  Measurement of intramuscular oxygen could play a key role in the early
diagnosis of acute compartment syndrome, a common condition occurring after
severe trauma leading to ischemia and long-term consequences including
rhabdomyolysis, limb loss, and death. However, to date, there is no existing
oxygen sensor approved for such a purpose. To address the need to improve the
assessment of compartment syndrome, a portable fiber-optic device for
intramuscular oxygen measurements was developed. The device is based on
phosphorescence quenching, where the tip of an optical fiber was coated with a
poly(propyl methacrylate) (PPMA) matrix containing a brightly emitting
Pt(II)-core porphyrin. The optoelectronic circuit is highly portable and is
based on a microspectrometer and a microcontroller readout with a smartphone.
Results from an in vivo tourniquet porcine model show that the sensor is
sensitive across the physiological oxygen partial pressure range of 0-880 mmHg
and exhibits an appropriate and reproducible response to changes in
intramuscular oxygen. A commercial laboratory oxygen sensor based on a lifetime
measurement did not respond as expected.
