Cell culture monitoring system with low power consumption
An improved cell culture monitoring system and method that detects cell growth and concentration in a dynamic environment of incubator/shaker. In order to reduce power consumption and make a wireless cell culture monitoring system practical, several methods of temperature compensation are used to replace a method of controlling the temperature of sensing module. Furthermore its power consumption can be significantly reduced by using an adaptive and synchronized light pulse detection technique.
1. A method for reducing power consumption and wirelessly monitoring biological cell culture medium in a dynamic environment of a biological culture incubator/shaker, comprising:
utilizing a container to hold a liquid biological culture medium in which biological cells are incubated, and at least a part of the container's wall is optically transparent;
positioning a light emission source relative to the transparent wall of said container and irradiating light through the wall of said container and interacting with said biological culture medium;
positioning and aiming at least one photodetector to detect light from the interacting section of the incident light with the biological culture medium;
positioning at least one temperature sensor close to said light emission source and said photodetector;
providing temperature compensation means for improving measurement accuracy without a temperature control of said light emission source and said photodetector, said temperature compensation means includes steps for controlling the driving current of the light emission source, and then pre-measuring, pre-calculating and pre-storing superimposed temperature coefficients of the controlled light emission source and the photodetector, and then correcting the measurable property values of the biological cell culture medium based on measured temperature of the light emission source and the photodetector and measured turbidity of the cell culture medium;
providing processing means for amplifying electrical signal from the photodetector, and for processing the signal and presenting properties of the biological cell culture medium.
2. A method of claim 1 , wherein said monitoring biological cell culture medium includes monitoring turbidity or/and OD of biological culture medium, wherein the properties include the turbidity and OD.
3. A method of claim 1 , wherein said monitoring biological cell culture medium includes monitoring biological cell growth curve and growth rate.
4. A method of claim 1 , wherein further providing at least one motion sensor for measuring shaking speed of the incubator/shaker.
5. A method of claim 1 , wherein said processing means further includes processing motion sensor signal and presenting the shaking speed of the incubator/shaker.
6. A method of claim 1 , wherein said processing means further includes steps for suspending light emission from the light emission source and A/D conversion for the photodetector signal when the shaking speed is below a specific value during a shaking cell culture process.
7. A method of claim 1 , wherein said light source drive circuit consists of at least one transistor and one current control circuit.
8. A method of claim 1 , wherein further generating a low duty cycle pulse signal with a light source drive circuit to drive said light emission source.
9. A method of claim 8 , wherein said generating a low duty cycle pulse signal means making the light-on and light-off time durations of the light emission source to be preset constants.
10. A method of claim 8 , wherein said generating a low duty cycle pulse signal means making the light-off time duration adaptive to measured cell culture turbidity or turbidity change rate.
11. A method of claim 8 , wherein said generating a low duty cycle pulse signal means making the light-off time duration adaptive to measured cell culture OD or OD change rate.
12. A method of claim 8 , wherein said processing means further includes making synchronized A/D conversion for multiple signals in respect to the light-on and light-off time of the light driving pulse signal.