Model muscle

Fig. 11. Artificial muscle model using amphoteric PVA gel film of SO pm thick. The model length was 12 cm. This model was able to raise a ball to the upper position within 10 s [15]...

Napaporn, J. Thomas, M. Svetic, K.A. Shahrokh, Z. Brazeau, G.A. Assessment of mytotoxicity of pharmaceutical buffers using an in vitro muscle model effect of pH, capacity, tonicity, and buffer type. Pharm. Dev. Technol. 2000, 5 (1), 123-130. 

Napaporn J, Thomas M, Brazeau G, and Shahrokh Z. Assessment of the Myotox-icity of Pharmaceutical Buffers Using an in vivo Muscle Model Elfect of pH, Buffer Capacity, Tonicity, and Buffer Type. Pharm Develop Technol 2000 5(1) 123-130. 

Property Myosin thread Fiber model Skeletal muscle Models Skeletal muscle... 

Muscle Model Predictive Power Muscle Contraction... 

Description of muscle contraction has essentially evolved into two separate approaches — lumped whole muscle models and specialized crossbridge models of the sarcomere. The former seek to interpret muscle s complex mechanical properties with a single set of model elements. Muscle experiments measure muscle force and length subjected to isometric (fixed length) conditions, isotonic (fixed load) conditions, and transient analysis where either length or load is rapidly changed. 

The large-scale distributed muscle model can be reduced to a compact model analogous to the ventricle model previously presented (Equation 8.8). Muscle fibers (cells), or strips, can be described as force... 

Figure 8.16 shows isometric force curves computed from the muscle model for initial muscle lengths Im = 8.5 to 10.0 mm. The curve shapes and magnitudes compare favorably with experimental curves in... 

Figure 8.17 shows computed isotonic contractions for different fixed loads. Although not shown, this muscle model exhibits an inverse relation between isotonic load and amount of shortening, and a direct relation between initial length and shortening (Starhng s law). Results are also consistent with experiments,... 

FIGURE 8.19 Quick releases of 10% of muscle length over 10 msec computed from the reduced muscle model (Equation 8.16) at three different times during contraction. 

Winters, J.M., Hill-based muscle models a systems engineering prospective. In Winters, J.M. and Woo, S.L.-Y. (Eds.), Multiple Muscle Systems Biomechanics and Movement Organization. Springer-Verlag, New York, pp. 66-93,1990. 

Physiological support for this model is based on the muscle model by Wilkie [1968], and estimates for the extraocular muscle elasticities and the passive tissues of the eyeball are based on experiments by Robinson et al. [1969,1981] and Collins [ 1975] and studies of extraocular muscle viscosity by BahOl et al. [1980]. 

The linear muscle model has the static and dynamic properties of rectus eye muscle, a model without any nonlinear elements. The model has a nonlinear force-velocity relationship that matches muscle data using linear viscous elements and the length tension characteristics are also in good agreement with muscle data within the operating range of the muscle. Some additional advantages of the linear muscle model are that a passive elasticity is not necessary if the equilibrium point Xe = —19.3°, rather than 15°, and muscle viscosity is constant that does not depend on the innervation stimulus level. 

Enderle, J.D., EngeUcen, E.J., and Stiles, R.N. 1991. A comparison of static and dynamic characteristics between rectus eye muscle and Hnear muscle model predictions. IEEE Trans. Biomed. Eng. 38 1235-1245. 

An alternative approach is to create models which mimic the actual biomechanical properties of the face, than simple rely of deformations of the grid [154], [354], [492], [493], [491]. This is the parallel approach to articulatory synthesis described in Section 13.4, and the pros and cons are just the same. While this in a sense is the proper and ultimate solution, the enormous complexities of the muscle movements involved makes this a complex process. Furthermore, as with articulatory synthesis, there is no single solution as to how complex each muscle model should be approaches range from simple models to close mimics. At present the computational requirements and complexity of this approach rule it out for engineering purposes. It continues to be an interesting field for scientific purposes though, as is articulatory synthesis itself... 

When an ionizable polymer is chemically cross-linked to form a three-dimensional network, an increase in the ionization of the network brings about extensive swelling of the gel, which can be observed visually on a macroscopic level. The expansion of the conformation is due to an increase in the electrostatic potential appearing on the macromolecules. On the basis of swelling and contraction of a weak polyelectrolyte gel, Katchalsky, Kuhn, and co-workers [25-27J proposed a muscle model referred to as mechanochemical or later as a che-momechanical system [1,28]. 

Some of the applicable muscle models include the Maxwell, Voigt, Hill and Carlson models (Figure 1). In particular, the Carlson (1957) equation is used in much of this work to describe the stress-velocity relationship of cardiac muscle over the entire cardiac cycle. Min et al. (1978) found very little difference in analyzing ventricular dynamics when he alternately used Carlson s equation only during isotonic contraction and Hill s equation during isovolumic contraction. 

In a symposium devoted to imaging and simulation of the cardiac system it is perhaps appropriate that I make a few comments about the various muscle models that exist and their relevance to the cardiovascular system. I will deliberately refrain from covering material already reviewed previously, Gibbs (1978),... 

The various studies, investigating the properties of the pomegranate by-products, carried out in fish muscle models, are summarized in Table 2. 

Our Appp + hjj jy[ jj]y[ xc jvjo(jei exhibits several aspects of the EBM pathologic phenotype including (a) pronounced vacuolization of most of the muscle fibers (b) congophUicinclusionsinsomeof the muscle fibers (c) aggresome formation (d) nuclear PHFs (e) mitochondria abnormalities including COX deficiency (f) cholesterol accumulation (g) increased (xBC (h) increased parkin (i) increasedmyos-tatin and (j) inability to become innervated [31,141, 214, 221, 230, 231], This cultured human muscle model clearly demonstrates that Appp/A i overexpression can be central to the induction of IBM-characteristic phenotype. 

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