“We presented an efficient technique of computer control that regulates the anesthesia in operating rooms, with the goal of individualizing drug doses infused with the characteristics of each patient,” explains to SINC Juan Albino Mendez, first author of the work and research of the Group Control of Anesthesia, University of La Laguna (ULL).

The group has developed a software tool, along with the team of anesthesiologists at the Hospital Universitario de Canarias, to facilitate the work of these health professionals. The new system, published in Computer Methods in Biomechanics and Biomedical Engineering, Keeps the person in the hypnotic state during surgery desired.

Through sensors and a monitor, the system records the electroencephalogram (EEG) of patient and bispectral index (BIS), a unitless parameter that quantifies the hypnotic state and is related to the level of consciousness.

The BIS value ranges from 100 (high alert as possible) and 0 (absence of cortical electrical activity, the more profound state of unconsciousness). This research focuses on the region of A corresponding to general anesthesia, ie between 40 and 60.

Algorithms that calculate the dose

The data are processed on a computer that includes a specific control software and can act on the pump that injects the anesthetic to regulate their numbers. The software is based on algorithms PID (Proportional Integral Derivative) adapter, a feedback control mechanism that automatically calculates the appropriate dosage based on measured and desired values.

To validate the technique the researchers have successfully performed simulations with various models developed by them, and further tested in 15 volunteer patients, aged between 30 and 60, the Hospital Universitario de Canarias.

“The first results obtained in both theater and simulation shows that the system provides a satisfactory performance and applicability in the operating room with reasonable expectations of success,” said Albino Mendez.

Scientists hope that the method helps to improve operational performance at the time of anesthetic dose and optimize patient recovery times and reduce the costs of interventions.

The study is a commonly used anesthetic, propofol, but could use others, such as isoflurane. The technique also has application in the regulation of other physiological variables such as blood glucose level, temperature or blood pressure.

The immediate challenges of the equipment, in addition to advancing the algorithmic part of the system are incorporated in the platform variables analgesia and muscle relaxation to provide the anesthesiologist for a comprehensive tool.

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Bibliographic Reference:

Albino Juan Mendez, Santiago Torres, Jose Antonio Reboso and Hector Reboso. “Adaptive computer control of anesthesia in humans. Computer Methods in Biomechanics and Biomedical Engineering 12 (6): 727-734, December 2009.

Source: SINC