The current system of chronic wound management may be revolutionized by researchers at Drexel University's School of Biomedical Engineering, Science and Health Systems.
There are currently no established methods for early detection of wound healing, or for precise identification of healing progress. Wound size is the only accepted indicator despite its variability and the fact that is reflects only what is happening on the surface.
Now, the prototype device measures the level of oxygenated and deoxygenated hemoglobin within and under a wound and compares it to a control/non-wound site of the same patient.
Based on a human study at the Wound Clinic of the Drexel College of Medicine, the time course of oxygenated hemoglobin change was found to be a strong indicator of wound healing.
Diffuse Near-Infrared Spectroscopy allows tissue to be non-invasively analyzed by measuring its optical absorption and scattering coefficients. A "diagnostic window" exists at near infrared wavelengths (650 -900 nm) allowing determination of tissue optical properties at significant depths, because light is able to penetrate several centimeters into tissue due to low absorption of hemoglobin. The absorption spectra of oxy-hemoglobin and deoxy-hemoglobin are distinct at near-infrared wavelengths and with proper instrumentation the absolute concentrations of each can be determined.
A device prototype has been developed and tested over the course of several years. The device is controlled by software from a laptop computer and can move from patient to patient in a busy clinical setting. Measurements can be taken at any spot within or around the wound and take seconds to complete. Results are displayed on the computer screen almost instantly following the measurement. Improved prototypes are being designed. In its final stages the device will become more portable.