Patients’ blood oxygen saturation is an important parameter to monitor during surgery, but it’s currently clinically impossible if the patient is still in the womb of its mother. At Rice University a team of engineering students has developed a prototype device, called WombOX, that is a pulse oximeter that can be delivered inside the womb and gently attached to the arm or leg of a fetus.

The pulse oximeter is integrated with a nitinol wire loop that is compressed when inside the delivery sheath. Once pushed out and exposed to the heat of the body, the nitinol expands and the loop opens up. It is then wrapped around the arm or leg of the fetus and tightened. LEDs within the device work along with a light detector to sense blood oxygenation just like in existing oximeters. It can be brought back into the sheath and removed following a procedure.

Here’s a video with the Rice student team discussing the device.