Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Reexamination Certificate
1999-02-17
2001-02-27
Arana, Louis (Department: 2862)
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
C600S412000
Reexamination Certificate
active
06194899
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a temperature monitoring method and apparatus which, in order to monitor the internal temperature of a subject during a period of a brain hypothermia primarily applied to a brain disease and cerebropathia, acquire a temperature variation in the inside of the subject by utilizing a magnetic resonance phenomenon and display it and to a magnetic resonance apparatus.
The results of treatment on the brain disorders, such as the brain trauma, brain blood vessel disorder and hypoxia cerebropathia at a time of the stoppage of a cardiopulmonary function are governed by conditions of the brain edema and intracranial pressure exacerbation involved due to the ischemia. For this reason, it is very important to measure the intracranial pressure level and internal jugular sinus venous blood oxygen saturation level and, by doing so, control the subject.
In recent times it has been clarified that, due to an intrabrain heat retention resulting from re-perfusion following the brain disorder a secondary phase of disease appears in advance of the brain edema. It has been, therefore, indicated that it is important to continue treatment while controlling the temperature of the brain.
Attention has recently been paid to the brain hypothermia which, in order to protect to a brain from a brain injury region and resuscitate the brain, lowers the temperature of the brain to 32° to 34° C. and maintains this state for an about 2-days to one-week period (an about two-days to two-weeks period though depending upon the case)—Intensive & critical care medicine Vol. 9, No. 6, 613-689 (1997) issued by Sohgo Igaku Co., Ltd.
It has been difficult to exactly measure the temperature of the brain in real time during the brain hypothermia period. It has been conventional practice to measure the blood temperature primarily responsible for the brain temperature formation, with the use of a catheter sensor set in the internal jugular vein and use it in place of the brain temperature.
It has been reported that, for a normal subject, such internal jugular vein temperature is approximately equal to the brain temperature (Hayashi, Intensive & critical care medicine vol. 7, No. 3, 267-274 (1997)). It has also been reported that a temperature profile is produced in the brain in the case of a patient with the brain disorder. And a non-invasive and high accurate temperature measuring method has thus been desired.
BRIEF SUMMARY OF THE INVENTION
It is accordingly the object of the present invention to measure a local internal temperature in a subject with a short temporal resolution with the use of an absolute temperature.
In the present invention, a pulse sequence for absolute temperature measurement is executed and then a pulse sequence for relative temperature measurement is repeatedly executed. Since the absolute temperature requires frequency information while the relative temperature can be measured from phase information, a time necessary to the pulse sequence for relative temperature measurement can be made shorter than that necessary to the pulse sequence for absolute temperature measurement. Further, the relative temperature reveals a temperature variation and, if an absolute temperature at a given time is found, then that absolute temperature at a sequential time can be calculated from the relative temperature. It is, therefore, possible to measure a local internal temperature in the subject, with a shorter temporal resolution, with the use of the absolute temperature.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
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Ishihara Yasutoshi
Okamoto Kazuya
Umeda Masaaki
Watanabe Hidehiro
Arana Louis
Kabushiki Kaisha Toshiba
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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