MR-compatible patient ventilator
A patient ventilator for the MRI environment
Starting situation
Magnetic resonance imaging (MRI) is now the standard imaging technique for examining patients. MRI imaging of the patient who must be ventilated during the examination is a particularly challenging task.
MRI uses extremely strong magnetic fields. Any ventilator that has not been developed and approved for this environment will be immediately attracted by the magnetic forces, resulting in considerable damage to the ventilator and the MRI system. In addition, any non-MRI-compatible ventilator will be impaired by the strong magnetic fields; on the other hand, the ventilator can interfere with sensitive MRI measurements. This renders the imaging unusable.
Until now, non-MRI-compatible ventilators, such as the bellavista, have been placed outside the MRI environment. This required the use of very long ventilator tubing, which has a negative impact on ventilator performance for the patient and complicates handling by medical staff.
Thus, a specially designed ventilator was needed for this extreme environment.
Project objectives
A ventilator for the MRI environment was to be developed based on the bellavista intensive care ventilator. The device was intended to ventilate the patient safely and be easy to use for medical staff.
Technical implementation
Conventional ventilators for use in MRI environments have a resistive touch screen and a fine wire mesh in front of the display. This mesh shields against interference but also reduces the resolution. The IMT team succeeded in developing a ventilator with a capacitive glass touch screen and high-resolution display. This obviates the need for the interfering wire screen.
To magnetically shield sensitive components, alloys specially optimized for this purpose, were used. The ventilator was optimized in steps to ensure that no interferences were observed in the MRI scans. The compatibility of the bellavista ventilator was proven using measurements on various MRI scanners.
Results
An MRI-compatible ventilator was developed. The ventilator was optimized through special shielding and interference suppression measures so that neither MRI imaging nor ventilation was influenced. A specially developed MR-Guard on the ventilator continuously measures the magnetic fields and enables easy and intuitive ventilator placement within the MRI environment through all-around visualization with LED strips. Thanks to the reduction in ferromagnetic content in the ventilator, it was possible to reduce magnetic attraction to a level that enables safe positioning of the ventilator directly next to the patient table. The automatic locking brake on the specially designed trolley ensures additional safety by preventing the accidental shifting of the ventilator after placement.
