Quantification of friction force reduction induced by obstetric gels
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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.
KeywordsLubrication Mechanical testing Movement speed Dwell time
The authors wish to thank Giochen Bearth, abattoir’s veterinary inspection service for providing fresh samples. The authors are further grateful to Mario Sikic and Diego Stutzer from the SMS-Lab and Rainer Burgkart from the University Hospital rechts der Isar, TU München, for their advice on this research.
- 1.Ahlers D (1993) Rechtsfragen in der Geburtshilfe. In: Richter/Goetze Tiergeburtshilfe. Paul Parey, BerlinGoogle Scholar
- 5.Cheng YW, Hopkins LM, Russel KL, Aaron BC (2007) Duration of the second stage of labor in multiparous women: maternal and neonatal outcomes. Am J Obstet Gynecol 196:585–587Google Scholar
- 9.Klingelnerg J (2008) Kegelräder: Grundlagen, Anwendungen. Springer, BerlinGoogle Scholar
- 10.Leypold K (2008) Experimental investigations on friction and lubrication during delivery. Master thesis, Departement of Medical Engineering, TU MünchenGoogle Scholar