Apparatus for monitoring hematocrit levels of blood
First Claim
1. An apparatus for measuring the hematocrit of blood comprisinglight emitting means for emitting light into a blood sample;
- first light detecting means for detecting light emitted from the light emitting means, said first light detecting means positioned to receive light emitted from the light emitting means into the blood sample along a first path from the light emitting means, through the blood sample, to the first light detecting means, the first light detecting means outputting a signal corresponding to the amount of light detected;
second light detecting means for detecting light emitted from the light emitting means, said second light detecting means being positioned to receive light emitted from the light emitting means into the blood sample, such that light emitted from the light emitting means must travel farther to reach the second light detecting means than to reach the first light detecting means, thereby forming a second path from the light emitting means, through the blood sample, to the second light detecting means which is longer than the first path from the light emitting means to the first light detecting means, the second light detecting means outputting a signal corresponding to the amount of light detected; and
light intensity regulating means for regulating the intensity of light emitted by the light emitting means such that the received light on one of the paths remains at a constant value.
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Accused Products
Abstract
An apparatus and method are provided for measuring the hematocrit level of blood. The presently preferred embodiment comprises a light emitting device which emits an amount of light into a blood sample. This light travels through the blood sample to two light detecting devices positioned relative to the light emitting device in a predetermined geometry such that light emitted from the light emitting device must travel farther to reach one of the light detecting devices than to reach the other, thereby forming a light path from the light emitting device to one light detecting device which is longer than the path from the light emitting device to the other light detecting device. According to the present invention, the amount of light detected by one of the light detecting devices is regulated so that the amount of light detected is constant. Thereafter, the amount of light detected by the unregulated light detecting device is a linear representation of the hematocrit of the blood in the blood sample. The hematocrit sensor may be used within a plasma separator apparatus wherein the hematocrit measurement regulates the operating parameters of the autotransfusion system to maintain the hematocrit of the blood within a predetermined range.
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Citations
25 Claims
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1. An apparatus for measuring the hematocrit of blood comprising
light emitting means for emitting light into a blood sample; -
first light detecting means for detecting light emitted from the light emitting means, said first light detecting means positioned to receive light emitted from the light emitting means into the blood sample along a first path from the light emitting means, through the blood sample, to the first light detecting means, the first light detecting means outputting a signal corresponding to the amount of light detected; second light detecting means for detecting light emitted from the light emitting means, said second light detecting means being positioned to receive light emitted from the light emitting means into the blood sample, such that light emitted from the light emitting means must travel farther to reach the second light detecting means than to reach the first light detecting means, thereby forming a second path from the light emitting means, through the blood sample, to the second light detecting means which is longer than the first path from the light emitting means to the first light detecting means, the second light detecting means outputting a signal corresponding to the amount of light detected; and light intensity regulating means for regulating the intensity of light emitted by the light emitting means such that the received light on one of the paths remains at a constant value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An apparatus for measuring the hematocrit of blood comprising:
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light emitting means for emitting light into a blood sample; first light detecting means the detecting light emitted from the light emitting means, said first light detecting means positioned to receive light emitted from the light emitting means into the blood sample along a first path from the light emitting means, through the blood sample. to the first light detecting means, said first light detecting means outputting a signal corresponding to the amount of light detected; second light detecting means for detecting light emitted from the light emitting means. said second light detecting means being positioned to receive light emitted from the light emitting means into the blood sample, such that light emitted from the light emitting means must travel farther to reach the second light detecting means than to reach the first light detecting means, thereby forming a second path from the light emitting means, through the blood sample, to the second light detecting means which is longer than the first path from the light emitting means to the first light detecting means, the second light detecting means outputting a signal corresponding to the amount of light detected; first conveying means, in communication with the light emitting means, for transmitting light from the light emitting means to the blood; second conveying means, in communication with the near detecting means, for transmitting to the first light detecting means light passing through the blood along the first path; third conveying means, in communication with the far detecting means, for transmitting to the second light detecting means light passing through the blood along the second path; and light intensity regulating means for regulating the intensity of light emitted by the light emitting means such that the received light on one of the paths remains at a constant value. - View Dependent Claims (16, 17, 18, 19, 20)
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21. An optical connector for use with a hematocrit sensor comprising:
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a generally hollow member adapted to receive a blood sample therein with respect to which hematocrit is to be measured; and an optically clear flexible optical window positioned on the generally hollow member, and through which the blood sample within the generally hollow member may be visually accessed for measurement of its hematocrit; wherein the optical connector presses firmly into the flexible optical window to permit a substantially tight fitting contact. - View Dependent Claims (22, 23)
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24. An apparatus for regulating the operation of a plasma separator apparatus to keep the hematocrit measurement of blood output therefrom within a predetermined range, comprising:
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a plasma separator apparatus for removing unwanted waste components from the blood in order to cleanse the blood; and monitoring means for measuring the hematocrit of the cleansed blood outputted from the plasma separator apparatus, and for thereafter automatically regulating operating parameters of the plasma separator apparatus so as to maintain a hematocrit of the blood within a predetermined range; wherein the monitoring means for automatically regulating operating parameters of the plasma separator apparatus comprises a hematocrit sensor for measuring the hematocrit of blood, interconnected with the plasma separator apparatus by a microcomputer, said hematocrit sensor comprising light emitting means for emitting light into a blood sample, first light detecting means for detecting light emitted from the light emitting means, said first light detecting means positioned to receive light emitted from the light emitting means, through the blood sample, along a first path, and the first light detecting means outputting a signal corresponding to the amount of light detected, second light detecting means detecting light emitted from the light emitting means, said second light detecting means being positioned to receive light emitted from the light emitting means, through the blood sample, along a second path, such that light emitted from the light emitting means must travel farther to reach the second detecting means than to reach the first light detecting means, thereby forming a second path from the light emitting means to the second light detecting means which is longer than the first path from the light emitting means to the first light detecting means, and light intensity regulating means for regulating the intensity of light emitted by the light emitting means such that the received light in one of the paths remains at a constant value.
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25. An apparatus for regulating the operation of a plasma separator apparatus to keep the measurement of blood output therefrom within a predetermined range, comprising:
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a plasma separator apparatus removing unwanted waste components from the blood in order to cleanse the blood; and monitoring means for measuring the hematocrit of the cleansed blood outputted from the plasma separator apparatus, and for thereafter automatically regulating operating parameters of the plasma separator apparatus so as to maintain a hematocrit of the blood within a predetermined range; wherein the monitoring means for automatically regulating operating parameters of the plasma separator apparatus comprises a hematocrit sensor for measuring the hematocrit of blood, interconnected with the plasma separator apparatus by limit switches, said hematocrit sensor comprising light emitting means for emitting light into a blood sample, first light detecting means for detecting light emitted from the light emitting means, said first light detecting means positioned to receive light emitted from the light emitting means, through the blood sample, along a first path, and the first light detecting memos outputting a signal corresponding to the amount of light detected, second light detecting means for detecting light emitted from the light emitting means, said second light detecting means being positioned to receive light emitted from the light emitting mean, through the blood sample, along a second path, such that light from the light emitting means must travel further to reach the second detecting means than to reach the first light detecting means, thereby forming a second path from the light emitting means to the second light detecting means which is longer than the first path from the light emitting means to the first light detecting means, and light intensity regulating means for regulating the intensity of light emitted by the light emitting means such that the received light on one of the paths remains at a constant value.
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Specification