System and Method of Non-Invasive Continuous Level Sensing

• US 20100192699A1
• Filed: 04/14/2010
• Published: 08/05/2010
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: Novartis Ag
• Inventors: Gao, Shawn X.
• Granted Patent: US 7,956,341 B2
• Time in Patent Office: Days
• US Class Current: 73/861
• CPC Class Codes: A61B 50/10 Furniture specially adapted for surgical or diagnostic appliances or instruments
• CPC Class Codes: A61B 50/13 Trolleys, e.g. carts
• CPC Class Codes: G01F 23/292 Light , e.g. infrared or ultraviolet
• CPC Class Codes: G01F 23/2927 for several discrete levels, e.g. with more than one light-conducting sensing element

Abstract

Embodiments of the present invention provide a system and method for detecting the level of a fluid in a surgical cassette by projecting light from a linear light source into a wall of a cassette. Depending on the amount a light reflected or refracted in the cassette (i.e., due to the cassette material/fluid interface or cassette material/air interface (or other interface)) various portions of a linear sensor array will be more or less illuminated. By examining the illumination of the linear sensor array, the level of fluid in the chamber can be determined.

Claims

1. A system for detecting the level of fluid in a surgical cassette, comprising:

a linear light array comprising;

a first light source to project a first beam of light into a first cassette wall along a first transmission path, wherein the first transmission path has an angle of incidence with a chamber surface so that at least a majority of the first light beam is refracted if a cassette material/first fluid interface intersects the first transmission path; and

a second light arranged along a vertical axis with respect to the first light source to project a second beam of light into the first cassette wall along a second transmission path, wherein the second transmission path has an angle of incidence with the chamber surface so that at least a majority of the second light beam is reflected if the cassette material/second fluid interface intersects the second transmission path; and

a linear sensor array comprising a first portion positioned to receive the first beam of light and a second portion positioned to receive the second beam of light and produce an output signal to indicate whether each of the first and second portions are illuminated.

2. The system of claim 1, wherein the linear sensor array is arranged to receive light through the chamber.

3. The system of claim 1, wherein the sensor array is arranged to receive light reflected from the cassette material/first fluid interface.

4. The system of claim 1, wherein the cassette material/first fluid interface is a cassette material/AIR fluid interface.

5. The system of claim 1, wherein the cassette material/first fluid interface is a cassette material/Liquid interface.

6. The system of claim 1, further comprising a controller operable to determine a fluid level based on the output of the linear sensor array.

7. The surgical system of claim 6, wherein the controller is further operable to:

apply a threshold to the output of the sensor array to determine that the first portion of the linear sensor array is in an ON state and determine that the second portion of the linear sensor array is in an OFF state; and

determine the fluid level based on the transition between the ON and OFF states of the first and second portions.

8. The surgical system of claim 7, wherein the controller is further operable to determine a flow rate based on a change in fluid level over time.