Reduced-order modeling for hyperthermia control.
This paper analyzes the feasibility of using reduced-order modeling techniques in the design of multiple-input, multiple-output (MIMO) hyperthermia temperature controllers. State space thermal models are created based upon a finite difference expansion of the bioheat transfer equation model of a scanned focused ultrasound system (SFUS). These thermal state space models are reduced using the balanced realization technique, and an order reduction criterion is tabulated. Results show that a drastic reduction in model dimension can be achieved using the balanced realization. The reduced-order model is then used to design a reduced-order optimal servomechanism controller for a two-scan input, two thermocouple output tissue model. In addition, a full-order optimal servomechanism controller is designed for comparison and validation purposes. These two controllers are applied to a variety of perturbed tissue thermal models to test the robust nature of the reduced-order controller. A comparison of the two controllers validates the use of open-loop balanced reduced-order models in the design of MIMO hyperthermia controllers.
Potocki
J K
JK
Department of Electrical and Computer Engineering, University of Arizona, Tucson 85721.
Tharp
H S
HS
D003198:Computer Simulation; D004867:Equipment Design; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation*; D008433:Mathematics; D008954:Models, Biological; D009369:Neoplasms / Q000628:therapy; D013696:Temperature; D013821:Thermometers