White blood cells, AI & health sensing
Could your phone count white blood cells—without a needle?
A fingertip video, a small pilot, and the checks between a clever idea and a trusted health test.
Imagine your phone says, “Hold still. I’m checking your blood cells.” You glance at the screen, then at your finger. No needle? Your finger votes yes. Your brain asks a better question: “What is this thing actually measuring?” This is an imagined scene, not an app recommendation—and that question is where the interesting science begins.
Meet UbiWhite: a small pilot, a big question
Research spotlight · Coauthored work
Smartphone based non invasive real time white blood cell counter leveraging blue light and static magnetic field
Could a phone help? In a 2025 study I coauthored, our team tested a special phone setup for estimating white blood cell counts. We compared estimates from 20 adults with laboratory CBC [complete blood count] results. This was an early pilot [a small first study], not proof that the setup can replace a lab test.[2]
The setup used a Google Pixel 2, a light source, a blue-light filter, a magnet and a holder. Software analyzed light patterns in fingertip videos to estimate a count. It was not a normal phone camera working alone. The paper also notes that motion and differences between phones can affect results.[2]
My take: the useful contribution is turning an appealing idea into something that can be compared with a real blood test. But the volunteers had relatively normal counts. Tests across a wider range of people and unusually low or high counts are still needed. If you study mobile health sensing, read the original paper and judge whether its methods support your work.[2]
View citation & all coauthors
Nafi Us Sabbir Sabith, Masud Rabbani, Kazi Shafiul Alam, Sheikh Iqbal Ahamed. “Smartphone based non invasive real time white blood cell counter leveraging blue light and static magnetic field”. Scientific Reports, 15, 1594. (2025). https://doi.org/10.1038/s41598-024-81459-y.
If this work supports your research, cite the original paper rather than this blog explanation.
First, what are we counting?
White blood cells, or WBCs, help your body fight infections and other diseases. A WBC count measures how many there are. A different test, called a differential [a count of each cell type], tells us about the mix. A total count and a breakdown by type answer different questions.[1]
Think of a rescue team. “How many people arrived?” is not the same as “How many are medics?” That is only an analogy, but it helps separate a headcount from a list of roles. A total alone does not tell the whole story.
A new twist: looking at what cells do
A study published on September 1, 2026 asks a related but different question. Researchers used optical metabolic imaging [using light to study how cells use energy] and computer analysis to distinguish resting from activated immune cells. They studied cells in lab cultures [cells kept outside the body] from three donors.[3]
Here is the twist: those cells came from donated blood. The imaging readout uses light from molecules already in the cells, rather than added labels. So “label-free” does not mean “needle-free.” It is a different research path from recording an intact fingertip—not a newer version of UbiWhite.[3][4][2]
A quick quiz: is more always better?
A quick thought experiment
Imagine a friend sees a high WBC count and says, “Great—extra protection!” Which reply is most useful?
Three questions worth keeping
When I see a promising health gadget, I would ask: Was it tested with a bare phone or extra equipment? Was it compared with an established test? Did the study include the people who would actually need it? I would want clear answers before trusting a headline, however shiny the screen.
I would also ask the team to explain a wrong result in plain words. What could a person misunderstand? What should happen next? These are questions I want research to answer, not claims that a prototype has already solved them. A small study can start a useful conversation without finishing it.
A question for a future post: why can the same health sensor give different results when someone moves? For now, keep one habit: look past the gadget and ask how its answer was checked.
Sources & further reading
- White Blood Count (WBC)MedlinePlus, U.S. National Library of Medicine · Updated August 6, 2024
- Smartphone based non invasive real time white blood cell counter leveraging blue light and static magnetic fieldNafi Us Sabbir Sabith, Masud Rabbani, Kazi Shafiul Alam, Sheikh Iqbal Ahamed · January 10, 2025
- Autofluorescence lifetime imaging resolves cell heterogeneity within peripheral blood mononuclear cellsJeremiah M. Riendeau, Lucia Hockerman, Elizabeth Maly, Kayvan Samimi, Melissa C. Skala · September 1, 2026
- New imaging technique reveals the inner workings of immune cellsRudy Molinek, Morgridge Institute for Research · September 1, 2026
Disclaimer: This post is for education, not medical or other professional advice; information may contain errors or become outdated, no outcome is guaranteed, views are my own, and third-party materials remain subject to their owners' rights.