I would just like to comment that this device pictured (3DPX-013806) and labeled as a "ventilator splitter" is not a ventilator splitter.  Instead, it is a leak port tee piece with a filter connector for the Philips Respironics V60 noninvasive ventilator.  As such, it could be useful as respiratory therapy departments adapt V60 non-invasive ventilators to function as invasive-type ventilators and need to apply a B/V or HEPA filter over the expiratory port.  At first blush, it appears to be a good copy of the same device as supplied by Philips.  However, upon close inspection, it appears as though the holes on the inside of the tee that lead to the filter port are not of the same diameter as those on the genuine Philips product.  These holes are designed to provide a certain pressure drop across the exhalation port so that the ventilator operates correctly with a deliberate continuous circuit leak.  I have not been able to do a side-by-side comparison with the genuine Philips product and have not operated a V60 with this 3D printed part to verify my suspicions, but if anyone does, please post your findings here in the comment section.