白丝美女被狂躁免费视频网站,500av导航大全精品,yw.193.cnc爆乳尤物未满,97se亚洲综合色区,аⅴ天堂中文在线网官网

Auto recovering protection of electromechanical components in a high magnetic field

專(zhuān)利號(hào)
US10096988B2
公開(kāi)日期
2018-10-09
申請(qǐng)人
KONINKLIJKE PHILIPS N.V.（NL Eindhoven）
發(fā)明人
Paul Wayne Bailey
IPC分類(lèi)
H02H3/08; G01R33/28; H02H7/20
技術(shù)領(lǐng)域
current,magnetic,device,mri,in,draw,power,magnet,scanner,field
地域： Eindhoven

摘要

An apparatus (100) protects a device (80) which has a ferrous electromechanical component which saturates in a high magnetic field (40) and draws a dangerously high electric current. A current sensor (110) senses current in excess of safe operating conditions of the protected device (80) in or near the magnetic field (40). A current switch (120) is controlled by the current sensor (110) and interposed between a power supply (90) and the device (80) to interrupt the current flow to the protected device (80) when the current sensor (110) senses current flow above a threshold due to the saturation.

說(shuō)明書(shū)

1 2 3 4 5 6 7 8 9
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national filing of PCT application Serial No. PCT/IB2012/055546, filed Oct. 12, 2012, published as WO 2013/061200 A1 on May 2, 2013, which claims the benefit of U.S. provisional application serial no. 61/550,476 filed Oct. 24, 2011, which is incorporated herein by reference.

The present application relates to protection of electromechanical components in a high magnetic field such as near a magnetic resonance scanner.

A magnet of a magnetic resonance imaging (MRI) scanner generates a strong static field or B0 field. A typical strength of the field is approximately 30,000 gauss (1 Tesla=10,000 gauss). Additional magnetic fields are generated in a MRI system using gradient coils or local coil, for spatially encoding resonance.

The scanning of some subjects occurs when the subject is under critical care. The critical care may involve an unconscious subject in an emergency situation or a subject under close monitoring. Subjects to be scanned often include other accompanying devices that participate in their care. These devices include life sustaining equipment such as ventilators, injectors, or infusion pumps. The devices may include monitoring devices such as blood pressure monitors, CO2 monitors, or anesthesia gas monitors. The devices may include ancillary devices such as printers, workstations, or even entertainment devices.

權(quán)利要求

1
Having thus described the preferred embodiments, the invention is now claimed to be:1. An apparatus for protecting electromechanical components from excessive current draw due to saturation by a magnetic field, the apparatus comprising:a current sensor which senses current draw in excess of safe operating conditions by a protected device; anda current switch connected to the current sensor and interposed between a power supply and the protected device which interrupts the current flow to the protected device based on the current draw sensed by the current sensor;wherein the apparatus is a separate component which the protected device plugs into and in turn plugs into a power outlet.2. The apparatus according to claim 1, wherein the current switch restarts the current flow when saturation conditions are reduced such that current in excess of the safe operating conditions is no longer drawn.3. The apparatus according to claim 1, wherein the safe operating conditions are determined by a hysteresis curve of a ferrous electromechanical component of the protected device.4. The apparatus according to claim 1, further including:a warning device which warns a clinician that current is interrupted and the device has stopped functioning, the warning device includes at least one of:a visual indicator;an audible indicator;a signal to the protected device; anda signal to a host system.5. The apparatus according to claim 1, further including:a time delay circuit which delays interruption of the current flow by the current switch by a pre-determined time period.6. The apparatus according to claim 1, further including:a circuit which controls the current switch based on the sensed current draw by the current sensor, the circuit holding the current switch open for a pre-selected duration.7. The apparatus according to claim 6 wherein after the preselected duration, the current switch closes supplying current to the device until and unless the current sensor senses that the current draw exceeds the safe operating conditions.8. The apparatus according to claim 1, wherein the protected device includes a patient monitoring device.9. The apparatus according to claim 1, wherein the protected device includes at least one of:a pump;a motor; anda solenoid.10. The apparatus according to claim 1, wherein the protected device includes at least one of:a NIBP monitor;a CO2 monitor;a printer;a ventilator;an anesthesia workstation;an injector;an infusion pump;an entertainment device; andan anesthesia gas monitor.11. A MRI scanner room power supply comprising:an MRI scanner which generates a magnetic field of at least 10,000 gauss; andthe apparatus according to claim 1, for protecting a medical device for use in conjunction with a patient to be scanned by the MRI scanner by interrupting the current flow to the medical device in response to being moved into sufficient proximity to the MRI scanner that ferrous components in the medical device saturate.12. An apparatus for protecting an electromechanical component from excessive current draw due to saturation by a magnetic field, the apparatus comprising:a current sensor connected to sense current draw by a protected device;a current switch interposed between a power supply and the protected device and configured to interrupt the current flow to the protected device in response to the current sensor sensing the current draw by the protected device exceeds a threshold; anda time delay circuit which delays interruption of the current flow by the current switch by a pre-determined time period.13. The apparatus according to claim 12, wherein:the current switch comprises an integrated circuit connected to the current sensor to compare the sensed current with the threshold and control an FET to open in accord with the comparison; andthe time delay circuit comprises a resistor and a capacitor connected with the integrated circuit to delay opening of the FET by the pre-determined time period.14. The apparatus of claim 13 wherein the integrated circuit operates to close the FET after a selected duration and to subsequently reopen the FET if the current draw by the protected device is still in excess of the threshold.15. The apparatus of claim 12 wherein the current switch is configured to periodically close to re-check the current draw and to re-open if the current draw by the protected device is still in excess of the threshold.16. The apparatus of claim 12 wherein the current switch activates a light or tone generator to indicate the interruption of current flow to the protected device.17. The apparatus of claim 12 wherein the apparatus is a separate component from the protected device.
微信群二維碼
意見(jiàn)反饋