Abstract:
Kidneys are the most often transplanted organs and renal transplantation is the best
treatment for patients experiencing End Stage Renal Disease (ESRD). It is imperative to suppress
immune system after renal transplant for appropriate kidney performance, which involves the use
of various immunosuppressant drugs. However, this suppression exposes patients in danger of
viral infections and can activate latent viruses. Aim is to avoid over-suppression or under suppression and to keep a delicate balance between two. Main concern among renal transplantation
recipients is Human Cytomegalovirus (HCMV), which is most prevalent virus. This proposed
research aims to design different variants of Sliding Mode Controller (SMC) and Backstepping
Controllers for an immunosuppressive drug control which will be used to reduce the
transplantation rejection risk and to assure that kidney is working well while viral load is observed
to be not a severe threat. The drug dosage is taken as the control input for the 6th order state space
model of renal transplant. Serum Creatinine is controlled to assure proper working of kidney as it
is a measure of kidney’s performance and concentration of Allospecific CD8+T cells that targets
kidney is controlled to prevent patient from HCMV infection. The performance of different
controllers will be compared to investigate which one is better and more useful for implementing
in different clinical scenarios. To ensure convergence of the system output to the desired reference,
Lyapunov Stability Theorem is applied. Many numerical simulations are implemented to examine
the efficacy of the proposed control techniques.
