Anatomical simulation

Cardiac models are amongst the most advanced in silico tools for bio-med-icine, and the above scenario is bound to become reality rather sooner than later. Both cellular and whole organ models have aheady matured to a level where they have started to possess predictive power. We will now address some aspects of single cell model development (the cars ), and then look at how virtual cells interact to simulate the spreading wave of electrical excitation in anatomically representative, virtual hearts (the traffic ). 

Fig. 8. Reconstruction of Young s modulus map in a simulated object. A 3D breast phantom was first designed in silico from MR anatomical images. Then a given 3D Young s modulus distribution was supposed with a 1 cm diameter stiff inclusion of 200 kPa (A). The forward problem was the computing of the 3D-displacement field using the partial differential equation [Eq. (5)]. The efficiency of the 3D reconstruction (inverse problem) of the mechanical properties from the 3D strain data corrupted with 15% added noise can be assessed in (B). The stiff inclusion is detected by the reconstruction algorithm, but its calculated Young s modulus is about 130 kPa instead of 200 kPa. From Ref. 44, reprinted by permission of Wiley-Liss, Inc., a subsidiary of John Wiley Sons, Inc.

When the creation of long-term memories— repeated stimulations interrupted by rest periods—was simulated in this preparation by repeated pulses of serotonin, anatomical changes occurred. Specifically, new synaptic connections were created. It is likely that there are two underlying components to formation of new synaptic connections. One is local protein synthesis in the nerve terminal and the other is CREB (cAMP response element binding) dependent transcription in the neuronal nucleus. Of course, serotoiun pulses also stimulated the release of glutamate. So now the question is how repeated pulses of serotonin are related to protein synthesis and formation of new synapses. 

This paper reviews briefly those anatomical and physiological concepts required for the mathematical analysis and the mathematical model derived for the simulation. The mathematical techniques which were developed to obtain steady- and unsteady-state solutions of the model and the results of these steady- and unsteady-state studies are discussed. 

In designing a mathematical simulation of any physical or chemical process, one must first determine an adequate geometric representation of the actual process. The success of the overall simulation depends often upon this initial step in the complete modeling process. When the physical or chemical process that is to be modeled is part of a physiologically and anatomically complex organ of the human body, the determination of a... 

Breast-on-a-chip and splenon-on-a-chip systems have also utilized microfluidic technology. However, their capacities are limited. The breast-on-a-chip devices only mimic the distribution of anatomical vessels of a breast rather than the whole microenvironment containing glandular, fatty, and vascular tissues. The device can be integrated with other tumor-on-a-chip devices to further mimic tumor development in the breast. The splenon-on-a-chip system just simulates the blood filtering function of in vivo splenon using a microfluidic two-phase flow structure. Those chips still lack of accuracy to mimic tissue and cellular level. 

A detailed simulation of the anatomical model that may be manipulated to the correct size and shape ... 

Tashiro Y, Okazaki K, Iwamoto Y (2015) Evaluating the distance between the femoral tunnel centers in anatomic double-bundle anterior cruciate ligament reconstruction using a computer simulation. Open Access J Sports Med 6 219-224. doi 10.2147/0AJSM.S80809... 

Kondo et al. [4] reported a unique laboratory study to verify biomechanical effects of this ACL reconstruction procedure. Namely, they arthroscopically performed this anatomic double-bundle reconstruction procedure and the conventional single-bundle reconstruction procedure with cadaver knees and biomechan-ically compared the knee stability among the two procedures and the normal knee, under the following loading conditions 90-N anterior tibial force, 5-Nm internal and external tibial torques, and a simulated pivot-shift test. In the results, there were significant reductions of anterior laxity of 3.5 mm and internal rotational laxity of... 

The effects of skeletal trauma may be simulated by normal anatomical variations during development, projection artefacts and overlap of adjacent structures. Secondary ossification centres or irregular sites of ossification that appear fragmented are often mistaken for traumatic injury. The mach effect is a physiological form of edge enhancement created when there is an abrupt change from light to dark (radio-opaque to radiolucent) or vice versa at a concave or convex interface of a subject. Its presence at the interface of structures can simulate a fracture line. Similarly, overlap of normal structures such as skin or soft tissue folds can produce an identical appearance (Fig. 7.1). 

Numerous non-pathological appearances can simulate disease processes in the developing skeleton. These maybe anatomical variants, related to irregular, decreased or increased mineralisation during ossification, or artefactual. Only those that simulate the effects of trauma will be covered in this chapter, which is not intended to be exhaustive. Skeletal variations that are more commonly encountered in paediatric practice are included but the reader is directed to more comprehensive texts such as Theodore Keats Atlas (Keats and Anderson 2001), which this chapter is not designed to replace as a reference text. 

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