Invasive Measurement Methods Research Articles

A model for multiphase flow velocity calculation in pipelines based on ultrasonic sensors

In the petroleum and natural gas industry, a wide variety of multiphase fluids are prevalent, and precise measurement of their flow velocity in pipelines holds significant importance for different stages of well drilling and construction. However, due to the presence of large solid particles and the corrosive nature of the liquid phase in multiphase fluids within the petroleum industry, invasive measurement methods struggle to maintain long-term acceptable detection accuracy. Therefore, the non-contact fluid flow velocity measurement method based on ultrasonic sensors exhibits substantial research value. Nonetheless, when employing this approach for pipeline multiphase fluid flow velocity measurement, the abundance of background interference noise at the site poses challenges in Doppler echo signal reconstruction and results in lower precision for frequency shift extraction, leading to considerable errors in flow velocity calculation results. To address this issue, the present study utilizes a transmit-receive separated continuous wave ultrasonic sensor. First, a mathematical model is developed for the superimposed signal of ultrasonic Doppler echoes within the pipeline. Next, a novel signal reconstruction method is proposed by employing Chebyshev polynomials for interpolation computation of the sampled discrete signals. Subsequently, a Doppler shift model is introduced, leading to the formulation of a new model for multiphase flow velocity calculation in pipelines based on ultrasonic sensors. Finally, a comparison experiment for full-pipe multiphase flow velocity detection is conducted to validate the computational performance of the new model. The experimental results show that, compared with the FFT model and the conventional cross correlation model, the comprehensive meter factor of the ultrasonic flow measurement system with the new model is reduced by 0.024 445, the accuracy is reduced by 2.98%, the nonlinear error is reduced by 2.4405%, the average relative error is reduced by 0.646%, the standard deviation is reduced by 0.045 175, and the root mean squared error is reduced by 0.029 615.

A review of Image Processing Technique for Monitoring The Growth and Health of Cows

In general, monitoring of animal growth and health is done directly by farmers (invasive measurement methods) which can cause cows to be injured or experience stress. To avoid this, several studies have been conducted on non-invasive methods using image processing technology. In this study, we systematically reviewed several works of literature to identify and synthesize published articles on image processing technology and image processing applications related to weight estimation and individual cattle identification. Analysis of image processing technologies used for weight estimation and individual cattle identification is the main objective of this article. Articles were searched through several databases and studies that met the inclusion criteria were analyzed and used in the review. The studies were divided into three main themes: image processing technologies, applications using image processing, and image processing research on cattle growth and health. It can be concluded that deep learning approaches are increasingly being studied, tested and considered as a viable and promising approach to monitor cattle weight and health in several aspects

Volume flow rate calculation model of non-full pipe multiphase flow based on ultrasonic sensors

In the oil and gas industries, it is crucial to employ appropriate drilling fluids in order to maintain equilibrium of formation pressure throughout the various stages of drilling operations. During the recycling process, the drilling fluid may precipitate gas and as a result exhibit non-full pipe flow upon return to the surface. Accurate measurement of the volume flow rate of the drilling fluid is imperative in obtaining valuable information from the bottom of the well. Commonly, on-site drilling operations use a multiphase target flowmeter in conjunction with an empirical model to rectify calculation results. However, the returned multiphase flow that is not fully in the pipe and its liquid component exhibits corrosive properties, making it a challenge for traditional invasive measurement methods to achieve adequate accuracy over an extended period. Therefore, the theoretical potential of utilizing non-contact ultrasonic sensors for measuring the multiphase volume flow rate of the non-full pipe flow is significant. In this research, an apparent flow velocity calculation model was established by integrating the ultrasonic Doppler shift model and pipeline fluid mechanics utilizing a four-channel ultrasonic array. Subsequently, the invariant scattering convolution—long short-term memory) network was trained on the data-fused ultrasonic signal to identify the liquid level. The velocity-area method was also employed to establish a new multiphase volume flow calculation model. To evaluate the validity of the proposed model, comparison experiments of liquid single-phase flow and liquid–solid two-phase flow were conducted. The experimental results show that, compared with the comparative flow measurement system, the accuracy of the ultrasonic flow measurement system is reduced by 0.965%, the nonlinear error by 2.293%, the average relative error by 2.570%, the standard deviation by 1.395, and the root mean square error by 14.394.

Analysis of thermal plasma diagnostics based on enthalpy probe system

The enthalpy probe with the advantages of simplicity, reliability, and low cost, is generally regarded as a powerful tool in thermal plasma diagnostics. However, the enthalpy probe, known as an invasive measurement method, has an impact on the diagnostic process. To this end, impact factors such as probe presence and size, coolant and sampling-gas flow rates on the thermal plasma diagnostics are investigated here based on experimental and simulation studies. Furthermore, an optimized measurement principle of the enthalpy probe was proposed. The results show that the presence of the probe has a strong effect on the plasma flow, and the effect increases as the probe size rises. The coolant flow rate has little effect on the temperature and flow fields, while the probe sensitivity was improved with the increase in coolant flow rate. However, consideration should be given to the sufficient temperature rise of the coolant by reducing the coolant flow rate. Probe sensitivity and velocity continue to increase as the sampling-gas flow rate rises. At the same time, an inappropriate sampling-gas flow rate would deviate from the isokinetic sampling condition which is critical for temperature measurements. In addition, the measurement accuracy was improved by about 3.6% based on the optimized measurement principle compared with the previous measurement principle.

Arterial stiffness - a cardiovascular risk factor to assess among primary care patients.

Arterial stiffness is a characteristic of the arterial wall strongly associated with ageing and hypertension. It has been confirmed as a significant cardio-vascular risk factor. Despite available non- invasive measurement methods of central artery stiffening, it has not become a prevalent diagnostic marker in primary care so far. This article provides an overview of pathophysiology of arterial stiffness, possible diagnostic techniques, association with cardiovascular conditions and potential perspective of primary care to implement an additional distinctive parameter to evaluate cardiac risk.

Decomposition and evaluation of SEMG for hand prostheses control

The evaluation of electromyogram signals (EMG) has been at the core of prosthetic control applications in the last decade, as prosthetic hands have become a valuable replacement for amputees for regaining some of the capabilities of their missing hand. The use of EMG signals as an input in decision-making systems offers a potential possibility for hand movement classification in the field of health and technology. The EMG signal can be recorded either using noninvasive or invasive measurement methods, however for many applications of human-computer interaction, non-invasiveness is a must. So, in this paper, seven different daily hand activities were recorded using surface electromyogram (SEMG) signals and analyzed using a statistical analysis approach to examine muscle force relationship based on analysis of variance and principal component analysis for hand movement interpretation. Muscle classification for control applications is essential to carrying out these activities, and once an appropriate algorithm for signal analysis is ready, the features of the signal can be easily investigated prior designing a prosthetic hand.

Electrochemical Evaluation and Control of Skin Function Via Transepidermal Potential

The epidermis at the forefront of the skin, wraps around the entire body and acts as a barrier to prevent the loss of internal moisture and the invasion of foreign substance. Its involvement in the transduction of external stimuli has been reported, and there has been growing interest in its intelligent aspects in recent years. A potential difference, called the transepidermal potential (TEP), is generated across the epidermis, and its magnitude is about tens of mVs where its surface is negative [1]. Active ion transportation by the epidermal keratinocytes is seemed to generate TEP, and its value changes according to the state of epidermal wounds and barrier. Unfortunately, the lack of an appropriate method for TEP measurement has hindered the progress of the research for decades. As TEP is generated across the epidermis, measuring electrodes have to be connected to the outside of the epidermis (surface of the skin) and the inside of the epidermis (tissue under the epidermis). Typically, a wound is created as an electrical path to the subepidermal tissue, despite its invasiveness. As an alternative, sublingual mucosa was utilized as a potential reference, suffering from the interference of other tissues. In this study, we developed a minimally invasive measurement method and applied it to the evaluation and control of skin function.To measure relatively small resting potential, a pair of reversible Ag/AgCl electrodes were connected to the inside and outside of the epidermis via a salt bridge. A commercially available painless medical micro-needle (Nanopass 34G, Terumo) was employed to support the salt bridge for subepidermal connection. The external diameter of the needle was 0.18 mm (34 G), which minimized the damage accompanied by the insertion. The salt bridge was made biocompatible from Ringer's solution and agarose, and held in the hydrophilized needle, which could quickly soak up tissue fluid and stabilize the ionic conduction. Then the needle salt bridge for subepidermal tissue and a tubular salt bridge for the surface of the epidermis were bundled into a measuring probe (Figure 1A) [2].For ex vivo measurement, porcine skin samples were used to observe the disruption and recovery of epidermal barrier induced by visible light stimulation. In vivo measurements were performed on human participants. All procedures performed in studies involving human participants were in accordance with the standards of the Ethics Committee of Graduate School of Engineering, Tohoku University (16A-5) and with the 1964 Helsinki declaration and its later amendments.In vivo measurements in human participants successfully observed a decrease in TEP according to the experimental barrier disruption, accompanied by an increase in the amount of water evaporation across the skin (Figure 1B) [3]. The penetration depth of the needle was about 1 mm, allowing access into the epidermis with minimal invasion. Compared to the water evaporation, which requires the controlled atmosphere for measurement, TEP was reflected by the electrical properties of the inside of the epidermis, and expected to be suitable for on-demand measurement. TEP of porcine skin sample also showed decrease along with the barrier disruption, and application of electrical potential that have been reported to therapeutic effect on skin barrier [4] caused greater recovery (Figure 1C). These results indicate that the developed device would be a practical tool for less-invasive TEP potential, and suggest further application of it in the electrical diagnosis and cure.

A Frequency-domain Approach to Noninvasive Intracranial Pressure Estimation.

Intracranial pressure (ICP) is a cranial vital sign, crucial in the monitoring and treatment of several neurological injuries. The clinically accepted measurement modalities of ICP are highly invasive, carrying risks of infection and limiting the benefits of ICP measurement to a small subset of critically ill patients. This work aims to take a step towards developing an accurate noninvasive means of estimating ICP, by utilizing a model-based frequency-domain approach. The mean ICP and pulse pressures of ICP are estimated from arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) waveforms, and the estimates are validated on an adult population, comprising of around two hours of data from five patients. The algorithm was shown to have an accuracy (mean error) of -1.5 mmHg and a precision (standard deviation of the error) of 4.3 mmHg in estimating the mean ICP. These results are comparable to the previously reported errors among the currently accepted invasive measurement methods, and well within the clinically relevant range.

Expression and genotype-dependent catalytic activity of N-acetyltransferase 2 (NAT2) in human peripheral blood mononuclear cells and its modulation by Sirtuin 1

N-acetyltransferase 2 (NAT2) catalyzes the biotransformation of numerous arylamine and hydrazine drugs and carcinogens. Genetic polymorphisms of NAT2 modify drug efficacy and toxicity and susceptibility to diseases such as cancer and type 2 diabetes. Expression of NAT2 has been documented in the liver and gastrointestinal tract but not in other tissues. Deacetylation of cytosolic proteins by sirtuins is a post-translational modification important in regulatory networks of diverse cellular processes. The aim of the present study was to investigate NAT2 expression in peripheral blood mononuclear cells (PBMC) and the effects of NAT2 genotype and Sirtuin 1 (SIRT1). Both NAT2 and SIRT1 proteins were expressed on PBMC. Their expression was more prevalent on CD3+ compared to CD19+ and CD56+ cell populations. N-acetylation capacity of PBMC exhibited a NAT2 gene-dose response toward the N-acetylation of isoniazid. Subjects with rapid NAT2 genotype showed an apparent Vmax of 42.1 ± 2.4; intermediate NAT2 genotypes an apparent Vmax of 22.6 ± 2.2; and slow acetylator NAT2 genotypes an apparent Vmax of 19.9 ± 1.7 nM acetyl-isoniazid/24 h/million cells. The N-acetylation capacity of NAT2 in the presence of SIRT1 enhancer was significantly decreased (p < 0.001), conversely, the transient silencing of SIRT1 resulted in an increase of N-acetylation capacity (p < 0.001). These findings are the first report of NAT2 genotype-dependent expression on PBMC and post-translational modification by SIRT1. These findings constitute a substantial advance in our understanding of human N-acetyltransferase expression and a new much less invasive method for measurement of human NAT2 expression and phenotype.

OPCPP: An Online Plug-Configure-Play Experiment Platform for WSN

Wireless sensor network (WSN) experiment platforms are used for teaching, research, and development of WSN. However, existing WSN experiment platforms generally have the following disadvantages: tedious manual operations, invasive measurement method, poor sensor self-awareness, and low resource utilization rate. To address the above problems, this paper proposes OPCPP, an online Plug-Configure-Play experiment platform for WSN. It has four prominent strongpoints: in-application programming in batch, noninvasive measurement method, sensor self-awareness, and remote operation. OPCPP has been used in eight colleges in China for teaching course of “internet of things” till now. We also develop a sensor-aware ZigBee-based smart home system prototype based on OPCPP.

An invasive but simple and accurate method for ascending aorta–femoral artery pulse wave velocity measurement

Introduction. Pulse wave velocity (PWV) is an emerging predictor in the assessment of cardiovascular risk in diseased and healthy populations. We suggest a novel method for the accurate measurement of PWV. Method. PWV is calculated from pulse transit time using two separate pulse recordings over a known distance. 8F sheaths were placed in the right femoral arteries and routine coronary angiographies were performed with 5F diagnostic catheters. Ascending aorta pressures were measured with right diagnostic catheter tip in the ascending aorta and synchronous femoral artery pressures were measured with the sheath in the femoral artery. The distance between the two pressure sites was calculated as follows: total length of the right diagnostic catheter−length of the catheter outside the sheath−Sheath length. Results. We evaluated the PWV measured using the catheter method in 24 subjects. PWV correlated positively and independently with age (p = 0.004), coronary artery disease (p = 0.04), ascending aorta systolic pressure (p = 0.006), femoral artery systolic pressure (p = 0.008), ascending aorta pulse pressure (p = 0.003) and femoral artery pulse pressure (p = 0.04). In coronary artery disease patients, the mean PWV value was significantly higher than in patients with normal coronary arteries (12.61 ± 6.31 m/s vs 7.58 ± 2.26 m/s p = 0.04). Conclusion. We describe a novel and accurate but invasive method for measurement of PWV. Our results may serve as a reference for non-invasive assessment of aorta–femoral artery PWV.

Early Detection of Metabolic Changes Using Microdialysis During and After Experimental Kidney Transplantation in a Porcine Model

Microdialysis (MD) can detect organ-related metabolic changes before they become measurable in plasma through the biochemical parameters. This study aims to evaluate the early detection of metabolic changes during experimental kidney transplantation (KTx). During preparation of 8 donor kidneys, one MD catheter was inserted in the renal cortex and samples were collected. After a 6-hour cold ischemia time (CIT), kidneys were implanted in the 8 recipient pigs. Throughout the warm ischemia time (WIT) and after reperfusion, kidneys were monitored. The interstitial glucose, lactate, pyruvate, glutamate, and glycerol concentrations were evaluated. A significant decline in glucose level was observed at the end of CIT. The lactate level was reduced to the minimum point of 0.35 ± 0.08 mmol/L in CIT. After reperfusion, lactate values raised significantly. During the WIT, the pyruvate level increased, continued until the end of the WIT. For glutamate, a steady increase was noted during explantation, CIT, WIT, and early reperfusion phases. The increase of glycerol value continued in the early postreperfusion, which was then followed by a sharp decline. MD is a fast and simple minimally invasive method for measurement of metabolic substrates in renal parenchyma during KTx. MD offers the option of detecting minor changes of interstitial glucose, lactate, pyruvate, glutamate, and glycerol in every stage of KTx. Through the use of MD, metabolic changes can be continuously monitored during the entire procedure of KTx.

P1-142: Factors related to degree of peripheral arterial occlusive disease in dementia with cerebrovascular disease patients

A low ankle–brachial index(ABI) is associated with an increased risk of peripheral artery disease, cardiovascular disease and stroke. Recently, the toe–brachial index(TBI) has been receiving attention for non–invasive method for measurement of atherosclerosis which is generally regarded as a risk factor for stroke. Limited data exist regarding the relation between a low TBI and dementia with cerebrovascular disease patients. In this study, we investigated the relation between a low TBI and dementia with cerebrovascular disease. We reviewed Ilsan Hospital stroke database of recent 3 years. A total of 50 dementia patients with cerebrovascular disease and TBI study was included. The relationship with TBI, TOAST classification, risk factors of stroke and degree of cerebral artery stenosis was investigated. According to degree of TBI, peripheral arterial occlusive disease(PAOD) was classified as normal (TBI≥0.8), borderline (0.6≤TBI<0.8) and abnormal (TBI<0.6). Abnormal TBI(PAOD) was observed in 9(18%) patients. PAOD(abnormal TBI) was more common in large artery atherosclerosis (LAA) patients than small vessel occlusion (SVO) and cardioembolism (CE) patients between subgroups by TOAST classification. TBI can be a useful marker which reflect the degree of peripheral atherosclerosis in dementia with cerebrovascular disease patients.

P0786 UREA PRODUCTION MEASURED WITH [13C]UREA IN FED AND FASTED PIGLETS: ACCURACY AND SIMPLIFICATION OF PROTOCOL.

Introduction: The oral [13C]urea bolus technique may provide a simple and minimally invasive method for measurement of urea rate of appearance (Ra). Methods: Plasma urea enrichments from a 10 h sampling protocol were measured by GC-c-IRMS following an intragastric [13C]urea bolus. Total urea pool size (Q) and Ra were calculated using compartmental and single pool regression computations in 8 fed and 5 fasted piglets. Total body water (TBW) was determined with deuterated water and TBW * (plasma urea concentration) was compared with Q. Blood [13C]bicarbonate was measured to trace gut [13C]urea oxidation. Results: Mean (± SE) Q from TBW and plasma urea concentration was 2.2 ± 0.16 mmole.kg−1. Two-compartmental modeling yielded similar pool size. Urea Ra was 306 ± 18 μmole.kg−1.h−1. Single pool computations overestimated pool size (p<0.001 vs. compartmental model) and Ra (323 ± 18 μmole.kg−1.h−1, p<0.05). When samples <2 h were discarded, single pool calculations of Ra were comparable to compartmental calculations. Reducing protocol length to 6 h and sample number to n=5 did not affect Ra values when samples <2h were discarded. Urea kinetics were not different between fed and fasted piglets. [13C]bicarbonate enrichment rose significantly 1 h after bolus. Conclusion: When initial plasma enrichments are discarded, urea Ra can be calculated using simple regression analysis of plasma enrichment decay values following an oral [13C]urea tracer. Sampling time can be reduced to 6 h and sample number to n=5, rendering a minimally invasive measurement protocol for urea Ra in fed and fasted individuals. In our piglets, a fraction of the oral urea tracer bolus was oxidized.

Production of 13C Labelled Pea Flour for Use in Human Digestion and Fermentation Studies

Stable isotope breath tests offer a new approach to the study of digestion and fermentation of carbohydrates in man. In this study, 13C labelled peas were grown by pulsing 250ml 13CO2 into a sealed growth chamber. A second pulse was added to a portion of the peas to increase the 13C enrichment. This generated pea flour with an enrichment of 2.36 at.% excess (range 2.09–2.71 n = 3) and 8.64 atom % excess (range 7.37–9.78 n = 3) respectively. This represented incorporation of an absolute yield of 3.8% of the 13CO2 into peas in the ‘once-labelled’ treatment and 7.5% in the ‘twice-labelled’ treatment. Ingestion of a mixture of the labelled pea flour (300 mg) by two volunteers generated measurable 13CO2 excretion for breath test analysis. The profile of breath 13CO2 enrichment increased to a maximum within three hours after consuming the pea flour followed by a decrease almost back to baseline by 13 hours. Breath 13CO2 appeared to rise again after this apparent nadir at 13 hours until the end of the sampling period. Mathematical analysis of the data suggested that two peaks best described the profile of breath 13CO2 up to 13 hours. A third peak was necessary to describe the late rise in breath 13CO2 enrichment. This use of 13C enriched pea flour may provide a useful non invasive method for measurement of digestion and fermentation in vivo.

Increased Luminal Nitric Oxide in Inflammatory Bowel Disease as Shown with a Novel Minimally Invasive Method

Background: The production of nitric oxide (NO) is increased in ulcerative colitis, as shown by bioassays of NO synthase activity in mucosal biopsy specimens.We wanted to develop a less invasive method for measurement of NO directly in the rectum in patients with inflammatory bowel disease (IBD). Methods: We studied 10 patients with active ulcerative colitis, 6 with active Crohn's disease, 6 with non-active ulcerative colitis, and 24 controls without inflammation A tonometer balloon catheter was inserted in the rectum and inflated with 5 ml of NO-free air. After 15 min of incubation the sample was extracted, and the NO concentration was immediately analysed with a chemiluminescence technique. Results: Patients with active disease had greatly increased concentrations of NO in the rectum as compared with controls and patients with non-active disease. Conclusions: During inflammation in the large intestine increased amounts of NO are released from the mucosa. Measurements of NO directly in the rectum could be of help in further understanding the role of this gas in IBD. Moreover, it is tempting to speculate that this minimally invasive method could be clinically useful as a diagnostic tool and in monitoring the effect of therapy.

Measurement of bile acid kinetics in human serum using stable isotope labeled chenodeoxycholic acid and capillary gas chromatography electron impact mass spectrometry.

A non invasive method for measurement of bile acid kinetics in serum using (24-13C)chenodeoxycholic acid has been developed. After oral administration of 50 mg (24-13C)chenodeoxycholic acid, the exponential decay of the 13C atom percent excess was measured in serum using capillary gas chromatography mass spectrometry. This required that isotope ratios were measured with high accuracy and coefficients of variation less than 1% by means of selected ion monitoring and scan averaging. The clinical applicability was tested by repeated determination of pool size, fractional turnover and synthesis rate of chenodeoxycholic acid in one healthy volunteer. This method permitted the determination of pool size, synthesis and conversion of chenodeoxycholic acid into lithocholic acid in man without the use of radioactive tracers and without repeated duodenal intubation.