scholarly journals Recumbent Exercise Bicycle for Low-Impact Rehabilitation of Obese Individuals

2009 ◽  
Vol 3 (2) ◽  
Author(s):  
K. Newman ◽  
K. Gibson ◽  
H. Zeller ◽  
S. Carter ◽  
B. Joyce
Keyword(s):  
Heart Rate ◽  
Safety Issue ◽  
Low Cost ◽  
Mechanical Analysis ◽  
Computer Interface ◽  
Cardiovascular Exercise ◽  
Fluid Resistance ◽  
Stability Issue ◽  
Custom Interface ◽  
The Stability

It is often difficult for persons who are extremely overweight to find exercise systems that are accessible and safe to use. Seating is required to handle heavier loads of up to 500 lbs. and provide safe access to the exercise unit. Additionally, the exercise should not cause additional pain or possible damage if the person needs to suddenly stop. A multidisciplinary team of undergraduate engineers participated in a training course to interview a non-technical customer to determine design requirements and then underwent a rigorous design process to implement the best solution. Mechanical analysis was performed to determine the best solution for the concept, materials, and resistance. An exercise machine with a rotating chair was selected as the best solution. The chair rotates 90 degrees so that the user can sit down without having to step onto the machine. Once the user sits, the chair can then rotate 90 degrees until the chair is in the exercise position; in either position the chair locks into position for stability. This particular concept uses a bicyle exercise. This exercise minimizes impact on the knees, which is a safety issue for patients with knee problems. A sitting position for this exercise eliminates the stability issue raised with a standing exercise, where there is worry of falling. This exercise is beneficial for cardiovascular exercise. Resistance is implemented using a magnet. Fluid resistance and fly-wheel resistance would create too much momentum which was not desired by the customer. Electrical analysis was performed to determine the best method to sense heart rate, speed, and computer interface. Wired handles were selected to monitor the heart rate. These are hand held and are much easier to use than a chest strap. An optical sensor was used to sense speed. It was placed near the center of the wheel and rotations were indicated by a tab to break the connection in the sensor. This method was selected over a Hall effect sensor because it is a much simpler sensing method that does not require an addition magnetic component that is not too accurate a low speeds. The computer interface was a Motorola HC12s since it had the necessary I/O interfaces and was low cost. A custom interface was created with seven segment displays to show the heart rate and time of exercise. The system was then developed, tested, and delivered to the customer for use. This project was supported by Grant No. 0607883 from the National Science Foundation.

scholarly journals A Low Cost Baby Incubator Design Equipped with Vital Sign Parameters

2021 ◽  
Vol 3 (2) ◽  
pp. 53-58
Author(s):  
Lamidi Lamidi ◽  
Abd Kholiq ◽  
Muslim Ali
Keyword(s):  
Heart Rate ◽  
Oxygen Saturation ◽  
Low Cost ◽  
Temperature Stability ◽  
Average Value ◽  
Premature Babies ◽  
Testing And Measurement ◽  
Infant Incubator ◽  
The Difference ◽  
The Stability

A baby incubator is a heating device for premature babies so that the baby's temperature matches the temperature in the mother's womb. Premature babies are babies born in abnormal conditions where the baby's body size is below average or the gestational age has not reached 9 months. The aim of this study was to create a compact system at a low cost in an infant incubator. Apart from stabilizing the temperature, it can also calculate the premature baby's heart rate and oxygen saturation value. The contribution of the system being built can detect the early symptoms of congenital abnormalities so that abnormalities detection becomes more practical. The temperature stability in this system uses a threshold system, where the sensor readings are compared with the set point value. Meanwhile, the SpO2 system uses a finger sensor attached to the baby's finger to detect oxygen saturation and heart rate. The signal from the sensor is processed in a signal conditioning circuit consisting of an astable circuit, filter and amplifier, LPF, and demultiplexer. Based on the results of testing and measurement, the difference produced by this tool is only 0.13 - 0.182 ° C. The biggest error in the system is 0.517%. Measurement of skin temperature was carried out on 10 respondents with an average value of 34.825 ° C. so that the difference generated from this tool is only 0.175 ° C, the difference on the Humidity parameter is 0.21%. The average BPM reading of respondent 1 was 81 beats per minute and the average SpO2 value was 97%. The average BPM reading of respondent 2 was 83 beats per minute and the average SpO2 value was 98%. You can see that the module with the Arduino control system can work automatically and is able to adjust the stability of the baby incubator according to the settings. In addition, the BPM and SpO2 systems are within tolerance so they can be used for patient measurements

Armor-Like Passivated CsPbBr3 Quantum Dots: Boosted Stability with Hand-in-Hand Ligands and Enhanced Performance of Nuclear Battery

2021 ◽  
Author(s):  
Haibo Zeng ◽  
Dandan Yang ◽  
Zhiheng Xu ◽  
Chunhui Gong ◽  
Xiaoming Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Inorganic Perovskite ◽  
Surface Ligands ◽  
Perovskite Quantum Dots ◽  
Stability Issue ◽  
The Stability ◽  
Nuclear Battery ◽  
Cspbbr3 Quantum Dots

One of the main reasons for the stability issue of inorganic perovskite quantum dots (PQDs) is the fragile protection of surface ligands. Here, an armor-like passivation strategy is proposed to...

scholarly journals Biomechanics of Trail Running Performance: Quantification of Spatio-Temporal Parameters by Using Low Cost Sensors in Ecological Conditions

2021 ◽  
Vol 11 (5) ◽  
pp. 2093
Author(s):  
Noé Perrotin ◽  
Nicolas Gardan ◽  
Arnaud Lesprillier ◽  
Clément Le Goff ◽  
Jean-Marc Seigneur ◽  
...  
Keyword(s):  
Heart Rate ◽  
Low Cost ◽  
Step Length ◽  
Measurement Unit ◽  
Ecological Conditions ◽  
Sports Science ◽  
Ground Contact Time ◽  
Spatio Temporal ◽  
Performance Results ◽  
Trail Running

The recent popularity of trail running and the use of portable sensors capable of measuring many performance results have led to the growth of new fields in sports science experimentation. Trail running is a challenging sport; it usually involves running uphill, which is physically demanding and therefore requires adaptation to the running style. The main objectives of this study were initially to use three “low-cost” sensors. These low-cost sensors can be acquired by most sports practitioners or trainers. In the second step, measurements were taken in ecological conditions orderly to expose the runners to a real trail course. Furthermore, to combine the collected data to analyze the most efficient running techniques according to the typology of the terrain were taken, as well on the whole trail circuit of less than 10km. The three sensors used were (i) a Stryd sensor (Stryd Inc. Boulder CO, USA) based on an inertial measurement unit (IMU), 6 axes (3-axis gyroscope, 3-axis accelerometer) fixed on the top of the runner’s shoe, (ii) a Global Positioning System (GPS) watch and (iii) a heart belt. Twenty-eight trail runners (25 men, 3 women: average age 36 ± 8 years; height: 175.4 ± 7.2 cm; weight: 68.7 ± 8.7 kg) of different levels completed in a single race over a 8.5 km course with 490 m of positive elevation gain. This was performed with different types of terrain uphill (UH), downhill (DH), and road sections (R) at their competitive race pace. On these sections of the course, cadence (SF), step length (SL), ground contact time (GCT), flight time (FT), vertical oscillation (VO), leg stiffness (Kleg), and power (P) were measured with the Stryd. Heart rate, speed, ascent, and descent speed were measured by the heart rate belt and the GPS watch. This study showed that on a ≤10 km trail course the criteria for obtaining a better time on the loop, determined in the test, was consistency in the effort. In a high percentage of climbs (>30%), two running techniques stand out: (i) maintaining a high SF and a short SL and (ii) decreasing the SF but increasing the SL. In addition, it has been shown that in steep (>28%) and technical descents, the average SF of the runners was higher. This happened when their SL was shorter in lower steep and technically challenging descents.

scholarly journals The MindGomoku: An Online P300 BCI Game Based on Bayesian Deep Learning

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1613
Author(s):  
Man Li ◽  
Feng Li ◽  
Jiahui Pan ◽  
Dengyong Zhang ◽  
Suna Zhao ◽  
...  
Keyword(s):  
Brain Computer Interface ◽  
Computer Interface ◽  
System Control ◽  
Average Accuracy ◽  
Training Samples ◽  
The Disabled ◽  
Limited Training Samples ◽  
The Stability ◽  
Electroencephalogram Eeg ◽  
Bci System

In addition to helping develop products that aid the disabled, brain–computer interface (BCI) technology can also become a modality of entertainment for all people. However, most BCI games cannot be widely promoted due to the poor control performance or because they easily cause fatigue. In this paper, we propose a P300 brain–computer-interface game (MindGomoku) to explore a feasible and natural way to play games by using electroencephalogram (EEG) signals in a practical environment. The novelty of this research is reflected in integrating the characteristics of game rules and the BCI system when designing BCI games and paradigms. Moreover, a simplified Bayesian convolutional neural network (SBCNN) algorithm is introduced to achieve high accuracy on limited training samples. To prove the reliability of the proposed algorithm and system control, 10 subjects were selected to participate in two online control experiments. The experimental results showed that all subjects successfully completed the game control with an average accuracy of 90.7% and played the MindGomoku an average of more than 11 min. These findings fully demonstrate the stability and effectiveness of the proposed system. This BCI system not only provides a form of entertainment for users, particularly the disabled, but also provides more possibilities for games.

scholarly journals Exploring the Structural Competition between the Black and the Yellow Phase of CsPbI3

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1282
Author(s):  
Ioannis Deretzis ◽  
Corrado Bongiorno ◽  
Giovanni Mannino ◽  
Emanuele Smecca ◽  
Salvatore Sanzaro ◽  
...  
Keyword(s):  
Perovskite Phase ◽  
Low Cost ◽  
Δ Phase ◽  
Nanocrystalline Structures ◽  
Halide Perovskites ◽  
The Stability ◽  
Structural Competition ◽  
Lead Halide ◽  
Main Candidate ◽  
Spontaneous Phase

The realization of stable inorganic perovskites is crucial to enable low-cost solution-processed photovoltaics. However, the main candidate material, CsPbI3, suffers from a spontaneous phase transition at room temperature towards a photo-inactive orthorhombic δ-phase (yellow phase). Here we used theoretical and experimental methods to study the structural and electronic features that determine the stability of the CsPbI3 perovskite. We argued that the two physical characteristics that favor the black perovskite phase at low temperatures are the strong spatial confinement in nanocrystalline structures and the level of electron doping in the material. Within this context, we discussed practical procedures for the realization of long-lasting inorganic lead halide perovskites.

scholarly journals Longevity of Raw and Lyophilized Crude Urease Extracts

2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian
Keyword(s):  
Crude Extract ◽  
Room Temperature ◽  
Low Cost ◽  
Extraction Process ◽  
Crude Extracts ◽  
Simple Extraction ◽  
Commercial Applications ◽  
Stable Source ◽  
The Stability ◽  
The Cost

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.

Stabilization of networked switched affine systems with event-triggered strategy

2021 ◽  
pp. 014233122110213
Author(s):  
Dandan Li ◽  
Zhiqiang Zuo ◽  
Yijing Wang
Keyword(s):  
Affine Systems ◽  
Switching Law ◽  
Event Time ◽  
Sliding Motion ◽  
State Dependent ◽  
Event Triggering ◽  
Stability Issue ◽  
The Stability ◽  
Event Based ◽  
Selection Of

Using an event-based switching law, we address the stability issue for continuous-time switched affine systems in the network environment. The state-dependent switching law in terms of the region function is firstly developed. We combine the region function with the event-triggering mechanism to construct the switching law. This can provide more candidates for the selection of the next activated subsystem at each switching instant. As a result, it is possible for us to activate the appropriate subsystem to avoid the sliding motion. The Zeno behavior for the switched affine system can be naturally ruled out by guaranteeing a positive minimum inter-event time between two consecutive executions of the event-triggering threshold. Finally, two numerical examples are given to demonstrate the effectiveness of the proposed method.

scholarly journals Redox initiation in semicontinuous polymerization to search for specific mechanical properties of copolymers

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 613-623
Author(s):  
José Manuel Sandoval-Díaz ◽  
Francisco Javier Rivera-Gálvez ◽  
Marta Fernández-García ◽  
Carlos Federico Jasso-Gastinel
Keyword(s):  
Low Cost ◽  
Mechanical Analysis ◽  
Industrial Applications ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Polymerization Reaction ◽  
Redox Initiation ◽  
Initiation System ◽  
Feeding Profile ◽  
Chain Composition

AbstractIn this work, for a semicontinuous emulsion polymerization reaction, it is shown that using a redox initiation system at 40°C, substantial modifications in copolymer chain composition with conversion can be easily obtained. To test controllable trajectories for comonomer feeding, linear and parabolic profiles were chosen to get different types of chain composition variations for the 50/50 w/w styrene/n-butyl acrylate system. For the “forced composition copolymers,” the molecular weight averages and distribution were obtained by size exclusion chromatography. The composition along conversion was followed by proton nuclear magnetic resonance to determine the weight composition distribution (WCD) of the copolymer chains. Mechanodynamic (dynamic-mechanical analysis), tensile, and hardness tests exhibited consistent results depending on the WCD that outcomes from the respective feeding profile. The results confirm that this methodology is of great potential for industrial applications when looking for synergy in copolymer properties, and low-cost processes.

scholarly journals A Real-Time Method for Improving Stability of Monolithic Quartz Crystal Microbalance Operating under Harsh Environmental Conditions

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4166
Author(s):  
Román Fernández ◽  
María Calero ◽  
Yolanda Jiménez ◽  
Antonio Arnau
Keyword(s):  
Real Time ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Limit Of Detection ◽  
Quartz Substrate ◽  
Low Cost ◽  
Discrete Wavelet ◽  
Reagent Consumption ◽  
Measurement Cell ◽  
The Stability

Monolithic quartz crystal microbalance (MQCM) has recently emerged as a very promising technology suitable for biosensing applications. These devices consist of an array of miniaturized QCM sensors integrated within the same quartz substrate capable of detecting multiple target analytes simultaneously. Their relevant benefits include high throughput, low cost per sensor unit, low sample/reagent consumption and fast sensing response. Despite the great potential of MQCM, unwanted environmental factors (e.g., temperature, humidity, vibrations, or pressure) and perturbations intrinsic to the sensor setup (e.g., mechanical stress exerted by the measurement cell or electronic noise of the characterization system) can affect sensor stability, masking the signal of interest and degrading the limit of detection (LoD). Here, we present a method based on the discrete wavelet transform (DWT) to improve the stability of the resonance frequency and dissipation signals in real time. The method takes advantage of the similarity among the noise patterns of the resonators integrated in an MQCM device to mitigate disturbing factors that impact on sensor response. Performance of the method is validated by studying the adsorption of proteins (neutravidin and biotinylated albumin) under external controlled factors (temperature and pressure/flow rate) that simulate unwanted disturbances.

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