Digital Manometer Research Articles

New Protocol for Evaluating Maximum Inspiratory Pressure: Concurrent Validity and Test-Retest Reliability.

The purpose of this study was to validate a maximum inspiratory pressure test protocol based on the principles of the one-repetition maximum test, assess its test-retest reliability, and establish minimal detectable change in individuals with chronic obstructive pulmonary disease (COPD). Forty-nine individuals with COPD were included in the study, of whom 44 individuals attended 2 appointments separated by 7 to 10days for test-retest reliability. The maximum inspiratory pressure test was performed using a threshold valve device (one-repetition maximum-based protocol) and the digital manometer (reference test). The one-repetition maximum-based protocol consisted of an incremental phase (inspiratory load increase [10 cmH2O] to achieve respiratory failure) and an approach phase (load halfway between the lowest failed attempt and the last valid attempt was prescribed). The concurrent validity of the one-repetition maximum-based protocol for the maximum inspiratory pressure test was good with respect to the reference test (day 1, ICC = 0.81; day 2, ICC = 0.85). The test-retest reliability was excellent (ICC = 0.92), with a standard error of measurement of 6.3 cmH2O and a minimal detectable change of 17.5 cmH2O. This study validated a new one-repetition maximum-based protocol for the maximum inspiratory pressure test using an inspiratory muscle training device in individuals with COPD, showing good concurrent validity compared with the reference test, as well as excellent test-retest reliability. The minimal detectable change reported can be interpreted and applied in the clinical setting. There was a need for developing new, inexpensive, simple, and feasible methods for the maximum inspiratory pressure test. The validation of the one-repetition maximum-based protocol addresses this issue, allowing for the appropriate prescription of inspiratory muscle training, favoring its widespread use in people with COPD and therefore improving their physical therapist care.

Inspection, Testing and Examination System at Gangsa 2 Laboratory at Uitm Bukit Besi

Examination and testing of the (LEV) system was conducted at the Gangsa 2 laboratory of (UiTM) Kampus Bukit Besi to evaluate performance and compliance with safety standards. The inspection aimed to obtain data on airflow, static pressure, and velocities at key points in the LEV system, focusing on a single fume hood (FH-GANGSA 2). Methodology followed guidelines from the (ACGIH) and adhered to (USECHH) 2000 Regulations. Face velocities were measured at different sash heights, and duct transport velocities were assessed. Smoke tests were performed to visually evaluate containment efficiency. Instruments used included a hot wire anemometer, pitot tube, digital manometer, and smoke tester kit. Results showed the fume hood had an average face velocity of 117.8 fpm at the recommended working height of 19.7 inches, within the 80-100 fpm range specified by ACGIH. Duct transport velocity was 3102 fpm, exceeding the recommended 1000-2000 fpm range. The smoke test demonstrated excellent containment with smooth inflow and no escape of smoke outside the hood. A comparison with the previous year's inspection revealed a slight decrease in performance, with face velocity dropping from 109 fpm to 88.5 fpm. While for the flowrate, there is a notable increase in the flow rate from 2023 to 2024. The LEV system was found to meet acceptable working conditions based on ACGIH standards and comply with (USECHH) 2000 Regulations. Recommendations included designing the system by a registered professional engineer as stipulated in (USECHH) Regulation 2000, continuing monthly performance monitoring, and improving accessibility to the centrifugal fan for more comprehensive measurements. This examination helps establish baseline measurements for ongoing monitoring of the LEV system's effectiveness in protecting worker health and safety in laboratory settings.

Validation of a Low-Cost Manometer to Assess of Tongue, Lip, Cheek, and Respiratory Strength: A Laboratory-Based Study.

The objective of this study was to characterize the level of agreement between three manometers: (1) Iowa Oral Performance Instrument (IOPI)-the reference standard for tongue, lip, and cheek strength assessments; (2) MicroRPM Respiratory Pressure Meter (MicroRPM)-the reference standard for respiratory strength assessments; and (3) Digital Pressure Manometer (DPM)-an alternative, low-cost pressure testing manometer. Manual pressures were simultaneously applied to the IOPI and DPM, and to the MicroRPM and DPM, within a controlled laboratory setting. Agreement in pressure readings were analyzed using descriptive statistics, Lin's concordance correlation, and Bland-Altman Plots. Agreement was interpreted as "poor" if ρc < 0.90, "moderate" if ρc = 0.90 - < 0.95, "substantial" if ρc = 0.95 - < 0.99, and "excellent" if ρc ≥ 0.99. Differences in pressure readings between the DPM and clinical reference standards were consistently present yet highly predictable. There was a median absolute difference of 2.0-3.9 kPa between the IOPI and DPM, and 4.5-9.8 cm H2O between the MicroRPM and DPM. Lin's concordance revealed "substantial" agreement between the IOPI and DPM (ρc = 0.98) and the MicroRPM and DPM (ρc = 0.99). The DPM revealed higher pressure readings when compared to the IOPI and MicroRPM. However, differences in pressure readings were relatively small, highly predictable, and yielded substantial overall agreement. These findings suggest the DPM may be a valid, lower-cost alternative for objective assessments of tongue, lip, cheek, and respiratory muscle strength. Future research should expand on the present findings in clinical patient populations. NA Laryngoscope, 2024.

Respiratory muscular strength in children with mucopolysacaridosis: comparison with predictive equations.

Mucopolysaccharidoses (MPS) are rare metabolic diseases that impair respiratory function leading to respiratory failure. This study aimed to compare maximal inspiratory and expiratory pressures (MIP and MEP) obtained in children with MPS and compare with predicted values from previous studies involving healthy children. This is a cross-sectional study, in which the chest deformity was evaluated; MIP, MEP through digital manometer, and lung function through spirometry. MIP and MEP were compared with five different predict equations and with a control group of healthy children. Agreement between respiratory muscle weakness regarding absolute values of MIP and MEP in relation to predictive values by the equations included in the study were assessed by Kappa coefficient. MPS group was composed of 22 subjects. 45.5% had pectus carinatum, 36.4% pectus excavatum, and presented lower MIP (37.14±36.23 cmH<inf>2</inf>O) and MEP (60.09±22.3 cmH<inf>2</inf>O) compared with control group (22 healthy subjects) (MIP: 91.45±35.60; MEP: 95.73±22.38). Only the MEP equations proposed by Tomalak et al. were close to those found in our MPS children (P=0.09). In the MPS group it was observed a weak agreement between inspiratory weakness through absolute and predicted values in only two equations: Tomalak et al. and Domenèch-Clar et al. (for both: k=0.35, P value =0.03); and for MEP a moderate agreement was found using all predictive equations. In MPS children MRP data should not be normalized using the reference equations for healthy ones, is more coherent to longitudinally follow absolute pressures and lung volumes in this group.

Type of Alcohol and Blood Pressure: The Copenhagen General Population Study

BackgroundMost adults ingest alcoholic beverages. Alcohol shows strong and positive associations with blood pressure (BP). We hypothesized that intake of red wine, white wine, beer, and spirits and dessert wine show similar associations with BP in the general population. MethodsWe included 104,467 males and females aged 20-100 years in the analysis of the Danish general population. Alcohol use and type of alcohol were assessed by questionnaire. Blood pressure was measured by automated digital BP manometer. Multivariable linear regression models were used when analyzing the association between number of drinks per week and BP, stratified by sex and adjusted for relevant confounders. Each alcohol type (red wine, white wine, beer, and spirits and dessert wine) was analyzed in similar models including adjustment for other alcohol types. ResultsMost of the subjects (76,943 [73.7%]) drank more than 1 type of alcohol. However, 12,093 (12.6%) consumed red wine only, 4288 (4.5%) beer only, 1815 (1.9%) white wine only, and 926 (1.0%) spirits and dessert wine only. There was a dose-response association between total drinks per week and systolic and diastolic BP (SBP, DBP) (P < .001). The crude difference was 11 mmHg SBP and 7 mmHg DBP between high (>35 drinks per week) and low (1-2 drinks per week) alcohol intake. Overall, SBP was increased by 0.15-0.17 mmHG, and DBP was increased by 0.08-0.15 mmHg per weekly drink. After stratification for age and sex, effects were slightly higher among females and among individuals aged less than 60 years. ConclusionAlcohol intake is associated with highly significant increased SPB and DBP. The effect is similar for red wine, white wine, beer, and spirits.

The effect of manual therapy on diaphragm function in adults with asthma: Protocol for a randomized controlled trial.

Diaphragm dysfunction is prevalent among individuals with asthma due to lung hyperinflation and hyperventilation in asthma paroxysm. This study was designed to evaluate the effect of the manual diaphragm release technique (MDRT) on diaphragm function in individuals with asthma. Adults with diagnosed stable asthma (n = 24), will be recruited from the General Hospital of Kifissia "Agioi Anargyroi" in Athens, Greece. The volunteers who meet the inclusion criteria will be randomly allocated to two groups: (a) the experimental group (n = 12) that will receive 12 sessions of MDRT in conjunction with breathing retraining exercises (BRE), and (b) the control group (n = 12) that will receive 12 sessions of BRE. Measurements will occur at three time points: before the initiation of treatment sessions (week 0), followed by 12 treatment sessions (week 6), and three months from the beginning of the trial (week 12). The main outcomes will be the diaphragm excursion (ultrasonography) and chest expansion (inch tape), with secondary outcomes the maximal respiratory pressures (digital pressure manometer), dysfunctional breathing (Nijmegen questionnaire), asthma control (ACT), dyspnea (Borg scale) and quality of life (SF-12v2). The proposed protocol is the first to examine the effectiveness of MRDT on diaphragm's function in individuals with asthma. Manual Therapy (MT) is a low-cost alternative and supplementary therapy to standard treatment procedures that might improve the biomechanics of respiration in pulmonary rehabilitation. Registered on Clinical Trials.gov (ID: NCT05709054). 29/09/2023.

Comparison of the Kron technique and digital manometry for measuring intra-abdominal pressure in emergency department patients diagnosed with ileus.

Numerous measurement techniques for intra-abdominal pressure have been explored, with the Kron Technique established as the gold standard. Despite its prominence, the search for alternative methods persists due to its lengthy application time, the requirement for additional equipment, and overall impracticality. This study investigated a quicker, more accessible method for effective intra-abdominal pressure measurement in the emergency department. It aimed to compare intra-abdominal pressure measurements in patients diagnosed with ileus using a digital manometer and the Kron Technique. Conducted from October 2022 to February 2023, this single-center, prospective, single-blind method comparison study involved patients diagnosed with ileus at a tertiary emergency department. Intra-abdominal pressure was measured using both the Kron Technique and a digital manometer by separate practitioners blinded to the study results. The study included 30 patients. No statistically significant difference was observed in the intra-abdominal pressure measurements between the two methods (p<0.237). A very strong correlation existed between the two methods (Spearman's Rho = 0.998). Bland-Altman analysis showed a bias value of 0.091 mmHg for the digital manometer, with upper and lower agreement limits of -0.825 and 1.007 mmHg, respectively. The measurement time was significantly shorter with the digital manometer than with the Kron Technique (15 vs. 390.5 seconds; p<0.001). We believe that the intra-abdominal pressure measurement technique using a digital manometer is a method that can be effectively employed by healthcare professionals in emergency departments. This technique offers ease of use, requires minimal equipment, provides rapid results, and delivers reliable measurement values compared to the Kron Technique.

IoT-Based Propane and Butane Pressure Measurement

Liquefied Potreleum Gas is a hydrocarbon containing two main gas components, propane, and butane, produced from oil and gas refineries Liquefied Potreleum Gas is a hydrocarbon containing two main gas components, propane, and butane, produced from oil and gas refineries. In this study, researchers will do the same thing in the IoT field but not in health monitoring but refer to Butane and Propane Gas Pressure Monitoring in LPG. Errors often occur when using an analog manometer (needle panel) when taking pressure measurements due to inaccurate measurements. There is a clear necessity for using digital manometers to ensure precise gas methane pressure measurement. The sensor receives data then the Arduino processes the data for conversion, the final results will be sent to the cloud using the esp8266 module and then forwarded to the smartphone as a monitoring user to see and also check gas conditions.

Effect of aspect ratio on mean flow characteristics of cruciform orifice jet

PurposeThe purpose of this study reports the effects of aspect ratio (AR) on mean flow characteristics of the cruciform orifice jet.Design/methodology/approachThe aspect ratio is the height-to-width ratio of the lobe of the cruciform shape. The aspect ratios considered are 0.25, 0.5, 0.75, 1, 2, 3 and 4. The turbulent jet flow is issued through an orifice being fitted to the jet tunnel facility. The velocity measurements are recorded with the help of pitot-static tube connected to a digital manometer setup. The Reynolds number calculated using the equivalent diameter 50.46 × 10–3 m and exit velocity 51.23 m/s was 1.75 × 105. Based on the experimental data, the streamline velocity decay plots, the potential core length (PCL), mean velocity profiles and velocity half widths were plotted, and discussions were made based on the measured data. A smoke-based flow visualization was carried out at moderate Reynolds number 5396.FindingsThe PCL remains almost constant for the aspect ratio 0.25:1 and then starts decreasing for the aspect ratio 1:4. The decrease in PCL indicates improved mixing. The off-center peaks are found along the major axis in mean velocity profiles for almost all cruciform jets. More than one axis switching occurs and can be identified by the crossover points. The location of the first crossover point shifts forward, and the second crossover point shows an oscillating trend. The flow visualization exhibits the jet evolution, and the distance up to which the jet maintains the cruciform shape is increased with the aspect ratio.Research limitations/implicationsThe experiments are limited to air in air jet under isothermal conditions.Social implicationsThe cruciform orifices can be used as fuel injectors and in air-conditioning systems, thereby improving efficiency and energy usage.Originality/valueThe aspect ratio effects on PCL and axis switching are used to explain the mixing characteristics. Flow visualization was also used to support the discussion.

Gender differences in lifestyle and psycho-social aspects of medical students. A cross sectional study

Abstract Background Incidence of premature cardiovascular deaths in medical practitioners is on the increase. Lifestyle habits, psychosocial and emotional status of medical students has the potential to initiate the premature onset of cardiovascular disease. Gender differences in diagnosis and management of cardiovascular diseases is well known. However, data on gender differences in heart healthy status of medical students are sparce. Purpose To investigate the gender differences heart healthy lifestyle habits among undergraduate medical students of a medical college from low-and-middle income country in south Asia. Methods All students pursing MBBS between 2017 and 2018 were included in the cross-sectional study. The study had Institutional ethics committee approval and the participation was voluntary. Anthropometric measurements (weight using digital weighting scale, height, waist and hip circumference using measuring tape), vital signs (pulse and blood pressure using digital manometer) and self-reported lifestyle/psychosocial cum behavioural pattern (using a specially designed proforma) were collected for all the participants. (525) Results 824 medical students were enrolled in the study of whom 377 (45.8%) were women. Overall 37.1% had abnormal body mass index (BMI) and 27.8% had abnormal waist hip ratio (WHR). Overall 14% and 10.3% students had abnormal systolic (≤ 85 mm of Hg) or diastolic blood pressure(BP) (≤ 135 mm of Hg) readings respectively. 19.4% of students had either systolic or diastolic abnormal BP values. Gender differences: Abnormal BMI and abnormal WHR (Figure 1A) were found in similar proportion among women and men. However less women has abnormal BP readings compared to men. More men has abnormal diastolic BP and abnormal systolic BP compared to women. Either systolic or diastolic BP values were abnormal in lower proportion of women (7.8% vs 29.4%; P&amp;lt;0.001). Women had less physically active minutes per day compared to men (71.15 ± 68.2 vs 109. 38± 81.7; P &amp;lt; 0.001). A feeling of lack of self-worth (73.5%) was common among medical students, however no significant gender differences were observed (Figure 1B). Significantly more women students have harbored suicidal thoughts than men. Women students were more likely to feel life style counseling is necessary for medical students and were more likely to implement lifestyle changes if advised. Conclusion High blood pressure and feeling of lack of self-worth is commonly observed in medical students. Women were more likely to harbor suicidal thoughts, bitterness and anger more likely to implement lifestyle modifications if advised. Interventions warranted at improving heart healthy lifestyle patterns is warranted, and must be optimized by observed gender differences.Figure 1Gender and life style habits

The effect of manual therapy on diaphragm function in adults with asthma: Protocol for a randomized controlled trial

Background: Diaphragm dysfunction is prevalent among individuals with asthma due to lung hyperinflation and hyperventilation in asthma paroxysm. This study was designed to evaluate the effect of the manual diaphragm release technique (MDRT) on diaphragm function in individuals with asthma. Methods: Adults with diagnosed stable asthma (n = 24), will be recruited from the General Hospital of Kifissia “Agioi Anargyroi” in Athens, Greece. The volunteers who meet the inclusion criteria will be randomly allocated to two groups: (a) the experimental group (n = 12) that will receive 12 sessions of MDRT in conjunction with breathing retraining exercises (BRE), and (b) the control group (n = 12) that will receive 12 sessions of BRE. Measurements will occur at three time points: before the initiation of treatment sessions (week 0), followed by 12 treatment sessions (week 6), and three months from the beginning of the trial (week 12). The main outcomes will be the diaphragm excursion (ultrasonography) and chest expansion (inch tape), with secondary outcomes the maximal respiratory pressures (digital pressure manometer), dysfunctional breathing (Nijmegen questionnaire), asthma control (ACT), dyspnea (Borg scale) and quality of life (SF-12v2). Discussion: The proposed protocol is the first to examine the effectiveness of MRDT on diaphragm’s function in individuals with asthma. Manual Therapy (MT) is a low-cost alternative and supplementary therapy to standard treatment procedures that might improve the biomechanics of respiration in pulmonary rehabilitation. Trial Registration: Registered on Clinical Trials.gov (ID: NCT05709054) Protocol version: 29/09/2023

Concurrent Validity of a Low-Cost Manometer for Objective Assessments of Respiratory Muscle Strength.

This study examined the agreement in maximal expiratory (MEP) and inspiratory (MIP) pressure readings between two digital manometers: (1) the MicroRPM - the gold-standard manometer for respiratory muscle strength testing; and (2) the LDM - a low-cost, commercially available, alternative manometer. Positive (MEP) and negative (MIP) pressures were simultaneously applied to the MicroRPM and LDM using a 3-liter syringe within a controlled laboratory setting. Pressure readings were compared, and agreement was analyzed using Lin's concordance correlation (ρc ). Agreement was interpreted as 'poor' if <0.90, 'moderate' if 0.90 - <0.95, 'substantial' if 0.95 - <0.99, and 'excellent' if ≥0.99. Twenty percent of the pressure trials were repeated by a second researcher to examine test-retest reliability. A total of 150 trials were completed, ranging from -167 to +208 cmH2 O. There was a median absolute difference of 0.3 cmH2 O in pressure readings between the MicroRPM and the LDM. Lin's concordance correlation revealed 'excellent' agreement between the LDM and MicroRPM devices, with test-retest reliability assessment revealing 'substantial-to-excellent' agreement between the LDM and MicroRPM devices, with a concordance correlation coefficient of ρc = 0.999 (95% CI: 0.999-0.999). There was a median difference of 1.0% in MEP and MIP pressure readings consistently observed between the LDM and MicroRPM. Despite these relatively small differences, excellent agreement between the two manometers was present. These data suggest the LDM may be a valid, lower cost alternative to the MicroRPM for objectively assessing respiratory strength in clinical practice; however, additional research is needed in healthy adults and in patient populations. NA Laryngoscope, 134:1831-1836, 2024.

Do Saliva-Saturated Spit Hoods Interfere With Ventilation?

Spit hoods are used by law enforcement, officers in correctional facilities, and medical personnel during the restraint of agitated subjects that are actively spitting to prevent the transmission of droplet-transmitted pathogens. We could find no studies reporting on the time course of normal breathing to clear saliva from such a saturated spit hood. We purchased samples of 3 popular spit hood models and applied a section over the output of a pneumatic test system. We used a digital anemometer, digital manometer, and an inline controllable fan for back pressure and flow. The pressure was 3 mm Hg to match quiet breathing. The tested area was saturated with artificial saliva, and air pressure was applied while we recorded the pressure and airflow. Within 5 seconds, the spit hoods all cleared sufficient artificial saliva to allow 1 m/s of airflow, which exceeds that of an N95 mask with similar pressure. Commonly used spit hoods offer very low resistance to breathing even after being initially saturated with artificial saliva. Our results do not support the hypothesis that a saliva-filled spit hood might contribute to death.

Maximal respiratory pressures: Measurements at functional residual capacity in individuals with different health conditions using a digital manometer

BackgroundMeasuring maximal respiratory pressure is a widely used method of investigating the strength of inspiratory and expiratory muscles. ObjectivesTo compare inspiratory pressures obtained at functional residual capacity (FRC) with measures at residual volume (RV), and expiratory pressures obtained at FRC with measures at total lung capacity (TLC) in individuals with different health conditions: post-COVID-19, COPD, idiopathic pulmonary fibrosis (IPF), heart failure (CHF), and stroke; and to compare the mean differences between measurements at FRC and RV/TLC among the groups. MethodsInspiratory and expiratory pressures were obtained randomly at different lung volumes. Mixed factorial analysis of covariance with repeated measures was used to compare measurements at different lung volumes within and among groups. ResultsSeventy-five individuals were included in the final analyses (15 individuals with each health condition). Maximal inspiratory pressures at FRC were lower than RV [mean difference (95% CI): 11.3 (5.8, 16.8); 8.4 (2.3, 14.5); 11.1 (5.5, 16.7); 12.8 (7.1, 18.4); 8.0 (2.6, 13.4) for COVID-19, COPD, IPF, CHF, and stroke, respectively] and maximal expiratory pressures at FRC were lower than TLC [mean difference (95% CI): 51.9 (37.4, 55.5); 60.9 (44.2, 77.7); 62.9 (48.1, 77.8); 58.0 (43.9, 73.8); 57.2 (42.9, 71.6) for COVID-19, COPD, IPF, CHF, and stroke, respectively]. All mean differences were similar among groups. ConclusionAlthough inspiratory and expiratory pressures at FRC were lower than measures obtained at RV/TLC for the five groups of health conditions, the mean differences between measurements at different lung volumes were similar among groups, which raises the discussion about the influence of the viscoelastic properties of the lungs on maximal respiratory pressure.

Relationship of static and dynamic inspiratory muscle strength

Background: the non-invasive evaluation of the inspiratory muscles strength makes it possible to detect their weakness globally. The use of digital or aneroid manometers to determine the inspiratory force can be taken by a static technique, known as pymometry, obtaining the maximum inspiratory pressure. However, equipment such as PowerBreathe is also used to obtain the strength index, which is considered a dynamic technique. Methods: the present work is a cross-sectional cohort study, focused on analyzing the inspiratory muscle force in a static and dynamic way in healthy subjects, using a non-clinical digital manometer Ht - 18909 compared with a PowerBreathe equipment. The study was conducted in 23 healthy volunteer patients with a mean age of 19 years. Results: Inspiratory force measurements for both instruments reached a mean of 57,5 cmH2O and 55,3 cmH2O (SD 16,38 – 14,91) when taken with manometry and PowerBreathe equipment respectively, the correlation by calculating of the ICC with a reliability of 95 %, was 0,87, having a high level of agreement or similarity between the measures. Conclusions: It was concluded that there are no significant differences when measuring the inspiratory force when using both devices that estimate the force statically and dynamically

New reference values for maximum respiratory pressures in healthy Brazilian children following guidelines recommendations: A regional study.

To determine reference values for maximum static respiratory pressures in healthy children from a Brazilian region, following recommendations of the European Respiratory Society (ERS) and the Brazilian Society of Pneumology and Tisiology (SBPT). A cross-sectional observational study was conducted with healthy children (6 to 11 years) of both sexes. The maximum inspiratory and expiratory pressures (PImax and PEmax, respectively) were measured using a digital manometer. Each child performed a minimum of three and a maximum of five maneuvers; three acceptable and reproducible maneuvers were considered for analysis. Minimum time for each maneuver was 1.5 seconds, with a one-second plateau, and one minute of rest between them. A stepwise multiple linear regression analysis was conducted for PImax and PEmax, considering correlations between independent variables: age, weight, and sex. We included 121 children (62 girls [51%]). Boys reached higher values for maximum respiratory pressures than girls. Respiratory pressures increased with age showing moderate effect sizes (PImax: f = 0.36; PEmax: f = 0.30) between the stratified age groups (6-7, 8-9, and 10-11 years). Age and sex were included in the PImax equation (PImax = 24.630 + 7.044 x age (years) + 13.161 x sex; R2 = 0.189). PEmax equations were built considering age for girls and weight for boys [PEmax (girls) = 55.623 + 4.698 x age (years) and PEmax (boys) = 82.617 + 0.612 x weight (kg); R2 = 0.068]. This study determined new reference equations for maximal respiratory pressures in healthy Brazilian children, following ERS and SBPT recommendations.

Experimental and numerical assessment on hydrothermal behaviour of MgO-Fe3O4/H2O hybrid nano-fluid

This study presents an experimental and numerical investigation of heat transfer enhancement inside plain and wavy tubes using a new type of hybrid Nano-fluid (50% Fe3O4+ 50% MgO/H2O) with volume concentrations (φ = 0.5%, 1%, and 2%) under fully developed turbulent flow and constant heat flux. The experimental Apparatus consists of the hybrid Nano-fluid tank, chiller system, four control valves, digital manometer, temperature controller, flow meter sensor, pump, and a transparency piping system to study the heat transfer improvement. All the tests were conducted with constant heat flux (18,189 W/m2) and Reynolds number (Re = 3,916 – 31,331). The experimental investigation also includes measurements and preparation of the considered hybrid Nano-fluid. Numerical simulation has been carried out employing Workbench [ANSYS FLUENT package-(19.3)] utilizing multiphase approaches; single-phase and mixture model to analyze flow field, migration of nanoparticles volume fraction effect, and heat transfer. The comparison between experimental and numerical outcomes revealed good agreement. The results demonstrated that increasing Reynolds numbers and volume fractions lead to a lower friction factor and a more enhancement in heat transfer (Nusselt number) and performance evaluation criteria (PEC) than the conventional base fluid along both considered tubes. The highest Nusselt number was observed at 2% of (Fe3O4−MgO/H2O) hybrid Nano-fluid in both tubes. However, the results were higher for a wavy tube than the plain one, as the maximum improvement in heat transfer was (135.2)% and (166.5)% with plain and wavy tubes, respectively. Moreover, new correlations were developed for a particular Fe3O4−MgO/H2O hybrid Nano-fluid volume fraction.

Agreement between two methods for assessment of maximal inspiratory pressure in patients weaning from mechanical ventilation.

Respiratory muscle strength in patients with an artificial airway is commonly assessed as the maximal inspiratory pressure (MIP) and is measured using analogue or digital manometers. Recently, new electronic loading devices have been proposed to measure respiratory muscle strength. This study evaluates the agreement between the MIPs measured by a digital manometer and those according to an electronic loading device in patients being weaned from mechanical ventilation. In this prospective study, the standard MIP was obtained using a protocol adapted from Marini, in which repetitive inspiratory efforts were performed against an occluded airway with a one-way valve and were recorded with a digital manometer for 40 seconds (MIPDM). The MIP measured using the electronic loading device (MIPELD) was obtained from repetitively tapered flow resistive inspirations sustained for at least 2 seconds during a 40-second test. The agreement between the results was verified by a Bland-Altman analysis. A total of 39 subjects (17 men, 55.4±17.7 years) was enrolled. Although a strong correlation between MIPDM and MIPELD (R=0.73, P<0.001) was observed, the Bland-Altman analysis showed a high bias of -47.4 (standard deviation, 22.3 cm H2O; 95% confidence interval, -54.7 to -40.2 cm H2O). The protocol of repetitively tapering flow resistive inspirations to measure the MIP with the electronic loading device is not in agreement with the standard protocol using one-way valve inspiratory occlusion when applied in poorly cooperative patients being weaned from mechanical ventilation.

To study the efficacy of AG CUFFILL (Digital) compared to that of standard PORTEX cuff inflator/pressure analog gauge for the measurement of endotracheal tube cuff pressure

Endotracheal tube (ETT) is commonly used to provide positive pressure ventilation. ETT cuff pressure is maintained within a range of 20 to 30 cmH2O. High pressure affects micro-circulation and integrity of the tracheal mucosa, resulting in complications. The cuff pressure is measured by connecting a pressure gauge device to pilot balloon. Two variety devices are available; analog or digital manometers. Present study is used to study the efficacy of AG CUFFILLL (Digital) compared with standard PORTEX Cuff inflator/pressure gauge (Analog) for the measurement of ETT cuff pressure.This study was conducted after obtaining institutional ethical clearance and written informed consent.100 patients between the age of 18-70yrs who fulfilled inclusion criteria. We measured ETT cuff pressure using AG CUFFILL (Digital) and standard PORTEX Cuff inflator/pressure gauge and compared the pressure recording of the two equipment and we studied ease of use for both.Out of 100 patients between the age of 18-70yrs, 61 patients (61%) were male and 39 patients (39%) were female. Mean cuff pressure of ETT using AG CUFFILL was 36.29±6.36 cmH2O and in PORTEX was 33.97±6.16cm H2O. Mean difference in the values between the cuff pressure measured by AG CUFFILL and PORTEX was ± 2.67. Comparing the two devices, it was noticed that in 05 (5%) patients measuring ETT cuff pressure using AG CUFFILL was difficult as the values were fluctuating. Based on results, authors recommend AG CUFFILL for ETT cuff pressure measurement owing to its accuracy, non-bulky, and ease to carry.

REACHING OF THERAPEUTICS GOALS IN PATIENTS WITH HYPERTENSION AND DIABETES MELLITUS. DO MULTIPLE THERAPY WORKS?

Objective: To analyze the efficacy of multiple pharmacological therapy on blood pressure control and therapeutics goals in a group of high-risk patients. Design and method: Blood pressure levels were analyzed in a group of 156 hypertensive patients with diabetes mellitus under pharmacological treatment, reviewed in the outpatient cardiology office. Blood pressure levels were classified according to the AHA and ESC classifications. Sociodemographic data, cardiovascular risk factors, number of drugs and therapeutic goals were recorded. Blood pressure measurement was performed using an digital manometer according to AHA and ESC guidelines. Results are shown in terms of measures of central tendency. Results: Average age was 55 ± 16 [20–93], 40% (62) were women. Smoking was the most common cardiovascular risk factor with 40% (62), followed by obesity 20% (31), CKD 10% (15), 25% (39) of the women were postmenopausal. The mean systolic blood pressure (SBP) obtained in the measurements was 124.27 mmHg (240–10 mmHg) and 74.7 mmHg (110–30 mmHg) of diastolic blood pressure (DBP), both in men and women (p = 0.06). Antihypertensive drug treatment was: 37% monotherapy, 42% dual,19% triple and 2% quadruple. Only 67% (104) were in therapeutics goals according to the ESC guidelines and 33% (52) according AHA guidelines respectively. Conclusions: Goal achievement is poor in this group of high-risk patients. Even though 63% of the patients had multiple pharmacological treatments, more than a third of patients were not reaching therapeutics goals in blood pressure control. This percentage doubles when more stringent goals are used, following the AHA guidelines.