A method and apparatus for the transcutaneous monitoring of blood gases
generally comprises a blood gas data acquisition device, a vacuum source
and a blood gas transducer unit. The blood gas transducer unit is adapted
for application to a patient's skin and administration of a local vacuum
at the area of patient application. It further comprises an
electrochemical blood gas transducer, well known to those of ordinary
skill in the art, which is disposed entirely within the local vacuum at
the area of patient application. The vacuum source is placed in fluid
communication with the blood gas transducer unit, through a hydrophobic
membrane filter for safety purposes, in order to induce a condition of
hyperperfusion in the locality of the electrochemical blood gas
transducer. Under the control of a microcontroller, or equivalent means,
the blood gas acquisition device is then utilized to capture a measure of
skin surface oxygen or carbon dioxide pressure. The microcontroller can
then utilize this measure to arrive at an estimate of arterial partial
pressure of oxygen or carbon dioxide, accordingly. Because vacuum induced
perfusion produces the requisite condition of hyperperfusion without local
heating and, therefore, without acceleration of the local metabolic
function, the present invention results in more accurate than previously
available estimates of partial pressure blood gas pressures and does so
while eliminating a significant risk for injury to the patient.
