Heart development, artificial

Blood/Material Interface Problems Confronting Artificial Heart Development... 

Artificial Hearts. An artificial heart is a machine that substitutes for a heart in which both halves no longer function properly. It is generally used as a temporary measure until a healthy human heart becomes available for transplantation. However, the goal of ongoing development is to create a lightweight, durable, functional machine that does not... 

Sonntag SJ, Kanfmann TA, Biisen MR, Laumen M, Linde T, Schmitz-Rode T, et al. Simulation of a pulsatile total artificial heart development of a partitioned fluid structure interaction model. J Fluids Struct 2013 38 187-204. 

Biomedical engineering. Chemical engineering principles have been used to model the processes of the human body as well as to develop artificial organs, such as the kidney, heart, and lungs. 

Efforts to develop an artificial heart have resulted in a number of advancements in the assist area. The centrifugal pump for open-heart surgery, the product of such an effort, has frequently been used to support patients after heart surgery (post-cardiotomy), or as a bridge to life prior to transplant. 

Artificial organs that perform the physical and biochemical functions of the heart, hver, pancreas, or lung are one class of organ replacements. A rather different target of opportunity is the development of biologieal materials that play a more passive role in the body for example,... 

The oscillation of membrane current or membrane potential is well-known to occur in biomembranes of neurons and heart cells, and a great number of experimental and theoretical studies on oscillations in biomembranes as well as artificial membranes [1,2] have been carried out from the viewpoint of their biological importance. The oscillation in the membrane system is also related to the sensing and signal transmission of taste and olfaction. Artificial oscillation systems with high sensitivity and selectivity have been pursued in order to develop new sensors [3-8]. 

In the 1960s the first heart valve was replaced. At approximately the same time the Englishman Sir John Charnley developed a bone cement on the basis of PMMA. Nowadays an improved version of this cement is still used, e g. to secure an artificial hip joint to the upper leg. 

Scientific research today sometimes produces strange bedfellows, teams of scholars from fields that might seem very far apart and distinct from each other. Research on biomaterials is one area with many such examples. Someone interested in developing an artificial heart, a blood substitute, or a new material that can be used for bone must know a little something about many topics from biology, chemistry, and physics. Even better, such research can be carried out most efficiently when scholars from each of these fields is involved in a research program. One of the best examples of that point is found in the history of research on artificial skin, in which loannis V. Yannas made an important breakthrough. 

One of the areas of greatest interest is the development of synthetic blood vessels. Heart disease is currently the number one cause of death among both men and women in the United States. The most common cause of heart disease, in turn, is atherosclerosis, a condition in which fatty deposits form on the inner walls of blood vessels, constricting the flow of blood. If it were possible to develop an artificial substitute for blood vessels damaged by atherosclerosis or other diseases, it would save the lives of millions of Americans each year. 

The long quest for blood-compatible materials to some extent overshadows the vast number of other applications of polymers in medicine. Development and testing of biocompatible materials have in fact been pursued by a significant number of chemical engineers in collaboration with physicians, with incremental but no revolutionary results to date. Progress is certainly evident, however the Jarvik-7 artificial heart is largely built from polymers [34]. Much attention has been focused on new classes of materials, such... 

Partial or complete replacement of natural organs with prosthetic components will someday be commonplace. For instance, the design of the total artificial heart, which has had limited clinical success, involved an application of many fundamental principles already discussed as they relate to hemodynamics, biomaterials, and control. Most would agree, however, that the materials-blood-tissue interface is the nidus for some of the most serious problems preventing the development of a safe and reliable artificial heart. This reinforces the importance of investigating at the molecular level the complex interactions that occur between artificial surfaces and the physiological environment. 

We also know that patients who have been kept on oxygenators for long periods of time develop problems which are poorly understood but if these problems are allowed to continue they inevitably result in death. Animals that are put on total heart replacement using an artificial heart pump also die eventually with some very poorly understood physiologic changes. These changes may well result from denatured enzymes and hormones within the body. 

A 78-year-old woman with a history of biventricular heart failure developed cardiogenic shock after she took a single tablet of verapamil 80 mg. She was resuscitated with artificial ventilation, dobutamine, noradrenaline, and calcium gluconate. Toxicological analysis showed an unexpectedly high plasma verapamil concentration, which was attributed to liver failure. 

Electrode Assembly. This device consists of a specially machined Teflon electrode holder, two disc electrodes (only one is energized), and a clamp machined from acrylic plastic (Figure 3). The electrode discs are of low-temperature isotropic carbon alloyed with SiC (Carbo-metics, Austin, TX). They were originally developed for use in artificial heart valves (14), and are approximately 1.6 cm in diameter and 1.25 mm thick, and have the surface properties of glassy carbon. Treatment of the discs requires only polishing to a high lustre with diamond grinding compounds of 14,000 and 50,000 mesh. 

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