Research on Pressure Measuring Device with Magnetic Fluid

Magnetic fluid is a novel material which could be applied in many fields including sensors, sealings, bilmedicines, and so on. Its super magnetism and fluidity could be used in the sensor as an inducting core. Magnetic fluid and its characteristics were introduced to adapt to the application in the pressure measuring devices. A pressure measuring device with magnetic fluid was proposed and the structure was analyzed and designed according to the characteristics of magnetic fluid. The working principle of pressure measuring device with magnetic fluid was analyzed, and the structure of pressure measuring device was designed and reformed to avoid the overflow and recovery of excessive of magnetic fluid. One arm of the U tube was designed to be a large cylinder to storage large quantities of magnetic fluid. The higher the required precision is, the larger the diameter of one arm should be designed with respect to the other arm of the tube. The measuring range of designed device could also be adjusted as needed. The measuring efficiency of the device could be improved by the designing and reforming work.

High Dynamic Range Photocurrent Sensory Circuit with a Multi-Transistor Background Light Cancellation Loop for Photoplethysmography Sensing

In this article, we present a new photocurrent sensory circuit with a three-transistor background light cancellation. We describe our innovative photocurrent sensor-based blood pressure measuring device using a resistor-based current-to-voltage converter with a background light cancellation (BLC) loop. The photocurrent sensor is implemented using 0.35 μm standard CMOS technology and has zero average power consumption. The post-layout simulation for the photocurrent sensor shows a 1.3 MΩ transimpedance gain, a referred input noise current of 11 pA, and can reject a DC photocurrent up to 200 μA. This high DC rejection has been achieved due to the newly proposed multi-transistor BLC loop integrated with the sensor.

Pressure measurement in the reticulum to detect different behaviors of healthy cows

The aim of the current study was to investigate the relation between reticulorumen contractions and monitored cow behaviors. A purpose-built pressure measuring device was used and shown to be capable of detecting the known contraction patterns in the reticulorumen of four rumen-fistulated cows. Reticular pressure data was used to build a random forest algorithm, a learning algorithm based on a combination of decision trees, to detect rumination and other cow behaviors. In addition, we developed a peak-detection algorithm for rumination based on visual inspection of patterns in reticular pressure. Cow behaviors, differentiated in ruminating, eating, drinking, sleeping and ‘other’, as scored from video observation, were used to develop and test the algorithms. The results demonstrated that rumination of a cow can be detected by measuring pressure differences in the reticulum using either the random forest algorithm or the peak-detection algorithm. The random forest algorithm showed very robust performances for detecting rumination with an accuracy of 0.98, a sensitivity of 0.95 and a specificity of 0.99. The peak-detection algorithm could detect rumination robustly, with an accuracy of 0.92, a sensitivity of 0.97 and a specificity of 0.90. In addition, we provide proof of principle that a random forest algorithm can also detect eating, drinking and sleeping behavior from the same data with performances above 0.90 for all measures. The measurement device used in this study needed rumen-fistulated cows, but the results indicate that behavior detection using algorithms based on only measurements in the reticulum is feasible. This is promising as it may allow future wireless sensor techniques in the reticulum to continuously monitor a range of important behaviors of cows.

Effects of vasopressin on anesthetic response time and circulatory dynamics of lidocaine

This study aimed to investigate the hypothesis that vasopressin extends the anesthetic response time of lidocaine and does not affect the circulatory dynamics. Rats were sedated with isoflurane; subsequently, breathing was maintained through mechanical ventilation. We infiltrated the first molar area of the upper left jaw with saline (NS, test solution), 2% lidocaine (L), 0.025 IU vasopressin-supplemented 2% lidocaine, 0.05 IU vasopressin-supplemented 2% lidocaine, 0.1 IU vasopressin-supplemented 2% lidocaine, and 0.2 IU vasopressin-supplemented 2% lidocaine (VL4). Further, anesthetic response times were measured up to 30 min using electric pulp testing methods (n = 4). The anesthetic response times of NS, L, and VL4 were measured up to 45 min with the aforementioned results as reference values (n = 7). The circulatory dynamics of NS, L, VL4, and 0.2 IU vasopressin (V) were measured up to 45 min using a non-invasive blood pressure measuring device. VL4 extended the anesthetic response times of lidocaine compared to L (p < 0.05). Further, V and VL4 significantly increased the systolic and diastolic blood pressure and significantly decreased the pulse rate (p < 0.05). VL4 is not a suitable addition to the local anesthetic solution used in dentistry. Further study is needed to determine vasopressin concentration that extends the anesthetic effect without affecting the circulatory dynamics.

Validation of the wrist blood pressure measuring device Omron RS6 (HEM-6221-E) among obese Sudanese patients according to the European Society of Hypertension International Protocol Revision 2010

Background: Electronic devices for measuring blood pressure (BP) need to go through independent clinical validation as recommended by different authorities, both in general and specific populations. The aim of this study was to assess the validity of the Omron RS6 (HEM-6221-E) wrist oscillometric devices in obese Sudanese patients. Methods: Of 90 obese individuals invited for recruitment, 33 were included in the study, and had their BP at the level of the wrist measured using Omron RS6 and standard mercury sphygmomanometer. Two observations were made and the mean was taken. BP differences between the two methods for the 33 participants were classified into three categories (≤5, ≤10, and ≤15 mmHg), according to the European Society of Hypertension-International Protocol revision 2010 (ESH-IP2) criteria. This was then used to assess the validity of the tested Omron RS6 device. Results: Participants had a mean age of 56.97 years (standard deviation (SD), 8.75; range, 36-79). Average systolic blood pressure (SBP) was 146.21 mmHg (SD, 23.07; range, 107-182), and average diastolic blood pressure (DBP) was 93.82 mmHg (SD, 16.06; range, 67-128). There was a good agreement between the two observations using the OMRON RS6 and the standard sphygmomanometer: −4 to + 3 mmHg for SBP and −4 to +4 mmHg for DBP, with the mean difference of 1.73±1.11 mmHg for SBP and 1.49±1.02 mmHg for DBP. Conclusion: Thus, the Omron RS6 (HEM-6221-E) is a valid and suitable measure of BP according to ESH-IP2.

Effect of Shod Walking on Plantar Pressure with Varying Insole

Walking and running are very critical factors in human being’s everyday life. A human being takes more than 2,000 steps to walk 1.6 km. The human being wear a boot with insole to protect feet when walking, playing and doing various activities. The boot with insole provides significant impact on the feet during these events and transmitted through the feet due to intense force and pressure. Measurements of plantar pressure are important for diagnosing lower limb disorders, designing footwear, injury prevention and applications in sports biomechanics. The objective of this study is to investigate the plantar pressure exerted on the feet during shod walking (wearing boot with three types of insoles); to identify effective insole for reducing plantar pressure during walking (wearing same boot with three insoles). Eighteen fits, healthy male adults volunteered for this study with mean and SD (mean±SD) age (36±9) years, height (169±4) cm, and weight (71±8) kg. During experiments, each volunteer underwent 5 min of treadmill walking (4.5 km/hr speed) with wearing of boot with varying types of insoles (Low-density polyurethane (LDPU) insole 1; High-density polyurethane (HDPU), insole 2; and Silicone rubber (SR), insole 3). Plantar pressures were measured by using a foot pressure measuring device. A paired t-test was conducted to observe significant changes in plantar pressures of different foot region (P<0.05). Observations of the present study revealed that plantar pressures (N/cm²*s) were minimum during the use of LDPU insole than HDPU and SR insoles. It was also noticed that during the using of LDPU insole, less plantar pressure observed in the heel (3.84 ±1.16 in right foot) followed by forefoot (right 3.92±0.88), lateral (right 3.56±0.85), and medial foot (right 3.60±0.69). Hence, the present study suggested that using LDPU insole reducing the transfer of impact forces to the body/foot in comparison to HDPU and SR insoles during walking and minimizing the risk of foot-related injuries in long term use.