A new flexible pressure sensor contributes to the early diagnosis of acute compartment syndrome.

Acute compartment syndrome (ACS) is a surgical emergency, caused by the sharp increase of interstitial pressure within a closed osteofascial compartment, which can impair local circulation and functions. A non-invasive sensor is needed of satisfactory sensitivity to continuously monitor the alterations of the ACS pressure, which could be used as a supplementary means in the early diagnosis of ACS. A prepared "pasting-type" flexible pressure sensor was used to establish an extracorporeal pig-skin model with a soft-tissue expander device to simulate compartment syndrome conditions. An acrylic panel was inserted into the pig skin, allowing the soft-tissue expander to expand in one direction, which is similar to the movements of a patient's bones in real life. The touch spot of the flexible pressure sensor was attached to the rind by medical tape, to record the internal and external pressure data. Relationships between the internal and external pressures at different thickness (0.87 mm, 3.53 mm and 3.97 mm), as well as that of the 3.97 mm thickness under various initial internal pressures (0.5 mmHg, 25 mmHg and 44 mmHg) were measured. Significant differences were observed in the range of internal pressures at various pig-skin thickness. After adding the acrylic panel, the measured ranges were significantly increased, with the lowest measurable internal pressure being 5 mmHg. Moreover, alterations in external pressure were also greater than in models without acrylic panels. The external pressure measured by the sensor was able to reflect an increase in intra-organizational pressure. This may be a new non-invasive and sustainable method for early diagnosis of ACS.