Impedance Principle Research Articles

Deviation in White Blood Cell Count Measurement between WNR and WDF Channels on an Automated Hematology Analyzer XN-3000: A Case Report

BACKGROUND: At present, complete blood count (CBC) testing is one of the most common clinical tests. The XN-3000 used in our hospital utilizes the principles of impedance and semiconductor laser flow cytometry, which contains two types of leukocyte fractionation methods: White cell nucleated (WNR) and white cell differential (WDF) channels. CASE PRESENTATION: Herein, we present the case of a 63-year-old male patient who was admitted to our hospital for the treatment of non-small cell lung cancer (T4N3M1 [LYM, HEP, and OSS]). Biochemical data showed abnormal liver function and anemia. WNR results showed poor leukocyte and debris fractions compared with WDF results, and leukocyte counts were different between the two channels. However, the poor fractionation of the leukocyte and debris fractions in the WNR was resolved at the twofold dilution stage. To investigate the cause of the problem, precipitates affecting the WNR measurement were visually checked. Consequently, insoluble precipitates were observed in the WNR mixture of the specimen of the patient. In our hospital, we measure 1200 CBCs/day and very rarely encounter abnormal specimens such as in the presented case. Normally, leukocyte counts are reported in priority to those measured by the WNR channel; however, in this case, the switching function was effective in giving priority to WDF count results because of the appearance of abnormal WNR plots. However, a system that can promptly confirm events when results are reported is necessary. CONCLUSION: We very rarely encounter abnormal specimens such as in the presented case. Normally, leukocyte counts are reported in priority to those measured by the WNR channel; however, in this case, the switching function was effective in giving priority to WDF count results because of the appearance of abnormal WNR plots. However, a system that can promptly confirm events when results are reported is necessary. When no clinical request for WDF measurement was made, the WNR scattergram must be confirmed, dilution measurement, if necessary, must be performed, or the WDF must be measured and reported to the clinician as useful criteria for diagnosis.

A Comparative Analysis of Feto-Maternal Monitoring Techniques Utilizing the Bio-Impedance Technique

It is impossible to overestimate the importance of the fetal monitoring approach in the field of obstetrics. The review study illustrates the wide range of fetal monitoring techniques used, from basic feto scope auscultation to more sophisticated electronic fetal monitoring (EFM) technologies in Engineering Society. The survey highlights the significance of constant monitoring throughout labor to identify any indicators of fetal distress and act quickly to ensure that necessary interventions are made in a timely manner. Furthermore, the paper presents an experimental study for Fetal Monitoring, which system is based on the bio impedance principle. The innovative technique described in this work is noninvasive, user-friendly, cost-effective, and suitable for mass health care, and it may be used by the impoverished population and basic health workers. Finally, the review highlights the importance of standardized protocols, continuous research, and healthcare professional training in order to increase the accuracy and effectiveness of fetal monitoring approaches..

Vibration Transmission Analysis in FGM Beams with Periodically Arranged Enhanced Multiple Dynamic Vibration Absorbers

Functionally graded material (FGM) beams are widely used in engineering as moving components. Nevertheless, their generated vibrations usually become annoying. To realize multi-broadband vibration reduction of FGM beams, an enhanced multiple dynamic vibration absorber (EMDVA), which utilizes an amplification mechanism, is proposed in this study. The devices are periodically arranged on the FGM beams. The dispersion and vibration transmission characteristics of the structure are investigated using the energy method and nullspace technique. The accuracy of the model is verified using the finite element method. The effects of parameter on its vibration damping performance are also analyzed. Finally, the relationship between the amplification coefficient and the operating performance of the EMDVA is revealed in terms of both the impedance principle and the energy method. The results show that the amplification mechanism can amplify the stiffness, damping, and mass of the MDVA by a factor of square of the amplification coefficient. Therefore, the proposed EMDVA has a wider damping band and stronger attenuation performance compared to the conventional MDVA. This study provides a simple and easy-to-implement solution for multi-band vibration reduction in FGM beams, which is useful for the engineering application of FGM beams in vibration and noise reduction.

A Unified Control for PFC Converter With Seamless Transition Between PWM/PFM Modes

Discontinuous conduction mode is often used in boost power factor correction converter. This article proposes a unified control method to achieve both pulsewidth modulation control and pulse frequency modulation control, which is based on the virtual impedance principle. The control modes can easily be changed by only adjusting one control parameter. Consequently, by comprehensively considering current ripple, switching frequency, and efficiency, the converter can operate flexibly in the situation of variable loads. This article first introduces the operation principle of the proposed unified control method. Then, the operation condition for each control mode is discussed. Besides, the current ripple, the switching frequency, and the power loss are analyzed. Finally, the experimental results of steady-state test and load switching test are presented. And the efficiency of the converter is more than 95% in the range from half load to full load. These experimental results fully verify the effectiveness of the proposed control.

Determination of Coagulation Profile among Children with Sickle Cell: Anemia in Steady-State and Crisis

Background: Patients with Sickle Cell Disease (SCD) have been found to have an aberrant coagulation profile. One of the primary elements hypothesized to contribute to the vaso-occlusive crisis that characterizes sickle cell disease is coagulopathy (SCD)
 Material and Methods: A total of 150 children were enrolled as follows, 50 children with Sickle Cell Anemia (SCA) in steady-state, 50 in crisis, and 50 with Hb AA genotype as control. 5 ml of Venous blood was collected. The platelets count was performed using Sysmex KX21N, the electrical impedance principle. The Mean Platelet Volume (MPV) is derived from the impedance platelet size distribution curve. STAGO PT31039352) semi-automated machine was used for estimation of PT, and APTT.
 Result: children with SCA have significantly a prolonged PT, and APTT compared with children with normal hemoglobin genotype (P. value < 0.001) the mean of PT was (16.64, and 12.6) respectively, and APTT (41.45 and 37.94) consequently. A significant increase in platelet count between patients with SCA when compared with control (p. value 0.02), however a significant prolonged in APTT when compared to steady-state (P. value 0.005). MPV among children with crises when compared with steady-state revealed a significant result (p. value 0.006) the mean of MPV in steady-state = 6.79 while the mean of MPV in crisis = 7.09.
 Conclusion: children with sickle cell anemia had a longer coagulation profile and marked variation in platelet count, which may increase the risk of thrombosis or bleeding.

Relationship between Muscle Mass of Limbs and aGVHD in Patients with Allogeneic Hematopoietic Stem Cell Transplantation

To explore the correlation of limb muscle mass and acute graft-versus-host disease. Clinical data from 144 patients treated by allo-HSCT in Guangzhou First People's Hospital were collected and analyzed retrospectively. The age, sex, diagnosis, donor age, sex of the donors, preparative regimen, ATG dose, HLA match, graft source, and number of infused stem cells of the patients were collected as baseline information. Meanwhile, bioelectrical impedance principle (BIA) was used to measure the limb muscle mass, body weight, body mass index (BMI), waist-to-hip ratio, upper arm muscle circumference, triceps skinfold thickness, and body fat rate of the patients before and after transplantation, so as to compare the changes of limb muscle mass and investigate its correlation with aGVHD. It was found that 61.11% of allo-HSCT patients showed muscle mass loss, and the proportion of male and female was 35.42% and 25.69%, respectively. There were reduction in the body weight, BMI, upper arm muscle circumference and muscle mass of limbs after transplantation as compared with those before transplantation (P<0.05). By comparing with the cumulative incidence of aGVHD between the patients in low muscle mass group and normal muscle mass group, it was found that the cumulative incidence of Ⅱ-Ⅳdegree aGVHD in patients with low muscle mass (30.38%) was higher than those with normal muscle mass (8.93%), which showed statistical difference (P<0.05). Univariate analysis showed that muscle mass, the sex of the donors, and preparative regimen were the influencing factors of aGVHD (P<0.05). Binary logistic regression showed that low muscle mass was the independent risk factor affecting aGVHD (P<0.05). Patients treated by allo-HSCT shows a decline in muscle mass after transplantation, and the incidence of aGVHD is high in patients with low muscle mass. Therefore, the assessment of muscle quality in early stage in patients with HSCT can facilitate earlier detection of aGVHD.

Unusual Morphological and Automated Hematology Analyzer Features in 3 Cases of B-cell Malignancy-associated Type I Cryoglobulinemic Vasculitis.

Type I cryoglobulins are monoclonal immunoglobulins produced due to underlying hematological malignancy. Cryoglobulins spontaneously precipitate from serum and plasma at low temperatures and become soluble again on rewarming to 37°C. Processing of blood at temperature lower than 37°C in the laboratory may cause precipitation of cryoglobulins resulting in interferences in the automated cell counter analysis. We report three patients with cryoglobulinemic vasculitis wherein each case had different morphology of cryoglobulin precipitates on peripheral blood film, like needle shaped bluish-gray crystals, amorphous weakly basophilic extracellular deposits extraneously indenting red blood cells and basophilic neutrophilic inclusions respectively. The effect of cryoglobulins on two technologically different automated cell counters based on principles of impedance, Volume-Conductivity-Scatter (VCS) and fluorescence flow cytometry was assessed. This case series provides interesting insight into the varying morphological features of cryoglobulins on May-Grunwald-Giemsa stained blood films and interference caused by cryoglobulins in different automated cell counter analysis resulting in pseudo-leucocytosis, pseudo-thrombocytosis, abnormal histograms and scatterplots. Identification of these hematologic abnormalities and artifacts induced by cryoglobulins is necessary since it may be the first clue leading to the timely diagnosis of cryoglobulinemia and hence the underlying hematological malignancy, as in our cases.

Performance-based Piezoelectric Material Applied in Health Inspection of Civil Engineering Structures

The application of piezoelectric impedance principle in health monitoring of civil engineering structures has attracted more and more attention. In this paper, the application of piezoelectric materials in health detection of civil engineering structures is reviewed. The basic principles, research progress, advantages and problems of impedance method and wave method are analyzed. Civil engineering structures, such as dams, bridges, high-rise buildings, etc., will inevitably suffer some damage during their service. Sometimes it is caused by natural factors of force majeure, or due to long-term accumulation damage, these damages will directly cause structural resistance to decay, and in severe cases may lead to catastrophic accidents. The support role of structural monitoring technology is needed to provide early warning of these disasters. Piezoelectric materials, piezoelectric impedance principles, interaction models of piezoelectric materials with monitored structures, and monitoring techniques based on impedance information. The research results of piezoelectric material size selection, scanning frequency selection, sensing range, binder influence, data acquisition equipment development and data processing methods are summarized.

Use of different segmental multi-frequency bioelectrical impedance devices for analysis of body composition in young adults: comparison with bioelectrical spectroscopy

Introduction: recently there have been several new versions of equipment based on the principles of bioelectrical impedance (BIA). Therefore, it is important to know the agreement between data produced by different commercially available equipment. Objective: to verify the agreement between fat-free mass (FFM), fat mass (FM), and body fat percentage (BF%) estimated using different segmental multi-frequency BIA (Tanita® MC-980U and InBody 770®) and whole-body spectral techniques (Xitron 4200). Methods: the sample consisted of 117 adults of both sexes, aged between 18 and 28 years. Methodological procedures followed specific guidelines for each equipment model. Agreement was analyzed by the t-test for paired data, concordance correlation coefficient (CCC), and Bland-Altman plot. Results: mean estimates of FFM, FM, and BF% produced by the Tanita® MC-980U and InBody 770® devices did not present statistical differences compared to the Xitron 4200® reference device. CCC values for FFM demonstrated magnitudes between 0.904 and 0.931, representing clinically acceptable strength of agreement, while for FM and BF% the strength of agreements was weak (< 0.90). Regarding the FFM, the bias showed underestimates of -0.98 kg to -1.69 kg, with limits of agreement between -7.32 kg and 3.94 kg. In the case of FM and BF%, overestimations were observed that reached values of 1.01 kg and 0.71%, with limits of agreement of -1.91 kg to 3.93 kg and -3.86% to 5.28%, respectively. Conclusion: FFM, FM, and BF% estimated by the Tanita® MC-980U and InBody 770® devices were not individually comparable with estimates produced by the Xitron 4200® reference device; therefore, its replacement for diagnostic purposes and inter- or intra-subject comparisons is not recommended.

Dressing Tool Condition Monitoring through Impedance-Based Sensors: Part 1-PZT Diaphragm Transducer Response and EMI Sensing Technique.

Low-cost piezoelectric lead zirconate titanate (PZT) diaphragm transducers have attracted increasing attention as effective sensing devices, based on the electromechanical impedance (EMI) principle, for applications in many engineering sectors. Due to the considerable potential of PZT diaphragm transducers in terms of excellent electromechanical coupling properties, low implementation cost and wide-band frequency response, this technique provides a new alternative approach for tool condition monitoring in grinding processes competing with the conventional and expensive indirect sensor monitoring methods. This paper aims at assessing the structural changes caused by wear in single-point dressers during their lifetime, in order to ensure the reliable monitoring of the tool condition during dressing operations. Experimental dressing tests were conducted on aluminum oxide grinding wheels, which are highly relevant for industrial grinding processes. From the results obtained, it was verified that the dresser tip diamond material and the position of the PZT diaphragm transducer mounted on the dressing tool holder have a significant effect on the sensitivity of damage detection. This paper contributes to the realization of an effective monitoring system of dressing operations capable to avoid catastrophic tool failures as the proposed sensing approach can identify different stages of the dressing tool lifetime based on representative damage indices.

Electrical power management and optimization with nonlinear energy harvesting structures

In recent years, great advances in understanding the opportunities for nonlinear vibration energy harvesting systems have been achieved giving attention to either the structural or electrical subsystems. Yet, a notable disconnect appears in the knowledge on optimal means to integrate nonlinear energy harvesting structures with effective nonlinear rectifying and power management circuits for practical applications. Motivated to fill this knowledge gap, this research employs impedance principles to investigate power optimization strategies for a nonlinear vibration energy harvester interfaced with a bridge rectifier and a buck-boost converter. The frequency and amplitude dependence of the internal impedance of the harvester structure challenges the conventional impedance matching concepts. Instead, a system-level optimization strategy is established and validated through simulations and experiments. Through careful studies, the means to optimize the electrical power with partial information of the electrical load is revealed and verified in comparison to the full analysis. These results suggest that future study and implementation of optimal nonlinear energy harvesting systems may find effective guidance through power flow concepts built on linear theories despite the presence of nonlinearities in structures and circuits.

A Novel Damage Indicator Based on the Electromechanical Impedance Principle for Structural Damage Identification.

This paper presents a novel structural damage detection indicator, i.e., fourth-order voltage statistical moment (FVSM) based on the electromechanical impedance (EMI) principle, and then proposes a two-step damage detection method based on the novel indicator and a differential evolution algorithm (DEA). In this study, several lead zirconate titanate (PZT) sensors bonded to an experimental steel beam were utilized to acquire the time-domain voltage responses. On this basis, the fourth-order voltage statistical moments (FVSMs) of the voltage responses are computed to locate the damage element in the detected structure, and the proposed damage detection method is utilized to quantify the damage. In addition, theoretical PZT voltage responses are also calculated based on the piezoelectric theory and the spectral element method (SEM). Experimental results verify the accuracy of the theoretical voltage values and the effectiveness of the proposed damage indicator. Results indicate that the FVSM is effective in locating the damage element. Integrated with DEA, the proposed technique is capable of quantifying damage.

Regeneration of Arrayed Gold Microelectrodes Equipped for a Real-Time Cell Analyzer.

The label-free cell-based assay is advantageous for biochemical study because of it does not require the use of experimental animals. Due to its ability to provide more dynamic information about cells under physiological conditions than classical biochemical assays, this label-free real-time cell assay based on the electric impedance principle is attracting more attention during the past decade. However, its practical utilization may be limited due to the relatively expensive cost of measurement, in which costly consumable disposable gold microchips are used for the cell analyzer. In this protocol, we have developed a general strategy to regenerate arrayed gold microelectrodes equipped for a commercial label-free cell analyzer. The regeneration process includes trypsin digestion, rinsing with ethanol and water, and a spinning step. The proposed method has been tested and shown to be effective for the regeneration and repeated usage of commercial electronic plates at least three times, which will help researchers save on the high running cost of real-time cell assays.

Fault-Tolerant Cooperative Control Design of Multiple Wheeled Mobile Robots

This brief investigates fault-tolerant cooperative control (FTCC) strategies for multiple differentially driven autonomous wheeled mobile robots (WMRs) in the presence of actuator faults during formation operation. First, for normal/fault-free cases and for preparation to the faults occurrence cases, an integrated approach combining input-output feedback linearization and distributed linear model predictive control techniques is designed and implemented on a team of WMRs to accomplish a formation task. Second, when actuator faults occur in one of the robots of the team, two cases are explicitly considered: 1) if the faulty robot cannot complete its assigned task due to a severe fault, then the faulty robot has to get out from the formation mission, and an FTCC strategy is designed such that the tasks of the WMRs team are reassigned to the remaining healthy robots to complete the mission with graceful performance degradation and 2) if the faulty robot can continue the mission with degraded performance, then the other team members reconfigure their controllers considering the capability of the faulty robot. Thus, the FTCC strategy is designed to re-coordinate the motion of each robot in the team. Within the proposed scheme, a fault detection and diagnosis unit using a two-stage Kalman filter to detect and diagnose actuator faults is presented. Then, the FTCC problem is formulated as an optimal assignment problem, where a Hungarian algorithm is applied. Moreover, a collision avoidance algorithm based on mechanical impedance principle is proposed to avoid the potential collision between the healthy robots and the faulty ones. Formation operation of the robot team is based on a leader-follower approach, while the control algorithm is implemented in a distributed manner. The results of real experiments demonstrate the effectiveness of the proposed FTCC scheme in different fault scenarios.

Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry

There is an increasing interest in electrochemical impedance spectroscopy as the method for the electrical characterization of biointerfaces and for the transducing method for label-free biosensors. In the field of affinity biosensors, this technique allows the direct detection of the complex formation through the variation of the capacitance or of the charge transfer resistance at the biofunctionalized electrode/biological liquid interface.This article presents the physical principles of electrochemical impedance and the performances of detection of different biotargets.

Diagnostic of capacitively coupled radio frequency plasma from electrical discharge characteristics: comparison with optical emission spectroscopy and fluid model simulation

The capacitively coupled radio frequency (CCRF) plasma has been widely used in various fields. In some cases, it requires us to estimate the range of key plasma parameters simpler and quicker in order to understand the behavior in plasma. In this paper, a glass vacuum chamber and a pair of plate electrodes were designed and fabricated, using 13.56 MHz radio frequency (RF) discharge technology to ionize the working gas of Ar. This discharge was mathematically described with equivalent circuit model. The discharge voltage and current of the plasma were measured at different pressures and different powers. Based on the capacitively coupled homogeneous discharge model, the equivalent circuit and the analytical formula were established. The plasma density and temperature were calculated by using the equivalent impedance principle and energy balance equation. The experimental results show that when RF discharge power is 50–300 W and pressure is 25–250 Pa, the average electron temperature is about 1.7–2.1 eV and the average electron density is about 0.5 × 1017–3.6 × 1017 m−3. Agreement was found when the results were compared to those given by optical emission spectroscopy and COMSOL simulation.

Extension of the elasticity-conductivity cross-property connections to impedance of plane microcracked structural elements

The paper focuses on empirical extension of the cross-property connection between changes in elasto-static compliance and electrical resistance associated with plane microcracking in structural elements to changes in electrical impedance. Theoretical underlying principles of impedance are discussed and experimental measurements are taken to compare AC impedance, DC resistance and changes in resistivity predicted by the cross-property connection before and after subjecting test specimens to an edge cut. If the reactive components of impedance are sufficiently isolated, experimental results show a strong correlation between changes in real-part resistive impedance, directly extending the cross-property connection to impedance.

Practical Considerations for High Impedance Restricted Earth Fault Relay Settings

A strategy for practical specifications of restricted earth fault (REF) relay settings of power transformers based on the high impedance principle has been described in this work. The conventional REF relay settings rely on the principle that the REF current transformers on the phase and neutral sides of the main power transformer are having identical parameters and hence the normal settings for REF relays depend on this assumption. It is found that in the conventional literature for REF relay settings normally available there is no attempt has been made to assume unequal CT parameters on the phase and neutral ends of the power transformers. In this work, an attempt has been made to formulate generalized equations for REF relay spill currents based on unequal CT parameters and to derive practical REF relay settings therefrom.

Design and implementation of wireless sensor networks for impedance-based structural health monitoring using ZigBee and Global System for Mobile Communications

This article presents the design and implementation of a novel wireless structural health monitoring system based on the electromechanical impedance principle. The proposed system is a wireless low-power scalable sensor network composed of multiple sensor nodes and a link node used as master to establish communication with the remote monitoring center (host node and server). The link node communicates with the remote monitoring center through a Global System for Mobile Communications/General Packet Radio Services network and with other sensor nodes through a ZigBee network. Each sensor node is a portable and autonomous structural health monitoring core based on microcontroller, digital synthesizer, and transceiver ZigBee. The identification of damage is performed by simply comparing the variations in root mean square voltage obtained from piezoelectric transducers, such as lead zirconate titanate patches, bonded to the structure. The lead zirconate titanate patches are excited on a wideband frequency range, and it is not necessary to compute the electromechanical impedance. The proposed system was built and experiments were carried out on an aluminum structure, and excellent results have been obtained. Our contribution ranges from the hardware to the graphical front end.

An Experimental Assessment of PZT Patches for Impedance-Based SHM Applications

Abstract In this paper, we present an alternative method for assessing the sensitivity of lead zirconate titanate (PZT) piezoceramics for damage detection in structural health monitoring (SHM) systems based on the electromechanical impedance (EMI) principle. An assessment of the sensitivity is obtained experimentally using the pencil lead break (PLB) method, which is frequently used in acoustic emission (AE) systems. Tests were carried out on an aluminum beam, and the results show a clear relationship between the damage indices obtained from the electrical impedance signatures of the PZT patch bonded to the monitored structure and the power spectral density (PSD) obtained using the PLB method.