Simultaneous Pressure Measurements Research Articles

Transient characteristics of a typical vacuum ejector—An experimental study

Using simultaneous measurements of unsteady pressures in conjunction with time-resolved Schlieren images and oil flow visualization, we investigate the characteristics of a typical vacuum ejector's starting transient, steady-state, and shut-down transient. With varying primary jet chamber pressure, the pressure evolution in the secondary chamber shows smooth, perturbed, rapid, and steady evacuation stages, as well as hysteresis and rapid filling stages. It is noticed that the evacuation in the secondary chamber is improved during stopping transient just before the unstart event. By using oil flow images, we illustrate the separation bubble characteristics during each stage of the vacuum ejector operation and their influence on the pressure evolution. Through cross correlation, it has been determined that the primary jet flapping during the starting transient causes the jet to attach to one of the diffuser walls. We also demonstrate that the primary jet undergoes both longitudinal and lateral oscillations in the starting transient, the former having a major effect on unsteadiness in the secondary chamber using proper orthogonal decomposition and spectral proper orthogonal decomposition algorithms and power spectral density (PSD). Simultaneous acquisition of unsteady pressures and high-speed Schlieren images allow us to correlate the frequency peaks (PSD spectra) in the flow. Using magnitude-squared coherence and cross correlation analyses, we confirm communication of unsteadiness and its direction of propagation between the secondary chamber and the diffuser. In this study, we demonstrate that a high ramping rate of primary jet chamber pressure reduces the unsteadiness in the secondary chamber during the transient starting phase.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Single optical microfiber enabled tactile sensor for simultaneous temperature and pressure measurement

The ability to sense heat and touch is essential for healthcare, robotics, and human–machine interfaces. By taking advantage of the engineerable waveguiding properties, we design and fabricate a flexible optical microfiber sensor for simultaneous temperature and pressure measurement based on theoretical calculation. The sensor exhibits a high temperature sensitivity of 1.2 nm/°C by measuring the shift of a high-order mode cutoff wavelength in the short-wavelength range. In the case of pressure sensing, the sensor shows a sensitivity of 4.5% per kilopascal with a fast temporal frequency response of 1000 Hz owing to the strong evanescent wave guided outside the microfiber. The cross talk is negligible because the temperature and pressure signals are measured at different wavelengths based on different mechanisms. The properties of fast temporal response, high temperature, and pressure sensitivity enable the sensor for real-time skin temperature and wrist pulse measurements, which is critical to the accurate analysis of pulse waveforms. We believe the sensor will have great potential in wearable optical devices ranging from healthcare to humanoid robots.

ASSESSMENT OF PERIPHERAL VASCULAR DAMAGE IN PATIENTS WITH DIFFERENT DEGREES OF BLOOD PRESSURE INCREASE

Purpose – to investigate the frequency of peripheral arteries damage by determining theankle- brachial index (ABI) in patients with hypertension of 1-3 degrees of the older agecategory (> 55 years) using automatic devices for measuring blood pressure.Material and methods. The object of the study were patients with hypertension olderthan 55 years, 150 people (50 patients with elevated blood pressure levels 1, 2 and3 degrees), as well as 20 healthy people of the same age. The study included only patientswho did not have obvious clinical symptoms of peripheral vascular disease. The studydid not include patients with persistent cardiac arrhythmias (atrial fibrillation, frequentventricular arrhythmias, etc.). Simultaneous measurement of blood pressure on the armwith a higher level of blood pressure and on the leg in a supine position was carriedout. After that, the ankle- brachial index was calculated as the ratio of the mean systolicblood pressure (SBP) separately on the right and left ankle to the mean SAT level on thebrachial of the arm with higher BP. If ABI less than 0.9 damage of peripheral arteries ona proper side was diagnosed. Results. For a detailed analysis, we divided all patients with hypertension dependingon the value of the ankle- shoulder index into two subgroups: subgroup A includedpatients (n = 141) with hypertension with an index value> 0.9, and subgroup B (n = 9) –respectively <0.9. The mean age of patients in subgroup A was 64.5 ± 1.1 years, subgroupB – 66.5 ± 2.1 years (p> 0.05 between subgroups). SAT in subgroup A was 159.4 ± 2.9mm Hg, in subgroup B – 162.1 ± 4.2 mm Hg. (p> 0.05 between subgroups). Patients inboth subgroups did not differ in age, sex, body mass index, smoking frequency. Patients inboth subgroups had significantly elevated serum total cholesterol of 6.5 ± 0.2 mmol / l and6.7 ± 0.5 mmol / l, respectively. The degree of increase in diastolic blood pressure (BP)in subgroup A was significantly higher than 103.2 ± 1.2 mm Hg. compared with subgroupB – 78 ± 4.6 mm Hg (p <0.01). Serum creatinine levels in patients with signs of peripheralarterial lesions were higher than in patients without signs of lesions of 99.4 ± 3.6 μmol /l versus 88.2 ± 3.1 μmol / l (p <0.05). Type 2 diabetes was found in 44 % in subgroup Band in 7 % in subgroup A.Conclusions. The most common signs of peripheral vascular disease were observed inpatients older than 55 years with isolated systolic hypertension, type 2 diabetes mellitusand elevated serum creatinine.

Estimation of Characteristic Impedance using Multi-Gaussian Modelled Flow Velocity Waveform: A Virtual Subjects Study.

Characteristic impedance (Zc) of the blood vessel relates the pulsatile pressure to pulsatile blood flow velocity devoid of any wave reflections. Estimation of ZC is useful for indirect evaluation of local pulse wave velocity and crucial for solving wave separation analysis (WSA) which separates the forward-backward pressure and flow velocity waveforms. As opposed to conventional WSA, which requires simultaneous measurement of pressure and flow velocity waveform, simplified WSA relies on modelled flow velocity waveforms, mainly introduced for the aorta. This work uses a multi-Gaussian decomposition (MGD) modelled flow velocity waveform to estimate ZC by employing a frequency domain analysis, which is applicable to other arteries such as carotid. Thus obtained ZC is compared with Zc estimated from true flow velocity waveform for healthy (virtual) subjects taken for the carotid artery. The MGD modelled flow velocity waveform estimated ZC for a range of 4.98 to 34.79 with a group average of 16.43±0.10. The difference between the group average values of both ZC was only 4.72%. A statistically significant and strong correlation (r = 0.708, p < 0.0001) was observed for ZC obtained from MGD modelled flow velocity waveform with ZC obtained from actual flow velocity waveform. The bias for ZC1 between the two methods was 0.74, with confidence intervals (CIs) between 7.44 and -5.96 for the Bland-Altman analysis. Therefore, ZC from MGD modelled flow velocity waveform is a potential surrogate of the flow velocity model for WSA at the carotid artery. Clinical Relevance- This study provides a new method to derive characteristic impedance without the measurement of actual flow velocity waveform. The method requires a single pulse waveform (pressure or diameter).

Simultaneous Measurement of Temperature and Pressure Based on Fabry-Perot Interferometry for Marine Monitoring.

The temperature and pressure of seawater are of great importance to investigate the environmental evolution for the research of ocean science. With this regard, we proposed and experimentally demonstrated a seawater temperature and pressure sensor realized by a polyimide (PI) tube-based Fabry-Perot interferometer (FPI) together with a fiber Bragg grating (FBG). Benefiting from the higher thermo-optical coefficient and larger elasticity of polymer than the fused silica fiber, the sensitivity of the sensor is largely improved. The FBG is used to compensate the cross effect of the temperature. The measured temperature and pressure sensitivities of the sensor are 18.910 nm/°C and −35.605 nm/MPa, respectively. Furthermore, the temperature and pressure information measured by the sensor can be achieved simultaneously using the sensitivity matrix method. In addition, the proposed sensor has advantages of easy fabrication, compact size, as well as capability of multiplexing and long-distance measurement, making it competitive and promising during the marine monitoring.

Experimental Study of Hydrodynamic Pressures Acting on a Submerged Gate

Vortical flow formed by a submerged hydraulic jump may produce significant hydrodynamic lift and drag pressures on a gate beneath the hydraulic jump. In this study, an experimental setup equipped with multi-pressure sensors was used to measure fluctuating impact pressures on the submerged gate for different flow conditions characterized by the inlet Froude number and submergence factor (S). Time-averaged and instantaneous pressure coefficients are evaluated based on simultaneous measurements of wall pressures at multiple locations, including those at the lip and downstream face of the gate. In particular, instantaneous lift pressure coefficients are observed to be independent of the submergence ratio for S &amp;gt; 0.6. It is found that low Froude number flows produce high surface pressure fluctuations and the dominant frequency of pressure fluctuations shifts to higher frequency as the Froude number increases. Pressure measurements for the free hydraulic jump suggest that the power spectra of lift pressure fluctuations are devoid of any significant energy level, whereas the resulting power spectra of the submerged flow exhibits significant energy level in the frequency range of 14-19 Hz. The proposed measurement system can be used for the in situ identification of hydrodynamic pressures acting on the gates in irrigation canals.

Assessing Rodent Cardiac Function in vivo Using Hemodynamic Pressure-Volume Loops.

Heart failure (HF) triggered by cardiovascular and non-cardiovascular diseases is a leading cause of death worldwide and translational research is urgently needed to better understand the mechanisms of the failing heart. For this purpose, rodent models of heart disease combined with in vivo cardiac functional assessment have provided valuable insights into the physiological significance of a given genetic or pharmacological modification. In small animals, cardiac function and structure can be evaluated by methods such as echocardiography, telemetry or hemodynamics using conductance catheters. Indeed, hemodynamic analysis of pressure-volume loops (PV-loops) has become the gold standard methodology to study in vivo cardiac function in detail. This method provides simultaneous measurement of both pressure and volume signals from rodents intact beating hearts. On the one hand, PV-loop analysis has deeply expanded the knowledge on molecular cardiac physiology by allowing establishing important functional correlations. On the other hand, these measurements allow dissecting the cardiovascular functional impact of certain therapeutic interventions or specific signaling pathways using transgenic models of disease. However, a detailed assessment of cardiac function and structure in vivo still warrants proper standardization and optimization to boost the progress of HF research. With increasing concerns over data accuracy and reproducibility, guidelines and best practices for cardiac physiology measurements in experimental settings are needed. This article aims to review the best practices for carrying out cardiac hemodynamic assessment using PV-loops in vivo in rodents intact beating hearts, also providing an overview of its advantages, disadvantages and applications in cardiovascular research.

Simultaneous Measurement of Water Pressure and Temperature Based on a Simple Fabry-Pérot Sensor

We proposed a simple and compact Fabry-Perot (FP) sensor for simultaneous measurement of water pressure and temperature, composed of a standard fiber ferrule connector/flat contact (FC/FC) connector and aluminum foil attached to a thin metal plate. Two dips in the interference spectrum are selected to illustrate the response of the FP sensor to the water pressure and temperature, we can obtain the simultaneous measurement via a method of sensitivity coefficient matrix. Experimental results show the maximum sensitivity of −2.948 nm/kPa for water pressure sensing in 0~9 kPa and 1.119nm/°C for temperature sensing in 33~45 °C. In addition, the dual-parameter sensor has the advantages of compactness, stability, simple production, small size, and high sensitivity, making it suitable for a wide range of practical applications.

Pressure-sensitive paint integrated with digital image correlation for instantaneous measurement on rotating blades

In wind tunnel tests, there is a strong demand for simultaneous pressure and deformation measurement techniques, especially for objects with complex aerodynamic shapes or with significant deformation and displacement. A novel speckle pattern pressure-sensitive paint (PSP) system was proposed in this work. The single-shot lifetime method and stereo digital image correlation (DIC) technique were integrated into this system. A random speckle pattern was printed on the PSP surface with a photosensitive seal. The luminescent images with this additional pattern were used to generate point cloud data through cross-correlation analysis and triangulation. The speckle pattern was also helpful to realize pixel to pixel image registration for pressure field reconstruction. This system was successfully applied to simultaneously measure the instantaneous pressure and deformation field of a high-speed rotating blade. The pressure measurement results from the speckle pattern PSP were highly consistent with those from the regular PSP. The average standard deviation (STD) was around 200 Pa. The accuracy of the deformation field measurement was evaluated by comparing the measured point cloud data with the CAD model, showing an average deviation of 0.13 mm.

Simultaneous Pressure and Displacement Measurement on Helicopter Rotor Blades Using a Binocular Stereophotogrammetry PSP System

A simultaneous surface pressure and displacement measurement method that integrates pressure-sensitive paint (PSP) and binocular stereophotogrammetry is proposed. The assays were completed on the Φ4 m rotor test stand at China Aerodynamic Research and Development Center (CARDC). A single-shot lifetime approach was utilized to acquire the instantaneous pressure field on a rotor blade coated with PSP. At the same time, the PSP feature points were used to obtain the 3D coordinates of stereo cameras, which yielded the blade displacement field. The experimental results showed that the displacement measuring accuracy was better than 0.2 mm, and the pressure measurement accuracy was not affected, with Standard Deviation (STD) values below 700 Pa. The advantages of the proposed system are its simple structure, low cost, high accuracy and high test efficiency, which will offer a practical solution for the exploration of fluid–structure interplay. Hence, such a system is a prospective for the wind tunnel tests of helicopter rotor blades.

Simultaneous Measurement of Maximum Respiratory Pressures and Respiratory Muscle Electromyography in a Stroke Patient – Changes After Implemented Physiotherapy – Preliminary Case Report

Introduction: In subject-based literature, there are no studies in which the results obtained simultaneously from surface electromyography of respiratory muscles and measurements of maximal respiratory pressures in stroke patients would be analysed.

Normalisation of diabetic heart pump function at decreased functional load.

Aim To study left ventricular (LV) hemodynamics in presence of decreased blood inflow to the heart as well as changes in myocardial content of energy metabolites in diabetic rats.Material and methods Diabetic cardiomyopathy is characterized by impaired heart contractility and by transition of cardiomyocyte energy metabolism fatty acids exclusively as a source of energy. This reduces the efficiency of energy utilization and increases the heart vulnerability to hypoxia. This study was performed on rats with type 1 diabetes mellitus induced by administration of streptozotocin (60 mg/kg). The LV pump function was studied with a catheter that allows simultaneous measurement of LV pressure and volume in each cardiac cycle.Results Blood glucose was approximately sixfold increased at 2 weeks. Heart failure was detected with decreases in ejection fraction by 27%, minute volume by 39%, and stroke work by 41%. Systolic dysfunction was based on a decrease in LV peak ejection velocity by more than 50%. Furthermore, the LV developed pressure and contractility index were within the normal range, while 1.5 times increased arterial stiffness was the factor that hampered ejection. The sum of adenine nucleotides was decreased by 21%, the ATP content was decreased by 29%, and also creatine phosphate formation was reduced in the myocardium of diabetic rats. Lactate content in the diabetic myocardium was increased almost threefold, which indicated mobilization of aerobic glycolysis. With the reduced preload, equal diastolic volume (0.3 ml), and equal blood pressure (60 mm Hg), the diabetic heart pump function did not differ from the control.Conclusion In type 1 diabetes mellitus, decreases in functional load and oxygen consumption normalize the myocardial pump function with disturbed energy metabolism.

Understanding Complex Interactions in Pediatric Diastolic Function Assessment

Diagnosing left ventricular diastolic dysfunction (DD) noninvasively in children is difficult as no validated pediatric diagnostic algorithm is available. The aim of this study is to explore the use of machine learning to develop a model that uses echocardiographic measurements to explain patterns in invasively measured markers of DD in children. Children at risk for developing DD were enrolled, including patients with Kawasaki disease, heart transplantation, aortic stenosis, and coarctation of the aorta when undergoing clinical left heart catheterization. Simultaneous invasive pressure measurements were made using a high-fidelity catheter (time constant of isovolumic relaxation [Tau, τ], left ventricular end-diastolic pressure, and maximum negative rate of pressure change) and echocardiographic DD measurements. Spearman correlations were performed for each echocardiographic feature with invasive markers to understand pairwise relationships. Separate random forest (RF) models were implemented to assess all echocardiographic features, key demographic data, and clinical diagnosis in predicting invasive markers. A backward stepwise regression model was simultaneously implemented as a comparative conventional reference model. The relative importance of all parameters was ranked in terms of accuracy reduction. Model approximation was then performed using a regression tree with the top-ranked features of each RF model to improve model interpretability. Regression coefficients of the linear models were presented. Fifty-nine children were included. Spearman correlations were generally low. The RF models' performance measures were noninferior to those of the linear model. However, the linear model's regression coefficients were unintuitive. The highest ranked important features for the RF models were propagation velocity for Tau, E/propagation velocity ratio for left ventricular end-diastolic pressure, and systolic global longitudinal strain rate for maximum negative rate of pressure change. Estimating individual components of DD can potentially improve the noninvasive assessment of pediatric DD. Although pairwise correlations measured were weak and linear regression coefficients unintuitive,approximated machine learning models aided in understanding how echocardiographic and invasive parameters of DD are related. This machine learning approach could help in further development of pediatric-specific diagnostic algorithms.

Phasic flow patterns of right versus left coronary arteries in patients undergoing clinical physiological assessment.

Coronary blood flow in humans is known to be predominantly diastolic. Small studies in animals and humans suggest that this is less pronounced or even reversed in the right coronary artery (RCA). This study aimed to characterise the phasic patterns of coronary flow in the left versus right coronary arteries of patients undergoing invasive physiological assessment. We analysed data from the Iberian-Dutch-English Collaborators (IDEAL) study. A total of 482 simultaneous pressure and flow measurements from 301 patients were included in our analysis. On average, coronary flow was higher in diastole both at rest and during hyperaemia in both the RCA and LCA (mean diastolic-to-systolic velocity ratio [DSVR] was, respectively, 1.85±0.70, 1.76±0.58, 1.53±0.34 and 1.58±0.43 for LCArest, LCAhyp, RCArest and RCAhyp, p<0.001 for between-vessel comparisons). Although the type of RCA dominance affected the DSVR magnitude (RCAdom=1.55±0.35, RCAco-dom=1.40±0.27, RCAnon-dom=1.35; standard deviation not reported as n=3), systolic flow was very rarely predominant (DSVR was greater than or equal to 1.00 in 472/482 cases [97.9%] overall), with equal prevalence in the LCA. Stenosis severity or microvascular dysfunction had a negligible impact on DSVR in both the RCA and LCA (DSVR x hyperaemic stenosis resistance R2 =0.018, p=0.03 and DSVR x coronary flow reserve R2 <0.001, p=0.98). In patients with coronary artery disease undergoing physiological assessment, diastolic flow predominance is seen in both left and right coronary arteries. Clinical interpretation of coronary physiological data should therefore not differ between the left and the right coronary systems.

Research on the High Temperature and High Pressure Gold-Plated Fiber Grating Dual-Parameter Sensing Measurement System.

In electrohydrostatic drive actuators, there is a demand for temperature and pressure monitoring in complex environments. Fiber Bragg grating (FBG) has become a promising sensor for measuring temperature and pressure. However, there is a cross-sensitivity between temperature and pressure. A gold-plated FBG is proposed and manufactured, and an FBG is used as a reference grating to form a parallel all-fiber sensing system, which can realize the simultaneous measurement of pressure and temperature. Based on the simulation software, the mechanical distribution of the pressure diaphragm is analyzed, and the fixation scheme of the sensor is determined. Using the demodulator to monitor the changes in the reflectance spectrum in real-time, the pressure and ambient temperature applied to the sensor are measured. The experimental results show that the temperature sensitivity of gold-plated FBG is 3 times that of quartz FBG, which can effectively distinguish the temperature changes. The pressure response sensitivity of gold-plated FBG is 0.3 nm/MPa, which is same as the quartz FBG. Through the sensitivity matrix equation, the temperature and pressure dual-parameter sensing measurement is realized. The accuracy of the temperature and pressure measurement is 97.7% and 99.0%, and the corresponding response rates are 2.7 ms/°C and 2 ms/MPa, respectively. The sensor has a simple structure and high sensitivity, and it is promising to be applied in health monitoring in complex environments with a high temperature and high pressure.

Accuracy and precision of oscillometric noninvasive blood pressure measurement in critically ill patients: systematic review and meta-analysis.

Mean arterial pressure (MAP) is akey haemodynamic variable monitored in critically ill patients. The advantages of oscillometric noninvasive blood pressure (NIBP) measurement are its easy and fast methodology; however, the accuracy and the precision of this measurement in critically ill patients is constantly debated. We performed asystematic review and meta-analysis of observational studies comparing oscillometric NIBP methods with invasive arterial pressure (IAP) measurements. We included studies of adult critically ill patients, which evaluated MAP in the same patient by both NIBP and IAP at any site. We included only studies comparing simultaneous measurements of arterial pressure by NIBP and IAP, reporting their results using mean difference and SD of agreement. The main outcome was to define the bias of the MAP measured by NIBP over the IAP measurement. The quality of the studies was analysed by the QUADAS 2 tool. Seven studies and 1593 patients were included in the main analysis. The oscillometric NIBP method had amean value of -1.50 mmHg when compared with IAP (95% CI: -3.34 to 0.35; I2 = 96% for random effects model, P < 0.01). The limits of agreement for MAP varied between -14.6 mmHg and +40.3 mmHg. NIBP had an adequate accuracy regarding MAP measurements by oscillometry. Limits of agreement may thus narrow the clinical applicability in scenarios in which there is aneed for amore precise management of blood pressure.

Simultaneous Measurement of Seawater Temperature and Pressure With Polydimethylsiloxane Packaged Optical Microfiber Coupler Combined Sagnac Loop

In the field of physical oceanography, the temperature and pressure of seawater are important fundamental parameters. In order to realize the simultaneous measurement of the temperature and pressure in seawater, a reflective optical fiber sensor based on polydimethylsiloxane (PDMS)-sealed optical microfiber coupler combined with a sagnac loop (OMCSL) is proposed. Benefiting from the high thermo-optical coefficient and large elasticity of PDMS, and the large-scale swift field transmission characteristics of optical microfiber coupler (OMC), the sensitivity and structural stability of our sensor is largely improved. The response performance of the sensor is further analyzed by numerical simulation calculations and theoretical modeling. Experimental results show that the temperature and pressure sensitivity of the sensor could reach &#x2212;2.133 nm&#x002F;&#x00B0;C and 3.416 nm&#x002F;Mpa, respectively, about one order higher than that of bare fiber OMCSL. Furthermore, via inversely calculating the cross-sensitivity matrix, the temperature and pressure sensing can be demodulated simultaneously, and the average errors of the preliminary experimental settlements are 1.61&#x0025; and 5.02&#x0025;, respectively. Due to the merits of compact structure, easy fabrication, high sensitivity, fast response speed and high stability, the basic performance of this dual parametric sensor is comparable to the existing electrical temperature-depth (TD) sensor, which is expected to meet the practical application requirements of marine environmental monitoring and ocean dynamics research.

Fault diagnostics and adjustment of the fuel system of a medium-speed diesel engine using heat release characteristics

Adjustment of the diesel fuel equipment is an important condition for maintaining the technical condition of the diesel engine in operation at the level declared by the manufacturer. This paper presents the results of an experimental study of the method previously proposed by the authors for tuning the fuel system of a diesel engine based on the analysis of diagrams of net heat release in the cylinder. Net heat release diagrams are calculated based on the first law of thermodynamics, written for a closed system, using only cylinder pressure and cylinder volume. The method allows some instability of the load mode during testing and does not require simultaneous measurement of in-cylinder pressure in all engine cylinders. The method is adapted for typical operating conditions and in-cylinder pressure measurement through the indicator channel. The object of the study was a medium-speed six-cylinder diesel engine with a high-pressure hydromechanical fuel pump. The article also considers the possibility of using net heat release diagrams to identify injector malfunctions that lead to poor fuel atomization.

Serial transurethral cystometry: A novel method for longitudinal evaluation of reflex lower urinary tract function in adult female rats.

AimsThe aim of the study is to develop a minimally invasive method for longitudinal evaluation of lower urinary tract function that allows for simultaneous measurements of bladder pressure and external urethral sphincter (EUS) electromyographic (EMG) activity.MethodsTo evaluate the reliability of serial transurethral cystometry (STUC), rats (n = 12) underwent three sessions of STUC, one session a week for 3 weeks. During each session, rats were anesthetized with ketamine–xylazine (90 mg/kg and 10 mg/kg), and micturition reflex data were acquired using transurethral cystometry and percutaneous recording of EUS (EMG) activity during continuous infusion of saline into the bladder. The reliability and consistency of the STUC method were assessed using intra‐class correlation (ICC) analysis and repeated measures ANOVA.ResultsICC values calculated from five successive events during the first micturition session indicate good to excellent reliability for measurements of peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, duration of EUS bursting, and number of EUS burst events. Across the three recording sessions no significant difference was observed in peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, number of EUS burst events, and duration of EUS bursting using repeated measures ANOVA.ConclusionSerial transurethral cystometry under ketamine–xylazine anesthesia with simultaneous percutaneous EUS EMG recording is a novel, reliable, accurate, and minimally invasive method for quantitative assessment of lower urinary tract (LUT) function in adult female rats over extended periods of time.