Page 46 - Control Theory in Biomedical Engineering

Modeling and control in physiology 33

As described previously, chaotic systems can describe physiological
behaviors. Moreover, detecting chaos in the human body is a difficult chal-
lenge for biologists. In fact, basic chaos detection tools are highly sensitive to
measurement noise and this problem can distort detection results. Many
attempts to detect chaos in physiological systems have fallen short due to this
sensitivity to measurement noise. For this reason, recent research has
attempted to construct noise-robust tools for detecting chaotic behaviors
in biology ( Jiao et al., 2020; Toker et al., 2020).
Finally, much progress has been made on the study of artificial organs and
devices. Artificial organs, such as the artificial pancreas, artificial and wear-
able prosthetic devices and pacemakers, improve the daily life of patients.
For example, the artificial pancreas improves the regulation of blood glucose
concentration, especially for type 1 diabetes patients (Boughton and
Hovorka, 2019; Ginsberg and Mauseth, 2019). The artificial organ contains
sensors (to measure blood glucose concentration), an insulin pump (to inject
insulin in the body) and a controller (to regulate the blood glucose concen-
tration), as described in Fig. 29.
Many patients are waiting for a heart transplantation, but unfortunately
there are not enough hearts available. One of the proposed solutions for this
problem is to develop a total artificial heart. The first researches were devel-
oped starting in 1960 and since then many prototypes have emerged (Cohn
et al., 2015). However, the total artificial heart is not an alternative solution
before transplantation due to the limited durability of the pumps. In fact, the
longest recorded survival time after artificial heart transplantation was
120 days. Another solution for heart problems is the cardiac pacemaker.

Fig. 29 Different components of the artificial pancreas.