye-Mi So ◽

Cheolmin Park ◽

Won Seok Chang

Keyword(s):

Carbon Nanotube ◽

Field Effect ◽

Field Effect Transistors ◽

Pressure Sensors ◽

External Pressure ◽

Electrical Characteristics ◽

Porous Structures ◽

Single Walled Carbon Nanotube ◽

Consistent Change ◽

Sensitive Pressure

Porous conductors with large surface-volume ratios have been applied to a variety of fields, including absorbents, flexible heaters, and electrodes for supercapacitors. In this study, we implemented sensitive pressure sensors using the mechanical and electrical characteristics of conductive porous structures manufactured by immersing sponges into a carbon nanotube solution and then measured the change in resistance. When pressure was applied to conductive sponges, carbon nanotubes were attached to each other and the resistance was reduced by up to 20%. The carbon nanotube sponges, which were soft and had superior elasticity, were quickly stabilized without any changes taking place in their shape, and they showed consistent change in resistance during experiments of repetitive pressure. The pressure devices based on conductive porous sponges were connected to single-walled carbon nanotube field effect transistors (SWCNT-FETs) and changes in their characteristics were investigated according to external pressure.

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Pressure Sensors: Highly Sensitive Pressure Sensor Based on Bioinspired Porous Structure for Real-Time Tactile Sensing (Adv. Electron. Mater. 12/2016)

Advanced Electronic Materials ◽

10.1002/aelm.201670065 ◽

2016 ◽

Vol 2 (12) ◽

Cited By ~ 1

Author(s):

Subin Kang ◽

Jaehong Lee ◽

Sanggeun Lee ◽

SeulGee Kim ◽

Jae-Kang Kim ◽

...

Keyword(s):

Porous Structure ◽

Real Time ◽

Pressure Sensor ◽

Pressure Sensors ◽

Tactile Sensing ◽

Highly Sensitive ◽

Sensitive Pressure

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Development of circuit solution and design of capacitive pressure sensor array for applied robotics

Robotics and Technical Cybernetics ◽

10.31776/rtcj.8406 ◽

2020 ◽

Vol 8 (4) ◽

pp. 296-307

Author(s):

Konstantin Krestovnikov ◽

Aleksei Erashov ◽

Аleksandr Bykov

Keyword(s):

Pressure Sensor ◽

Output Signal ◽

Sensor Array ◽

Applied Pressure ◽

Pressure Sensors ◽

Fine Tuning ◽

Capacitive Pressure Sensor ◽

Cell Parameters ◽

Linear Pattern ◽

Sensor Structure

This paper presents development of pressure sensor array with capacitance-type unit sensors, with scalable number of cells. Different assemblies of unit pressure sensors and their arrays were considered, their characteristics and fabrication methods were investigated. The structure of primary pressure transducer (PPT) array was presented; its operating principle of array was illustrated, calculated reference ratios were derived. The interface circuit, allowing to transform the changes in the primary transducer capacitance into voltage level variations, was proposed. A prototype sensor was implemented; the dependency of output signal power from the applied force was empirically obtained. In the range under 30 N it exhibited a linear pattern. The sensitivity of the array cells to the applied pressure is in the range 134.56..160.35. The measured drift of the output signals from the array cells after 10,000 loading cycles was 1.39%. For developed prototype of the pressure sensor array, based on the experimental data, the average signal-to-noise ratio over the cells was calculated, and equaled 63.47 dB. The proposed prototype was fabricated of easily available materials. It is relatively inexpensive and requires no fine-tuning of each individual cell. Capacitance-type operation type, compared to piezoresistive one, ensures greater stability of the output signal. The scalability and adjustability of cell parameters are achieved with layered sensor structure. The pressure sensor array, presented in this paper, can be utilized in various robotic systems.

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Development of a Self-Powered Piezo-Resistive Smart Insole Equipped with Low-Power BLE Connectivity for Remote Gait Monitoring

Sensors ◽

10.3390/s21134539 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4539

Author(s):

Roberto de Fazio ◽

Elisa Perrone ◽

Ramiro Velázquez ◽

Massimo De Vittorio ◽

Paolo Visconti

Keyword(s):

Low Power ◽

Smart Materials ◽

Applied Pressure ◽

Pressure Sensors ◽

Complete Characterization ◽

Electric Signal ◽

Sensing Matrix ◽

Capacitive Accelerometer ◽

Gait Parameters ◽

Smart Insole

The evolution of low power electronics and the availability of new smart materials are opening new frontiers to develop wearable systems for medical applications, lifestyle monitoring, and performance detection. This paper presents the development and realization of a novel smart insole for monitoring the plantar pressure distribution and gait parameters; indeed, it includes a piezoresistive sensing matrix based on a Velostat layer for transducing applied pressure into an electric signal. At first, an accurate and complete characterization of Velostat-based pressure sensors is reported as a function of sizes, support material, and pressure trend. The realization and testing of a low-cost and reliable piezoresistive sensing matrix based on a sandwich structure are discussed. This last is interfaced with a low power conditioning and processing section based on an Arduino Lilypad board and an analog multiplexer for acquiring the pressure data. The insole includes a 3-axis capacitive accelerometer for detecting the gait parameters (swing time and stance phase time) featuring the walking. A Bluetooth Low Energy (BLE) 5.0 module is included for transmitting in real-time the acquired data toward a PC, tablet or smartphone, for displaying and processing them using a custom Processing® application. Moreover, the smart insole is equipped with a piezoelectric harvesting section for scavenging energy from walking. The onfield tests indicate that for a walking speed higher than 1 ms−1, the device’s power requirements (i.e., ) was fulfilled. However, more than 9 days of autonomy are guaranteed by the integrated 380-mAh Lipo battery in the total absence of energy contributions from the harvesting section.

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Wearable Sensor-Based Real-Time Gait Detection: A Systematic Review

Sensors ◽

10.3390/s21082727 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2727

Author(s):

Hari Prasanth ◽

Miroslav Caban ◽

Urs Keller ◽

Grégoire Courtine ◽

Auke Ijspeert ◽

...

Keyword(s):

Systematic Review ◽

Gait Analysis ◽

Real Time ◽

Wearable Sensors ◽

Pressure Sensors ◽

Clinical Applications ◽

Performance Comparison ◽

Heel Strike ◽

Rule Based ◽

Pathological Gait

Gait analysis has traditionally been carried out in a laboratory environment using expensive equipment, but, recently, reliable, affordable, and wearable sensors have enabled integration into clinical applications as well as use during activities of daily living. Real-time gait analysis is key to the development of gait rehabilitation techniques and assistive devices such as neuroprostheses. This article presents a systematic review of wearable sensors and techniques used in real-time gait analysis, and their application to pathological gait. From four major scientific databases, we identified 1262 articles of which 113 were analyzed in full-text. We found that heel strike and toe off are the most sought-after gait events. Inertial measurement units (IMU) are the most widely used wearable sensors and the shank and foot are the preferred placements. Insole pressure sensors are the most common sensors for ground-truth validation for IMU-based gait detection. Rule-based techniques relying on threshold or peak detection are the most widely used gait detection method. The heterogeneity of evaluation criteria prevented quantitative performance comparison of all methods. Although most studies predicted that the proposed methods would work on pathological gait, less than one third were validated on such data. Clinical applications of gait detection algorithms were considered, and we recommend a combination of IMU and rule-based methods as an optimal solution.

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CMOS-MEMS Based Current Mirror MOSFET Embedded Pressure Sensor for Healthcare and Biomedical Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.647.315 ◽

2013 ◽

Vol 647 ◽

pp. 315-320 ◽

Cited By ~ 6

Author(s):

Pradeep Kumar Rathore ◽

Brishbhan Singh Panwar

Keyword(s):

Pressure Sensor ◽

Biomedical Applications ◽

Circuit Simulation ◽

Applied Pressure ◽

Pressure Sensors ◽

Cmos Technology ◽

Current Mirror ◽

Sensing Element ◽

Pressure Sensing ◽

Cmos Mems

This paper reports on the design and optimization of current mirror MOSFET embedded pressure sensor. A current mirror circuit with an output current of 1 mA integrated with a pressure sensing n-channel MOSFET has been designed using standard 5 µm CMOS technology. The channel region of the pressure sensing MOSFET forms the flexible diaphragm as well as the strain sensing element. The piezoresistive effect in MOSFET has been exploited for the calculation of strain induced carrier mobility variation. The output transistor of the current mirror forms the active pressure sensing MOSFET which produces a change in its drain current as a result of altered channel mobility under externally applied pressure. COMSOL Multiphysics is utilized for the simulation of pressure sensing structure and Tspice is employed to evaluate the characteristics of the current mirror pressure sensing circuit. Simulation results show that the pressure sensor has a sensitivity of 10.01 mV/MPa. The sensing structure has been optimized through simulation for enhancing the sensor sensitivity to 276.65 mV/MPa. These CMOS-MEMS based pressure sensors integrated with signal processing circuitry on the same chip can be used for healthcare and biomedical applications.

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A Systematic Approach to the Design and Characterization of a Smart Insole for Detecting Vertical Ground Reaction Force (vGRF) in Gait Analysis

Sensors ◽

10.3390/s20040957 ◽

2020 ◽

Vol 20 (4) ◽

pp. 957 ◽

Cited By ~ 6

Author(s):

Anas M. Tahir ◽

Muhammad E. H. Chowdhury ◽

Amith Khandakar ◽

Sara Al-Hamouz ◽

Merna Abdalla ◽

...

Keyword(s):

Gait Analysis ◽

Reaction Force ◽

Applied Pressure ◽

Pressure Sensors ◽

Clinical Diagnostics ◽

Piezoelectric Sensors ◽

Sensor Calibration ◽

Vertical Ground Reaction Force ◽

Vertical Ground ◽

Smart Insole

Gait analysis is a systematic study of human locomotion, which can be utilized in various applications, such as rehabilitation, clinical diagnostics and sports activities. The various limitations such as cost, non-portability, long setup time, post-processing time etc., of the current gait analysis techniques have made them unfeasible for individual use. This led to an increase in research interest in developing smart insoles where wearable sensors can be employed to detect vertical ground reaction forces (vGRF) and other gait variables. Smart insoles are flexible, portable and comfortable for gait analysis, and can monitor plantar pressure frequently through embedded sensors that convert the applied pressure to an electrical signal that can be displayed and analyzed further. Several research teams are still working to improve the insoles’ features such as size, sensitivity of insoles sensors, durability, and the intelligence of insoles to monitor and control subjects’ gait by detecting various complications providing recommendation to enhance walking performance. Even though systematic sensor calibration approaches have been followed by different teams to calibrate insoles’ sensor, expensive calibration devices were used for calibration such as universal testing machines or infrared motion capture cameras equipped in motion analysis labs. This paper provides a systematic design and characterization procedure for three different pressure sensors: force-sensitive resistors (FSRs), ceramic piezoelectric sensors, and flexible piezoelectric sensors that can be used for detecting vGRF using a smart insole. A simple calibration method based on a load cell is presented as an alternative to the expensive calibration techniques. In addition, to evaluate the performance of the different sensors as a component for the smart insole, the acquired vGRF from different insoles were used to compare them. The results showed that the FSR is the most effective sensor among the three sensors for smart insole applications, whereas the piezoelectric sensors can be utilized in detecting the start and end of the gait cycle. This study will be useful for any research group in replicating the design of a customized smart insole for gait analysis.

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Micromachined Pressure Sensors on Optical Fiber Tip

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.74.149 ◽

2009 ◽

Vol 74 ◽

pp. 149-152

Author(s):

X.M. Zhang ◽

M. Yu ◽

Silas Nesson ◽

H. Bae ◽

A. Christian ◽

...

Keyword(s):

Optical Fiber ◽

Pressure Sensor ◽

Linear Response ◽

Applied Pressure ◽

Pressure Sensors ◽

Outer Diameter ◽

Sensor Element ◽

Batch Fabrication ◽

In Vitro Measurements

This paper reports the development of a miniature pressure sensor on the optical fiber tip for in vitro measurements of rodent intradiscal pressure. The sensor element is biocompatible and can be fabricated by simple, batch-fabrication methods in a non-cleanroom environment with good device-to-device uniformity. The fabricated sensor element has an outer diameter of only 366 μm, which is small enough to be inserted into the rodent discs without disrupting the structure or altering the intradiscal pressures. In the calibration, the sensor element exhibits a linear response to the applied pressure over the range of 0 - 70 kPa, with a sensitivity of 0.0206 μm/kPa and a resolution of 0.17 kPa.

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Indoor Air Quality Real-Time Monitoring in Airport Terminal Areas: An Opportunity for Sustainable Management of Micro-Climatic Parameters

Sensors ◽

10.3390/s18113798 ◽

2018 ◽

Vol 18 (11) ◽

pp. 3798 ◽

Cited By ~ 9

Author(s):

Sara Zanni ◽

Francesco Lalli ◽

Eleonora Foschi ◽

Alessandra Bonoli ◽

Luca Mantecchini

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Real Time ◽

Indoor Air ◽

Electronic Monitoring ◽

Ventilation System ◽

Real Time Monitoring ◽

Airport Terminal ◽

Air Ventilation ◽

Gaseous Contaminants

Indoor air quality (IAQ) management in public spaces is assuming a remarkable importance. Busy environments, like airport terminals, are currently regarded as possible hotspots and IAQ is a crucial element for passengers and staff protection, as well as a key aspect of airport passenger experience. A one-month monitoring period has been performed on IAQ in the airport of Bologna (Italy), as prototypal example of large regional airport. Four strategic areas within the airport have been equipped with electronic monitoring platforms, including different contaminants and two microclimatic sensors. Data suggest that daily variation in IAQ parameters typically follow the activity pattern of the different environments under study (i.e., passengers’ flows) for gaseous contaminants, where particulate matter counts oscillate in a definite range, with a significant role played by ventilation system. Gaseous contaminants show a correlation between indoor and outdoor concentrations, mainly due to airside activities. Micro-climatic comfort parameters have been tested to match with standards for commercial environments. As results appears in line with typical households IAQ values, the current air ventilation system appears to be adequate. Nevertheless, an integrated air management system, based on real-time monitoring, would lead to optimization and improvement in environmental and economical sustainability.

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