scholarly journals Implantable Blood Pressure Sensors with Analogic Thermal Drift Compensation

2021 ◽  
Vol 6 (1) ◽  
pp. 34
Author(s):  
Serigne Modou Die Mbacke ◽  
Mohammed El Gibari ◽  
Benjamin Lauzier ◽  
Chantal Gautier ◽  
Hongwu Li
Keyword(s):  
Output Voltage ◽  
Pressure Sensors ◽  
Equivalent Model ◽  
Battery Life ◽  
Implantable Sensors ◽  
Thermal Drift ◽  
Research Activity ◽  
Drift Compensation ◽  
The Cost ◽  
Conditioning Circuit

Implantable pressure sensors represent an important part of the research activity in laboratories. Unfortunately, their use is limited by cost, autonomy and temperature-related drifts. The cost of use depends on several parameters, particularly their low battery life and the need for miniaturization to be able to implant the animals and monitor them over a time that is long enough to be physiologically relevant. This paper studied the possibility of reducing the thermal drift of implantable sensors. To quantify and compensate for the thermal drift, we developed the equivalent model of the piezoresistive probe by using the Cadence software. Our model takes into account the temperature (34–39 °C) as well as the pressure (0–300 mmHg). We were thus able to identify the source of the drift and thanks to our model, we were able to compensate for it thanks to the compensation circuits added to the conditioning circuits of the sensor. The maximum relative drift of the sensor is (0.1 mV/°C)/3.6 mV (2.7%), a drift of the conditioning circuit is (0.98 mV/°C)/916 mV (0.1%) and the whole is (13.4 mV/°C)/420 mV (32%). The compensated sensor shows a relative maximum drift of (0.371 mV/°C)/405 mV (0.09%). The output voltage remains stable over the measurement temperature range.

Thermal drift compensation of piezoresistive implantable blood pressure sensors with low cost analog solutions

2017 ◽  
Author(s):  
Mohammed El Gibari ◽  
Clement Le Bleis ◽  
Guillaume Lirzin ◽  
Benjamin Lauzier ◽  
Stephane Ginestar ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Low Cost ◽  
Pressure Sensors ◽  
Thermal Drift ◽  
Drift Compensation

scholarly journals A low-cost wireless endoscope camera: a preliminary report

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
J. M. Lazarus ◽  
M. Ncube
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Video Transmission ◽  
Low Cost ◽  
Battery Life ◽  
Resource Constrained ◽  
High Definition ◽  
Industry Standard ◽  
Constrained Environments ◽  
The Cost

Abstract Background Technology currently used for surgical endoscopy was developed and is manufactured in high-income economies. The cost of this equipment makes technology transfer to resource constrained environments difficult. We aimed to design an affordable wireless endoscope to aid visualisation during rigid endoscopy and minimally invasive surgery (MIS). The initial prototype aimed to replicate a 4-mm lens used in rigid cystoscopy. Methods Focus was placed on using open-source resources to develop the wireless endoscope to significantly lower the cost and make the device accessible for resource-constrained settings. An off the shelf miniature single-board computer module was used because of its low cost (US$10) and its ability to handle high-definition (720p) video. Open-source Linux software made monitor mode (“hotspot”) wireless video transmission possible. A 1280 × 720 pixel high-definition tube camera was used to generate the video signal. Video is transmitted to a standard laptop computer for display. Bench testing included latency of wireless digital video transmission. Comparison to industry standard wired cameras was made including weight and cost. The battery life was also assessed. Results In comparison with industry standard cystoscope lens, wired camera, video processing unit and light source, the prototype costs substantially less. (US$ 230 vs 28 000). The prototype is light weight (184 g), has no cables tethering and has acceptable battery life (of over 2 h, using a 1200 mAh battery). The camera transmits video wirelessly in near real time with only imperceptible latency of < 200 ms. Image quality is high definition at 30 frames per second. Colour rendering is good, and white balancing is possible. Limitations include the lack of a zoom. Conclusion The novel wireless endoscope camera described here offers equivalent high-definition video at a markedly reduced cost to contemporary industry wired units and could contribute to making minimally invasive surgery possible in resource-constrained environments.

Design and Simulation of Pressure Sensor for Ocean Depth Measurements

2013 ◽  
Vol 313-314 ◽  
pp. 666-670 ◽  
Author(s):  
K.J. Suja ◽  
Bhanu Pratap Chaudhary ◽  
Rama Komaragiri
Keyword(s):  
Pressure Sensor ◽  
Integrated Circuit ◽  
Output Voltage ◽  
Pressure Sensors ◽  
Micro Electro Mechanical System ◽  
Constant Thickness ◽  
Piezoresistive Pressure Sensor ◽  
Wide Pressure Range ◽  
Processing Techniques ◽  
Wide Pressure

MEMS (Micro Electro Mechanical System) are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Pressure sensors are usually manufactured using square or circular diaphragms of constant thickness in the order of few microns. In this work, a comparison between circular diaphragm and square diaphragm indicates that square diaphragm has better perspectives. A new method for designing diaphragm of the Piezoresistive pressure sensor for linearity over a wide pressure range (approximately double) is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage.

Signal conditioning circuit for gel strain sensors

2021 ◽  
Author(s):  
Ismael Payo ◽  
J. L. Polo ◽  
Blanca Lopez ◽  
Diana Serrano ◽  
Antonio M. Rodríguez ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Pressure Sensors ◽  
Strain Sensors ◽  
Resistance Force ◽  
Electrode Impedance ◽  
Signal Conditioning ◽  
Resistance Change ◽  
Signal Conditioning Circuit ◽  
Conditioning Circuit ◽  
Electrical Resistance Change

Abstract Conductive Hydrogels are soft materials which have been used by some researchers as resistive strain sensors in the last years. The electrical resistance change, when the sensor is stretched or compressed, is usually measured by the two-electrode method. This method is not always suitable to measure the electrical resistance of polymers-based materials, like hydrogels, because it could be highly influenced by the electrode/sample interface, as explained in this study. For this reason, a signal conditioning circuit, based on four-electrode impedance measurements, is proposed to measure the electrical resistance change when the gel is stretched or compressed. Experimental results show that the tested gels can be used as resistance force/pressure sensors with a quite linear behaviour.

scholarly journals A Heuristic Evolutionary Algorithm of UAV Path Planning

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Zhangjie Fu ◽  
Jingnan Yu ◽  
Guowu Xie ◽  
Yiming Chen ◽  
Yuanhang Mao
Keyword(s):  
Energy Consumption ◽  
Evolutionary Algorithm ◽  
Rapid Development ◽  
Optimal Path ◽  
Battery Life ◽  
Intelligent Robot ◽  
Urgent Problem ◽  
Intelligent Robots ◽  
Aerial Vehicle ◽  
The Cost

With the rapid development of the network and the informatization of society, how to improve the accuracy of information is an urgent problem to be solved. The existing method is to use an intelligent robot to carry sensors to collect data and transmit the data to the server in real time. Many intelligent robots have emerged in life; the UAV (unmanned aerial vehicle) is one of them. With the popularization of UAV applications, the security of UAV has also been exposed. In addition to some human factors, there is a major factor in the UAV’s endurance. UAVs will face a problem of short battery life when performing flying missions. In order to solve this problem, the existing method is to plan the path of UAV flight. In order to find the optimal path for a UAV flight, we propose three cost functions: path security cost, length cost, and smoothness cost. The path security cost is used to determine whether the path is feasible; the length cost and smoothness cost of the path directly affect the cost of the energy consumption of the UAV flight. We proposed a heuristic evolutionary algorithm that designed several evolutionary operations: substitution operations, crossover operations, mutation operations, length operations, and smoothness operations. Through these operations to enhance our build path effect. Under the analysis of experimental results, we proved that our solution is feasible.

scholarly journals Technology for monitoring everyday prosthesis use: a systematic review

2020 ◽  
Author(s):  
Alix Chadwell ◽  
Laura Diment ◽  
Encarna Micó Amigo ◽  
Dafne Zuleima Morgado Ramirez ◽  
Alexander Dickinson ◽  
...  
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Battery Life ◽  
Activity Levels ◽  
Everyday Activity ◽  
Prosthetic Devices ◽  
Clinical Scores ◽  
Standard Clinical Practice ◽  
The Cost

BackgroundUnderstanding how prostheses are used in everyday life is central to the design, provision and evaluation of prosthetic devices and associated services. This paper reviews the scientific literature on methodologies and technologies that have been used to assess the daily use of both upper- and lower-limb prostheses. It discusses the types of studies that have been undertaken, the technologies used to monitor physical activity, the benefits of monitoring daily living and the barriers to long-term monitoring.MethodsA systematic literature search was conducted in PubMed, Web of Science, Scopus, CINAHL and EMBASE of studies that monitored the activity of prosthesis-users during daily-living.Results60 lower-limb studies and 9 upper-limb studies were identified for inclusion in the review. The first studies in the lower-limb field date from the 1990s and the number has increased steadily since the early 2000s. In contrast, the studies in the upper-limb field have only begun to emerge over the past few years. The early lower-limb studies focused on the development or validation of actimeters, algorithms and/or scores for activity classification. However, most of the recent lower-limb studies used activity monitoring to compare prosthetic components. The lower-limb studies mainly used step-counts as their only measure of activity, focusing on the amount of activity, not the type and quality of movements. In comparison, the small number of upper-limb studies were fairly evenly spread between development of algorithms, comparison of everyday activity to clinical scores, and comparison of different prosthesis user populations. Most upper-limb papers reported the degree of symmetry in activity levels between the arm with the prosthesis and the intact arm.ConclusionsActivity monitoring technology used in conjunction with clinical scores and user feedback, offers significant insights into how prostheses are used and whether they meet the user’s requirements. However, the cost, limited battery-life and lack of availability in many countries mean that using sensors to understand the daily use of prostheses and the types of activity being performed has not yet become a feasible standard clinical practice. This review provides recommendations for the research and clinical communities to advance this area for the benefit of prosthesis users.

An Innovative Technology for Measuring The Dynamic Characteristics of Pressure Sensors

2006 ◽  
Vol 505-507 ◽  
pp. 1057-1062 ◽  
Author(s):  
Ho Chang ◽  
Mu Jung Kao ◽  
Tsing Tshih Tsung ◽  
J.L. Wu
Keyword(s):  
Dynamic Characteristics ◽  
Spectrum Analysis ◽  
Pressure Sensor ◽  
High Frequency ◽  
Pressure Wave ◽  
Hydraulic System ◽  
Output Voltage ◽  
Pressure Sensors ◽  
Innovative Technology ◽  
Wave Generator

This study developed a square-like pressure wave generator as an excitation source to test dynamic characteristics of pressure sensors. The developed generator can generate a square-like pressure wave of as high as 2 kHz and can achieve high-frequency switching by utilizing the differential principle through a series of mechanical rotations between the revolving spindle and revolving ring. The square-like pressure wave generated is input into the hydraulic system while the output voltage signals given by the pressure sensor can be analyzed by spectrum analysis to obtain dynamic characteristics of the pressure sensor

Modeling and Simulation of the Thermal Drift Characteristics of the Piezoresistive Pressure Sensor

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000373-000378
Author(s):  
R. Otmani ◽  
N. Benmoussa ◽  
K. Ghaffour
Keyword(s):  
Thermal Behavior ◽  
Modeling And Simulation ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Thermal Drift ◽  
Piezoresistive Pressure Sensor ◽  
Output Characteristics ◽  
Piezoresistive Pressure Sensors

Piezoresistive pressure sensors based on Silicon have a large thermal drift because of their high sensitivity to temperature (ten times more sensitive to temperature than metals). So the study of the thermal behavior of these sensors is essential to define the parameters that cause the drift of the output characteristics. In this study, we adopted the behavior of 2nd degree gauges depending on the temperature. Then we model the thermal behavior of the sensor and its characteristics.

Performance Evaluation of 3Φ Asymmetrical MLI with Reduced Switch Count

2016 ◽  
Vol 3 (3) ◽  
pp. 671
Author(s):  
Chinnapettai Ramalingam Balamurugan ◽  
S.P. Natarajan ◽  
T.S. Anandhi
Keyword(s):  
Performance Evaluation ◽  
High Power ◽  
Output Voltage ◽  
Multilevel Inverter ◽  
Matlab Simulink ◽  
Ac Drives ◽  
Three Phase ◽  
Multi Level ◽  
The Cost ◽  
Switching Strategies

The multi level inverter system is habitually exploited in AC drives, when both reduced harmonic contents and high power are required. In this paper, a new topology for three phase asymmetrical multilevel inverter employing reduced number of switches is introduced. With less number of switches, the cost, space and weight of the circuit are automatically reduced. This paper discusses the new topology, the switching strategies and the operational principles of the chosen inverter. Simulation is carried out using MATLAB-SIMULINK. Various conventional PWM techniques that are appropriate to the chosen circuit such as PDPWM, PODPWM, APODPWM, VFPWM and COPWM are employed in this work. COPWM technique affords the less THD value and also affords a higher fundamental RMS output voltage.

scholarly journals Class-C Linearized Amplifier for Portable Ultrasound Instruments

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 898 ◽  
Author(s):  
Hojong Choi
Keyword(s):  
Power Consumption ◽  
Output Voltage ◽  
Signal Amplitude ◽  
Piezoelectric Transducers ◽  
Battery Life ◽  
Potential Candidate ◽  
Portable Ultrasound ◽  
Dc Power ◽  
Class C ◽  
Main Components

Transistor linearizer networks are proposed to increase the transmitted output voltage amplitudes of class-C amplifiers, thus, increasing the sensitivity of the echo signals of piezoelectric transducers, which are the main components in portable ultrasound instruments. For such instruments, class-C amplifiers could be among the most efficient amplifier schemes because, compared with a linear amplifier such as a class-A amplifier, they could critically reduce direct current (DC) power consumption, thus, increasing the battery life of the instruments. However, the reduced output voltage amplitudes of class-C amplifiers could deteriorate the sensitivity of the echo signals, thereby affecting the instrument performance. Therefore, a class-C linearized amplifier was developed. To verify the capability of the class-C linearized amplifier, typical pulse-echo responses using the focused piezoelectric transducers were tested. The echo signal amplitude generated by the piezoelectric transducers when using the class-C linearized amplifier was improved (1.29 Vp-p) compared with that when using the class-C amplifier alone (0.56 Vp-p). Therefore, the class-C linearized amplifier could be a potential candidate to increase the sensitivity of echo signals while reducing the DC power consumption for portable ultrasound instruments.

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