Magnetic resonance system and method including an automated non-magnetic medical monitor
In magnetic resonance imaging (MRI), the powerful magnetic fields can interfere with, damage, cause premature failure in, and attract certain non-MR safe instruments. Electromagnetic ally sensitive components are eliminated in favor of MR safe components, such as ceramic piezoelectric components and bi-metallic components. Instruments that previously had to be kept a safe distance away from the main magnet ( 12 ), e.g., beyond the 5 Gauss line, while a patient was being scanned are now allowed near the patient without fear of damage to the instrument ( 40 ) or danger to the patient and medical staff or the MRI device ( 10 ).
1. A magnetic resonance system comprising:
a main magnet for generating a substantially uniform main magnetic field in an examination region;
a gradient coil assembly for imposing gradient magnetic fields on the main magnetic field in the examination region, spatially encoding the main magnetic field;
a radio frequency assembly for inducing magnetic resonance in selected dipoles of a subject in the examination region, and receiving the magnetic resonance; and
an automated non-magnetic monitor disposed in the examination region to measure at least one physiological parameter of the subject, the non-magnetic monitor including one of a blood pressure monitor and a gas analysis monitor, wherein the non-magnetic monitor further includes an electrically operated pump disposed in the main magnetic field.
2. The magnetic resonance system of claim 1 wherein the pump includes a piezoelectric ceramic peristaltic pump.
3. The magnetic resonance system as set forth in claim 2 , further including:
a high voltage driver for the piezoelectric pump disposed in the examination region.
4. The magnetic resonance system as set forth in claim 1 , wherein the monitor includes at least one valve disposed in the main magnetic field.
5. The magnetic resonance system as set forth in claim 4 , wherein the at least one valve includes:
a piezoelectric ceramic diaphragm valve; and
a high voltage driver for the piezoelectric diaphragm valve.
6. The magnetic resonance system as set forth in claim 1 , wherein the monitor includes a blood pressure monitor, the blood pressure monitor further including:
at least one valve disposed in the main magnetic field;
a controller for controlling high voltage drivers for driving the pump and the at least one valve;
a memory for storing at least blood pressure readings and a time at which they were taken;
an electromagnetically compatible enclosure around the controller and the memory to shield from radiate emissions.
7. The magnetic resonance system as set forth in claim 1 , wherein the main magnet generates a magnetic field of at least 2500 Gauss (0.25 T) in the examination region.
8. A method of magnetic resonance comprising:
generating a main magnetic field with a main magnet of at least 2500 Gauss of a magnetic resonance imaging device;
applying gradient magnetic fields to the examination region with a gradient coil system;
applying RF pulses to the examination region with an RF assembly;
controlling at least one valve and at least one pump located in the at least 2500 Gauss main magnetic field to alternately inflate and deflate a blood pressure cuff.
9. The method as set forth in claim 8 , further including:
inflating a pressure cuff located in the main magnetic field by closing a first, linear piezoelectric ceramic diaphragm valve, closing a second, piezoelectric ceramic diaphragm dump valve, and actuating a piezoelectric ceramic pump;
reading a pressure by releasing air from the pressure cuff by opening the first valve and turning the pump off; and
releasing remaining air from the cuff by opening the second valve.
10. The method as set forth in claim 9 wherein the main magnetic field is greater than or equal to 5000 Gauss.
11. The method as set forth in claim 8 , further including: wirelessly transmitting a blood pressure measurement to a remote location.