Medical/surgical smoke evacuator that continually draws waste into the evacuator to control the operation of the evacuator

Abstract

A smoke evacuator that draws smoke generated during a medical surgical procedure away from the site at which the smoke is generated. The smoke evacuator includes a pump that draws air into a filter. A sensor internal to the filter monitors the smoke in the air stream drawn through the filter. Normally the pump runs at a low speed, a speed sufficient to draw some air in the filter. When the sensor detects the presence of an appreciable amount of smoke in the air stream the sensor sends a signal indicating the air stream is in this state to the pump controller. The controller then increases the pump speed to result in a like increase in the volume of air drawn through the smoke evacuator. Since the sensor is contained in the filter, a new sensor is installed in the system each time a new filter is installed.

What is claimed is: 
     
         1 . A smoke evacuation system for use during a medical procedure, said system comprising:
 a conduit including an inlet into which air that includes smoke generated during a medical/surgical procedure is drawn;   a filter assembly in fluid communication with said conduit, said filter assembly including:
 a housing to which said conduit is connected: 
 at least one filter element disposed in said housing for removing smoke from air drawn through said housing; and 
 a smoke sensor disposed in said housing so as to be removed with the removal of said filter, said smoke sensor configured to sense smoke in the air drawn through said housing and generate a smoke signal representative of the amount of smoke in the air drawn though said housing; 
   a pump connected to said filter for drawing air into said the conduit inlet, through said conduit, and through said filter housing for filtering smoke from the air;   a variable speed motor for operating the pump;   a controller connected to said smoke sensor for receiving therefrom the signal corresponding to an amount of detected smoke and connected to said pump for regulating the speed of said pump, wherein said controller is configured so that:
 when the signal from said smoke sensor indicates the amount of smoke is below a predetermined limit, said controller regulates said motor to cause the pump to run at a first speed, the first speed being sufficient to draw air into the conduit and through said filter housing so that smoke can be sensed by said sensor; and 
 when the signal from said smoke sensor indicates the smoke is at or above he predetermined limit, said controller regulates said motor to cause the pump to run at a second speed, the second speed being greater than the first speed. 
   
     
     
         2 . The smoke evacuation system of  claim 1 , wherein:
 said controller is configured to control the pump to transition from the first speed to the second speed by increasing the power level to said motor from a first level to a second level greater than the first level; and   decreasing the power level to said motor from the second level to a third level, the third power level being greater than the first power level and less than the second power level.   
     
     
         3 . The smoke evacuation system of  claim 1 , wherein said controller is electrically isolated from the power supply that energizes the motor. 
     
     
         4 . The smoke evacuation system of  claim 1 , wherein said smoke sensor is located in said filter housing to be located upstream from said at least one filter element. 
     
     
         5 . The smoke evacuation system of  claim 1 , wherein plural separate filter elements are disposed in said filter housing. 
     
     
         6 . The smoke evacuation system of  claim 1 , wherein said at least one filter element is carbon activated filter. 
     
     
         7 . The smoke evacuation system of  claim 1 , wherein said at least one filter element is a ULPA filter. 
     
     
         8 . The smoke evacuation system of  claim 1 , wherein said smoke sensor comprises a infrared light source for generating IR light and an IR detector for sensing IR light. 
     
     
         9 . The smoke evacuation system of  claim 1 , wherein said filter assembly, said pump, said motor, said controller are mounted to a wheeled cart. 
     
     
         10 . The smoke evacuation system of  claim 9 , wherein at least one waste container for receiving medical waste is mounted to said cart and said at least one waste container has a connecting member for receiving a suction line through which medical/surgical waste is drawn into the waste container. 
     
     
         11 . A method for drawing smoke away from a surgical procedure, the method comprising the steps of:
 actuating a variable speed pump having that is driven by a variable speed motor and that is in fluid communication with a conduit having an inlet so that the pump draws the air with smoke through the conduit; and   passing the air drawn into the conduit through a filter assembly, so that the filter removes the smoke from the air prior to discharge of the air, wherein the filter assembly includes: a housing that is removably attached to the pump; at least one filter element disposed in the housing that removes smoke from air drawn through the housing; and a smoke sensor disposed in the housing that is removed and replaced with said housing and said at least one filter element;   sensing the amount of smoke in the air drawn through the conduit with the smoke sensor;   wherein, the speed of the motor is regulated based on a signal output by the smoke sensor representative of the amount of smoke in the air draw through the filter housing such that:
 when the smoke sensed by the smoke sensor is below a predetermined limit, the motor is set to drive the pump a first speed that generates a suction sufficient to draw air into the conduit and drawn through the filter housing so that the smoke can be sensed by the smoke sensor; 
 when the smoke sensed by the smoke sensor is above the predetermined limit, the motor is set to drive the pump at a second speed that is higher than the first speed so that the pump generates a greater suction than when the pump operates at the first pump speed; and 
 when the smoke sensed by the smoke sensor falls to below the predetermined limit, the motor is set to drive the pump at the first speed. 
   
     
     
         12 . The method of drawing smoke away from a surgical procedure of  claim 11 , further comprising the steps of:
 wherein, after the smoke sensor initially detects smoke in excess of the predetermined limit, controlling the motor to increase the speed of the pump from the first pump speed to the second pump speed by:
 increasing electrical power applied to the motor from a first level to a second level greater than the first level; and 
 decreasing the electrical power applied to the motor ( 808 ) from the second level to a third level, the third level being less than the second level but greater than the first level. 
   
     
     
         13 . The method of drawing smoke away from a surgical procedure of  claim 11 , wherein the smoke sensor includes an infrared light source and an infrared detector. 
     
     
         14 . The method of drawing smoke away from a surgical procedure of  claim 11 , wherein said filter assembly is arranged so that said smoke sensor performed said step of sensing smoke in the air drawn through conduit prior to the flowing of the air through said at least one filter element. 
     
     
         15 . The method of drawing smoke away from a surgical procedure of  claim 11 , wherein:
 the pump, the motor and the filter assembly are mounted to wheeled a wheeled cart, the wheeled cart also including at least one waste container for receiving medical waste, and the at least one waste container having a connecting member for receiving a suction line through which medical/surgical waste is drawn into the waste container;   and simultaneously with said actuation of said pump drawing a suction through said suction line so that that simultaneously with the drawing of air through the conduit and the flowing of the air through the at least one filter element waste is drawn away from the surgical procedure through the suction line into the at least one waste container.