Abstract
The urinary bladder of the rat was examined by nearly ideal, unit step volume infusions. Spontaneous detrusor contractions occurred in vivo but ceased soon after death. A hydrodynamic model of the post mortem bladder wall was evaluated. Elastic properties were described by introducing two types of compliances; a dynamic compliance for fast response characteristics and a static compliance for the relaxed bladder wall. These compliances were easy to measure and found to vary with the degree of bladder expansion. The influence of viscosity was well described by a model with two relaxation time constants and was the optimal model in almost 50 per cent of the measurements. The long time constant was found to increase with bladder expansion.
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References
Bjerle, P. (1974) Tension, stress and modulus of elasticity of the urinary bladder wall.Acta Physiol. Scand.,92, 488–495.
Coolsæt, B. L. R. A., van Duyl, W. A. andvan der Zwart, A. (1973) Stepwise cystometry of urinary bladder.Urol.,2, 255–257.
Coolsæt, B. L. R. A., van Duyl, W. A., van Mastrigt, R. andSchouten, J. W. (1975) Viscoelastic properties of bladder wall strips.Invest. Urol.,12, 351–356.
Coolsæt, B. L. R. A., van Mastrigt, R., van Duyl, W. A. andHuygen, R. E. F. (1976) Viscoelastic properties of bladder wall strips at constant elongation.-——Ibid.,13, 435–440.
Kondo, A., Susset, J. B. andLefaivre, J. (1972) Viscoelastic properties of bladder. I Mechanical model and its mathematical analysis.-——Ibid.,10, 154–163.
Kondo, A. andSusset, J. G. (1974) Viscoelastic properties of bladder. II Comparative studies in normal and pathologic dogs.-——Ibid.,11, 459–465.
Provencher, S. W. andVogel, R. H. (1980) Information loss with transform methods in system identification—A new set of transforms with high information-content.Math. Biosci.,50, 251–262.
Susset, J. G. andRegnier, C. H. (1981) Viscoelastic properties of bladder strips. Standardization of a technique.Invest. Urol.,18, 445–450.
van Mastrigt, R., Coolsæt, B. L. R. A. andvan Duyl, W. A. (1978a) The passive properties of the urinary bladder in the collection phase.Urol. Inst.,33, 14–21.
van Mastrigt, R., Coolsæt, B. L. R. A. andvan Duyl, W. A. (1978b) Passive properties of the urinary bladder in the collection phase.Med. & Biol. Eng. & Comput.,16, 471–482.
van Mastrigt, R. andNagtegaal, J. C. (1981) Dependence of the viscoelastic response of the urinary bladder wall on strain rate.-——Ibid.,19, 291–296.
van Mastrigt, R., Coolsæt, B. L. R. A. andvan Duyl, W. A. (1981) First results of stepwise straining of the human urinary bladder and human bladder strips.Invest. Urol.,19, 58–61.
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Andersson, S., Kronström, A. Hydrodynamic model of the urinary bladder derived from stepwise cystometry in the rat. Med. Biol. Eng. Comput. 26, 267–270 (1988). https://doi.org/10.1007/BF02447079
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DOI: https://doi.org/10.1007/BF02447079