How blood moves throughout the body and into the smallest capillaries is hard to observe using existing imaging methods. Yet, poor blood perfusion can be an indicator for a variety of medical conditions, potentially serving as a diagnostic tool and a way to help manage diseases.
Infrared thermography is a decent tool for this, but it is expensive, slow, and not very accurate. Researchers at Rice University have now developed a much cheaper technology that seems to perform significantly better at blood perfusion imaging than anything else currently in existence.
The system uses a conventional optical camera to detect slight changes in skin tone as blood flows in and out, but also a pulse oximeter to allow the technology to constantly calibrate itself against the patient’s pulse.
In testing, the new imaging modality showed a 1 mm spatial resolution, generating a new scan every second. Thanks to a built-in motion compensation algorithm and polarizing light filters, the technology maintains accuracy even under challenging conditions.
When tried on volunteers, the technology was able to detect small changes in blood perfusion under the skin. It was also able to spot venous or partial blood flow occlusions, an impressive achievement for a non-contact, radiation-free technology. It was even tried in a surgical setting, demonstrating reliability and robustness beyond basic clinical settings.
Potentially it can be used at the bedside and point-of-care settings to easily image patients using cheap LED lights and optical cameras.
Open access study in Scientific Reports: PulseCam: a camera-based, motion-robust and highly sensitive blood perfusion imaging modality