On using a self-tuning controller for blood pressure regulation during surgery in man

Area of Science:

• Anesthesiology
• Biomedical Engineering
• Pharmacology

Background:

• Maintaining stable arterial pressure is critical during surgery.
• Automated control systems offer potential for precise hemodynamic management.
• Previous methods for blood pressure control have limitations.

Purpose of the Study:

• To evaluate the efficacy of a generalized minimum-variance self-tuning controller for arterial pressure regulation.
• To assess the controller's performance in maintaining normal arterial pressure during abdominal surgery.
• To determine the controller's utility in inducing controlled hypotension for other surgical procedures.

Main Methods:

• Utilized the Clarke and Gawthrop generalized minimum-variance self-tuning controller.
• Adjusted phenylephrine infusion rates in 20 patients for abdominal surgery under epidural analgesia.
• Employed sodium nitroprusside infusions in 18 patients for plastic and neurosurgical procedures.

Main Results:

• The controller effectively restored and maintained normal arterial pressure in patients undergoing abdominal surgery.
• The method successfully produced controlled hypotension in patients undergoing plastic and neurosurgical procedures.
• Provided valuable insights into patient hemodynamic responses to various surgical factors.

Conclusions:

• The generalized minimum-variance self-tuning controller is a highly effective tool for arterial pressure management in diverse surgical settings.
• This automated approach offers precise control for both normotension and hypotension.
• The system enhances understanding of patient physiological responses during anesthesia and surgery.