Fiber optic interferometric vital sign monitor for use in magnetic resonance imaging, confined care facilities and in-hospital
First Claim
1. A method of detecting vital signs of a patient exposed to nuclear magnetic resonance imaging, comprising:
- providing optical fiber proximate to a patient exposed to a nuclear magnetic resonance imaging environment, said optical fiber comprising a first optical path and a second optical path;
coupling optical radiation into an input of said first optical path and an input of said second optical path;
coupling acousto-mechanical signals indicative of vital signs generated by said patient into said optical fiber to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
creating interference of optical radiation emitted from an output of said first optical path and an output of said second optical path;
detecting time variations of said interference and providing a time-varying electrical signal responsive thereto; and
signal processing said time-varying electrical signal to provide one or more output signals indicative of said vital signs.
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Accused Products
Abstract
A fiber optic monitor that utilizes optical phase interferometry to monitor a patient'"'"'s vital signs such as respiration, cardiac activity, blood pressure and body'"'"'s physical movement. The monitor, which is non-invasive, comprises an optical fiber interferometer that includes an optical fiber proximately situated to the patient so that time varying acousto-mechanical signals from the patient are coupled into the optical fiber. Responsive thereto, the interferometer generates a time-varying optical intensity resulting from the interference of optical signals, which are detected at a photo-detector. A signal processor coupled to the optical detector provides one or more processed output signals indicative of the vital functions. The monitor system has broad applicability, from routine monitoring of infants at home to detection of apnea, arrhythmia, blood pressure and trauma. The system can be implemented in embodiments ranging from a low cost in-home monitor for infants to a high end product for in hospital use. The monitor can be integrated with other sensors such as an EKG, a video or still camera, an oxygen sensor, a carbon dioxide sensor, temperature sensor or a microphone to get additional required information depending on the application. When integrated and combined with EKG information, the monitor provides ballisto-mechanical information of the heart for early diagnosis of cardiac conditions or prediction of events or for correcting corrupted EKG signals due to time varying magnetic and electric fields. In some embodiments of the monitor, the system can be made portable so that the patient can walk around while still being continuously monitored for vital signs. Another suitable design measures blood pressure continuously and non-invasively by containing the fiber optic sensor in a cuff that wraps around an arterial wall of the patient. The fiber optic monitor may be designed for use in a variety of settings including an operating room, a recovery room, an intensive care unit, a magnetic resonance imaging laboratory, a computerized tomography scan laboratory and an elderly care facility.
258 Citations
45 Claims
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1. A method of detecting vital signs of a patient exposed to nuclear magnetic resonance imaging, comprising:
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providing optical fiber proximate to a patient exposed to a nuclear magnetic resonance imaging environment, said optical fiber comprising a first optical path and a second optical path;
coupling optical radiation into an input of said first optical path and an input of said second optical path;
coupling acousto-mechanical signals indicative of vital signs generated by said patient into said optical fiber to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
creating interference of optical radiation emitted from an output of said first optical path and an output of said second optical path;
detecting time variations of said interference and providing a time-varying electrical signal responsive thereto; and
signal processing said time-varying electrical signal to provide one or more output signals indicative of said vital signs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of detecting vital signs of a patient, comprising:
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providing optical fiber proximate to a patient comprising a first optical path and a second optical path;
coupling optical radiation into an input of said first optical path and an input of said second optical path;
coupling acousto-mechanical signals indicative of vital signs generated by said patient into said optical fiber to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
creating interference of optical radiation emitted from an output of said first optical path and an output of said second optical path;
detecting time variations of said interference and providing a time-varying electrical signal responsive thereto; and
signal processing said time-varying electrical signal to provide one or more output signals indicative of said vital signs. - View Dependent Claims (14, 15)
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16. A fiber optic monitor for detecting vital signs in a patient comprising:
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optical fiber comprising a first optical path and a second optical path, said optical fiber being adapted to be situated proximate to a patient so that acousto-mechanical signals generated by said patient are coupled into said optical fiber effective to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
optrodes for affixing at least a portion of said optical fiber to the patient;
an optical source coupled to supply optical radiation into an input of said first optical path and an input of said second optical path;
an optical system for creating optical interference from the optical radiation emitted from an output of said first optical path and an output of said second optical path;
a photo-detector arranged to sense an optical signal provided by time variations in said interference, said photo-detector providing a raw electrical signal responsive thereto;
a signal processor coupled to said photo-detector to process said raw electrical signal to provide one or more processed output signals indicative of vital signs of the patient; and
an output system that communicates said one or more output signals. - View Dependent Claims (17, 18)
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19. A method of detecting vital signs of patient in a confined care facility in which the patient is confined to a bed or room during treatment or monitoring, comprising:
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providing optical fiber proximate to the patient comprising a first optical path and a second optical path;
coupling optical radiation into an input of said first optical path and an input of said second optical path, coupling acousto-mechanical signals indicative of vital signs generated by said patient into said optical fiber to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
creating interference of optical radiation emitted from an output of said first optical path and an output of said second optical path;
detecting time variations of said interference and providing a time-varying electrical signal responsive thereto;
signal processing said time-varying electrical signal to provide one or more output signals indicative of said vital signs; and
communicating said output signals in a manner selected from the group consisting of;
1) as a local numerical or graphical readout near the patient,
2) over at least one of fiber optic lines, phone lines, power lines, local area network lines, and TV cable lines to a central monitoring station to produce a numerical or graphical readout, and the combination of
1) and
2).- View Dependent Claims (20, 21, 22, 23)
1) breath rate is faster or slower than a preset threshold value of the breath rate, 2) heart rate is faster or slower than a preset threshold value of the heart rate, 3) no breath or heart rate signal is available because the patient has left the bed and not returned to the bedroom after a preset time duration has elapsed;
4) no breath or heart rate signal is available because the patient has left the bed and has not moved from a particular location after a preset time duration has elapsed, and combinations of
1) through
4).
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23. The method of claim 19 comprising containing said optical fiber in one of a mattress pad and jacket vest operated by batteries.
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24. A fiber optic monitor for detecting vital signs in a patient, comprising:
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optical fiber comprising a first optical path and a second optical path, said optical fiber being adapted to be situated proximate to a patient so that acousto-mechanical signals generated by said patient are coupled into said optical fiber effective to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
a casing containing at least a portion of said optical fiber and being adapted to be affixed to the patient, said casing being one of a cuff and a patch;
an optical source coupled to supply optical radiation into an input of said first optical path and an input of said second optical path;
an optical system for creating interference from the optical radiation emitted from an output of said first optical path and an output of said second optical path;
a photo-detector arranged to sense an optical signal provided by time variations in said interference, said photo-detector providing a raw electrical signal responsive thereto;
a signal processor coupled to said photo-detector to process said raw electrical signal to provide one or more processed output signals indicative of vital signs of the patient; and
an output system that communicates said one or more output signals. - View Dependent Claims (25, 26, 27, 28, 29)
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30. A fiber optic monitor for detecting vital signs in a patient, comprising:
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optical fiber comprising a first optical path and a second optical path, said optical fiber being adapted to be situated proximate to a patient so that acousto-mechanical signals generated by said patient are coupled into said optical fiber effective to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
an optical source coupled to supply optical radiation into an input of said first optical path and an input of said second optical path;
an optical system for creating interference from the optical radiation emitted from an output of said first optical path and an output of said second optical path;
a photo-detector arranged to sense an optical signal provided by time variations in said interference, said photo-detector providing a raw electrical signal responsive thereto;
a signal processor coupled to said photo-detector to process said raw electrical signal to provide one or more processed output signals indicative of vital signs of the patient; and
an output system that communicates said one or more output signals. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37)
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38. A method of detecting vital functions of a patient, comprising:
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providing optical fiber comprising a first optical path and a second optical path, said optical fiber being proximate to a patient located in an area selected from the group consisting of an operating room, a recovery room, an intensive care unit, a magnetic resonance imaging laboratory, a computerized tomography scan laboratory, an elderly care facility and combinations thereof;
coupling optical radiation into an input of said first optical path and an input of said second optical path;
coupling acousto-mechanical signals indicative of vital signs generated by said patient into said optical fiber to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
creating interference of optical radiation emitted from an output of said first optical path and an output of said second optical path;
detecting time variations of said interference and providing a time-varying electrical signal responsive thereto; and
signal processing said time-varying electrical signal to provide one or more output signals indicative of said vital signs. - View Dependent Claims (39, 40, 41, 42, 43)
1) breath rate is faster or slower than a preset threshold value of the breath rate, 2) heart rate is faster or slower than a preset threshold value of the heart rate, 3) blood pressure is higher or lower than a preset threshold value of the blood pressure.
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44. A method of detecting blood pressure of a patient, comprising:
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providing optical fiber comprising a first optical path and a second optical path, said optical fiber being contained by a cuff;
wrapping said cuff around a body part of the patient;
applying pressure to said cuff effective to cause said optical fiber to contact the body part;
coupling optical radiation into an input of said first optical path and an input of said second optical path;
coupling acousto-mechanical signals indicative of blood pressure generated by said patient into said optical fiber to modulate a physical parameter of said optical fiber responsive to said acousto-mechanical signals;
creating interference of optical radiation emitted from an output of said first optical path and an output of said second optical path;
detecting time variations of said interference and providing a time-varying electrical signal responsive thereto; and
signal processing said time-varying electrical signal to provide one or more output signals indicative of said blood pressure. - View Dependent Claims (45)
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Specification