Method for ascertaining a transmission value

Patent metadata

Field	Value
Publication number	US-9664670-B2
Application number	US-201314088588-A
Country	US
Kind code	B2
Filing date	Nov 25, 2013
Priority date	Nov 27, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

The invention is in the field of in vitro diagnostics and relates to a method for ascertaining a transmission value for a light signal that is pulsed at a frequency through a specimen in an automatic analysis appliance. It also relates to a transmission measurement apparatus for an automatic analysis appliance, comprising a light source that is pulsed at a frequency and a photodetector having a downstream A/D converter.

First claim

The invention claimed is:

1. A transmission measurement apparatus for an automatic analysis appliance, comprising a light source pulsed at a frequency, a photodetector, an A/D converter with a sampling frequency that corresponds to an even multiple of the frequency of the light source, the A/D converter being connected downstream of the photodetector, and an integrated circuit connected downstream of the A/D converter and programmed to:
associate sample values from the A/D converter with a light pulse or with a dark time between two light pulses based on the frequency of the light source and a phase of the light source,
delay the associated sample values by an integer multiple of a half-period corresponding to the frequency of the light source, and
subtract the delayed sample values from one another; wherein:
the integrated circuit comprises no signal multiplier; and
the transmission measurement apparatus has no bandpass filter connected downstream of the photodetector and no low pass filter connected downstream of the A/D converter.

2. The transmission measurement apparatus as claimed in claim 1 , in which the sampling frequency has at least four times the value of the frequency of the light source.

3. The transmission measurement apparatus as claimed in claim 1 , in which the integrated circuit is designed to form a mean value over the subtracted sample values.

4. The transmission measurement apparatus as claimed in claim 1 , in which the integrated circuit contains a field programmable gate array (FPGA).

5. An automated analysis appliance having a transmission measurement apparatus as claimed in claim 1 , wherein the integrated circuit comprises a delay element and a subtractor element, the delay element coupled to receive a first output of the A/D converter and the subtractor element coupled to receive an output of the delay element and a second output of the A/D converter.

6. A transmission measurement apparatus for an automatic analysis appliance, comprising a light source pulsed at a frequency, a photodetector, an A/D converter with a sampling frequency that corresponds to an even multiple of the frequency of the light source, the A/D converter being connected downstream of the photodetector, and an integrated circuit connected downstream of the A/D converter and programmed to:
associate sample values from the A/D converter with a light pulse or with a dark time between two light pulses based on the frequency of the light source and a phase of the light source,
delay the associated sample values by an integer multiple of a half-period corresponding to the frequency of the light source, and
subtract the delayed sample values from one another; wherein:
the integrated circuit comprises no signal multiplier and no low pass filter, and the integrated circuit is configured to provide a signal-to-noise ratio of more than 130 dB.

7. The transmission measurement apparatus as claimed in claim 6 , in which the sampling frequency has at least four times the value of the frequency of the light source.

8. The transmission measurement apparatus as claimed in claim 6 , in which the integrated circuit is designed to form a mean value over the subtracted sample values.

9. The transmission measurement apparatus as claimed in claim 6 , in which the integrated circuit contains a field programmable gate array (FPGA).

10. An automated analysis appliance having a transmission measurement apparatus as claimed in claim 6 , wherein the integrated circuit comprises a delay element and a subtractor element, the delay element coupled to receive a first output of the A/D converter and the subtractor element coupled to receive an output of the delay element and a second output of the A/D converter.

Assignees

• Siemens Healthcare Diagnostics Products Gmbh

Inventors

• Steinebach Wolfgang

Classifications

• G01N21/59 Primary

  Transmissivity (G01N21/25 takes precedence) · CPC title

• G01N2201/0696

  Pulsed · CPC title

• G01N33/5002 Primary

  Partitioning blood components · CPC title