Wireless Measurement Technique for Telemetry Low-Value Resistive Sensors

AbstractThe measurement of different quantities in harsh environments, such as those at high temperatures and/or in hermetic environments, presents considerable difficulties due to various factors, including the characteristics of the harsh environment itself, which do not allow the proper use of the electronics and / or using connection cables between the harsh and the safe environment. An adoptable solution is given by passive telemetry systems that include a passive sensor placed inside the harsh environment. Non-contact techniques are adopted to read the quantities. The measurement technique that is proposed may be adopted for resistive sensors. The system consists of a resistive sensor that is connected to an inductor and coupled to a second inductor positioned externally. The external inductor is connected to the readout electronics and permit, using the proposed technique, to calculate the value of the sensor resistance. The adopted telemetric technique is based on a measurement of the impedance at the terminals of the readout inductor and on a mathematical elaboration to extract the sensor resistance. The circuit model of the telemetric system is presented, several consideration on the telemetric technique are reported based on simulations and experimental results

Concept Generation and Preliminary Prototyping of a Tailored Smart Glove with Capacitive Pressure Sensors for Force Grip Analysis in Cycling

Design methods for sports engineering allow to improve the world around the athlete. In cycling, a sport device that can be useful to reduce and monitor the risk of injuries is a smart glove equipped with pressure sensors. The literature underlined how the current design methods lack the comprehensive consideration of sensors integration for force analysis at the handlebar. Furthermore, the majority of existing solutions is based on resistive pressure sensors. In this work, we present mainly two advancements with respect to the state-of-the-art: (1) user-centered design methodology for the glove development, which allows to take care about the main design parameters which involve the cyclist, namely her/his anthropometric characteristics and her/his sport gesture analysis (achieved by the pressure analysis on the handlebar) during classic grip position of cycling (i.e., top grip); (2) prototyping of custom-made capacitive pressure sensors instead of classic commercial resistive pressure sensors. The work involves the concept generation, the selection of the optimal concept through Kano and Quality of Function Development as well as the preliminary prototyping of one capacitive pressure sensor, realized using a fabrication process involving additive manufacturing techniques and silicon molding

Magnetic localization system for short-range positioning: a ready-to-use design tool

Magnetic localization is used in many indoor positioning applications, such as industrial, medical, and IoT, for its benefits related to the absence of line of sight needs, multipath and fading, the low cost of transmitters and receivers, and the simple development of setups made of coils and magnetic sensors. In short-range applications, this technology could bring some advantages with respect to ultrasound, laser, or RF ones. Nevertheless, fixed both the desired accuracy and the energy constraints, the optimal design of a localization system based on magnetic measurement depends on several factors: the dimension, the number and the optimal positions of the anchors, the uncertainties due to the sensing elements, and the data acquisition systems (DAQs). To preliminary fix all these parameters, suitable simulation environments allow developers to save time and money in developing localization applications. Many magnetic field simulators are available, but it is rare to find those that, considering the uncertainty due to the receiver and DAQs, are able to provide optimal anchors scenario given a target accuracy. To address this problem, this article presents a simulation tool providing the user with design requirements for given target accuracy. The aim of this article is to perform the first steps in providing a ready-to-use specification framework that given the localization domain, the mobile sensors, the DAQ characteristics, and the target accuracy and helps the developer of indoor magnetic positioning systems. The actual validity of the simulation model has been tested on a real setup.Postprint (published version

Wireless Point-of-Care Platform With Screen-Printed Sensors for Biomarkers Detection

Measurement systems for early and reliable detection of degenerative diseases, such as Alzheimer's disease (AD), are extremely important in clinical diagnosis. Among these, biochemical assays represent a commonly used method to distinguish patients from healthy population thanks to the sensitive recognition of specific biomarkers in biological fluids. In order to overcome actual limitations of these techniques in term of cost, standardization, and sensitivity, this study aimed to realize a low-cost highly sensitive portable point-of-care (PoC) testing system based on screen-printed electrochemical sensors. The development of the platform specifically included both the design of the sensing probe and the electronic circuit devoted to condition and acquires the transduced electric signal. The designed circuit was implemented in a printed circuit board and interfaced to a wireless system based on bluetooth data transmission in order to improve the portability of the proposed solution. Preliminary results were obtained by using controlled concentrations of electrolytic solutions and calibrating the sensors for antibodies and for a well-known protein (i.e., interleukin 8) quantified by anodic stripping voltammetry (ASV). Findings from ASV measurements showed a sensitivity of 38 μA/(ng/ml) with a tested range from 1.25 to 20 ng/ml, with a limit of detection of 2 ng/ml. Further investigation will include the validation of this PoC device by testing the concentration of a specific p53 protein isoform, which was recently identified to early correlate to AD development

Passive and Self-Powered Autonomous Sensors for Remote Measurements

Autonomous sensors play a very important role in the environmental, structural, and medical fields. The use of this kind of systems can be expanded for several applications, for example in implantable devices inside the human body where it is impossible to use wires. Furthermore, they enable measurements in harsh or hermetic environments, such as under extreme heat, cold, humidity or corrosive conditions. The use of batteries as a power supply for these devices represents one solution, but the size, and sometimes the cost and unwanted maintenance burdens of replacement are important drawbacks. In this paper passive and self-powered autonomous sensors for harsh or hermetical environments without batteries are discussed. Their general architectures are presented. Sensing strategies, communication techniques and power management are analyzed. Then, general building blocks of an autonomous sensor are presented and the design guidelines that such a system must follow are given. Furthermore, this paper reports different proposed applications of autonomous sensors applied in harsh or hermetic environments: two examples of passive autonomous sensors that use telemetric communication are proposed, the first one for humidity measurements and the second for high temperatures. Other examples of self-powered autonomous sensors that use a power harvesting system from electromagnetic fields are proposed for temperature measurements and for airflow speeds

Measuring inside your mouth! Measurement approaches, design considerations, and one example for tongue pressure monitoring

The tongue is an important muscular organ, and its interaction with the hard palate is fundamental during speech and deglutition (the act or process of swallowing). For example, typical complications of cerebrovascular diseases are speech and deglutition disorders due to limited range of motion and tongue weaknesses. Different measurement approaches of these limitations are described in the literature. The development of low-invasive measuring systems is currently considered a priority. In this paper, we describe different approaches, design considerations, and one example: a new implantable intraoral device that we developed to measure tongue pressure [1]. This paper was first submitted to the IEEE MeMeA Symposium 2014 (© 2014 IEEE, in Proc. IEEE MeMeA, used with permission, [1].) This new device measures tongue pressure on the hard palate directly inside the oral cavity and transmits the data via a wireless link. Since no cable links the pressure sensors inside the oral cavity and the readout unit is located outside of the mouth, this device is low invasive, which represents an important feature for this type of device. We describe a typical experimental setup to study the mechanical behavior of these devices in the laboratory and specific test protocols. The field of application of these devices is the treatment of patients with deglutition and speech disorders or with gnathological (related to the entire chewing apparatus) and dental disturbances

Wireless Wearable T-Shirt for Posture Monitoring During Rehabilitation Exercises

The monitoring of any human physiological parameters during rehabilitation exercises requires noninvasive sensors for the patient. This paper describes a wireless wearable T-shirt for posture monitoring during rehabilitation or reinforcement exercises. The subject posture is measured through a sensorized T-shirt using an inductive sensor sewn directly on the fabric. The wireless wearable T-shirt design specifications are the following: independence from the remote unit, easy to use, lightweight and comfort of wearing. This paper reports the conceptual framework, the fabricated device description, and the adopted experimental setup. The instrumented T-shirt's output data are compared with the data obtained via an optical system, as a gold standard, that measures the marker positions over the patient's back and chest. The trials performed on four subjects obtained on different days demonstrate that the wireless wearable sensor described in this paper is capable of producing reliable data compared with the data obtained with the optical system. The constitutive sensor simplicity that includes only a copper wire and a separable circuit board allows achieving the objectives of simplicity, ease of use, and noninvasiveness. The sensorized T-shirt, integrated with designed conditioning and transmission electronics for remote communication, could be used as a support tool for postural monitoring during rehabilitation exercises

Wireless Instrumented Crutches for Force and Movement Measurements for Gait Monitoring

This paper describes the design, development, and characterization of two wireless instrumented crutches for gait monitoring in order to provide clinicians quantitative parameters of upper limbs’ contributions during walking. These parameters could be used to teach orthopedic patients to correctly use these supports and minimize problems connected to their usage. These instrumented crutches allow monitoring axial forces and shear forces, tilt angles, and time of impact on the ground in real time. Each crutch is composed of three strain-gauge bridges for measuring axial and shear forces, a conditioning circuit with transmission module, a triaxial accelerometer, a power management circuit, two batteries, and a biofeedback. The data are wirelessly transmitted via Bluetooth without needing any further readout unit, from the crutches to a personal computer, where the data are processed and displayed by a program created in LabVIEW. Each instrumented crutch was tested to assess the response of the accelerometer and the three strain-gauge bridges using a setup designed ad hoc. The mean experimental standard deviation was about 42 mV for axial forces corresponding to about 8 N and about 35 mV for shear forces corresponding to about 4 N. Hysteresis, linearity, and drift were calculated, and the obtained accuracy was about 8–9 N for axial forces and 4–5 N for shear forces. Furthermore, the crutches were tested during a walking activity of ten healthy subjects along a straight path for several trials. These crutches were used for a common analysis usually reported in the literature for weight bearing evaluation. The subjects were monitored performing a nonweight bearing (NWB) and a partial weight bearing (PWB) during a three-point gait. The results showed a mean of 102%±16% for NWB tests and a mean of 19%±14% for 10% PWB tests; these values are in agreement with similar studies in the literature. The simplicity that includes only constitutive strain gauges and a separable circuit board allows the achievement of the objectives of simplicity, ease of use, and noninvasiveness. Therefore, these crutches could be used as a support tool for controlling the use of crutches during walking not only in hospitals but also at home

Telemetric Model for Passive Resistive Sensors in Biomedical Applications

The present work describes a telemetric resistive sensor to be exploited in biomedical applications, in order to monitor vital parameters in real time. The corresponding telemetry technique is based on an impedance measurement performed at its input terminal and on a theoretical study which identifies a complex mathematical relation between sensor's resistance and impedance phase value at a specific frequency point. A model for this system is proposed, analysed and discussed, while the telemetric technique based on it is described