Cost-effective and rapid blood analysis on a cell-phone

Abstract

We demonstrate a compact and cost-effective imaging cytometry platform installed on a cell-phone for the measurement of the density of red and white blood cells as well as hemoglobin concentration in human blood samples. Fluorescent and bright-field images of blood samples are captured using separate optical attachments to the cell-phone and are rapidly processed through a custom-developed smart application running on the phone for counting of blood cells and determining hemoglobin density. We evaluated the performance of this cell-phone based blood analysis platform using anonymous human blood samples and achieved comparable results to a standard bench-top hematology analyser. Test results can either be stored on the cell-phone memory or be transmitted to a central server, providing remote diagnosis opportunities even in field settings.

Figure 1

(A-1) and (A-2) Illustration and picture of our cell-phone based blood analysis platform. It includes a base attachment with two AA batteries and a universal port for adapting three different add-on components for white blood cell counting, red blood cell counting and hemoglobin measurements respectively. (B-1) and (B-2) Illustration and picture of the white blood cell counting device. (C-1) and (C-2) Illustration and picture of the red blood cell counting device. (D-1) and (D-2) Illustration and picture of hemoglobin measurement device.

Figure 2

(A) “Blood analysis” icon on the cell phone home screen. (B) Once the user clicks on the “blood analysis” icon, the login screen pops up and the user can choose to start a new test. (C) When a new test is initiated, a test menu is shown and the user can choose the test type: white blood cell counting, red blood cell counting or hemoglobin measurement. (D) After the user chooses the test type, she/he can take the picture of the sample using the camera installed on the cell-phone. (E) The application displays a raw image of the test and the user can dynamically change the default values for the region of interest such as image pixel size, sample dilution factor and sample chamber depth. (F) After clicking the “Analyze” button, test results are displayed on the phone within a processing time of ~10 sec per test. The test results can then be stored at the cell-phone memory or be uploaded to a central database/server.

Figure 3

Block diagram of the digital processing steps that run on our cell-phone for white blood cell concentration measurements.

Figure 4

Block diagram of the digital processing steps that run on our cell-phone for red blood cell concentration measurements.

Figure 5

Block diagram of the digital processing steps that run on our cell-phone for hemoglobin concentration measurements.

Figure 6

Automated WBC density measurement accuracy of our cell-phone based blood analyzer. (A) Comparison of cell-phone based WBC counting results with the standard test results obtained from SysmexKN21 for 30 different blood samples. A linear regression of the experimental data (n = 30; red line) with WBC concentrations ranging from ~ 3,000/μL to 12,000/μL demonstrates a good agreement between the two modalities with a correlation coefficient of ~ 0.98. The cell-phone based blood analyzer provides an absolute counting error that is less than 7%. (B) The Bland-Altman analysis results, evaluating the accuracy of the cell-phone blood analyzer for WBC concentration measurements vs. the standard hematology analyzer. The black solid lines show a bias of 230 cells/μL and 95%limits of agreement: 955 cells/μL (upper limit) and −495 cells/μL (lower limit).

Figure 7

Automated RBC counting accuracy of our cell-phone based blood analyzer. (A) Comparison of cell-phone based RBC counting results with the standard test results obtained from Sysmex KN21 for 12 different blood samples. A linear regression of the experimental data (n= 12; red line) with RBC concentrations ranging from ~ 3 × 10⁶/μL to 5.5 × 10⁶/μL demonstrates a good agreement between the two modalities with a correlation coefficient of ~ 0.98. The cell-phone blood analyzer counting provides an absolute counting error of less than 5%. (B) The Bland-Altman analysis results, evaluating the accuracy of the cell-phone blood analyzer for RBC concentration measurements vs. the standard hematology analyzer. The black solid lines show a bias of −2.9×10⁴ cells/μL and the 95% limits of agreement of: ~2.5×10⁵ cells/μL (upper limit) and −3.2×10⁵ cells/μL (lower limit).

Figure 8

Automated hemoglobin measurement accuracy of our cell-phone based blood analyzer. (A) Comparison of cell-phone based hemoglobin measurement results with the standard test results obtained by using Sysmex KN21 for 37 different blood samples. A linear regression of the experimental data (n = 37; red line) with hemoglobin concentrations ranging from ~ 11 g/dL to 17 g/μL demonstrates a good agreement between the two modalities with a correlation coefficient of ~ 0.92. The cell-phone blood analyzer provides an absolute measurement error of less than 5%. (B) The Bland-Altman analysis results, evaluating the accuracy of the cell-phone blood analyzer for hemoglobin concentration measurements vs. the standard hematology analyzer. The black solid lines show a bias of 0.036 g/dL and the 95% limits of agreement: ~ 0.63 g/dL (upper limit) and −0.54g/dL (lower limit).