System and method for detecting target substances
View Patent ↗A method includes capturing a signal of a detection substrate exposed to a sample containing a target substance; determining that the detection substrate is in a testable state; and generating an assessment of the presence of the target substance in the sample.
1. A method for optical detection of target substances, comprising:
at a sample analyzer, capturing a test image, at a first time point, of a detection substrate exposed to a sample containing a target substance;
in response to receiving the test image:
determining a degree of liquid saturation of the detection substrate based on a comparison of a measured intensity of a portion of the test image to a reference image intensity;
determining a delay time, based on the determined degree of liquid saturation;
recapturing the test image at a second time point, delayed relative to the first time point by the determined delay time;
based on the recaptured test image, determining that the detection substrate is in a testable state;
determining a set of image locations corresponding to a set of active regions of the detection substrate, based on a predetermined spacing of each of the set of active regions from a first of the set of active regions;
generating an assessment of the presence of the target substance in the sample based on an analysis of the set of image locations;
generating an output based on the assessment;
displaying the output to a user of the sample analyzer.
2. The method of claim 1 , wherein generating the assessment comprises:
locating an upstream edge of a test region of the set of active regions and determining an upstream signal level;
capturing an upstream test image with a first exposure time, based on upstream signal level;
locating a downstream edge of the test region and determining a downstream signal level;
capturing a downstream test image with a second exposure time, based on the downstream signal level;
combining the upstream test image and the downstream test image to form a composite test image; and
analyzing the composite test image to produce an assessment of the presence of the target substance in the sample.
3. The method of claim 1 , further comprising determining a source of the sample, selecting a convolution kernel based on the determined source, and wherein analyzing the composite test image comprises:
convolving the selected convolution kernel with the composite test image to produce a convolved test image; and
determining a peak intensity value in the convolved test image.
4. The method of claim 1 , wherein analyzing the composite test image comprises:
convolving a first convolution kernel having a first kernel size with the composite test image to produce a first convolved test image;
convolving a second convolution kernel having a second kernel size with the composite test image to produce a second convolved test image, wherein the first kernel size is greater than the second kernel size;
determining a peak intensity value in each of the first and second convolved test image; and
comparing the peak intensity value from at least one of the first and second convolved test image with an intensity value of a reference image, in order to determine that the peak intensity value exceeds a detection threshold.
5. The method of claim 4 , further comprising determining a source of the sample based on a morphological feature of at least one of the first and second convolved test images.
6. The method of claim 1 , further comprising determining an orientation of the sample analyzer, and wherein determining that the sample is in a testable state is based on the determined orientation of the sample analyzer.
7. The method of claim 1 , further comprising determining a structural state of the detection substrate, and wherein determining that the detection substrate is in a testable state is based on the structural state of the detection substrate.
8. The method of claim 1 , further comprising receiving operational data from a mixing module of the sample analyzer.
9. The method of claim 8 , further comprising increasing an operating power of the mixing module mixer based on received operational data; wherein the received operational data is indicative of a rotational speed of the mixer falling below a speed threshold.
10. The method of claim 8 , wherein the output is generated based on received operational data indicative of a rotational speed of the mixer falling within a nominal range of rotational speeds for a predetermined time duration.
11. The method of claim 1 , further comprising measuring a peak signal value in the test region, capturing a set of images of the test region, wherein a number of images in the set is calculated based on the peak signal value, and generating a composite test image based on the set of images.
12. The method of claim 1 , further comprising identifying a first location of a peak signal value in the upstream test image, identifying a second location of a peak signal value in the downstream image, comparing the first and second locations to generate a peak confidence metric, and generating the assessment based on the peak confidence metric.
13. The method of claim 1 , further comprising determining substrate characterization data based on the test image, and evaluating the test image based on the substrate characterization data.