Page 9 - Control Theory in Biomedical Engineering

xiv Preface

technologies. Furthermore, control theory is probably of great significance
in the pervasiveness of medical robots in surgery, exploration, diagnosis, and
therapy. Control theory is absolutely at the heart of medical sciences and the
future of medicine.
On one hand, the human body has a natural and autonomous control
process responsible for maintaining human life called homoeostasis.
Homeostasis is the property of a physiological system to regulate its internal
environment to a given set point in the presence of specific stimulus-
producing changes in that variable. The control process in the human body
is ensured through the coordination of the control center and the natural
sensors and effectors. The roster of vital parameters concerned by homeo-
stasis is long and includes blood pressure, blood oxygen, heart rate, blood
calcium, blood glucose, and so on. In this framework, there are several
well-known examples of mathematical model-based control. The most emi-
nent ones are the endocrine system, the immune system, the neurological
system, the cardiac and pulmonary system, and the locomotor system. These
models are widely used in the medical field and have shown great advances
in prediction, diagnosis, and therapy. However, further progress is still
expected for several domains, especially to prevent, detect, and control sev-
eral chronic diseases (e.g., chronic respiratory diseases, cardiovascular dis-
eases, diabetes mellitus, thyroid disease, cancers, HIV/AIDS, etc.) and to
predict the evolution of and control devastating epidemics (severe acute
respiratory syndrome (SARS), yellow fever, cholera, Ebola, hepatitis B,
H1N1/09 virus, COVID-19, etc.).
On the other hand, control theory deeply impacts the everyday life of a
large part of the human population like disabled and elderly people using
assistive and rehabilitation robots for improving their quality of life and
increasing their personal independence. For this large community, the body
process requires external control laws in order to regulate its natural func-
tions via artificial organs, including artificial arms, legs, pancreas, heart,
lungs, liver, and so on, and assistive technologies, including wheelchairs,
prostheses, walkers, exoskeletons, and companion robots.
Medical robotics has undergone a profound revolution in the past three
decades. Nowadays, they are used to perform delicate surgical procedures
in specific disciplines including orthopedics, urology, cardiac surgery, neuro-
surgery, ophthalmology, pediatric surgery, general surgery, and so on. Robots
help in drug administration and disinfection duties and perform a growing
number of other health tasks. Compared to manual machines in healthcare,
medical robotic systems offer a wide range of advantages. They can eliminate