Wireless patient monitoring device for magnetic resonance imaging

• US 20050107681A1
• Filed: 07/23/2004
• Published: 05/19/2005
• Est. Priority Date: 07/23/2003
• Status: Abandoned Application

• Current Assignee: Medrad Incorporated (Bayer AG)
• Original Assignee: Medrad Incorporated (Bayer AG)
• Inventors: Griffiths, David M.
• Application Number:
  US10/897,737
• Publication Number:
  US 20050107681A1
• Time in Patent Office: Days
• US Class Current: 600/410
• CPC Class Codes: A61B 5/0046 Arrangements of imaging apparatus in a room, e.g. room provided with shielding or for improved access to apparatus
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/283 Intercom or optical viewing arrangements, structurally associated with NMR apparatus
• CPC Class Codes: G01R 33/567 gated by physiological signals , i.e. synchronization of acquired MR data with periodical motion of an object of interest, e.g. monitoring or triggering system for cardiac or respiratory gating
• CPC Class Codes: G01R 33/5673 Gating or triggering based on a physiological signal other than an MR signal, e.g. ECG gating or motion monitoring using optical systems for monitoring the motion of a fiducial marker

Abstract

The invention relates to systems, methods, and associated devices for wirelessly communicating physiologic signals or other data in an electromagnetically noisy environment, such as a magnetic resonance imaging (MRI) suite. They permit wireless communication of data obtained from a sensor module attached to a patient while situated within the bore of an MR scanner. The system includes a first transceiver and a second transceiver. The first transceiver is linked to the sensor module for transmitting the data received therefrom. The second transceiver, which is connected to an apparatus remote from the first transceiver, is used to convey to the apparatus the data received from the first transceiver. The first and second transceivers enable the sensor module and the apparatus to communicate unidirectionally or bidirectionally without being adversely affected by, or adversely affecting, the operation of the MR system.

Claims

1. A system for wirelessly communicating physiologic data indicative of a condition of a patient exposed to a scanner of a magnetic resonance (MR) system, said system comprising:

(a) a sensor mechanism for acquiring from said patient said physiologic data;

(b) a first transducer circuit connected to said sensor mechanism for converting said physiologic data received therefrom from optical format to electrical format;

(c) a first RF transceiver circuit connected to said first transducer circuit for transmitting said physiologic data received therefrom;

(d) a second RF transceiver circuit remote from said first RF transceiver circuit for receiving said physiologic data transmitted by said first RF transceiver circuit; and

(e) a second transducer circuit connected to said second RF transceiver circuit for converting said physiologic data received therefrom from electrical format to optical format and for conveying said physiologic data to an apparatus remote from said sensor mechanism;

wherein communication between said sensor mechanism and said apparatus via said first and said second RF transceiver circuits is accomplished without adversely affecting, or being adversely affected by, operation of said MR system.

2. The system of claim 1 wherein said first RF transceiver circuit includes:

(a) an RF transceiver module having an input into which said physiological data from said first transducer circuit is received and an output from which said physiologic data is transmitted in radio frequency (RF) format;

(b) a filter connected to said output of said RF transceiver module for passing said physiologic data but effectively attenuating frequencies outside those carrying said physiologic data; and

(c) an antenna connected to said filter for radiating said physiologic data received therefrom.

3. The system of claim 2 wherein said filter is one of a bandpass filter, a high pass filter and a notch filter.

4. The system of claim 1 wherein said second RF transceiver circuit includes:

(a) an antenna for receiving said physiologic data transmitted by said first RF transceiver circuit;

(b) a filter connected to said antenna for passing said physiologic data but effectively attenuating frequencies outside those carrying said physiologic data; and

(c) an RF transceiver module having an input into which said physiological data from said filter is received and an output from which said physiologic data is conveyed to said second transducer circuit.

5. The system of claim 4 wherein said filter is one of a bandpass filter, a high pass filter and a notch filter.

6. The system of claim 1 wherein said second transducer circuit includes:

(a) a driver circuit having an input connected to an output of said second RF transceiver circuit; and

(b) an electro-optic transducer connected to an output of said driver circuit for converting said physiologic data received therefrom from electrical format to optical format and for conveying said physiologic data to said apparatus remote from said sensor mechanism.

7. The system of claim 1 wherein said sensor mechanism is an electrocardiographic (ECG) module for acquiring said physiologic data in the form of cardiac signals.

8. A system for wirelessly communicating data in an electromagnetically noisy environment, said system comprising:

(a) a first transducer circuit connected to a first device of a bifurcated system for converting said data received therefrom from optical format to electrical format;

(b) a first RF transceiver circuit connected to said first transducer circuit for transmitting said data received therefrom;

(c) a second RF transceiver circuit remote from said first RF transceiver circuit for receiving said data transmitted by said first RF transceiver circuit; and

(d) a second transducer circuit connected to said second RF transceiver circuit for converting said data received therefrom from electrical format to optical format and for conveying said data to a second device of said bifurcated system;

wherein a scheme of communication employed by said first and said second RF transceivers enables said first and said second devices to communicate without being adversely affected by noise in said environment.

9. The system of claim 8 wherein said first device of said bifurcated system includes an electrocardiographic (ECG) module for acquiring from a patient said data in the form of cardiac signals.

10. The system of claim 8 wherein said first device of said bifurcated system includes a sensor such that said data acquired thereby is indicative of a condition of a patient.

11. The system of claim 8 wherein said second device of said bifurcated system includes a monitoring apparatus capable of communicating with said first device via said second and said first RF transceiver circuits.

12. A system for wirelessly communicating data in a magnetic resonance (MR) suite, said system comprising:

(a) a first transceiver circuit connected to a sensor module for transmitting said data received therefrom and for conveying to said sensor module said data transmitted thereto; and

(b) a second transceiver circuit, connected to a monitoring apparatus, for conveying said data received from said first transceiver circuit to said monitoring apparatus and for transmitting to said first transceiver circuit said data received from said monitoring apparatus;

wherein said first and said second transceiver circuits communicate using predetermined frequencies outside a range of, and without adversely affecting, operation of equipment situated in said MR suite.

13. The system of claim 12 wherein said first transceiver circuit includes:

(a) a transceiver module having an input to which said data from said sensor module is conveyed and an output from which said data is transmitted in radio frequency (RF) format;

(b) a filter connected to said output of said transceiver module for passing said data but effectively attenuating frequencies outside those carrying said data; and

(c) an antenna connected to said filter for radiating said data received therefrom.

14. The system of claim 12 wherein said second transceiver circuit includes:

(a) an antenna for receiving said data transmitted by said first transceiver circuit in radio frequency (RF) format;

(b) a filter connected to said antenna for passing said data but effectively attenuating frequencies outside those carrying said data; and

(c) a transceiver module having an input into which said data from said filter is received and an output from which said data is conveyed to said monitoring apparatus.

15. The system of claim 12 wherein said data conveyed by said sensor module to said first transceiver circuit includes at least one of (i) physiologic signals indicative of a condition of a patient and (ii) operational signals indicative of a status of said sensor module.

16. The system of claim 15 wherein said data conveyed by said monitoring apparatus to said second transceiver circuit includes control signals commanding said sensor module to select appropriate lead(s) of a multiple-lead lead-set from which to pickup said physiologic signals.

17. The system of claim 12 wherein said data conveyed by said sensor module to said first transceiver circuit includes at least one of (i) cardiac signals indicative of heart condition and (ii) operational signals indicative of a status of said sensor module.

18. The system of claim 17 wherein said data conveyed by said monitoring apparatus to said second transceiver circuit includes control signals commanding said sensor module to select appropriate lead(s) of a multiple-lead lead-set from which to derive said cardiac signals.

19. A system for wirelessly communicating data obtained from a sensor module attached to a patient situated within an imaging scanner, said system comprising:

(a) a first transceiver linked to said sensor module for transmitting said data received therefrom; and

(b) a second transceiver, connected to an apparatus remote from said first transceiver, for conveying to said apparatus said data received from said first transceiver;

wherein said first and said second transceivers enable said sensor module and said apparatus to communicate without being adversely affected by, or adversely affecting, an operation of said imaging scanner.

20. The system of claim 19 further including a first transducer circuit between said sensor module and said first transceiver for converting said data received in optical format from said sensor module to electrical format for use by said first transceiver.

21. The system of claim 19 further including a second transducer circuit between said second transceiver and said apparatus for converting said data received in electrical format from said second transceiver to a format usable by said apparatus.

22. The system of claim 19 wherein said sensor module is an electrocardiographic (ECG) module for acquiring said data in the form of cardiac signals.

23. A method of wirelessly communicating data indicative of at least a condition of a patient exposed to a scanner of a magnetic resonance (MR) system, said method comprising the steps of:

(a) acquiring said data from a sensor mechanism attached to said patient;

(b) converting said data obtained from said patient from optical format to electrical format;

(c) transmitting in radio frequency (RF) format said data received in electrical format;

(d) receiving said data transmitted in said transmitting step;

(e) converting said data received in said receiving step from electrical format to optical format; and

(f) conveying said data to an apparatus remote from said patient;

wherein communication of said data is accomplished without being adversely affected by, or adversely affecting, an operation of said MR system.

24. The method of claim 23 wherein the step of acquiring said data includes using an electrocardiographic (ECG) module for acquiring said data in the form of cardiac signals.

25. A method of wirelessly communicating data in an imaging suite, said method comprising the steps of:

(a) providing a first transceiver connected to a sensor for transmitting said data received therefrom and for conveying to said sensor said data transmitted thereto; and

(b) providing a second transceiver, connected to an apparatus remote from said first transceiver, for conveying said data received from said first transceiver to said apparatus and for transmitting to said first transceiver said data received from said apparatus;

wherein said first and said second transceivers communicate without being adversely affected by, or adversely affecting, an operation of equipment in said imaging suite.

26. The method of claim 25 further including the step of providing a first transducer circuit between said sensor and said first transceiver for converting said data received (i) in optical format from said sensor to electrical format for use by said first transceiver and (ii) in electrical format from said first transceiver to optical format for use by said sensor.

27. The method of claim 25 further including the step of providing a second transducer circuit between said second transceiver and said apparatus for converting said data received (i) in electrical format from said second transceiver to a format usable by said apparatus and (ii) in optical format from said apparatus to electrical format for use by said second transceiver.

28. The method of claim 25 wherein said sensor is an electrocardiographic (ECG) module for acquiring said data in the form of cardiac signals.

29. A communications module for wirelessly communicating electrocardiographic (ECG) signals obtained from a patient situated in a noisy environment, said module comprising:

(a) at least one RF filter linked to a sensor of bioelectric signals for removing therefrom frequencies outside those carrying said bioelectric signals;

(b) a network for selecting, in response to control signals, appropriate lead(s) of a multiple-lead lead-set from which to pickup selected one(s) of said bioelectric signals;

(c) a differential amplifier for deriving said ECG signals from said bioelectric signals selected via said network;

(d) an amplifier circuit for amplifying said ECG signals received from said differential amplifier;

(e) a signal processing circuit for improving a condition of said ECG signals received from said amplifier circuit;

(f) a modulator circuit for digitally modulating a carrier signal in accordance with said ECG signals received from said signal processing circuit to form a modulated signal therewith;

(g) a transmitter circuit connected to said modulator circuit for transmitting said modulated signal received therefrom; and

(h) a filter circuit connected to said transmitter circuit for passing, and effectively attenuating frequencies outside of, said modulated signal.

30. The communications module of claim 29 wherein said transmitter circuit transmits said modulated signal at frequencies in the microwave band.

31. The communications module of claim 29 further including:

(a) a limiter circuit linked to said filter circuit for limiting an amplitude of control signals picked up by an antenna from a remote apparatus;

(b) a receiver circuit connected to said limiter circuit for receiving said control signals; and

(c) an encoder circuit for encoding said ECG signals with information pertaining to at least one of (i) an amount of power available to said communications module and (ii) from which of said leads of said multiple-lead lead-set were said ECG signals derived.

32. The communications module of claim 29 further including a means for assuring integrity of communications between said communications module and a remote apparatus with which said communications module communicates.

33. A communications module for wirelessly communicating physiologic signals obtained from a patient situated in a noisy environment, said module comprising:

(a) an input conditioning circuit linked to a sensor of said physiologic signals for adapting said physiologic signals received therefrom for use in said module;

(b) a signal processing circuit for improving a condition of said physiologic signals received from said input conditioning circuit;

(c) a converter circuit for converting said physiologic signals received from said signal processing circuit to digital signals corresponding thereto;

(d) a transmitter circuit connected to said converter circuit for transmitting said digital signals received therefrom; and

(e) a filter circuit connected to said transmitter circuit for passing, and effectively attenuating frequencies outside of, said digital signals.

34. The communications module of claim 33 wherein said converter circuit includes a modulator for digitally modulating a carrier signal in accordance with said physiologic signals received from said signal processing circuit to form said digital signals therewith.

35. The communications module of claim 33 wherein said transmitter circuit transmits said digital signals at frequencies in the microwave band.

36. The communications module of claim 33 further including:

(a) a limiter circuit linked to said filter circuit for limiting an amplitude of control signals picked up by an antenna from a remote apparatus;

(b) a receiver circuit connected to said limiter circuit for receiving said control signals; and

(c) a control circuit for controlling operation of said communications module in accordance with said control signals received from said remote apparatus.

37. The communications module of claim 33 wherein said control circuit enables said physiologic signals to be encoded with information pertaining to at least an amount of power available to said communications module.

38. The communications module of claim 33 further including a means for assuring integrity of communications between said communications module and a remote apparatus with which said communications module communicates.