Dew-Based Wireless Mini Module for Respiratory Rate Monitoring (original) (raw)
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Wireless microsensors system for monitoring breathing activity
… Conference of the …, 2009
A portable, non-invasive and easy to operate wireless system has been developed for monitoring the breathing activity of patient. The system is composed of a capacitive microsensor (airflow-humidity sensor) integrated on a silicon chip and of a Negative Temperature Coefficient thermistor; both are coupled to a Radio Frequency wireless link. The sensitive part of the microsensor is an array of interdigitated metallic electrodes covered by 100 nm-thick dense anodized aluminum oxide layer. The breath water vapor is adsorbed over the interdigitated electrode and changes the sensor characteristic capacitance. This modulated signal is then digitized and either stored in a memory or directly transmitted to a monitor through the short distance RF link. Full size of the microsensor is less than 1 cm² and can be easily implemented in a classical adhesive bandage. This microsystem is proposed for monitoring sleep-disordered breathing as well as breathing rhythm of athletes during effort.
Humidity sensors for a pulmonary function diagnostic microsystem
Sensors and Actuators B: Chemical, 2001
The work reported here is a part of an European research project. The aim of the project is the implementation of a multisensor microsystem for pulmonary diagnostic functions for chronic obstructive pulmonary diseases and asthma patients. The proposed microsystem is required to measure simultaneously peak expiratory¯ow, temperature, relative humidity and pressure. We have in charge the realisation of the humidity sensor. The structure realised with compatible CMOS technology consists in two coplanar electrodes covered by a humidity sensing dielectric. Interdigitated sensors have been realised using silicon as substrate, aluminium as conductor and polyimide Ultradel as dielectric. Sensors responses show that we have a quick absorption of humidity (less than 1 s) and a longer desorption (15 s). The in¯uence of the geometry and the dielectric material on the performance of the sensor (sensitivity, response time) will be reported. Specially, we will demonstrate that a plasma etching of the dielectric surface notably increases the sensitivity. #
Integrated micro power frequency breath detector
Sensors and Actuators A-physical, 2016
Monitoring vital signs, which include breathing, is often used both in clinical practice and at home. The paper presents a novel low power system that can be used to control breathing frequency and detect apnea, which uses a condenser-type humidity sensor supplied with input bias current of an operational amplifier. The new configuration of the sensor, which compensates for the amplifier saturation state during the exhalation phase, increases breath detection effectiveness. The presented system is energy efficient, consumes approx. 50A and operates over a wide range of supply voltages, 1.818VDC. It enables to detect even very weak breathing. The concept of the integrated system has also been presented. This system can work directly with digital circuits without converting the electric signal. The presented system is characterized by a very simple construction and offers a new solution both in the field of sensor technology and for the use of operational amplifiers.
Miniaturized and Low Cost Innovative Detection Systems for Medical and Environmental Applications
Innovative, simple, miniaturized, low-cost and low-power consumption devices are required in future medical applications. In our laboratory we have developed different devices in this field. Firstly, oxide aluminum-coated interdigitated (ID) Al capacitors have been successfully tested for DNA hybridization test (down to 30 pM target concentrations), as well as for specific bacteria recognition (S. Aureus, down to 100 CFU on a sensing area of 200x200 μm 2 ) with an appropriate anti-monoclonal antibody (MoAb) and finally for humidity detection with application in a breath rate monitoring system, an important element for preventive medical studies, which is light, non-invasive, comfortable to wear for the patient. Secondly a complete microsystem enabling the measurement of biomolecules concentration in assay tubes has been developed based on ultraviolet (UV) light absorption with miniaturized LEDs and SOI high-efficiency photodiodes. Our technologies combine high-performance CMOS integrated circuits, sensors and MEMS; operation in harsh conditions (micro power, high-temperature, remote RF link, etc.); very low power consumption; and broad applications in biomedical and environmental sectors. This opens the door to many new emerging applications into medical devices.
Disease Biomarkers Detection in Breath with a Miniaturized Electronic Nose
Lecture Notes in Electrical Engineering, 2021
A miniaturized wireless electronic nose for the detection of diseases through the breath is introduced in this communication. The device presented has an electronic design similar to previous prototypes, but with a smaller size and consumption. It is equipped with four miniaturized digital gas sensors and an integrated temperature and humidity sensor. Power is provided by a battery that can be charged through a micro USB connector. The system is connected through a low-energy Bluetooth connection. Different biomarkers corresponding to three diseases have been selected to verify the capacity of the prototype to discriminate among them. CO, NO and NO 2 have been selected as biomarkers of COPD or asthma, and acetone for diabetes. The e-nose has been used to measure the selected biomarkers at different concentrations, corresponding with different levels of gravity of illnesses. The target compound mixtures are generated from calibrated gas bullets and permeation tubes, with relative humidity up to 50%.
A Battery-Less Wireless Respiratory Sensor Using Micro-Machined Thin-Film Piezoelectric Resonators
Micromachines
In this work, we present a battery-less wireless Micro-Electro-Mechanical (MEMS)-based respiration sensor capable of measuring the respiration profile of a human subject from up to 2 m distance from the transceiver unit for a mean excitation power of 80 µW and a measured SNR of 124.8 dB at 0.5 m measurement distance. The sensor with a footprint of ~10 cm2 is designed to be inexpensive, maximize user mobility, and cater to applications where disposability is desirable to minimize the sanitation burden. The sensing system is composed of a custom UHF RFID antenna, a low-loss piezoelectric MEMS resonator with two modes within the frequency range of interest, and a base transceiver unit. The difference in temperature and moisture content of inhaled and exhaled air modulates the resonance frequency of the MEMS resonator which in turn is used to monitor respiration. To detect changes in the resonance frequency of the MEMS devices, the sensor is excited by a pulsed sinusoidal signal receive...
A Capacitive Humidity Sensor Suitable for CMOS Integration
IEEE Sensors Journal, 2000
This paper describes the design, fabrication, and performance of a thin film humidity sensor fabricated in standard CMOS process, hence it may be combined with an integrated circuit. The sensor is based on a capacitance between interdigitated electrodes in the top metal layer and water adsorption in the polyimide layer. The design is optimized by analytical and then finite element models which show that, within the constraint of the CMOS structure, the sensitivity can be no greater than one third of the sensitivity of the polyimide alone. Experimental sensors were fabricated in-house before an improved design was fabricated in a commercial foundry. The different behavior of these sensors, despite their similar designs, leads to an investigation into the effects of fabrication process on the sensor linearity. Characterizing the polyimide film by contact angle, AFM and FTIR revealed that the difference in linearity of the response between the two sensors resulted from different etching techniques employed to pattern the film.
IEEE Sensors Journal, 2002
This paper presents our work toward the integration of a multisensor microsystem with wireless communication, using system-on-chip (SoC) methodology. Four different forms of microelectronic sensors have been fabricated on two separate 5 5 mm 2 silicon chips measuring pH, conductivity, dissolved oxygen concentration, and temperature. The sensors are integrated with a sensor fusion chip comprising analog circuitry for sensor operation and signal amplification prior to digital decoding and transmission. The microsystem prototype will be packaged in a miniature capsule, which measures 16 mm 55 mm including batteries and dissipates 6.3 mW for a minimal life cycle of 12 h.
Smart Sensor Systems for Human Health Breath Monitoring Applications
Volatile Biomarkers, 2013
Breath analysis techniques offer a potential revolution in health care diagnostics, especially if these techniques can be brought into standard use in the clinic and at home. The advent of microsensors combined with smart sensor system technology enables a new generation of sensor systems with significantly enhanced capabilities and minimal size, weight and power consumption. This paper discusses the microsensor/smart sensor system approach and provides a summary of efforts to migrate this technology into human health breath monitoring applications. First, the basic capability of this approach to measure exhaled breath associated with exercise physiology is demonstrated. Building from this foundation, the development of a system for a portable asthma home health care system is described. A solid-state nitric oxide (NO) sensor for asthma monitoring has been identified, and efforts are underway to miniaturize this NO sensor technology and integrate it into a smart sensor system. It is concluded that base platform microsensor technology combined with smart sensor systems can address the needs of a range of breath monitoring applications and enable new capabilities for healthcare.