METHOD FOR ADAPTIVE CONTROL OF INFUSION DURING PHACOEMULSIFICATION Russian patent published in 2023 - IPC A61F9/07 A61M1/00 

FIELD: medical equipment.

SUBSTANCE: invention relates to medical equipment, namely to a method for adaptive control of infusion during phacoemulsification. In the method, the supply pressure of the infusion flow is adjusted based on monitoring the speed of the infusion and aspiration flows and the level of vacuum in the aspiration line to establish one of three pressure modes in the infusion line of the system, corresponding to the pressure state of the infusion flow passable phaco-needle or the pressure state of the infusion flow phaco-needle occlusion or the pressure state infusion flow breakthrough occlusion. The pressure of the infusion flow in the state mode of the passable phaconeedle is set in accordance with the settings of the infusion pressure, while at the same time there is no excess of the vacuum level in the aspiration line of the value fixed at a given speed of the aspiration pump, corresponding to the aspiration flow rate equal to 5% of the average aspiration speed during the operation, and compliance with the infusion flow rate equal to 10% of the average infusion rate during the operation. The pressure of the infusion flow in the phaconeedle occlusion state mode is set in accordance with the settings of the infusion pressure, while at the same time there is an excess of the vacuum level in the aspiration line of the value fixed at a given speed of the aspiration pump, the correspondence of the aspiration flow rate to less than 5% of the average aspiration rate during the operation and the compliance of the speed infusion flow less than 10% of the average infusion rate during surgery. In the absence of compliance with at least one of the listed parameters, the state of phaconeedle occlusion and the infusion pressure settings of the infusion flow are considered to correspond to the state of passable phaconeedle. The pressure of the infusion flow in the breakthrough occlusion state mode is set in accordance with the settings of the infusion pressure in the established state of phaconeedle occlusion, while there is a decrease in the vacuum level of more than 1 mmHg in 10 ms, matching the aspiration flow rate more than 5% of the average aspiration rate during the operation, matching the infusion flow rate more than 10% of the average infusion rate during the operation. If at least one of the listed parameters does not match, the breakthrough occlusion state of the infusion pressure setting of the infusion flow is considered to correspond to the state of phaconeedle occlusion. The predicted volume of the post-occlusion wave is determined in two stages. At the first one, the deceleration of the aspiration flow is taken into account by multiplying the difference in the readings of the speed of the aspiration flow between the states of the passable phaco-needle and the occlusion of the phaco-needle by the corresponding time interval for reducing the aspiration flow. At the second stage, the adjusted volume of the post-occlusion wave is determined as equal to half the product of the deceleration of the aspiration flow rate per the square of the time interval. Infusion compensation of post-occlusion waves, taking into account the calculated volume, is carried out simultaneously with the identification of the state of occlusion breakthrough.

EFFECT: ensuring hydrodynamic safety in relation to intraocular structures during phacoemulsification by improving the accuracy of assessing the patency of the phaconeedle, precise quantitative calculation and timely compensation of post-occlusion waves and reducing the amount of infusion fluid used.

1 cl, 4 dwg