WO2000010447A2 - Sensing pad assembly employing variable coupler fiberoptic sensor - Google Patents
Sensing pad assembly employing variable coupler fiberoptic sensor Download PDFInfo
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- WO2000010447A2 WO2000010447A2 PCT/US1999/019259 US9919259W WO0010447A2 WO 2000010447 A2 WO2000010447 A2 WO 2000010447A2 US 9919259 W US9919259 W US 9919259W WO 0010447 A2 WO0010447 A2 WO 0010447A2
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- sensor
- assembly according
- coupling region
- optical fibers
- output optical
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Classifications
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6887—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient mounted on external non-worn devices, e.g. non-medical devices
- A61B5/6892—Mats
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/021—Measuring pressure in heart or blood vessels
- A61B5/02108—Measuring pressure in heart or blood vessels from analysis of pulse wave characteristics
- A61B5/02125—Measuring pressure in heart or blood vessels from analysis of pulse wave characteristics of pulse wave propagation time
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/024—Detecting, measuring or recording pulse rate or heart rate
- A61B5/02416—Detecting, measuring or recording pulse rate or heart rate using photoplethysmograph signals, e.g. generated by infrared radiation
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/026—Measuring blood flow
- A61B5/0285—Measuring or recording phase velocity of blood waves
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7235—Details of waveform analysis
- A61B5/7239—Details of waveform analysis using differentiation including higher order derivatives
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/02—Details of sensors specially adapted for in-vivo measurements
- A61B2562/0204—Acoustic sensors
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/02—Details of sensors specially adapted for in-vivo measurements
- A61B2562/0261—Strain gauges
- A61B2562/0266—Optical strain gauges
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/16—Details of sensor housings or probes; Details of structural supports for sensors
- A61B2562/168—Fluid filled sensor housings
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B7/00—Instruments for auscultation
- A61B7/02—Stethoscopes
- A61B7/04—Electric stethoscopes
Definitions
- This invention relates to a sensing pad assembly for monitoring acoustic activity and/or motion of an object supported on the pad.
- the invention is more particularly concerned with a sensing pad assembly that utilizes an improved variable coupler fiberoptic sensor as a pressure transducing element.
- the sensing pad is suitable for use in a variety of monitoring applications and is especially useful in systems for continuously monitoring medical patients, or more generally, human subjects.
- Continuous monitoring systems typically require the attachment of electrical and/or physical sensors to the patient's body using adhesive or straps. Such sensors are generally uncomfortable to the patient and often limit patient activity due to the presence of the sensors, straps, and associated sensor leads. Moreover, such monitoring systems are subject to false outputs due to unreliability of skin contact with patient movement.
- An alternative form of monitoring system has been proposed in which the patient is supported on a sensing pad having an associated pressure transducer that does not contact the patient. Acoustic activity and motion of the patient generate pressure fluctuations in the material of the pad. These fluctuations, which vary in accordance with the parameter or parameters being monitored, propagate through the pad material to the transducer. The transducer then converts them to electrical signals for processing by a monitoring circuit.
- FIG. 1 illustrates this system in simplified block diagram form.
- the system includes a fluid- filled sensing pad 1 adapted to support a patient and to transmit pressure fluctuations due to the patient's acoustic activity or motion to a pressure transducer 2 that converts the pressure fluctuations to an electrical output.
- the pressure transducer is coupled to the internal fluid medium 3 of the pad via a hose 4.
- a monitoring circuit 5 monitors the output from the transducer and provides outputs to activate a patient stimulator 6 and an alarm 7 upon the occurrence of predetermined conditions, such as when the transducer output corresponds to no sound and/or movement (below a predetermined threshold) or indicates abnormal activity of the patient.
- the sensing pad 1 may be in the form of a fluid- filled mattress or configured for use in some other suitable support such as a vehicle seat or a stroller.
- Proposed applications of the system for monitoring human subjects include the monitoring of infants at risk for sudden infant death syndrome (SIDS) , controlling sleep apnea and snoring, and sensing the onset of sleep for drivers of motor vehicles. Other proposed applications include monitoring machinery for noises and vibrations indicative of atypical operation.
- SIDS sudden infant death syndrome
- Other proposed applications include monitoring machinery for noises and vibrations indicative of atypical operation.
- the '460 patent mentions several classes of sensors as being suitable for use as the pressure transducer. Examples include electrical, mechanical, pie
- variable coupler fiberoptic sensor One type of fiberoptic sensor not explicitly mentioned in the '460 patent, but known to have performance characteristics that are especially well suited for patient monitoring and a variety of other applications, is the variable coupler fiberoptic sensor.
- Variable coupler fiberoptic sensors conventionally employ so-called biconical fused tapered couplers manufactured by a draw and fuse process in which a plurality of optical fibers are stretched (drawn) and fused together at high temperature.
- the plastic sheathing is first removed from each of the fibers to expose the portions for forming the fusion region. These portions are juxtaposed, usually intertwisted one to several twists, and then stretched while being maintained above their softening temperature in an electric furnace or the like.
- As the exposed portions of the fibers are stretched, they fuse together to form a narrowed waist region—the fusion region—that is capable of coupling light between the fibers.
- the stretching process light is injected into an input end of one of the fibers and monitored at the output ends of each of the fibers to determine the coupling ratio.
- the coupling ratio changes with the length of the waist region, and the fibers are stretched until the desired coupling ratio is achieved, typically by a stretching amount at which the respective fiber light outputs are equal.
- the coupler is drawn to such an extent that, in the waist region, the core of each fiber is effectively lost and the cladding may reach a diameter near that of the former core .
- the cladding becomes a new "core, " and the evanescent field of the propagating light is forced outside this new core, where it envelops both fibers simultaneously and produces the energy exchange between the fibers.
- Biconical fused tapered couplers have the advantageous property that the output ratio can be changed by bending the fusion region. Because the output ratio changes in accordance with the amount of bending, sensors employing such couplers can be used in virtually any sensing application involving motion that can be coupled to the fusion region.
- U.S. Patent 5,074,309 to Gerdt discloses the use of such sensors for monitoring cardiovascular sounds including both audible and sub-audible sounds from the heart, pulse, and circulatory system of a patient.
- Other applications of variable coupler fiberoptic sensors can be found in U.S. Patent 4,634,858 to Gerdt et al . (disclosing application to accelerometers) , U.S. Patent 5,671,191 to Gerdt (disclosing application to hydrophones), and elsewhere in the art.
- variable coupler fiberoptic sensors have relied upon designs in which the fiberoptic coupler is pulled straight, secured under tension to a plastic support member and, in the resulting pre- tensioned linear (straight) form, encapsulated in an elastomeric material such as silicone rubber.
- the encapsulant forms a sensing membrane that can be deflected by external forces to cause bending of the coupler in the fusion region. The bending of the fusion region results in measurable changes in the output ratio of the coupler.
- the displacement of the membrane can be made sensitive to as little as one micron of movement with a range of several millimeters.
- Fig. 2 of the accompanying drawings illustrates the basic principles of a sensing apparatus including a variable coupler fiberoptic sensor 10 as described above.
- the sensor 10 includes a 2 x 2 biconical fused tapered coupler 11 produced by drawing and fusing two optical fibers to form the waist or fusion region 13. Portions of the original fibers merging into one end of the fusion region become input fibers 12 of the sensor, whereas portions of the original fibers emerging from the opposite end of the fusion region become output fibers 14 of the sensor. Reference numbers 18 denote the optical fiber cores.
- the fusion region 13 is encapsulated in an elastomeric medium 15, which constitutes the sensing membrane.
- the support member is not shown in Fig. 1.
- one of the input fibers 12 is illuminated by a source of optical energy 16, which may be an LED or a semiconductor laser, for example.
- the optical energy is divided by the coupler 11 and coupled to output fibers 14 in a ratio that changes in accordance with the amount of bending of the fusion region as a result of external force exerted on the sensing membrane.
- the changes in the division of optical energy between output fibers 14 may be measured by two photodetectors 17 which provide electrical inputs to a differential amplifier 19.
- the output signal of differential amplifier 19 is representative of the force exerted upon medium 15. It will be appreciated that if only one of the input fibers 12 is used to introduce light into the sensor, the other input fiber may be cut short.
- the coupler 11 is shown without the aforementioned fiber twisting in the fusion region. Such twisting is ordinarily preferred, however, to reduce lead sensitivity, which refers to changing of the output light division in response to movement of the input fiber (s) .
- variable coupler sensors offer a uniquely advantageous combination of low cost, relatively simple construction, high performance (e.g., high sensitivity and wide dynamic range) , and versatility of application.
- Other known fiberoptic sensors have used such principles as microbending loss, light phase interference, and polarization rotation by means of birefringence.
- Fiberoptic micro-bending sensors are designed to sense pressure by excluding light from the fiber in proportion to the changes in pressure. The output light intensity decreases with increases in measured pressure, as pressure is transduced into light loss. Because the measurement accuracy is reduced at lower light levels, the dynamic range of such sensors is severely limited.
- Interferometric fiberoptic sensors measure changes in pressure by applying pressure to an optical fiber to change its index of refraction.
- Polarization varying fiberoptic sensors alter the polarization state of a polarized optical signal in accordance with a change in temperature or pressure. Such polarized light sensors require special optical fiber and expensive polarizing beam splitters.
- variable coupler fiberoptic sensors have been subject to certain limitations inherent in their pre-tensioned linear (straight) coupler design.
- the conventional design imposes, among other things, significant geometrical limitations.
- the size of the sensor must be sufficient to accommodate the fiberoptic leads at both ends of the sensor.
- the fiberoptic lead arrangement also requires the presence of a clear space around both ends of the sensor in use.
- Another limitation results from the fact that any displacement of the fusion region necessarily places it under increased tension. At some point of displacement, the tension in the fusion region will become excessive, causing the fusion region to crack or break, with resulting failure of the coupler.
- the present invention provides a sensing pad assembly that uses an improved variable coupler fiberoptic sensor designed to overcome one or more disadvantages of the conventional pre-tensioned linear sensor design. More particularly, the sensor used in the present invention may have an improved design that permits deflection of the coupler fusion region without accompanying tension.
- the coupler fusion region is preferably arranged substantially in a U-shape, but may more generally be configured as disclosed in co-pending U.S. Application No. 09/316,143 filed May 21, 1999, which is incorporated herein by reference. With a substantially U-shaped configuration, it becomes possible to locate the fiberoptic leads adjacent to each other rather than at opposite ends of the sensor, thus avoiding the earlier discussed geometrical limitations inherent in the conventional pre-tensioned linear coupler design.
- the pad may be of any desired configuration so long as it can transmit pressure fluctuations to be monitored to the variable coupler fiberoptic sensor.
- the pad may be in the form of a mattress, a sheet-like member to be placed upon or beneath a mattress, a seat cushion, or a sheet-like member incorporated in a sheet cushion.
- the senor is disposed within the internal material of the sensing pad.
- the sensor is secured to an outer surface of the pad with its sensing area (containing at least part of the fusion region) coupled to the internal medium of the pad via a hole formed in the pad outer surface.
- the sensor may be arranged in any manner that couples the sensing area so as to receive pressure fluctuations propagated by the material of the pad.
- the present invention provides a sensing pad assembly that comprises a pad member having a surface configured to support an object to be monitored thereon, the. pad member being capable of transmitting pressure fluctuations due to acoustic activity or motion of the supported object.
- the assembly further comprises a variable coupler fiberoptic sensor having a fused- fiber coupling region, with at least a portion of the coupling region being disposed in a sensing area of the sensor and configured such that it can be deflected to change an output of the sensor without the coupling region being put under tension.
- the sensing area is disposed such that the pressure fluctuations are transmitted thereto to deflect the aforementioned portion of the coupling region and thereby change the output of the sensor in accordance with the pressure fluctuations.
- the invention provides a sensing pad assembly that comprises a pad member as characterized above, and a variable coupler fiberoptic sensor having a substantially U-shaped, fused- fiber coupling region disposed in a sensing area of the sensor such that the coupling region can be deflected to change the output of the sensor.
- the sensing area is disposed such that the pressure fluctuations are transmitted thereto to deflect the coupling region and thereby change the output of the sensor in accordance with the pressure fluctuations .
- Fig. 1 is a simplified block diagram of a conventional monitoring system using a sensing pad.
- Fig. 2 illustrates the basic construction of a conventional variable coupler fiberoptic sensor.
- Fig. 3 is a perspective view of a sensor pad assembly according to a first embodiment of the invention.
- Fig. 4 is a cut-away side view showing, in more detail, the arrangement of the variable coupler fiberoptic sensor in Fig. 3.
- Fig. 5 is a plan view showing the sensor in Fig. 3.
- Fig. 6 shows explanatory views (Views 6a - 6d) of normal and deflected states of the fusion region of a conventional pre-tensioned linear coupler.
- Fig. 7 shows corresponding explanatory views (Views 7a - 7d) for a sensor having a U-shaped fusion region.
- Fig. 8 is a perspective view of a sensor pad assembly according to a second embodiment of the present invention.
- Fig. 9 is a perspective view of the variable coupler fiberoptic sensor used in the embodiment of Fig. 8.
- Figs. 3-5 show a sensing pad assembly according to a first embodiment of the invention.
- the assembly includes a pad member 1' and a variable coupler fiberoptic sensor 20 attached to an outside surface of the pad member.
- the pad member may be of a fluid-filled (e.g., water- filled or air- filled) construction as described in the aforementioned patent to Scanlon.
- the pad has upper and lower walls la and lb joined by four sidewalls lc, and is configured to support an object to be monitored on its upper (as viewed) outside surface. Note that only two of the sidewalls lc are designated in Fig. 3.
- the object to be monitored may be a human or animal subject, or even a machine, and the dimensions of the pad are suitably selected in consideration of the particular application at hand.
- the pad may be constructed as a crib mattress or in a more sheet-like form (say about 2 cm. thick) to be placed on top of a conventional crib mattress. In such case, the pad may be placed beneath a conventional linen sheet and a water-proof sub-sheet to avoid soiling, as well as to protect the infant in the event of leakage from the pad.
- the heart rate is around 120 to 180 beats per minute, or 2-3 Hz, and the respiratory rate is about 60 breaths per minute, or 1 Hz.
- the heartbeat occurs at a frequency of about 1 Hz, while breathing occurs at a frequency of about 0.2 Hz.
- the electrical signal obtained by converting the optical output of the sensor can be filtered to exclude frequencies above, say, 10 Hz, thereby eliminating electrical noise in the EKG domain and other higher frequency noise that may degrade the signal-to-noise ratio.
- the pad member may suitably be gel- filled or even formed of a soft, solid material such as silicone rubber. It is sufficient that the pad be effective to transmit pressure fluctuations due to acoustic activity or motion of the supported object to the variable coupler fiberoptic sensor 20 for detection.
- the variable coupler fiberoptic sensor 20 is best seen in Fig. 5.
- the sensor 20 comprises a support member 22 having a generally circular head portion 24 and a handlelike extension 28.
- the head portion is formed with a well or through hole to define a circular sensing area 26 of the sensor.
- a biconical fused tapered coupler 30 is mounted to the support member with at least a portion (here, the entirety) of its fused coupling region 32 disposed in the area 26 and arranged in a U-shape.
- Input fiber leads 34 and output fiber leads 36 of the coupler are disposed beside one another in a channel 29 formed in the extension 28 and open to the area 26.
- the leads are manipulated so as to bend the coupling region 32 through 180° into the desired shape and then secured within the channel by a suitable adhesive, such as an epoxy-based glue.
- the coupling region which is not under tension, is potted by filling the surrounding well or through hole with elastomer to form a sensing membrane 38 in the known manner—for example, by filling with a silicone rubber such as GE RTV 12.
- a silicone rubber such as GE RTV 12.
- the maximum diameter of the membrane may be about the same as that of a nickel coin, but the membrane may be smaller or larger as desired to suit a particular application.
- the support plate dimensions may be any convenient size, so long as the coupler fusion region and the fiber portions near the fusion region are securely supported. The sensitivity of the device is dependent upon the stiffness of the membrane, as in prior devices.
- the sensor 20 is sealingly secured to the pad member 1' adjacent to a hole H through one of the pad sidewalls lc so as to acoustically couple the sensing membrane 38 to the internal medium 3 of the pad member.
- the through hole diameter is about the same as that of the sensing membrane 38 to maximize the coupling of the membrane to the internal medium 3.
- the sensor may be secured about the hole H in any suitable leakproof manner, such as by gluing the head portion 24 to the outer surface of the pad sidewall about the circumference of the hole. Facing the channeled side of the support member 22 away from the pad member, as shown, facilitates reliable sealing to the pad sidewall.
- the hole H may be used for filling the pad member, or a separate filling port may be provided.
- FIG. 6 and 7 provide a pictorial comparison between the deflection of a conventional pre-tensioned linear fiberoptic coupler and the deflection of the U-shaped coupler of the sensor in the embodiment of Figs. 3-5.
- Views 6a and 6c are top and side views, respectively, showing the fusion region of the conventional coupler in its normal state.
- Views 6b and 6d are corresponding views of the fusion region being deflected by a downward force F.
- Views 7a - 7d in Fig. 7 are corresponding views to Fig. 6, but show the U-shaped coupler employed in the present invention.
- the deflection of the fusion region in the conventional coupler causes a bowing that tends to stretch and thereby increase the tension on the fusion region.
- the deflection of the U-shaped fusion region in View 7d which is seen to occur along a direction perpendicular to the plane of the U- shape, merely causes a flexing of the U along its height (horizontal dimension in View 7d) , without subjecting the fusion region to tension.
- even large displacements of the fusion region will not cause cracking or breaking.
- Figs. 8 and 9 illustrate a sensing pad assembly according to a second embodiment of the invention.
- an improved variable coupler fiberoptic sensor 20' is disposed internally of a sensing pad member 1".
- the sensor 20' and its fiber-optic input and output leads 34, 36 are inserted into through a hole H' in one of the pad sidewalls, which is then sealed with a suitable sealing material.
- the sensor 20' is constructed as an air-backed hydrophone having a construction similar to that of the sensor shown in Figs. 3- 5, except that the sensing membrane 38 is backed by entrapped air that is contained in a hollowed-out cap 24a sealingly attached to the back side (bottom side in Figs.
- the support member head portion 24 may be secured, as by gluing, to the inner surface of the sensing pad member bottom wall lb.
- the sensor 20' may simply be suspended within the pad interior, having a fixed connection only where the fiber leads are secured to the sidewall.
- the optical fiber leads in either of the illustrative embodiments would be contained within one or more protective sheaths .
- optical fiber used in the sensors of the present invention is most preferably of very high quality, such as Corning SMF28 which exhibits an optical loss of about 0.18 dB per Km.
- the photodetectors may be gallium-aluminum-arsenide or germanium detectors for light wavelengths above 900 nm and silicon detectors for shorter wavelengths.
- the photodetectors may be connected in either a photovoltaic mode or a photoconductive mode.
- transimpedance amplifiers which convert current to voltage
- the transimpedance amplifier outputs may also be filtered to eliminate broadband noise.
- the detector outputs can be connected to a conventional voltage amplifier. This approach results in more noise, but may be used in applications where cost is a major concern and a lower noise level is not.
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Surgery (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Pathology (AREA)
- Biophysics (AREA)
- Cardiology (AREA)
- Physiology (AREA)
- Hematology (AREA)
- Psychiatry (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Artificial Intelligence (AREA)
- Signal Processing (AREA)
- Vascular Medicine (AREA)
- Acoustics & Sound (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
- Micromachines (AREA)
- Measuring Fluid Pressure (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000565775A JP2002523118A (en) | 1998-08-24 | 1999-08-24 | Sensing pad assembly using variable coupler optical fiber sensor |
US09/763,718 US6687424B1 (en) | 1998-08-24 | 1999-08-24 | Sensing pad assembly employing variable coupler fiberoptic sensor |
EP99942453A EP1116055A2 (en) | 1998-08-24 | 1999-08-24 | Sensing pad assembly employing variable coupler fiberoptic sensor |
CA002341450A CA2341450A1 (en) | 1998-08-24 | 1999-08-24 | Sensing pad assembly employing variable coupler fiberoptic sensor |
AU55825/99A AU5582599A (en) | 1998-08-24 | 1999-08-24 | Sensing pad assembly employing variable coupler fiberoptic sensor |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US9761898P | 1998-08-24 | 1998-08-24 | |
US60/097,618 | 1998-08-24 | ||
US12633999P | 1999-03-26 | 1999-03-26 | |
US60/126,339 | 1999-03-26 |
Publications (2)
Publication Number | Publication Date |
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WO2000010447A2 true WO2000010447A2 (en) | 2000-03-02 |
WO2000010447A3 WO2000010447A3 (en) | 2000-12-07 |
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PCT/US1999/019258 WO2000010453A1 (en) | 1998-08-24 | 1999-08-24 | Apparatus and method for measuring pulse transit time |
PCT/US1999/019259 WO2000010447A2 (en) | 1998-08-24 | 1999-08-24 | Sensing pad assembly employing variable coupler fiberoptic sensor |
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PCT/US1999/019258 WO2000010453A1 (en) | 1998-08-24 | 1999-08-24 | Apparatus and method for measuring pulse transit time |
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EP (2) | EP1107691A4 (en) |
JP (2) | JP2002523118A (en) |
KR (1) | KR20010074845A (en) |
CN (1) | CN1325285A (en) |
AU (2) | AU756142B2 (en) |
CA (2) | CA2341450A1 (en) |
IL (1) | IL141460A0 (en) |
WO (2) | WO2000010453A1 (en) |
Cited By (1)
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GB2407154A (en) * | 2003-10-13 | 2005-04-20 | Univ Cranfield | Acoustic emission sensor based on a fused tapered optical coupler with sharp taper angle |
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AU2001221391A1 (en) | 2000-01-26 | 2001-08-07 | Vsm Medtech Ltd. | Continuous blood pressure monitoring method and apparatus |
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ITBO20020564A1 (en) | 2002-09-06 | 2004-03-07 | Alfa Wassermann Spa | BIFIDOBACTERIA AND PREPARATIONS THAT CONTAIN THEM. |
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CN100518634C (en) * | 2006-06-05 | 2009-07-29 | 中国科学院力学研究所 | Device and method for measuring pulse waving speed |
KR20090103861A (en) * | 2006-10-05 | 2009-10-01 | 델라웨어 스테이트 유니버시티 파운데이션 인코포레이티드 | Fiber optics sound detector |
WO2008149559A1 (en) * | 2007-06-08 | 2008-12-11 | Panasonic Corporation | Pulse wave detection device, apparatus control device, and pulse wave detection method |
KR100908997B1 (en) * | 2007-09-12 | 2009-07-22 | 한국 한의학 연구원 | Pulse system using fiber grating sensor |
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US10709383B2 (en) | 2015-04-02 | 2020-07-14 | Microsoft Technology Licnesing, Llc | Wrist-worn pulse transit time sensor |
JP6662167B2 (en) * | 2016-04-15 | 2020-03-11 | オムロンヘルスケア株式会社 | Pulse wave detection device, biological information measurement device, mounting aid for pulse wave detection device |
CN110403580B (en) * | 2018-04-28 | 2023-01-17 | 深圳市大耳马科技有限公司 | Pulse wave conduction parameter measuring method and pulse wave conduction parameter processing equipment |
KR20200005445A (en) * | 2018-07-06 | 2020-01-15 | 삼성전자주식회사 | Apparatus and method for measuring bio-information |
EP3818930A4 (en) * | 2018-07-06 | 2022-04-20 | Samsung Electronics Co., Ltd. | Biometric information measurement device and method |
DE102019206361A1 (en) * | 2019-05-03 | 2020-11-05 | Audi Ag | Spectrometry device for the non-invasive measurement of at least one medical characteristic value on a biological tissue |
WO2022006634A1 (en) * | 2020-07-08 | 2022-01-13 | The University Of Sydney | Blood pressure measurement system |
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- 1999-08-24 JP JP2000565775A patent/JP2002523118A/en not_active Withdrawn
- 1999-08-24 CA CA002341450A patent/CA2341450A1/en not_active Abandoned
- 1999-08-24 AU AU55824/99A patent/AU756142B2/en not_active Ceased
- 1999-08-24 JP JP2000565781A patent/JP2002523122A/en not_active Withdrawn
- 1999-08-24 CN CN99812444A patent/CN1325285A/en active Pending
- 1999-08-24 EP EP99942452A patent/EP1107691A4/en not_active Withdrawn
- 1999-08-24 WO PCT/US1999/019258 patent/WO2000010453A1/en not_active Application Discontinuation
- 1999-08-24 KR KR1020017002319A patent/KR20010074845A/en not_active Application Discontinuation
- 1999-08-24 CA CA002341416A patent/CA2341416A1/en not_active Abandoned
- 1999-08-24 EP EP99942453A patent/EP1116055A2/en not_active Withdrawn
- 1999-08-24 AU AU55825/99A patent/AU5582599A/en not_active Abandoned
- 1999-08-24 WO PCT/US1999/019259 patent/WO2000010447A2/en not_active Application Discontinuation
- 1999-08-24 IL IL14146099A patent/IL141460A0/en unknown
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GB2407154A (en) * | 2003-10-13 | 2005-04-20 | Univ Cranfield | Acoustic emission sensor based on a fused tapered optical coupler with sharp taper angle |
GB2407154B (en) * | 2003-10-13 | 2007-01-10 | Univ Cranfield | Improvements in and relating to fibre optic sensors |
Also Published As
Publication number | Publication date |
---|---|
IL141460A0 (en) | 2002-03-10 |
CN1325285A (en) | 2001-12-05 |
EP1116055A2 (en) | 2001-07-18 |
AU756142B2 (en) | 2003-01-02 |
JP2002523122A (en) | 2002-07-30 |
KR20010074845A (en) | 2001-08-09 |
CA2341416A1 (en) | 2000-03-02 |
WO2000010453A1 (en) | 2000-03-02 |
AU5582499A (en) | 2000-03-14 |
AU5582599A (en) | 2000-03-14 |
WO2000010447A3 (en) | 2000-12-07 |
EP1107691A4 (en) | 2005-04-06 |
JP2002523118A (en) | 2002-07-30 |
EP1107691A1 (en) | 2001-06-20 |
CA2341450A1 (en) | 2000-03-02 |
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