Table 12.

Optimization Algorithms for Clinical Brain Therapeutics.

Method	Method Description	Input	Output	Data Sources	Publication Identifier
Surrogate Optimization	Random and sparse parameter space search to optimize a constrained function.	Stimulation Current	Movement Disorder Symptom (Tremor, Bradykinesia, Axial Symptoms) Reduction	Finite Element Model of electrode current to fiber activation and symptom reduction.	[29]
Gaussian-Process based Bayesian Optimization	Tests inputs to develop a descriptive function and uses all previous attempts to determine the next test input.	Stimulation Frequency, Stimulation Charge Delivery, Stimulation Pulse Duration	Seizure Duration	Mice model test data of over 1000 parameter combinations.	[279]
Forward & Reverse Model-Free Neural Networks	Two neural networks are utilized. A measurement predictor network (MPN) learns a forward model from training data while a stimulus generator network (SGN) learns a reverse model from MPN data.	Recorded Retinal Electrical Receptive Field Response	Desired Electrode Stimulation Amplitude Pattern	The MPN is trained on electrical receptive field values from a microelectrode array. Random stimulation of the retinal generates testing data.	[285]
Greedy, Stochastic Learning Algorithm	Reduce error between a template neural response and recorded neural response. Minimize error with random selection of parameters around previous best value with an updating factor to prevent local minima.	Recorded Visual Cortex Pattern of Firing Rates	Visual Cortex Stimulation Amplitude Necessary to Match Desired Template	Template patterns were created from showing an animal a visual stimulus and recording neural responses.	[286]
Multi-Objective Particle Swarm Optimization	Searches the parameter space in parallel, moving “particles” based on velocity, particle optimum, and group optimum. Multiple objectives are considered by a “Pareto front” vectors in addition to a combined objective.	Electrode Position	Electrode contacts and current to maximize target pathways and minimize side effect pathways.	Multi-physics (COMSOL) and cable model (NEURON) software.	[278]