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HEIDELBERG, GERMANY—Scientists have developed a smartphone application called HemaApp that can be used to measure hemoglobin levels and screen for anemia non-invasively.
HemaApp uses illumination sources from a smartphone, in combination with other light sources, and algorithms that analyze the color of a patient’s blood to estimate hemoglobin levels.
In a trial of 31 patients, HemaApp’s results compared favorably to an approved medical device that measures hemoglobin non-invasively.
Researchers described HemaApp in a paper presented at the Association for Computing Machinery’s 2016 International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2016).
“In developing countries, community health workers have so much specialized equipment to monitor different conditions that they literally have whole bags full of devices,” said study author Edward Wang, a doctoral student at the University of Washington in Seattle.
“We are trying to make these screening tools work on one ubiquitous platform—a smartphone.”
How the app works
By shining light from the phone’s camera flash through the patient’s finger, HemaApp analyzes the color of the patient’s blood to estimate hemoglobin concentrations.
HemaApp bombards the finger with different wavelengths of light and infrared energy and creates a series of videos. By analyzing how colors are absorbed and reflected across those wavelengths, it can detect concentrations of hemoglobin and other blood components like plasma.
To ensure that the app works on different skin tones and body masses, the researchers developed processing algorithms that use the patient’s pulse to distinguish between the properties of the patient’s blood and the physical characteristics of his or her finger.
Testing
The researchers tested HemaApp on 31 subjects, including healthy students and staff at the University of Washington, inpatients at a children’s cancer and transfusion clinic, and inpatients at an adult cancer and bone marrow transplant clinic.
The subjects ranged in age from 6 to 77. Their hemoglobin levels ranged from 8 to 16 g/dL, and they had skin tones ranging from pale to dark.
The researchers compared results with HemaApp to results obtained via a complete blood count (CBC) and via the Masimo Pronto 7, a device that non-invasively measures hemoglobin by clipping a sensor onto a person’s finger.
The team tested HemaApp under 3 different scenarios—using the smartphone camera’s flash alone, in combination with a common incandescent lightbulb, and with a low-cost LED lighting attachment.
The additional illumination sources tap into other parts of the electromagnetic spectrum that have useful absorption properties but that aren’t currently found on all smartphone cameras.
“New phones are beginning to have more advanced infrared and multi-color LED capabilities,” said study author Shwetak Patel, PhD, of the University of Washington.
“But what we found is that even if your phone doesn’t have all that, you can put your finger near an external light source like a common lightbulb and boost the accuracy rates.”
Results
HemaApp’s hemoglobin measurements using a smartphone camera alone had a 69% correlation to results with the CBC. The app had a 74% correlation with the CBC when used with an incandescent light bulb and an 82% correlation when used with the LED lights.
In comparison, the Masimo Pronto 7’s measurements had an 81% correlation to the CBC.
When used to screen for anemia, HemaApp had higher sensitivity than the Masimo Pronto but lower specificity.
The app’s sensitivity was 79% using just the phone camera and 86% when used with the incandescent light bulb or LED lights, whereas Masimo Pronto’s sensitivity was 69%.
The app’s specificity was 71% when using just the phone or the incandescent light bulb and 77% with the LED lights, whereas Masimo Pronto’s specificity was 88%.
Next steps
The researchers said HemaApp is not intended to replace blood tests, which remain the most accurate way to measure hemoglobin. But the early test results suggest HemaApp can be an effective and affordable initial screening tool to determine whether further blood testing is warranted.
“Anemia is one of the most common problems affecting adults and children worldwide,” said study author Doug Hawkins, MD, of Seattle Children’s Hospital.
“The ability to screen quickly with a smartphone-based test could be a huge improvement to delivering care in limited-resource environments.”
Next research steps include wider national and international testing of HemaApp, collecting more data to improve accuracy rates, and using smartphones to try to detect abnormal hemoglobin properties that could help screen for sickle cell disease and other blood disorders.
“We’re just starting to scratch the surface here,” Dr Patel said. “There’s a lot that we want to tackle in using phones for non-invasively screening disease.” 
Photo by Daniel Sone
HEIDELBERG, GERMANY—Scientists have developed a smartphone application called HemaApp that can be used to measure hemoglobin levels and screen for anemia non-invasively.
HemaApp uses illumination sources from a smartphone, in combination with other light sources, and algorithms that analyze the color of a patient’s blood to estimate hemoglobin levels.
In a trial of 31 patients, HemaApp’s results compared favorably to an approved medical device that measures hemoglobin non-invasively.
Researchers described HemaApp in a paper presented at the Association for Computing Machinery’s 2016 International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2016).
“In developing countries, community health workers have so much specialized equipment to monitor different conditions that they literally have whole bags full of devices,” said study author Edward Wang, a doctoral student at the University of Washington in Seattle.
“We are trying to make these screening tools work on one ubiquitous platform—a smartphone.”
How the app works
By shining light from the phone’s camera flash through the patient’s finger, HemaApp analyzes the color of the patient’s blood to estimate hemoglobin concentrations.
HemaApp bombards the finger with different wavelengths of light and infrared energy and creates a series of videos. By analyzing how colors are absorbed and reflected across those wavelengths, it can detect concentrations of hemoglobin and other blood components like plasma.
To ensure that the app works on different skin tones and body masses, the researchers developed processing algorithms that use the patient’s pulse to distinguish between the properties of the patient’s blood and the physical characteristics of his or her finger.
Testing
The researchers tested HemaApp on 31 subjects, including healthy students and staff at the University of Washington, inpatients at a children’s cancer and transfusion clinic, and inpatients at an adult cancer and bone marrow transplant clinic.
The subjects ranged in age from 6 to 77. Their hemoglobin levels ranged from 8 to 16 g/dL, and they had skin tones ranging from pale to dark.
The researchers compared results with HemaApp to results obtained via a complete blood count (CBC) and via the Masimo Pronto 7, a device that non-invasively measures hemoglobin by clipping a sensor onto a person’s finger.
The team tested HemaApp under 3 different scenarios—using the smartphone camera’s flash alone, in combination with a common incandescent lightbulb, and with a low-cost LED lighting attachment.
The additional illumination sources tap into other parts of the electromagnetic spectrum that have useful absorption properties but that aren’t currently found on all smartphone cameras.
“New phones are beginning to have more advanced infrared and multi-color LED capabilities,” said study author Shwetak Patel, PhD, of the University of Washington.
“But what we found is that even if your phone doesn’t have all that, you can put your finger near an external light source like a common lightbulb and boost the accuracy rates.”
Results
HemaApp’s hemoglobin measurements using a smartphone camera alone had a 69% correlation to results with the CBC. The app had a 74% correlation with the CBC when used with an incandescent light bulb and an 82% correlation when used with the LED lights.
In comparison, the Masimo Pronto 7’s measurements had an 81% correlation to the CBC.
When used to screen for anemia, HemaApp had higher sensitivity than the Masimo Pronto but lower specificity.
The app’s sensitivity was 79% using just the phone camera and 86% when used with the incandescent light bulb or LED lights, whereas Masimo Pronto’s sensitivity was 69%.
The app’s specificity was 71% when using just the phone or the incandescent light bulb and 77% with the LED lights, whereas Masimo Pronto’s specificity was 88%.
Next steps
The researchers said HemaApp is not intended to replace blood tests, which remain the most accurate way to measure hemoglobin. But the early test results suggest HemaApp can be an effective and affordable initial screening tool to determine whether further blood testing is warranted.
“Anemia is one of the most common problems affecting adults and children worldwide,” said study author Doug Hawkins, MD, of Seattle Children’s Hospital.
“The ability to screen quickly with a smartphone-based test could be a huge improvement to delivering care in limited-resource environments.”
Next research steps include wider national and international testing of HemaApp, collecting more data to improve accuracy rates, and using smartphones to try to detect abnormal hemoglobin properties that could help screen for sickle cell disease and other blood disorders.
“We’re just starting to scratch the surface here,” Dr Patel said. “There’s a lot that we want to tackle in using phones for non-invasively screening disease.”
Photo by Daniel Sone
HEIDELBERG, GERMANY—Scientists have developed a smartphone application called HemaApp that can be used to measure hemoglobin levels and screen for anemia non-invasively.
HemaApp uses illumination sources from a smartphone, in combination with other light sources, and algorithms that analyze the color of a patient’s blood to estimate hemoglobin levels.
In a trial of 31 patients, HemaApp’s results compared favorably to an approved medical device that measures hemoglobin non-invasively.
Researchers described HemaApp in a paper presented at the Association for Computing Machinery’s 2016 International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2016).
“In developing countries, community health workers have so much specialized equipment to monitor different conditions that they literally have whole bags full of devices,” said study author Edward Wang, a doctoral student at the University of Washington in Seattle.
“We are trying to make these screening tools work on one ubiquitous platform—a smartphone.”
How the app works
By shining light from the phone’s camera flash through the patient’s finger, HemaApp analyzes the color of the patient’s blood to estimate hemoglobin concentrations.
HemaApp bombards the finger with different wavelengths of light and infrared energy and creates a series of videos. By analyzing how colors are absorbed and reflected across those wavelengths, it can detect concentrations of hemoglobin and other blood components like plasma.
To ensure that the app works on different skin tones and body masses, the researchers developed processing algorithms that use the patient’s pulse to distinguish between the properties of the patient’s blood and the physical characteristics of his or her finger.
Testing
The researchers tested HemaApp on 31 subjects, including healthy students and staff at the University of Washington, inpatients at a children’s cancer and transfusion clinic, and inpatients at an adult cancer and bone marrow transplant clinic.
The subjects ranged in age from 6 to 77. Their hemoglobin levels ranged from 8 to 16 g/dL, and they had skin tones ranging from pale to dark.
The researchers compared results with HemaApp to results obtained via a complete blood count (CBC) and via the Masimo Pronto 7, a device that non-invasively measures hemoglobin by clipping a sensor onto a person’s finger.
The team tested HemaApp under 3 different scenarios—using the smartphone camera’s flash alone, in combination with a common incandescent lightbulb, and with a low-cost LED lighting attachment.
The additional illumination sources tap into other parts of the electromagnetic spectrum that have useful absorption properties but that aren’t currently found on all smartphone cameras.
“New phones are beginning to have more advanced infrared and multi-color LED capabilities,” said study author Shwetak Patel, PhD, of the University of Washington.
“But what we found is that even if your phone doesn’t have all that, you can put your finger near an external light source like a common lightbulb and boost the accuracy rates.”
Results
HemaApp’s hemoglobin measurements using a smartphone camera alone had a 69% correlation to results with the CBC. The app had a 74% correlation with the CBC when used with an incandescent light bulb and an 82% correlation when used with the LED lights.
In comparison, the Masimo Pronto 7’s measurements had an 81% correlation to the CBC.
When used to screen for anemia, HemaApp had higher sensitivity than the Masimo Pronto but lower specificity.
The app’s sensitivity was 79% using just the phone camera and 86% when used with the incandescent light bulb or LED lights, whereas Masimo Pronto’s sensitivity was 69%.
The app’s specificity was 71% when using just the phone or the incandescent light bulb and 77% with the LED lights, whereas Masimo Pronto’s specificity was 88%.
Next steps
The researchers said HemaApp is not intended to replace blood tests, which remain the most accurate way to measure hemoglobin. But the early test results suggest HemaApp can be an effective and affordable initial screening tool to determine whether further blood testing is warranted.
“Anemia is one of the most common problems affecting adults and children worldwide,” said study author Doug Hawkins, MD, of Seattle Children’s Hospital.
“The ability to screen quickly with a smartphone-based test could be a huge improvement to delivering care in limited-resource environments.”
Next research steps include wider national and international testing of HemaApp, collecting more data to improve accuracy rates, and using smartphones to try to detect abnormal hemoglobin properties that could help screen for sickle cell disease and other blood disorders.
“We’re just starting to scratch the surface here,” Dr Patel said. “There’s a lot that we want to tackle in using phones for non-invasively screening disease.”