scholarly journals Mechanical Properties of the Every Second Matters for Mothers-Uterine Balloon Tamponade (ESM-UBT) Device: In Vitro Tests

2019 ◽  
Vol 09 (04) ◽  
pp. e376-e383 ◽  
Author(s):  
Kamyar Mollazadeh-Moghaddam ◽  
Michelle Dundek ◽  
Anuj Bellare ◽  
Anderson Borovac-Pinheiro ◽  
Alice Won ◽  
...  

Abstract Objective Postpartum hemorrhage (PPH) is the most common cause of maternal mortality and morbidity worldwide, most of which occurs in resource-poor settings. Placement of a uterine balloon may be life-saving in uncontrolled PPH. The Every Second Matters for Mothers-Uterine Balloon Tamponade (ESM-UBT) device is an ultra-low-cost uterine balloon designed for global access. The purpose of this study was to evaluate the mechanical properties of the ESM-UBT device. Study design Intraluminal pressures, diameters, and burst volumes of condom uterine balloons and Foley catheter balloons of ESM-UBT devices were measured in open air and inside uterus models. Condom uterine balloons were tested with uterus model sizes of 100, 250, and 500mL. The condom-catheter O-ring attachment tensile strength was also evaluated. Results All 28 samples of ESM-UBT condom uterine balloons maintained their integrity for at least 3 hours when subjected to pressures of 200 mm Hg or greater across each of the tested uterine volumes. No Foley catheter balloons burst after instillation of 30mL, O-rings withstood forces of 15.4 ± 2.1 N, and condom uterine balloons stretched to 35.8 ± 2.1 cm without loss of integrity. Conclusion The mechanical properties of the ESM-UBT device make it attractive for scale across resource-poor settings.

Author(s):  
Kamyar Mollazadeh-Moghaddam ◽  
Michelle Dundek ◽  
Anuj Bellare ◽  
Anderson Borovac-Pinheiro ◽  
Alice Won ◽  
...  

2021 ◽  
Vol 11 (9) ◽  
pp. 4025
Author(s):  
Dario Messenio ◽  
Marco Ferroni ◽  
Federica Boschetti

Glaucoma is the second cause of irreversible blindness in the world. Intraocular pressure (IOP) is a recognized major risk factor for the development and progression of glaucomatous damage. Goldmann applanation tonometry (GAT) is internationally accepted as the gold standard for the measurement of IOP. The purpose of this study was to search for correlations between Goldmann tonometry and corneal mechanical properties and thickness by means of in vitro tests. IOP was measured by the Goldmann applanation tonometer (GIOP), and by a pressure transducer inserted in the anterior chamber of the eye (TIOP), at increasing pressure levels by addition of saline solution in the anterior chamber of enucleated pig eyes (n = 49). Mechanical properties were also determined by inflation tests. The GAT underestimated the real measurements made by the pressure transducer, with most common differences in the range 15–28 mmHg. The difference between the two instruments, highlighted by the Bland–Altman test, was confirmed by ANOVA, normality tests, and Mann–Whitney’s tests, both on the data arranged for infusions and for the data organized by pressure ranges. Pearson correlation tests revealed a negative correlation between (TIOP-GIOP) and both corneal stiffness and corneal thickness. In conclusion, data obtained showed a discrepancy between GIOP and TIOP more evident for softer and thinner corneas, that is very important for glaucoma detection.


2005 ◽  
Vol 56 (11) ◽  
pp. 1211 ◽  
Author(s):  
D. Harris ◽  
W. A. Breese ◽  
J. V. D. K. Kumar Rao

On-farm seed priming with water is a low-cost, low-risk technology that is easily adopted by resource-poor farmers. It increases the yield of tropical and subtropical annual crops in marginal areas by a combination of better crop establishment and improved individual plant performance. The effects of seed priming, i.e. soaking seeds overnight in water before sowing, on plant growth and development are consequences of faster germination, emergence, and more vigorous early growth. Results from in-vitro, on-station and on-farm experiments are discussed. Recent work has tested opportunities for resource-poor farmers to use seed priming as a vehicle for applying biofertilisers (Rhizobia). Preliminary results from field experiments suggest that these interventions are very effective over and above the already demonstrated benefits of priming with water alone. In a pot experiment using chickpea, combining a Rhizobium inoculation with seed priming significantly increased nodulation but had little effect on yield. Nevertheless, the results confirmed that Rhizobium inoculation is compatible with on-farm seed priming. Observations in the field have shown that some primed crops show enhanced resistance to disease, either as a consequence of increased vigour, altered phenology, or due to some more fundamental mechanism associated with exposure of seeds to anaerobic conditions during priming. Priming seeds of a highly susceptible cultivar of pearl millet in water for 8 h before sowing significantly reduced the incidence of downy mildew in artificially infected seedlings from 80% to less than 60%.


2012 ◽  
Vol 27 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Michela Gioffrè ◽  
Paola Torricelli ◽  
Silvia Panzavolta ◽  
Katia Rubini ◽  
Adriana Bigi

The effect of the film-forming solution pH on the triple-helix content, thermal stability, and mechanical properties of gelatin films was investigated. The films were prepared from solutions at different pHs of type A pigskin gelatin, and their mechanical characteristics were determined. At pHs higher than 9 and lower than 5, Young’s modulus, E, and the stress at break, σb, of the films decreased significantly. Cross-linking with genipin reduced deformation at break, ϵb, and increased Young’s modulus. The intensity of the 1.1-nm X-ray diffraction reflection and the denaturation enthalpy decreased at these pHs, indicating that the triple helix reduced. Preliminary in vitro tests on the cross-linked samples indicated good cell proliferation and viability.


2018 ◽  
Vol 2018 ◽  
pp. 1-3 ◽  
Author(s):  
Jennifer Makin ◽  
Daniela I. Suarez-Rebling ◽  
Poonam Varma Shivkumar ◽  
Vincent Tarimo ◽  
Thomas F. Burke

Background. Postpartum hemorrhage is the most common cause of maternal deaths worldwide, the majority of which occur in low-resource settings. Uterine balloon tamponade (UBT) is an effective method of addressing uncontrolled postpartum hemorrhage (PPH) from uterine atony; however, UBT devices are often not affordable. We report on three novel uses of an ultra-low-cost condom uterine balloon tamponade (ESM-UBT) device. Cases. ESM-UBT devices were used in innovative ways to arrest severe uncontrolled pregnancy-related hemorrhage among three women in India and Tanzania. The first had sustained deep vaginal lacerations, the second a cervical pregnancy, and the third a complete molar pregnancy. Conclusion. The ESM-UBT device may be useful for control of obstetric hemorrhage caused by complex vaginal tears as well as cervical and molar pregnancies.


2011 ◽  
Vol 120 (12) ◽  
pp. 814-819 ◽  
Author(s):  
Eduard B. van der Houwen ◽  
Tjouwke A. van Kalkeren ◽  
Johannes G. M. Burgerhof ◽  
Bernard F. A. M. van der Laan ◽  
Gijsbertus J. Verkerke

Objectives: We performed in vitro evaluation of a novel, disposable, automatic hands-free tracheostoma speech valve for laryngectomy patients based upon the principle of inhalation. The commercially available automatic speech valves close upon strong exhalation and open again when the pressure drops. This method makes long sentences or pauses difficult. The novel iValve is designed to allow almost natural speech, with mid-sentence pausing and whispering. Methods: The inhalation closing flows and exhalation opening pressures of 6 iValve prototype versions at different settings were compared with physiological values. The airflow resistance at inhalation was compared to physiological values and to commercial valve values. Results: The iValve prototypes showed flow and pressure ranges in concordance with the physiological values in the literature. The airflow resistance in the breathing mode was within the physiological airflow resistance range, yet above the values from the two commercial valves. The resistance in the speaking mode was above the physiological airflow resistance range. Conclusions: In vitro tests show that the iValve versions can be selected and adjusted to operate within the physiological range. The airflow resistance in the breathing mode is good. In speaking mode, inhalation should, and can, be decreased. The iValve should offer the patient a more intuitively useable alternative with more dynamic speech. Its low cost allows disposability and wider use.


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