Integrated detector for detecting bubbles in fluid flow and occlusions in a tube

An integrated compact sensor for detecting bubbles in a fluid flow and occlusions in a tube comprising:

• a housing having opposing curved sides forming a channel adapted to receive and pre-load the tube, said channel having a narrowest portion;
• a base connecting the opposing curved sides;
• an opening formed in said base between the opposing curved sides and adjacent the narrowest portion of said channel;
• a pressure sensor load button placed in said opening adjacent the narrowest portion of said channel;
• a sensor coupled to said pressure sensor load button, whereby a force received by said pressure sensor load button is measured by said sensor;
• an ultrasonic transmitter placed adjacent one of the opposing curved sides of said housing;
• and
• an ultrasonic receiver placed adjacent the other one of the opposing curved sides of said housing, and
• wherein said ultrasonic transmitter and said ultrasonic receiver and said pressure sensor load button are each adjacent the narrowest portion of the opposing curved sides forming said channel,
• whereby the narrowest portion of the opposing curved sides pre-load the tube improving accuracy across a range of different tube materials and electrical signals from said sensor and said ultrasonic transmitter and receiver are used to detect bubbles in the fluid flow and occlusions in the tube.

An integrated compact sensor for detecting bubbles in a fluid flow and occlusions in a flexible tube comprising:

• a housing having opposing curved sides forming a channel having a narrowest portion, the narrowest portion of the channel having a predetermined fixed width adapted to receive the flexible tube;
• an elongated base attached to the housing and connecting the opposing curved sides of the channel;
• an opening formed in said base between the opposing sides of said channel, and adjacent the narrowest portion of the channel;
• a pressure sensor load button placed in said opening and extending into said channel between the opposing curved sides;
• sensor supports formed in said elongated base on either side of said opening formed in said base;
• a pressure sensor insert extending between and supported by said sensor supports adjacent said pressure sensor load button;
• a first and second strain gauge sensor formed on said pressure sensor insert, one each of said first and second strain gauge sensors placed between one of said sensor supports and said pressure sensor load button, whereby said pressure sensor load button is positioned between said first and second strain gauge sensors stressing said first and second strain gauge sensors when a pressure is applied to said pressure sensor load button;
• an ultrasonic transmitter placed adjacent one of the opposing curved sides of said channel in said housing;
• an ultrasonic receiver placed adjacent the other one of the opposing curved sides of said channel in said housing;
• and
• wherein said pressure sensor load button, said ultrasonic transmitter and said ultrasonic receiver are each adjacent the narrowest portion of the opposing curved sides,
• whereby electrical signals from said first and second strain gauge sensors are used to detect bubbles in the fluid flow and signals from said ultrasonic transmitter and receiver are used to detect occlusions in the tube.

A method of detecting bubbles in fluid flow and occlusions in a tube comprising the steps of:

• placing a tube carrying a fluid in a curved channel having a bottom and a width with a narrowest portion in a housing so as to provide the tube with a predetermined pre-compression at the narrowest portion;
• transmitting ultrasound adjacent one side of the tube within the curved channel;
• receiving the transmitted ultrasound adjacent an opposing side of the tube within the curved channel;
• processing a received ultrasound signal, whereby a bubble in the fluid flow can be detected;
• positioning a sensor load button at the bottom of the curved channel and adjacent the narrowest portion;
• contacting the sensor load button adjacent the tube between sides of the curved channel and adjacent the narrowest portion;
• coupling a strain gauge to the sensor load button;
• and
• processing a signal from the strain gauge proportional to a pressure placed on the sensor load button, whereby an occlusion in the tube can be detected,
• whereby both bubbles in fluid flow and occlusions in the tube are detected with the received ultrasound signal and the sensor load button adjacent the narrowest portion of the housing.