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Medical technology

Blood sampling by robot?


With the help of the modified webcam and the image processing algorithms, the veins on Aron Hemmi's forearm are clearly visible on the PC monitor.

Almost everyone has (had to) have blood taken or a cannula inserted at some point. This - attention: technical term - peripheral venipuncture is the central element of modern medicine. The procedure is performed thousands of times a day. Always by people. Why is it actually done?

Aron Hemmis studies at the Faculty of Information Technology at Dortmund University of Applied Sciences and Arts. His main focus: Robotics and imaging techniques. He has never drawn blood from a person. But some of his friends work in the emergency services. "They told me that it's not always easy to hit the vein correctly," says Aron Hemmis. He does some research. In fact, many more mistakes are made during this procedure than during other interventions. "The error rate decreases as medical staff become more experienced. But perhaps a machine can reduce the rate even further," Aron Hemmis ponders.

He is making robot-assisted venipuncture his biomedical engineering project for several semesters. His bachelor's thesis on this was recognized as the faculty's best graduate at Fachhochschule Dortmund's annual academic ceremony at the end of 2023(Opens in a new tab) .

Converting a standard webcam

The first step is imaging. How does the machine recognize the vein? To find out, the student tests different areas of the light spectrum. "The results are better when wavelengths that are not visible to humans come into play," says Aron Hemmis. He unscrews commercially available webcams, removes the infrared cut filter built into them and applies various image processing algorithms. The veins in his forearm thus become clearly visible on the PC monitor.

Second step: the needle prick. This involves not only recognizing the vein, but also displaying its course and defining the angle for the needle. A challenge. "The test setup with the robotic arm still has inaccuracies here that should no longer be present in a finished system," admits Aron Hemmis. But: the test also shows "that despite the use of inexpensive hardware components, useful results can be achieved that prove the feasibility of such a system." This is the conclusion of his bachelor thesis. However, a lot of research is still needed before it can be used in doctors' surgeries and ambulances.

I can well imagine that the success rate is higher when the robot punctures the skin.

Aron Hemmis
Robot arm control

"There are companies that are already working on an automated system for venipuncture," reports the UAS student, who is now working towards a Master's degree in Biomedical Information Technology at the University of Applied Sciences. So was his work in vain? Not at all. "The course is not primarily about groundbreaking basic research," says Aron Hemmis. "Choosing a topic according to my own interests, working intensively on it and focusing on it in electives and project work right through to my Bachelor's thesis - that really helped me during my studies." Access to the labs and support from the professors is always available at Fachhochschule Dortmund. Even during the coronavirus pandemic. "I was always able to try out and test a lot here," he praises.

Will patients have to adapt to the fact that blood will only be taken by robots in the future? Aron Hemmis thinks for a moment. Then he says: "I can well imagine that the success rate will be higher if the robot is used for punctures. But a system like this also depends on the extent to which patients trust the machines." It is therefore more likely that the technology will support the doctors but be monitored by them. At least for the time being.

Notes and references

Photo credits

  • Fachhochschule Dortmund | Benedikt Reichel
  • Fachhochschule Dortmund | Benedikt Reichel