Quantification of friction force reduction induced by obstetric gels.
The objective of this study was to quantify the reduction of friction forces by obstetric gels aimed to facilitate human childbirth. Lubricants, two obstetric gels with different viscosities and distilled water, were applied to a porcine model under mechanical conditions comparable to human childbirth. In tests with higher movement speeds of the skin relative to the birth canal, both obstetric gels significantly reduced dynamic friction forces by 30-40% in comparison to distilled water. At the lowest movement speed, only the more viscous gel reduced dynamic friction force significantly. In tests modifying the dwell time before a movement was initiated, static friction forces of trials with highly viscous gel were generally lower than those with distilled water. The performed biomechanical tests support the recommendation of using obstetric gels during human childbirth. Using the presented test apparatus may reduce the amount of clinical testing required to optimize gel formulation.
Riener
Robert
R
Department of Mechanical and Process Engineering, ETH Zurich, Switzerland. riener@mavt.ethz.ch
Leypold
Kerstin
K
Brunschweiler
Andreas
A
Schaub
Andreas
A
Bleul
Ulrich
U
Wolf
Peter
P
D000818:Animals; D036861:Delivery, Obstetric / Q000379:methods*; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005260:Female; D017276:Friction / Q000187:drug effects; D054327:Lubricants / Q000494:pharmacology*; D023421:Models, Animal; D034421:Sus scrofa; D014622:Vaginal Creams, Foams, and Jellies / Q000494:pharmacology; D014783:Viscosity
D054327:Lubricants; D014622:Vaginal Creams, Foams, and Jellies