scholarly journals Miniaturization of Respiratory Measurement System in Artificial Ventilator for Small Animal Experiments to Reduce Dead Space and Its Application to Lung Elasticity Evaluation

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5123
Author(s):  
Homare Yoshida ◽  
Yoshihiro Hasegawa ◽  
Miyoko Matsushima ◽  
Tomoshi Sugiyama ◽  
Tsutomu Kawabe ◽  
...  
Keyword(s):  
Respiratory System ◽  
Measurement System ◽  
Dead Space ◽  
Animal Experiments ◽  
Small Animal ◽  
Silicone Resin ◽  
Directional Detection ◽  
Mems Technology ◽  
Respiratory Measurement ◽  
Static Conditions

A respiratory measurement system composed of pressure and airflow sensors was introduced to precisely control the respiratory condition during animal experiments. The flow sensor was a hot-wire thermal airflow meter with a directional detection and airflow temperature change compensation function based on MEMS technology, and the pressure sensor was a commercially available one also produced by MEMS. The artificial dead space in the system was minimized to the value of 0.11 mL by integrating the two sensors on the same plate (26.0 mm × 15.0 mm). A balloon made of a silicone resin with a hardness of A30 was utilized as the simulated lung system and applied to the elasticity evaluation of the respiratory system in a living rat. The inside of the respiratory system was normally pressurized without damage, and we confirmed that the developed system was able to evaluate the elasticity of the lung tissue in the rat by using the pressure value obtained at the quasi-static conditions in the case of the ventilation in the animal experiments.

scholarly journals Longitudinal Raman Spectroscopic Observation of Skin Biochemical Changes due to Chemotherapeutic Treatment for Breast Cancer in Small Animal Model

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Myeongsu Seong ◽  
NoSoung Myoung ◽  
Songhyun Lee ◽  
Hyeryun Jeong ◽  
Sang-Youp Yim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Animal Model ◽  
Raman Spectra ◽  
Fiber Optic ◽  
Animal Experiments ◽  
Small Animal ◽  
Fiber Optic Probe ◽  
Small Animal Model ◽  
Biochemical Compositions ◽  
Optic Probe

The cancer field effect (CFE) has been highlighted as one of indirect indications for tissue variations that are insensitive to conventional diagnostic techniques. In this research, we had a hypothesis that chemotherapy for breast cancer would affect skin biochemical compositions that would be reflected by Raman spectral changes. We used a fiber-optic probe-based Raman spectroscopy to perform preliminary animal experiments to validate the hypothesis. Firstly, we verified the probing depth of the fiber-optic probe (~800 μm) using a simple intravenous fat emulsion-filled phantom having a silicon wafer at the bottom inside a cuvette. Then, we obtained Raman spectra during breast cancer treatment by chemotherapy from a small animal model in longitudinal manner. Our results showed that the treatment causes variations of biochemical compositions in the skin. For further validation, the Raman spectra will have to be collected from more populations and spectra will need to be compared with immunohistochemistry of the breast tissue.

Biocompatible Cardiac Sensor with Continuous Arrhythmia Monitoring for Human Wellness

2016 ◽  
Vol 835 ◽  
pp. 71-77
Author(s):  
Jong Ha Lee
Keyword(s):  
Atrial Fibrillation ◽  
Power Transmission ◽  
Sampling Rate ◽  
Animal Experiments ◽  
Small Animal ◽  
The Body ◽  
Major Surgery ◽  
Data Sampling ◽  
Integrated Sensor ◽  
Sensor Module

Prolonged monitoring is more likely to result in an accurate diagnosis of atrial fibrillation patients than intermittent or short-term monitoring. In this study, we present an implantable ECG sensor to monitor atrial fibrillation patients in real time. The developed implantable sensor is composed of a micro controller unit, analog to digital converter, signal transmitter, antenna, and two electrodes. The sensor detects ECG signals from the two electrodes and transmits these signals to the external receiver that is carried by the patient. The sensor continuously transmits signals, so its battery consumption rate is extremely high. To overcome this problem, we consider using a wireless power transmission module in the sensor module. This module helps the sensor charge power wirelessly without holding the battery in the body. The size of the integrated sensor is approximately 0.12 inch x 1.18 inch x 0.19 inch. This sensor size is appropriate enough for cardiologists to insert the sensor into patients without the need for a major surgery. The data sampling rate was 300 samples/sec, and the frequency was 430 Hz for signal and power transmission. To verify the validation of the developed sensor, the small animal experiments were conducted.

scholarly journals A novel method optimizing the normalization of cardiac parameters in small animal models: the importance of dimensional indexing

2019 ◽  
Vol 316 (6) ◽  
pp. H1552-H1557 ◽  
Author(s):  
Quint A. J. Hagdorn ◽  
Guido P. L. Bossers ◽  
Anne-Marie C. Koop ◽  
Arnold Piek ◽  
Tim R. Eijgenraam ◽  
...  
Keyword(s):  
Body Weight ◽  
Animal Models ◽  
Animal Experiments ◽  
Three Dimensional ◽  
Small Animal ◽  
Left Ventricular ◽  
Heart Weight ◽  
Small Animal Models ◽  
Rats And Mice ◽  
Tibia Length

For indexing cardiac measures in small animal models, tibia length (TL) is a recommended surrogate for body weight (BW) that aims to avoid biases because of disease-induced BW changes. However, we question if indexing by TL is mathematically correct. This study aimed to investigate the relation between TL and BW, heart weight, ventricular weights, and left ventricular diameter to optimize the current common practice of indexing cardiac parameters in small animal models. In 29 healthy Wistar rats (age 5–34 wk) and 116 healthy Black 6 mice (age 3–17 wk), BW appeared to scale nonlinearly to TL1 but linearly to TL3. Formulas for indexing cardiac weights were derived. To illustrate the effects of indexing, cardiac weights between the 50% with highest BW and the 50% with lowest BW were compared. The nonindexed cardiac weights differed significantly between groups, as could be expected ( P < 0.001). However, after indexing by TL1, indexed cardiac weights remained significantly different between groups ( P < 0.001). With the derived formulas for indexing, indexed cardiac weights were similar between groups. In healthy rats and mice, BW and heart weights scale linearly to TL3. This indicates that not TL1 but TL3 is the optimal surrogate for BW. New formulas for indexing heart weight and isolated ventricular weights are provided, and we propose a concept in which cardiac parameters should not all be indexed to the same measure but one-dimensional measures to BW1/3 or TL1, two-dimensional measures to BW2/3 or TL2, and three-dimensional measures to BW or TL3. NEW & NOTEWORTHY In healthy rats and mice, body weight (BW) scales linearly to tibia length (TL) to the power of three (TL3). This indicates that for indexing cardiac parameters, not TL1 but TL3 is the optimal surrogate for BW. New formulas for indexing heart weight and isolated ventricular weights are provided, and we propose a concept of dimensionally consistent indexing. This concept is proposed to be widely applied in small animal experiments.

Design and calibration of unicapillary pneumotachographs

1998 ◽  
Vol 84 (1) ◽  
pp. 335-343 ◽  
Author(s):  
A. Giannella-Neto ◽  
C. Bellido ◽  
R. B. Barbosa ◽  
M. F. Vidal Melo
Keyword(s):  
Respiratory Mechanics ◽  
Ambient Pressure ◽  
Animal Experiments ◽  
Small Animal ◽  
Positive Pressure ◽  
Linear Calibration ◽  
Third Order ◽  
Order Polynomial ◽  
Internal Radius ◽  
Volume Measurements

Giannella-Neto, A., C. Bellido, R. B. Barbosa, and M. F. Vidal Melo. Design and calibration of unicapillary pneumotachographs. J. Appl. Physiol.84(1): 335–343, 1998.—This study presents a method for design and calibration of unicapillary pneumotachographs for small-animal experiments. The design, based on Poiseuille’s law, defines a set of internal radius and length values that allows for laminar flow, measurable pressure differences, and minimal interference with animal’s respiratory mechanics and gas exchange. A third-order polynomial calibration (Pol) of the pressure-flow relationship was employed and compared with linear calibration (Lin). Tests were done for conditions of ambient pressure (Pam) and positive pressure (Ppos) ventilation at different flow ranges. A physical model designed to match normal and low compliance in rats was used. At normal compliance, Pol provided lower errors than Lin for mixed (1–12 ml/s), mean (4–10 ml/s), and high (8–12 ml/s) flow rate calibrations for both Pam and Ppos inspiratory tests (P < 0.001 for all conditions) and expiratory tests ( P < 0.001 for all conditions). At low compliance, they differed significantly with 8.6 ± 4.1% underestimation when Lin at Pam was used in Ppos tests. Ppos calibration, preferably in combination with Pol, should be used in this case to minimize errors (Pol = 0.8 ± 0.5%, Lin = 6.5 ± 4.0%, P < 0.0005). Nonlinear calibration may be useful for improvement of flow and volume measurements in small animals during both Pam and Ppos ventilation.

Application of the hot-wire anemometer to respiratory measurements in small animal

1976 ◽  
Vol 40 (2) ◽  
pp. 275-277 ◽  
Author(s):  
A. Godal ◽  
D. A. Belenky ◽  
T. A. Standaert ◽  
D. E. Woodrum ◽  
L. Grimsrud ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Dead Space ◽  
Linear Response ◽  
Small Animal ◽  
Co2 Concentration ◽  
Respiratory Frequency ◽  
Hot Wire ◽  
Background Flow ◽  
Temperature And Humidity ◽  
Frequency Temperature

A hot-wire anemometer was evaluated to determine its suitability for measurement of small tidal volumes. Used with a constant background flow of gas, the output of the hot-wire anemometer was linear and independent of respiratory frequency, temperature, and humidity. The change in output with CO2 concentration was negligible within the physiologic range. The use of a background flow eliminates the need for one-way valves, minimizes dead space, and maintains the flow velocity past the hot wire within its range of linear response.

scholarly journals First Evaluation of Temporal and Spatial Fractionation in Proton Minibeam Radiation Therapy of Glioma-Bearing Rats

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4865
Author(s):  
Annaïg Bertho ◽  
Ramon Ortiz ◽  
Marjorie Juchaux ◽  
Cristèle Gilbert ◽  
Charlotte Lamirault ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Animal Experiments ◽  
Small Animal ◽  
Therapeutic Index ◽  
Tumor Control ◽  
Broad Beam ◽  
Local Toxicity ◽  
Additional Group ◽  
The Impact ◽  
Long Term Survivors

(1) Background: Proton minibeam radiation therapy (pMBRT) is a new radiotherapy technique using spatially modulated narrow proton beams. pMBRT results in a significantly reduced local tissue toxicity while maintaining or even increasing the tumor control efficacy as compared to conventional radiotherapy in small animal experiments. In all the experiments performed up to date in tumor bearing animals, the dose was delivered in one single fraction. This is the first assessment on the impact of a temporal fractionation scheme on the response of glioma-bearing animals to pMBRT. (2) Methods: glioma-bearing rats were irradiated with pMBRT using a crossfire geometry. The response of the irradiated animals in one and two fractions was compared. An additional group of animals was also treated with conventional broad beam irradiations. (3) Results: pMBRT delivered in two fractions at the biological equivalent dose corresponding to one fraction resulted in the highest median survival time, with 80% long-term survivors free of tumors. No increase in local toxicity was noted in this group with respect to the other pMBRT irradiated groups. Conventional broad beam irradiations resulted in the most severe local toxicity. (4) Conclusion: Temporal fractionation increases the therapeutic index in pMBRT and could ease the path towards clinical trials.

scholarly journals Positive end-expiratory pressure in COVID-19 acute respiratory distress syndrome: the heterogeneous effects

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Davide Chiumello ◽  
Matteo Bonifazi ◽  
Tommaso Pozzi ◽  
Paolo Formenti ◽  
Giuseppe Francesco Sferrazza Papa ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Respiratory System ◽  
Dead Space ◽  
Respiratory Mechanics ◽  
Peep Level ◽  
Lung Mechanics ◽  
Mechanical Power ◽  
Respiratory System Compliance ◽  
Lung Elastance ◽  
Lung Stress

Abstract Background We hypothesized that as CARDS may present different pathophysiological features than classic ARDS, the application of high levels of end-expiratory pressure is questionable. Our first aim was to investigate the effects of 5–15 cmH2O of PEEP on partitioned respiratory mechanics, gas exchange and dead space; secondly, we investigated whether respiratory system compliance and severity of hypoxemia could affect the response to PEEP on partitioned respiratory mechanics, gas exchange and dead space, dividing the population according to the median value of respiratory system compliance and oxygenation. Thirdly, we explored the effects of an additional PEEP selected according to the Empirical PEEP-FiO2 table of the EPVent-2 study on partitioned respiratory mechanics and gas exchange in a subgroup of patients. Methods Sixty-one paralyzed mechanically ventilated patients with a confirmed diagnosis of SARS-CoV-2 were enrolled (age 60 [54–67] years, PaO2/FiO2 113 [79–158] mmHg and PEEP 10 [10–10] cmH2O). Keeping constant tidal volume, respiratory rate and oxygen fraction, two PEEP levels (5 and 15 cmH2O) were selected. In a subgroup of patients an additional PEEP level was applied according to an Empirical PEEP-FiO2 table (empirical PEEP). At each PEEP level gas exchange, partitioned lung mechanics and hemodynamic were collected. Results At 15 cmH2O of PEEP the lung elastance, lung stress and mechanical power were higher compared to 5 cmH2O. The PaO2/FiO2, arterial carbon dioxide and ventilatory ratio increased at 15 cmH2O of PEEP. The arterial–venous oxygen difference and central venous saturation were higher at 15 cmH2O of PEEP. Both the mechanics and gas exchange variables significantly increased although with high heterogeneity. By increasing the PEEP from 5 to 15 cmH2O, the changes in partitioned respiratory mechanics and mechanical power were not related to hypoxemia or respiratory compliance. The empirical PEEP was 18 ± 1 cmH2O. The empirical PEEP significantly increased the PaO2/FiO2 but also driving pressure, lung elastance, lung stress and mechanical power compared to 15 cmH2O of PEEP. Conclusions In COVID-19 ARDS during the early phase the effects of raising PEEP are highly variable and cannot easily be predicted by respiratory system characteristics, because of the heterogeneity of the disease.

scholarly journals Analisis Sistem Pengukuran Getaran Mems Accelerometer ADXL345

2019 ◽  
Vol 9 (02) ◽  
pp. 63-67
Author(s):  
Indra Feriadi ◽  
Fajar Aswin ◽  
M Iqbal Nugraha
Keyword(s):  
Measurement System ◽  
Low Cost ◽  
Measurement Data ◽  
Micro Electro Mechanical System ◽  
Vibration Measurement ◽  
Measurement Technology ◽  
Mems Accelerometer ◽  
Analysis Technique ◽  
Develop Approach ◽  
Mems Technology

Vibration measurement technology using conventional sensors such as piezoelectric (PZT) Accelerometer is still expensive. Currently, many low-cost vibration measuring devices have been developed by using Micro Electro Mechanical System (MEMS) technology. This study aims to analyze the results of vibration measurement system MEMS Accelerometer ADXL345 with PZT Accelerometer. This research applies design and develop approach with comparative data analysis technique, that is comparing data of result of measurement of MEMS Accelerometer ADXL345 to PZT Accelerometer Vibroport80. The construction comprises the ADXL345 sensor connected to the Arduino Mega 2560 microcontroller operated by Widows operating system and programming language Arduino IDE 1.08. Testing of measurements at Bearing speeds of 500, 1000, and 1500 RPM with length of time measurements at 5, 10, and 20 seconds respectively. The analysis of the test results shows that the MEMS Accelerometer ADXL345 of vibration measurement system can measure, process and display vibration measurement data larger 3% than PZT Accelerometer and can provide the best measurement accuracy at 20 seconds measurement length of time.

scholarly journals Preliminary development of computed tomography (CT) scanner using transillumination imaging

10.29007/kgfg ◽  
2020 ◽  
Author(s):  
Ngoc An Dang Nguyen ◽  
To Ni Phan Van ◽  
Ngoc Anh Tuan Vo ◽  
Van Phu Le ◽  
Anh Tu Tran ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Blood Vessel ◽  
Near Infrared ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Animal Experiments ◽  
Three Dimensional ◽  
Small Animal ◽  
Body Parts ◽  
Ct Scanner

Near-infrared transillumination imaging is useful in many biomedical applications such as human biometrics and animal experiments. Using near-infrared (NIR) light, we can able to obtain a two dimensional (2D) transillumination image of the internal absorption structure such as blood vessel structure, liver ... in a small animal body. If we can obtain projection images from many orientations, we can reconstruct a three dimensional (3D) image using various computed tomography techniques. In previous studies of our group, even with a simple system (light-emitting diode (LED)'s array and low-cost camera), we can obtain the blood vessel transillumination image of the human arm. In this paper, we propose preliminary research on the development of a computed tomography (CT) scanner prototype of human body parts using transillumination imaging.

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