Patent Application
20050283081
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The present invention relates to a non-invasive apparatus for measuring physiological variables, and more particularly, to a non-invasive apparatus for continuous measuring a plurality of physiological variables from a user's ear.
In the diagnosis process, the clinical thermometer does great favor to physicians. Among all positions to be measured, the temperature of tympanic membrane is the best indication of the body temperature rather than those of oral cavity, rectum or armpit. The temperature of the tympanic membrane is measured by detecting the infrared radiation emitted from tympanic membrane. Consequently, the infrared ear thermometer is able to measure and display the ear temperature efficiently within one or two seconds, and is widely used by hospitals, clinics or family, gradually replacing the traditional mercury thermometer.
While measuring the infrared radiation in an auditory meatus, the detector of the ear thermometer has to be inserted into the external auditory meatus of a patient before the infrared radiation can be measured accurately, and the body temperature can then be derived based on the infrared radiation. However, the insertion of the detector into the external auditory meatus may cause the patient's discomforts such as the sense of a foreign matter, so the traditional detector is only allowed to stay in the external auditory meatus of the patient for a very short while to mitigate his discomforts. In other words, the traditional ear thermometer is not suitable to be fixed on the patient's ear for gathering consecutive body temperature data of the patient.
A traditional pulse oxymeter uses a non-invasive optical detector to consecutively measure the blood oxygen saturation of a subject such as a patient's body. Particularly, the pulse oxymeter uses the diverse characteristics of the optical absorbance between the hemoglobin without oxygen (Hb) and the hemoglobin with oxygen (HbO2), and derives the blood oxygen saturation in a human body from the absorbency of the Hb and HbO2. However, one disadvantage of the traditional pulse oxymeter is that the oxymeter has to be fixed on the finger of the patient so that any movement of the patient's hand may detach the detector from the finger to invalidate the measurement. In addition, contraction in tip blood vessels of the patient's fingers caused by the variation of the ambient temperature may decrease the strength of the signal.
The objective of the present invention is to provide a non-invasive apparatus for continuous measuring a plurality of physiological variables from a user's ear.
In order to achieve the above-mentioned objective, and avoid the problems of the prior art, the present invention provides a non-invasive apparatus for measuring a plurality of physiological variable from a user's ear. The non-invasive apparatus comprises a sensing device, a plastic housing encapsulating the sensing device, a fastener connected to the plastic housing, and a light receiver. The plastic housing is made of a material selected from the group consisting of resin, wax, silicon-containing compound and the mixture thereof, and can be deformed in accordance with the contour of an auditory meatus of the user. Particularly, the plastic housing includes an awl-shaped portion capable of being inserted into the auditory meatus and a protrusion capable of engaging with a triangular fossa of the user's ear.
The fastener can be a flexible tube, which is deformable in accordance with the shape of a helix of the user' ear to engage with the helix. The non-invasive apparatus can be positioned on the user's ear by engaging the fastener with the helix and engaging the protrusion with the triangular fossa. In addition, an opaque tape can be optionally used to further adhere the non-invasive apparatus onto the ear to avoid the non-invasive apparatus departing from the ear, and to prevent the non-invasive apparatus from being disturbed by the environment.
The sensing device comprises a body with an inner end, a temperature detector positioned at the inner end and a light emitting device positioned on the body. The temperature detector can be a thermistor aiming exactly at the tympanic membrane for measuring the user's body temperature from the tympanic membrane. The temperature detector is preferably positioned on the awl-shaped portion of the plastic housing with a wax coating on the surface. The wax coating will be softened by the user's body heat as the temperature detector approaches the tympanic membrane so that the temperature detector is allowed to precisely measure the user's body temperature without causing discomfort to the user.
The light emitting device comprises at least one light source positioned preferably at the inner side of the tragus, while the light receiver comprises a light detector positioned at the outer side of the tragus or vice versa. The light source of the light emitting device can emit a light beam to the tragus, and the light receiver can receive the light beam penetrating through the tragus. Consequently, the light emitting device incorporating the light receiver can detect the blood oxygen saturation by measuring the energy loss of the light beam due to the penetration through the tragus, i.e., the absorbency of the light beam by blood vessels in the tragus.
Compared with prior art measuring the user's body temperature from the ear and the blood oxygen saturation from the finger, respectively, the present invention non-invasive apparatus can continuously measure a plurality of physiological variables from the user's ear along. Since the plastic housing can be automatically deformed by the user's body temperature to match with the contour of the auditory meatus, it will not cause discomfort to the user and can be fixed on the user's ear for a long period of time to measure the blood oxygen saturation from the tragus and body temperature from the tympanic membrane.
In addition, measuring the blood oxygen saturation from the tragus has the following advantage:
Other objectives and advantages of the present invention will become apparent upon reading the following description and upon reference to the accompanying drawings in which:
The plastic housing 20 can be deformed in accordance with the contour of the auditory meatus 108, and softened when the ambient temperature is above 33° C. Namely, the plastic housing 20 can be softened and deformed into any shape by the user's body temperature (about 37° C.), without a molding process. Moreover, although there may be some difference between the shape of the plastic housing 20 and the contour of the helix 108 before the plastic housing 20 is inserted into the user's ear 100, the body temperature at 37° C. will automatically heat and soften the unfit position of the plastic housing 20 to make it match with the contour of the helix 108 exactly so that the insertion of the non-invasive apparatus 10 will not cause discomforts.
The plastic housing 20 is made of organic materials selected from the group consisting of resin, wax, silicon-containing compound and the mixture thereof. The resin used in the plastic housing 20 substantially contains carbon, nitrogen and oxygen, and the content of resin in the plastic housing 20 is in a range between 40 and 60 wt %. The content of wax in the plastic housing 20 is in a range between 15 and 35 wt %, and wax will soften when the temperature is above 28° C. The content of silicon-containing material in the plastic housing 20 is in the range between 25 and 50 wt %, and primarily functions to modulate the hardness of the plastic housing 20.
The light emitting device 40 comprises at least one light source 42 positioned preferably at the inner side of the tragus 106, while the light receiver 50 comprises a light detector 52 positioned at the outer side of the tragus 106. The light source 42 of the light emitting device 40 can emit a light beam 44 to the tragus 106, and the light receiver 50 can receive the light beam 44 penetrating through the tragus 106. Consequently, the light emitting device 40 incorporating the light receiver 50 can measure the blood oxygen saturation by detecting the energy loss of the light beam 44 due to the penetration through the tragus 106, i.e., absorbency of the light beam 44 by blood vessels in tragus 106.
Compared with prior art, the present non-invasive apparatus 10 for measuring physiological variables possesses the following advantages:
The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 093117307 | Jun 2004 | TW | national |
