An inexpensive 3D printed amperometric oxygen sensor for transcutaneous oxygen monitoring

Noninvasive and wearable sensing methods are becoming more preferable in clinical settings. Transcutaneous oxygen monitoring is a noninvasive and standard method for oxygen partial pressure measurement. Oxygen partial pressure indicates the hypoxic/hyoeroxic condition of the tissue and is vital in clinical examinations. Transcutaneous oxygen tension is suggested as an alternative for measuring the partial pressure of arterial blood oxygen (PaO2). Although relation between the PaO2 and transcutaneous oxygen (PtcO2) depends on cardiac output and oxygen-hemoglobin dissociation curve, PtcO2 is considered as a reliable indication of oxygen partial pressure in tissue. The gold standard in transcutaneous measurement is amperometric measuring system. The relation between the current and oxygen tension is linear in neonatals and it shifts by a constant factor in adults since a part of oxygen is consumed by epidermis layer. The current paper focuses on designing an amperometric cell to measure the PtcO2 accurately. Flexibility, wearability and small size are the key factors considered in this design. Here, 3D printing is employed as a low cost and reliable method to satisfy the expectations. Using ECG electrodes as working electrode is another aspect of this design. In-vitro evaluations show that this design works properly and is ready to be evaluated on human skin.