OxyTrack: A Novel Needle Sensor for In Situ Oximetry.

Area of Science:

• Biomedical Engineering
• Medical Physics
• Analytical Chemistry

Background:

• In vivo electron paramagnetic resonance (EPR) oximetry is crucial for tissue oxygen measurements.
• Existing implantable probes like OxyChip have limitations in depth sensitivity for deep tissues.
• There is a need for advanced sensors capable of accurate deep-tissue oxygen monitoring.

Purpose of the Study:

• To develop a novel sensor, OxyTrack, for deep-tissue oximetry.
• To overcome the depth sensitivity limitations of existing EPR oximetry resonators.
• To enable accurate in situ monitoring of oxygen levels in deeper biological tissues.

Main Methods:

• Designed and fabricated OxyTrack sensors with coax-tip micro-loop resonators and OxyChip.
• Utilized various needle sizes (0.5-1 mm OD, 3-17 cm length) for sensor embedding.
• Tested sensor performance using an L-band continuous wave EPR spectrometer.

Main Results:

• OxyTrack demonstrated a high signal-to-noise ratio (SNR) even at low radiofrequency (RF) powers.
• Sensor orientation and insertion depth had no significant impact on oxygen measurements.
• The device showed rapid response to oxygen changes, stability to sterilization, and compatibility with medical imaging.

Conclusions:

• OxyTrack technology significantly advances EPR oximetry for deep-tissue oxygen monitoring.
• The novel sensor enables reliable in situ measurement of oxygenation in challenging anatomical locations.
• This development holds promise for improved diagnostics and research in conditions involving altered tissue oxygen levels.