Phasing detector for continuous flow systems

• US 4,255,788 A
• Filed: 03/01/1979
• Issued: 03/10/1981
• Est. Priority Date: 03/01/1979
• Status: Expired due to Term

• Current Assignee: American National Red Cross
• Original Assignee: American National Red Cross
• Inventors: Schwartz, P. Christopher, Spielberg, Richard I.
• Primary Examiner(s): Wise, Edward J.
• Application Number:
  US06/016,532
• Time in Patent Office: 740 Days
• Field of Search: 364/416, 364/509, 364/510, 364/497, 364/499, 364/526, 128/2 F, 128/2 G, 356/39-43
• US Class Current: 356/39
• CPC Class Codes: G01N 35/08 using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis

Abstract

A phasing system is provided for parallel channel continuous flow systems wherein the individual test channels have different flow times although intersample timing is constant. A phasing sample is introduced and its presence is sensed at the output of each of the parallel test channels. The presence of the phasing sample is detected by means of an analog detector, a digitizer, and a digital computation system. After detection of the phasing sample in a channel the time at which it arrives at the detector is marked. Since intersample timing is constant and the time when the sample is introduced into the parallel channels is known, the time at which subsequent samples should arrive at the detector can be established for each channel. Time zones are opened for each channel and each detector which correspond to the times plus or minus a certain tolerance at which subsequent samples can be expected to arrive. In a preferred embodiment, two light emitting diode/photo-transistor combinations operating on different frequencies are utilized to give a differentiated output upon sensing the presence of a colored phasing solution at the beginning of a automated blood grouping process.

Claims

1. In a continuous flow test system, having a plurality of sensor channels, each channel including means for providing an output related to a characteristic to be measured in said channel, an apparatus for phasing data output from those channels when the time delay of sample flow through a channel varies, said apparatus comprising:

a phasing sample, introducable into said sample flow in said channels, having a detectable characteristic;

means for detecting and providing an indication of the presence of the phasing sample in each of said channels; and

data processing means, responsive to said indication, for measuring and reporting the time delay of said phasing sample through each channel and correlating the time delays of each channel with output from said means for providing, said data processing means providing said characteristics to be measured in each channel at a predetermined time regardless of variations in time delays among channels.

2. The apparatus of claim 1 wherein each sensor channel is a reactant channel in which the sample flowing therethrough is being tested to determine the sample reaction to known quantities and said means for detecting includes said means for providing which comprises sensor means for determining the reaction in each of said reactant channels.

3. The apparatus of claim 2 wherein said sensor means comprises a light emitting diode/phototransistor combination for providing an electrical indication of the reaction in said reactant channel.

4. The apparatus of claim 2 wherein said sensor means includes means for distinguishing between a phasing sample and said reaction in said reactant channels.

5. The apparatus of claim 4 wherein said sensor means comprises a light emitting diode/photo-transistor combination for providing an electrical indication of the reaction in said reactant channel.

6. The apparatus of claim 4 wherein said means for detecting includes two light emitting diode/photo-transistor combinations, each of said combinations operating on a different wavelength and said phasing solution detectable characteristic being color, with the reaction determination being the relative level of light transmittance through a channel and said phasing sample determination being a predetermined disparity between the outputs of said transistors.

7. The apparatus of claim 1 wherein each sensor channel is a reactant channel in which the sample flowing therethrough is being tested to determine the sample reaction to known quantities and said means for detecting comprises two light emitting diode/photo-transistor combinations, each of said combinations operating on a different wavelength and said phasing sample detectable characteristic being color.

8. The apparatus of claim 1 including a clock pulse means for periodically sequencing said data processing means such that data outputs from said sensor channels are provided to an output device.

9. A method of blood grouping utilizing an apparatus with a plurality of sensor channels, each channel with a means for measuring a blood grouping characteristic and a means for detecting the presence of a phasing solution, said apparatus capable of automatically sampling a plurality of blood samples, said method comprising the steps of:

applying a phasing sample to said apparatus for sampling;

recording the time delay, between the initial sampling of the phasing sample and the detection of the presence of the phasing sample by said means for detecting, for each channel; and

recording data from said means for measuring in accordance with said recorded time delay such that the data from the channels corresponds timewise to a single blood sample regardless of variations in different channel time delays.

10. The method of claim 9 wherein prior to said applying step, said method includes the scaling step of supplying a known standard sample to said apparatus in order to establish the proper operating response of the means for measuring in each channel.

11. The method of claim 10 wherein prior to said supplying step, said method includes a first timing step where a phasing sample is supplied to said apparatus for establishing the time delays necessary for correlation of data in said supplying step.

12. The method of claim 11 wherein prior to said first timing step, said method includes a prescaling step wherein a clear solution is applied to all channels for the initial zeroing of each said means for measuring.