Kill event optimization

Patent metadata

Field	Value
Publication number	US-12092632-B2
Application number	US-202218050819-A
Country	US
Kind code	B2
Filing date	Oct 28, 2022
Priority date	May 29, 2019
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A method of choosing which undesired cell to destroy in a multi-cell fluorescent event includes detecting fluorescence of cells, converting photons detected in the fluorescence into an analog voltage output signal, and identifying at least two discernable peaks associated with the cells. By looking solely at properties measured within the multi-cell fluorescent event, a decision of which cell to target for elimination can be made. Using this method with large population sizes can result in an effective sex skewed product. The sex skewed product can, for example, be formed from bull semen which is then later used to inseminate cows which results in an increased likelihood of giving birth to female cattle.

First claim

What is claimed is:

1. A method of monitoring for a multi-cell fluorescent event, comprising:
detecting fluorescence in a plurality of cells;
converting photons detected in the fluorescence of the plurality of cells into an analog voltage output signal;
sending the analog voltage output signal to a field programmable gate array with an analog to digital converter (ADC) state tracker machine; and
monitoring a raw ADC value of the analog voltage output signal with the ADC state tracker machine; and
classifying each cell of the plurality of cells based upon the analog voltage output signal.

2. The method of claim 1 further comprising:
defining a background threshold value; and
when the raw ADC value received is less than or equal to the background threshold value, maintaining the ADC tracker state machine in an IDLE state.

3. The method of claim 2 further comprising:
when the raw ADC value rises above the background threshold value, advancing the ADC tracker state machine from the IDLE state to a RISING state.

4. The method of claim 3 further comprising:
maintaining the ADC tracker state machine in the RISING state until:
the raw ADC value falls below the background threshold value, thereby returning the ADC tracker state machine to the IDLE state; or
the raw ADC value falls below an immediately preceding raw ADC value but not below the background threshold value, thereby advancing the ADC tracker state machine to the PEAK state.

5. The method of claim 4 further comprising:
recording the immediately preceding raw ADC value as a peak value while in the PEAK state; and
maintaining the ADC tracker state machine in the PEAK state until:
the raw ADC value continues to fall below the immediately preceding raw ADC value, thereby advancing the ADC tracker state machine to the FALLING state; or
the raw ADC value rises above the peak value, thereby returning the ADC tracker state machine to the RISING state.

6. The method of claim 5 further comprising:
maintaining the ADC tracker state machine in the FALLING state until:
the raw ADC value falls below the background threshold value, thereby returning to the ADC tracker state machine to the IDLE state; or
the raw ADC value rises above than the immediately preceding raw ADC value, thereby advancing the ADC tracker state machine to the VALLEY state.

7. The method of claim 6 further comprising:
recording the immediately preceding raw ADC value as a valley value while in the VALLEY state; and
maintaining the ADC tracker state machine in the VALLEY state until:
the raw ADC value falls below the background threshold value, thereby returning to the ADC tracker state machine to the IDLE state;
the raw ADC value rises above the immediately preceding value, thereby advancing the ADC tracker state machine to the RISING state and confirming occurrence of a multi-cell fluorescent event; or
the raw ADC value falls below the valley value, thereby returning the ADC tracker state machine to the FALLING state.

8. The method of claim 7 further comprising generating an event with a general purpose processor or a digital signal processor to determine if the cell should be destroyed when the ADC tracker state machine transitions from the FALLING state or the VALLEY state to the IDLE state.

9. A sexed semen system comprising:
a detection laser capable of exciting a sperm cell;
a first detection laser lens that steers a detection pulse emitted by the detection laser into a sample flow, wherein the detection pulse is capable of illuminating the sperm cell within the sample flow;
a fluorescent dye that bounds DNA of the cell and produces a fluorescent emission event;
a second detection laser lens that directs the fluorescent emission event onto a surface of a fluorescence detector;
a computer processing unit for determining the sex of the sperm cell based on an output of the fluorescence detector;
an analog to digital converter (ADC) which converts an analog voltage output signal from the fluorescence detector into a digital output signal;
an ADC state tracker machine which monitors a raw ADC value of the analog voltage output signal to determine if a multi-cell fluorescent event has occurred, and if so, to classify each sperm cell as desirable or undesirable; and
a kill laser for destroying an undesirable sperm cell.

10. The system of claim 9 further comprising a source of sperm cells that produces the sperm cell.

11. The system of claim 9 further comprising a sheath fluid encapsulating the sperm cell.

12. The system of claim 9 further comprising a kill laser lens to direct a kill beam from the kill laser to a kill spot.

13. The system of claim 9 wherein the fluorescence detector is an avalanche photodiode (APD) sensor.

14. The system of claim 9 wherein the ADC tracker state machine includes an IDLE state, a RISING state, a PEAK state, a FALLING state, and a VALLEY state.

15. The system of claim 9 further comprising a general purpose processor (GPP) or a digital signal processor (DSP) using a defined gate to generate a fire signal to the FPGA with the option of the FPGA to make a kill decision based on the defined gate.

16. The system of claim 9 further comprising a low pass filter for passing signals with a frequency lower than a selected cutoff frequency.

17. A sexed semen system comprising:
a detection laser capable of exciting a sperm cell;
a fluorescence detector;
a computer processing unit for determining the sex of the sperm cell based on an output of the fluorescence detector;
an analog to digital converter (ADC) which converts an analog voltage output signal from the fluorescence detector into a digital output signal;
an ADC state tracker machine which monitors a raw ADC value of the analog voltage output signal to determine if a multi-cell fluorescent event has occurred, and if so, to classify each sperm cell as desirable or undesirable; and
a kill laser for destroying an undesirable sperm cell; and
a kill laser lens to direct a kill beam from the kill laser to a kill spot.

18. The sexed semen system of claim 17 further comprising a first detection laser lens that steers a detection pulse emitted by the detection laser into a sample flow, wherein the detection pulse is capable of illuminating a sperm cell within the sample flow.

19. The sexed semen system of claim 18 further comprising a second detection laser lens that directs a fluorescent emission event caused, at least in part, by illumination of the sperm cell onto a surface of the fluorescence detector.

20. The sexed semen system of claim 18 further comprising a fluorescent dye that bounds DNA of the sperm cell and produces a fluorescent emission event.

Assignees

• Abs Global Inc

Inventors

• Savage Frederick
• Ebersole Matthew D
• Mcada Daniel
• Appleyard David
• Xia Zheng

Classifications

• G01N21/6486

  Measuring fluorescence of biological material, e.g. DNA, RNA, cells (G01N21/6428 takes precedence) · CPC title

• G01N21/6456

  Spatial resolved fluorescence measurements; Imaging · CPC title

• G01N2015/1006

  for cytology · CPC title

• G01N2015/1461

  Coincidence detecting; Circuits therefor · CPC title

• G01N15/1459

  the analysis being performed on a sample stream · CPC title