WO2009138883A2 - Integrated heart monitoring device and method of using same - Google Patents

Integrated heart monitoring device and method of using same Download PDF

Info

Publication number
WO2009138883A2
WO2009138883A2 PCT/IB2009/006088 IB2009006088W WO2009138883A2 WO 2009138883 A2 WO2009138883 A2 WO 2009138883A2 IB 2009006088 W IB2009006088 W IB 2009006088W WO 2009138883 A2 WO2009138883 A2 WO 2009138883A2
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
computing device
blood
housing
monitoring device
Prior art date
Application number
PCT/IB2009/006088
Other languages
French (fr)
Other versions
WO2009138883A3 (en
Inventor
Dan Gur Furman
Original Assignee
Cardio Art Technologies, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US12/119,339 external-priority patent/US20080287800A1/en
Priority claimed from US12/206,885 external-priority patent/US20090048518A1/en
Application filed by Cardio Art Technologies, Ltd. filed Critical Cardio Art Technologies, Ltd.
Priority to CA2722662A priority Critical patent/CA2722662A1/en
Priority to EP09746178A priority patent/EP2282671A4/en
Priority to JP2011509042A priority patent/JP5591794B2/en
Priority to CN2009801223131A priority patent/CN102202568A/en
Publication of WO2009138883A2 publication Critical patent/WO2009138883A2/en
Priority to IL209212A priority patent/IL209212A/en
Publication of WO2009138883A3 publication Critical patent/WO2009138883A3/en

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/145Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
    • A61B5/1459Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters invasive, e.g. introduced into the body by a catheter
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/02Detecting, 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
    • A61B5/02007Evaluating blood vessel condition, e.g. elasticity, compliance
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/145Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/14542Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue for measuring blood gases
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/48Other medical applications
    • A61B5/4887Locating particular structures in or on the body
    • A61B5/489Blood vessels
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/04Measuring blood pressure
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/06Measuring blood flow
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/12Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/44Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
    • A61B8/4483Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer
    • A61B8/4494Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer characterised by the arrangement of the transducer elements

Definitions

  • the present invention relates to sensing devices and, more specifically, to devices for monitoring cardiac behaviour.
  • Cardiovascular disease is a large, growing health problem world wide. Some studies indicate that approximately 15% of the Western World suffers from one or more cardiovascular disease. In the United States, nearly 25% of the population is affected, resulting in more than six million hospitalizations every year.
  • in vivo parameters of a patient may need to be monitored over a period of time; for example, such monitoring may be necessary in a subject who has occasional irregular cardiac beats.
  • Heart arrhythmias are changes in the normal sequence of electrical impulses that cause the heart to pump blood through the body. As such abnormal heart rhythms may only occur sporadically, continuous monitoring may be required for detection.
  • medical personnel determine if there is a tendency for production of sustained irregular beats in a life-endangering fashion. Medical personnel also use the monitoring results to establish a proper course of treatment.
  • One prior art device that measures heart rate is the "Reveal" monitor by Medtronic (Minneapolis, MN, USA).
  • This device comprises an implantable heart monitor used, for example, in determining if syncope (fainting) in a subject is related to a heart rhythm problem.
  • the Reveal monitor continuously monitors the rate and rhythm of the heart for up to 14 months.
  • the subject places a first recorder device external to the skin over the implanted Reveal monitor and presses a button to transfer data from the monitor to the recorder.
  • the subject gives the first recorder to a physician who provides the subject with a second recorder to use for continued data acquisition.
  • the physician analyzes the information stored on the first recorder to determine whether abnormal heart rhythm has been recorded.
  • the use of the recorder is neither automatic nor autonomic, and therefore requires either the subject to be conscious or another person's intervention.
  • transponder-type device in which a transponder is implanted in a patient and is subsequently accessed with a hand-held electromagnetic reader in a non-invasive manner.
  • a hand-held electromagnetic reader in a non-invasive manner.
  • Relevant information may include the oxygen saturation level of blood flowing through the aorta, blood pressure, heart rate, blood flow, stroke volume, cardiac output, the electrical activity of the heart (for generating electrocardiogram (ECG) data), and body temperature.
  • ECG electrocardiogram
  • the monitoring device includes an optical sensor assembly including a plurality of photon emitters and a plurality of photon detectors for detecting a plurality of optical signals.
  • the emitters and detectors face the aorta.
  • a computing device operates the plurality of emitters and detectors and processes the plurality of optical signals to obtain optical measurement values representing the location and size of the aorta and the oxygen saturation of the blood flowing through the aorta.
  • the monitoring device further includes a Doppler sensor for emitting and detecting a plurality of ultrasonic waves.
  • the computing device also operates the Doppler sensor and, with the aid of the optical measurement values obtained using the optical sensor assembly, processes the plurality of ultrasonic waves to obtain Doppler measurement values representing heart rate, blood flow, stroke volume, blood pressure, and cardiac output.
  • the monitoring device further includes an ECG sensor for detecting the electrical signals which cause the heart to pump. Additionally, the monitoring device includes a temperature sensor for measuring the temperature of the patient.
  • An energy storage device powers the computing device, the various sensors, and a communication device which is configured to transmit the collected data, or information relating to the collected data, according to a predetermined schedule or upon the occurrence of an event, such as abnormal data or a request for data from an external device.
  • the sensors, the computing device, the communication device, and the energy storage device are enclosed in a housing, which may be worn by the patient or implanted.
  • embodiments of the present invention permit a single device, mounted at one location on the patient's body, to accurately measure a comprehensive set of parameters relating to the behaviour of the heart, including cardiac output.
  • the integrated monitoring device described herein may perform analyses of the parameters and perform functions in response to the "on-board" analyses, as opposed to other sensing devices that export raw data for analysis by another device.
  • the integrated monitoring device according to embodiments of the invention also communicates with other devices, wirelessly or otherwise, providing information and receiving commands and data. As such, the monitoring device collects, analyzes, and communicates data without any human intervention.
  • Figure 1 A is a schematic side view of a monitoring device according to one embodiment of the invention.
  • Figure 1 B is an outwardly-facing view of the monitoring device of Figure 1.
  • Figure 1 C is a perspective view of the monitoring device of Figure 1.
  • Figure 2 is a schematic side view of the monitoring device of Figure 1 and a vessel.
  • Figure 3 is a schematic side view of a Doppler sensor according to one embodiment of the invention.
  • Figure 4 is a conceptual view of fluid flowing through a vessel.
  • Figure 5 is a schematic representation of a temperature sensing circuit.
  • Figure 6 is a conceptual view of a computing device according to one embodiment of the present invention.
  • Figure 7 is a conceptual view of a system adapted to transmit and receive communication signals from the monitoring device of Figure 1.
  • Fig. 1A depicts an integrated monitoring device according to one embodiment of the present invention.
  • the monitoring device 1 generally includes a plurality of components including an optical sensor assembly 2, a Doppler sensor 60, an ECG sensor including probes 5OA and 5OB (hereinafter collectively referred to as ECG sensor 50), a temperature sensor 70, a computing device 20, a communication device 30, and an energy storage device 40, each of the components mounted on a board 80 and being in electronic communication with computing device 20.
  • the components are enclosed in a housing 90.
  • optical sensor assembly 2 refers to the optical sensor assembly 2 described in the Optical Sensor Apparatus application incorporated herein by reference above.
  • Doppler sensor 60 refers to the Doppler sensor 60 described in the Doppler Motion Sensor application incorporated by reference above. The full description of optical sensor assembly 2 and Doppler sensor 60 will not be repeated in this application.
  • monitoring device 1 is adapted to measure the physiological behaviour of a patient's heart.
  • patient it is meant a person or animal.
  • monitoring device 1 is implanted subcutaneously in the patient's body. It should be understood, however, that monitoring device 1 may be implanted at different locations using various implantation techniques. For example, monitoring device 1 may be implanted within the chest cavity beneath the rib cage. Housing 90 may be formed in the shape of a circular or oval disc, with dimensions roughly the same as two stacked quarter dollar coins. More specifically, housing 90 may be approximately three centimetres in diameter and approximately one centimetre thick. Of course, housing 90 may be configured in a variety of other shapes and sizes, depending upon the application. Housing 90 may include four outwardly projecting loops 92, shown in Figs.
  • loops 92 may be provided depending upon the shape of housing 90.
  • optical sensor assembly 2 Doppler sensor 60, ECG sensor 50, and temperature sensor 70 are positioned facing inwardly while an energy coupler 42, which is described with particularity below, faces outwardly.
  • monitoring device 1 is integrated with an implanted cardiac device such as a pacemaker, a Cardiac Resynchronization Therapy (CRT) device, an implantable cardioverter defibrillator (ICD), etc.
  • monitoring device 1 may communicate with the implanted cardiac device and provide information from the implanted cardiac device as well as from its own sensors to external devices in the manner described in the System for Monitoring application incorporated herein by reference above.
  • integration of monitoring device 1 into such other devices may provide an effective means for achieving market acceptance. The above-described integration may be achieved by combining the components of monitoring device 1 and the cardiac device.
  • the cardiac device includes a computing device
  • the algorithms that carry out the functions according to the invention may be incorporated with the computing device of the cardiac device instead of adding a second computing device.
  • energy storage and communication devices may be combined to avoid duplication and lower cost.
  • some components of monitoring device 1 are included within housing 90 and some components are included with the cardiac device. The cardiac device and the components in housing 90 are operably connected.
  • monitoring device 1 is positioned externally to the patient's body.
  • a support member is provided to support monitoring device 1 externally to the body.
  • the support member may be permanently or temporarily coupled to monitoring device 1.
  • the support member comprises an adhesive layer for adhesively coupling the support member to the patient's body.
  • the support member comprises a belt, which may be elastic, for holding monitoring device 1 against the patient's body.
  • Monitoring device 1 may be implanted or positioned on the patient with the aid of an external mapping system such as an ultrasound machine. Proper placement ensures that the aorta is located within the sensing range of the various sensors of monitoring device 1. For example, monitoring device 1 may be positioned on the chest or back of the patient in a location that reduces interference by the ribs of the measurements acquired in the manner described herein.
  • an external mapping system such as an ultrasound machine.
  • monitoring device 1 may be positioned on the chest or back of the patient in a location that reduces interference by the ribs of the measurements acquired in the manner described herein.
  • optical sensor assembly 2 senses the oxygen saturation level of the patient's blood conveyed through the aorta.
  • Sensing assembly 2 emits beams of electromagnetic energy in the infrared (IR) range of the electromagnetic spectrum and detects IR signals reflected from haemoglobin in the aorta, which is the iron- containing oxygen-transport metalloprotein in red blood cells.
  • IR infrared
  • Fig. 2 illustrates the relationship between the aorta 3 conveying blood 4 having haemoglobin in red blood cells 5 and a pair of photocells, emitter 101 and detector 201 , included in emitter array 100 and detector array 200 of sensor assembly 2, respectively.
  • Emitter array 100 may include sixteen emitters 101 -1 16 (only emitter 101 is shown) and detector array 200 may include sixteen detectors 201 -216 (only detector 201 is shown), each being paired with an emitter.
  • Sensor assembly 2 and arrays 100, 200 may be selected from the 8572 family of optical sensors manufactured by Motorola.
  • Emitter 101 emits a beam of photons, including photon 101 ' , some of which pass through aorta 3, and others of which are reflected off of red blood cells 5, including photon 101 '.
  • computing device 20 controls the operation of emitter 101 and measures the time required for detector 201 to detect the reflected beam, and interprets signals provided by detector 201 to determine the power or intensity of the reflected beam. This information, along with the known characteristics of the emitted beam, permits computing device 20 to determine a variety of characteristics of aorta 3 and blood 4.
  • computing device 20 processes signals received from detector array 200 to calculate the time required for the emitted beam to travel from the emitter, to the aorta 3, and to the detector as a reflected beam. As the speed of the beam is known and the distance between the emitter and detector is known, a simple calculation yields the distance from monitoring device 1 to the aorta 3. Computing device 20 also uses the signals from detector array 200 to determine the power of the reflected beam received by each detector in detector array 200. These power values are then used to determine the diameter of aorta 3 using the methods and principles described in the Optical Sensor Apparatus application.
  • each of emitters 101 -1 16 are activated individually, in rapid succession.
  • the beams are emitted individually in a row-by-row scanning fashion, beginning with emitter 101 , which is followed sequentially until emitter 1 16 is activated. In other embodiments, other sequences are followed.
  • optical sensor assembly 2 also provides monitoring device 1 with the ability to determine the oxygen saturation level of blood carried by the aorta.
  • sensing device 1 activates all emitters 101 -116 of emitter array 100 simultaneously. Having already determined the size and location of the aorta as described above, the expected size or area of the reflected beam received by detector array 200 may be computed by computing device 20. The intensity or power of the reflected beam is, however, unknown prior to this measurement.
  • Detector array 200 receives the reflected beam and provides a signal indicating the intensity of the reflected beam. As the intensity of the emitted beam is known, the intensity measurement of the reflected beam permits computation of the oxygen saturation percentage of the blood in the aorta. Under normal operating conditions, monitoring device 1 may perform an oxygen saturation measurement once or twice per day.
  • monitoring device 1 also calculates cardiac pulse.
  • detectors 201 -216 produce power signals representative of iron content in blood.
  • the power signals fluctuate.
  • a plurality of power signals may be obtained in rapid succession to capture the power measurement fluctuation. More specifically, by performing many oxygen saturation measurements (e.g., ten times per second), over a period of time (e.g., fifteen seconds), the saturation measurements will exhibit a pattern or periodicity that represents the beating of the heart.
  • Computing device 20 may determine a curve to fit the saturation measurements, such as a sinusoidal curve, which corresponds directly to the cardiac cycle.
  • Computing device 20 may determine the frequency of peak values of the curve to determine its period. Each period represents a cardiac cycle.
  • computing device 20 may determine pulse rate in terms of cardiac cycles per minute.
  • computing device 20 stores cardiac pulse values as normal reference values and detects an abnormal or irregular cardiac rhythm by comparing cardiac pulse values to reference values.
  • aorta diameter and location provided by optical sensor assembly 2 may be used to calculate the velocity of blood flowing through the aorta, the volume of blood flowing through the aorta, the patient's blood pressure, and the cardiac output. These parameters may be used to calculate and diagnose an abnormal condition relating to cardiac output.
  • Doppler sensor 60 includes three transducers for insonating the aorta and receiving reflected ultrasonic waves. The velocity of the blood in the aorta is determined by directing the ultrasonic waves towards the blood at a known angle, measuring the frequency shift of the reflected ultrasound energy, and then calculating the velocity of the blood.
  • the Doppler frequency shift is proportional to the component of the velocity vector that is parallel to the insonifying wave.
  • Doppler sensor 60 which may be a continuous wave sensor or a pulsed wave sensor, measures frequency shift by comparing phase shifts between subsequently received waves according to principles that are well known in the art. As the distance between Doppler sensor 60 and the aorta has already been determined by optical sensor assembly 2, and the speed of sound through tissue is known, the frequency shift permits computing device 20 to determine the actual velocity of blood in the aorta.
  • Fig. 3 illustrates Doppler sensor 60 including linear array transducers A, B and C according to one embodiment of the invention.
  • Each of transducers A, B and C is operably connected with a driver device (not shown) that powers the transducer.
  • Transducers A, B and C are disposed at an angle relative to each other.
  • Transducers B and C are disposed at a 45 degree angle relative to transducer A and at 90 degrees relative to each other. Other relative angles among the transducers may be used.
  • Each of transducers A, B and C may be driven at a different frequency to distinguish the source of the reflected waves received by Doppler sensor 60.
  • each transducer in a linear array is referred to herein as a transducer segment.
  • each linear array transducer comprises five transducer segments. Transducer segments may be operably connected to be activated separately or concurrently. Separate activation of one or more transducer segments is desirable to limit power consumption.
  • transducer A includes segments A1 -A5
  • transducer B includes segments B1 -B5
  • transducer C includes segments C1 -C5.
  • Each segment may transmit and receive ultrasonic energy in the form of waves.
  • the arrows originating at each segment and projecting perpendicularly to the segment represent the direction of waves transmitted by each segment.
  • arrows 72, 74, and 76 represents the directions of waves produced by transducers A, B and C, in aggregate, respectively.
  • one or more segments of transducer A are energized at a frequency of 5 Mhz, one or more segments of transducer B are energized at a frequency of 4.5 Mhz, and one or more segments of transducer C are energized at a frequency of 5.5 Mhz.
  • Frequency selection is a function of the distance between the transducer and the target fluid and is selected accordingly.
  • a reflected wave may be measured at each segment of a linear array transducer. Each segment may be energized sequentially and may be energized a plurality of times.
  • the Doppler shift is proportional to the component of the velocity vector parallel to the impinging wave. Since the Doppler shift depends from the cosine of the angle ⁇ between the wave and the velocity vector, and the cosine function ranges between 0 and 1 , signals produced by waves oriented parallel to the velocity vector produce selected signals and, as the angle ⁇ increases, it becomes increasingly more difficult to determine the Doppler shift from those signals. As is fully described in the Doppler Motion Sensor application, the K-shape arrangement of transducers A, B, C ensures that at least one of the transducers is oriented at an acceptable angle ⁇ .
  • Doppler sensor 60 Three transducers enable Doppler sensor 60 to obtain a sufficient number of signals even when the relative position of Doppler sensor 60 and aorta 3 change slightly with time or other factors such as a patient's activity level and posture.
  • broad waves When broad waves are transmitted, reflected waves may be received by each transducer.
  • waves have frequencies corresponding to each transmitting transducer, Doppler sensor 60 is able to select which signals to filter based on the relative position of the corresponding transmitting transducer and its transmission frequency.
  • the calculation of blood velocity requires knowledge of the incident angle ⁇ between the emitted waves and aorta 3.
  • Incident angle and other data characterizing the relative position of aorta 3 and Doppler sensor 60 may be obtained in various ways. Once obtained, it may be stored in memory 26 (see Fig. 6) as reference values.
  • the relative position data is provided to computing device 20 by optical sensor assembly 2. With this information, computing device 20 computes a blood velocity value by comparing the frequency of the transmitted and the received waves according to well known frequency-shift and angle algorithms or tables. The velocity of the blood flowing through the aorta is different depending upon which portions of the blood are being measured. According to well-understood principles of fluid dynamics, fluid flowing near the outer wall of a vessel flows more slowly than fluid flowing through the central axis of the vessel because of shear
  • the distance and diameter measurements provided by optical sensor apparatus 2 permit computing device 20 to determine, from the measurements of Doppler sensor 60, the location of aorta 3 within the reflected wave detected by Doppler sensor 60.
  • Each of the five velocity measurements in each of the three sets of measurements taken in the manner o described in the Doppler Motion Sensor application is averaged to determine an approximate overall blood flow through aorta 3 and to account for the velocity profile across the diameter of aorta 3.
  • the sets of velocity measurements are taken at the maximum (systolic) and minimum (diastolic) flow conditions of the cardiac cycle. Accordingly, by averaging the five velocity measurements for each of the three sets
  • computing device 20 determines an average maximum flow measurement.
  • An average minimum flow measurement is computed in a similar fashion.
  • the average minimum and average maximum blood flow measurements are averaged to determine the mean blood flow for the patient.
  • computing device 20 may compute stroke volume by simply multiplying the mean blood flow measurement described above by the area of aorta 3 (i.e., mean blood flow * ⁇ r 2 ), where r is the radius of aorta 3.
  • r is the radius of aorta 3.
  • the radius of aorta 3 is simply one half of the aorta diameter, which is determined using optical sensor assembly 2 in the manner described above.
  • ECG sensor 50 is, in one embodiment of the invention, a single lead device including an anode probe 5OA and a cathode probe 5OB (collectively referred to herein as "ECG sensor 50"). ECG sensor 50 uses probes 5OA, 5OB to detect changes in voltage of the electrical impulses provided to the heart muscles. As is,
  • ECG sensor 50 permits computing device 20 to determine how fast the heart is beating (i.e., pulse) by determining the number of cardiac cycles per minute (or fraction of a minute).
  • the pulse measurement may be used with the stroke volume discussed above to determine cardiac output. More specifically, the stroke volume measurement may be multiplied by the number of strokes per minute (i.e., pulse) to determine the total volume of blood displaced per minute (i.e., cardiac output).
  • the pulse measured by ECG sensor 50 is compared to the pulse measured by optical sensor assembly 2 as described in the Optical Sensor Apparatus application. If the measurements differ by more than a predetermined amount, the ECG pulse measurement may be discarded under the assumption that electrical interference or some other disturbance caused errors in the detected signals. In this manner, optical sensor assembly 2 functions as a backup pulse measurement device for ECG sensor 50.
  • ECG sensor 50 provides voltage measurements to computing device 20, which in turn processes the data by filtering out frequencies outside the known range of frequencies generated by the heart's electrical activity.
  • ECG sensor 50 is also mounted within housing 90 in a manner and location that electrically isolates ECG sensor 50 from the other electronic components of monitoring device 1 to minimize the electrical interference caused by those other electronic devices.
  • the output of ECG sensor 50 is passed through a band pass filter having a lower cut-off frequency and an upper cut-off frequency.
  • computing device 20 may further process the data to produce a smooth ECG trace by applying any of a number of suitable digital smoothing functions.
  • ECG sensor 50 also permits computing device 20 to identify the maximum and minimum blood flow through the aorta, which are used in the stroke volume and cardiac output calculations described above. Additionally, It shows the heart ' s rhythm (steady or irregular) and where in the body the heart beat is being recorded. It also records the strength and timing of the electrical signals as they pass through each part of the heart.
  • ECG sensor 50 and Doppler sensor 60 are used in combination to determine the blood pressure of the patient directly from the aorta 3.
  • One skilled in the art may, using the ECG trace provided by ECG sensor 50, determine with accuracy the maximum blood flow position of the cardiac cycle and the minimum blood flow position.
  • Doppler sensor 60 facilitates determination of the speed or velocity of blood in aorta 3 under the maximum and minimum blood flow conditions in the manner described above.
  • Computing device 20 converts the velocity measurements under each condition into pressure measurements using the known internal surface area of aorta 3 (determined from the diameter measurements facilitated by optical sensor assembly 2) according to principles dictated by Bernoulli's equation.
  • pressure measurements reflect the dynamic pressure of the blood flowing through aorta 3 under the maximum and minimum flow conditions. More specifically, at Ti of Fig. 4, the dynamic pressure PDi corresponds to the pressure determined from the velocity measurements taken under maximum blood flow conditions. At T 2 , PD 2 corresponds to the pressure determined from the velocity measurements taken under minimum blood flow conditions. It is well known that the total pressure of a fluid flowing through a vessel is the sum of the dynamic pressure and the static pressure.
  • the static pressure (depicted as force arrows directed outwardly against the outer wall of the aorta 3) under maximum flow conditions (PSi) directly corresponds to the systolic blood pressure measurement and the static pressure under minimum flow conditions (PS 2 ) directly corresponds to the diastolic blood pressure measurement.
  • the systolic and diastolic blood pressure measurements may be derived by further computing the total pressure (PT) of blood flowing through aorta 3 and taking advantage of the fact that the total pressure through the aorta at Ti (i.e., PTi) must be the same as the total pressure at T 2 (i.e., PT 2 ).
  • Total pressure is derived by computing the change in pressure from the minimum flow conditions to the maximum flow conditions. This change or acceleration, in conjunction with the stroke volume and the known elasticity of aorta 3, permits computing device 20 to determine total pressure according to well known principles in the art.
  • PSi and PS 2 are the systolic and diastolic blood pressure measurements, respectively.
  • monitoring device 1 distinguishes between the pulmonary artery and aorta 3 by measuring the oxygen saturation of both, and determining which vessel carries blood with higher oxygen saturation. That vessel must be aorta 3.
  • monitoring device 1 instead identifies the vessel with lower oxygen saturation as the vessel of interest (i.e., the pulmonary artery). The location and size of the pulmonary artery is then determined in the same manner as described with reference to aorta 3. With the geometry of the pulmonary artery defined, the pressure of the blood flowing through the pulmonary artery is measured as described above with reference to aorta 3.
  • housing 90 includes a connector 85 to permit connection of additional ECG leads.
  • Connector 85 is electrically coupled to ECG sensor 50 and other components of monitoring device 1 through board 80.
  • connector 85 passes signals from the additional leads to ECG sensor 50.
  • the additional leads may be affixed to various locations on the chest, back, arms, or legs of the patient, and each lead includes a receiver for detecting electrical activity.
  • connector 85 may also function as a I/O port for monitoring device 1 , permitting downloading of data to a docking station 304 and uploading of data and instructions during a programming operation.
  • Temperature sensor 70 is, in one embodiment of the invention, a readily available resistance temperature detector (RTD).
  • temperature sensor 70 may include a metallic component (wire wound or thin film) with the physical property of an electrical resistance which varies with changes in temperature. Typically, the higher the temperature in the environment of temperature sensor 70, the greater the electrical resistance across the metallic component of temperature sensor 70.
  • Temperature sensors having a platinum metallic component may be desirable because of the nearly linear relationship between resistance and temperature platinum exhibits over a fairly wide temperature range. Of course, one skilled in the art could readily adapt a temperature sensor having a non-linear temperature/resistance curve, so long as the sensor's behaviour over the temperature range of interest is suitably repeatable.
  • temperature sensor 70 is coupled to a constant current source 100, which is also located within housing 90.
  • V ⁇ is passed through analog-to- digital converter 22, which is read by computing device 20. Computing device 20 then determines the measured temperature and stores the temperature measurement in memory 26.
  • Fig. 5 depicts a constant-current, voltage measurement circuit for use in conjunction with temperature sensor 70, a variety of different circuits could readily be adapted for use with temperature sensor 70, including circuits that measure changes in current passing through temperature sensor 70.
  • Temperature sensor 70 is mounted within housing 90 such that the temperature sensitive component of temperature sensor 70 is adjacent the outer surface of housing 90, and substantially thermally isolated from any thermal energy that may be created by the operation of the other electronic components mounted within housing 90. In this way, temperature sensor 70 is positioned to detect temperature changes in the body of the patient (either when monitoring device 1 is implanted or when it is worn by the patient) as opposed to changes in temperature of the electronics of monitoring device 1. It should be understood, however, that temperature sensor 70 may also be calibrated to compensate for changes in detected temperature due to thermal energy from monitoring device 1 .
  • Memory 26 of computing device 20 includes a look-up table relating the digital voltage across temperature sensor 70 to temperature, according to the specified operational characteristics of temperature sensor 70. Computing device 20 periodically reads the digital voltage signal, accesses the look-up table in memory 26, and determines the current body temperature of the patient. The temperature is stored in memory 26 and may be transmitted from monitoring device 1 in the manner described below with reference to communication device 30.
  • Computing device 20 comprises a plurality of components. While components are described herein as if they were independent components, the components may be combined in a single device such as an application specific integrated circuit. As shown in Fig. 6, computing device 20 includes an A/ D converter 22 (which also converts optical signals to digital signals), a processor 24, a memory 26, a program 28, inputs 23, and outputs 25. Memory 26 may include, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology. A/ D converter 22, processor 24 and memory 26 may be constructed in an integrated circuit. The integrated circuit may further include emitter array 100, detector array 200, and communication device 30.
  • Program 28 represents computer instructions directing processor 24 to perform tasks responsive to data.
  • Program 28 resides in memory 26.
  • Data including reference data and measurement data, also resides in memory 26.
  • Reference data may be stored in ROM or it may be stored in RAM so that it may be modified over time, either in response to external inputs or in response to characteristics of measurement data collected over time.
  • Protocols for responding to measurement values may also be provided. Protocols may be stored in permanent memory or may be stored in non-permanent memory such as RAM and are described in further detail in the System for Monitoring application reference above.
  • Computing device 20 may be configured to cause communication device 30 to transmit an alert if an abnormal condition is detected, particularly a condition determined to be a serious or dangerous condition according to a prescribed protocol.
  • the alert may be used to actuate an alarm or to alert the patient to take remedial action.
  • a remedial action may be terminating or reducing physical activity.
  • the alert may also provide global positioning (GPS) information to an emergency service.
  • GPS global positioning
  • the abnormal condition when found to be present, may also be displayed on a computer 36 and/or transmitted via communication device 30 to a caregiver.
  • the alert may comprise a text message or a code corresponding to the condition.
  • Computing device 20 may also initiate a new measurement cycle and measure on a continuous basis in response to the detection of an abnormal condition.
  • Computing device 20 may also initiate a treatment.
  • Monitoring device 1 may receive, through communication device 30, an external command to perform a treatment in response to the alert.
  • an abnormal condition may also be used to direct a device adapted to provide treatment to deliver such treatment.
  • Treatment may include, for example, an electric shock or a drug delivery.
  • Parameter values and/or other information may be communicated to an external device.
  • the parameter values may be stored in memory 26 and transmitted wirelessly by communication device 30.
  • the communication signal from communication device 30 may be activated on a periodic basis (e.g., once per day, once per week, etc.), in response to an abnormal condition, in response to an externally received command, whenever memory usage exceeds a predetermined amount, or whenever the energy storage level is determined to be low, the latter two conditions established to prevent data loss as a result of memory overflow or energy loss.
  • monitoring device 1 may include communication devices in addition to communication device 30. For example, where communication device 30 is a cellular modem, monitoring device 1 may also include a backup Bluetooth or RF communication device.
  • Such a backup device may be desirable in situations where, after one or more attempts, it becomes apparent that the cellular modem is unable to transmit information (e.g., due to low available power, poor network coverage, etc.). In such a situation, computing device 20 may activate the backup communication device to transmit information or an alert to an alternate external receiving device.
  • computing device 20 may be programmed to respond to requests for data received by communication device 30 (e.g., from a health care provider) by causing communication device 30 to transmit the requested data or information representing the requested data.
  • requests for data received by communication device 30 e.g., from a health care provider
  • the communication signal may be received by equipment near the patient to alert the patient to the condition, or received remotely (such as over a network) by a healthcare provider, relative, or other predetermined recipient. Further description of a networked system including at least some of the principles of the present invention is provided in the System for Monitoring application reference above.
  • communication device 30 is a two-way communication device, e.g. via the cellular telephone system and/or the GPS satellite system, such as NOKIA model number KNL1 147-V.
  • communication device 30 is capable of transmitting information, but does not receive information or commands.
  • communication device 30 includes an antenna 32 for transmitting and receiving communication signals.
  • the communication signals, represented by symbol 34, travel wirelessly to and from one of a plurality of optional external communication devices.
  • an external communication device may be a computer 302 or any electronic device capable of wirelessly receiving a communication signal, such as telephone 306 which is exemplified as a cellular phone.
  • communication signal is meant a signal that has one or more of its characteristics set or changed to encode information in the signal.
  • communication signals include acoustic, RF, infrared, other wireless media, and combinations of any of the above.
  • An external communication device may also be a relay unit located externally of the patient's body, e.g. clipped to the patient's belt.
  • the relay unit may include a receiver for receiving the transmissions from communication device 30, and a transmitter for retransmitting the communication signal to another external communication device.
  • the relay unit may also be stationary and hardwired for connection to the internet or direct connection to a healthcare provider's computer. Likewise, the relay unit may receive a communication signal from a healthcare provider and transmit the signal to communication device 30.
  • a system for recharging energy storage device 40 may be provided in one embodiment according to the invention.
  • Computing device 20 receives energy from energy storage device 40.
  • Energy storage device 40 includes an energy storage component such as a battery.
  • monitoring device 1 may also include an energy coupler for receiving energy from an external source to charge energy storage device 40.
  • an energy coupler is an electromagnetic device, such as induction coils 42, for receiving external electromagnetic signals 44 and converting such signals into electrical energy for recharging the energy storage component.
  • An external electromagnetic device 46 generates electromagnetic signal 44 which is received and converted into electrical energy by energy storage device 40.
  • Energy storage device 40 may provide a charge signal to computing device 20.
  • Computing device 20 may compare the charge signal to a reference charge signal and initiate a low charge communication signal for alerting the patient and/or healthcare providers.
  • a detector such as a voltage sensor, may be used to monitor the charge of energy storage device 40 and provide a signal to computing device 20 when the charge falls below a threshold.
  • Electromagnetic device 46 may be placed near monitoring device 1 to charge energy storage device 40.
  • Energy may instead, or additionally, be provided in the form of ultrasonic vibrations.
  • a piezoelectric transducer may be included in monitoring device 1 .
  • An ultrasonic vibration may be provided externally.
  • the transducer generates electricity when driven by ultrasonic vibrations.
  • energy or power may also be provided to monitoring device 1 through connector 85.
  • each of or some of optical sensor assembly 2, Doppler sensor 60, ECG sensor 50, and temperature sensor 70 may be modular in design.
  • a plurality of different Doppler sensors 60 may be produced to have different performance characteristics (e.g., different output frequencies).
  • any of the plurality of the sensors may be installed in monitoring device 1 to achieve the desired performance.
  • monitoring device 1 Once monitoring device 1 is equipped with the selected sensors, computing device 20 may be programmed to adapt the various algorithms to accommodate the selected sensors. In this manner, a basic monitoring device 1 including computing device 20, communication device 30, etc., may be "custom" built with any of a variety of sensors and programmed to operate with the selected sensors.
  • optical sensor assembly 2 Doppler sensor 60, and temperature sensor 70 are described herein as being activated to obtain measurements relatively infrequently (at least under normal conditions) to conserve power, as battery technology improves, the frequency of activation of these sensors may be increased. Also, where monitoring device 1 is worn externally, connector 85 may be used to supply power to monitoring device 1 , thereby eliminating the power consumption concern and permitting frequent, or even continuous, operation of these sensors.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Public Health (AREA)
  • Molecular Biology (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Biophysics (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Veterinary Medicine (AREA)
  • Radiology & Medical Imaging (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Hematology (AREA)
  • Vascular Medicine (AREA)
  • Optics & Photonics (AREA)
  • Cardiology (AREA)
  • Physiology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Gynecology & Obstetrics (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
  • Measuring And Recording Apparatus For Diagnosis (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Optical Measuring Cells (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

A device for monitoring the heart of a patient including a housing, a computing device, an optical sensor adapted to provide signals to the computing device indicative of a distance from the optical sensor to a vessel carrying blood, as well a diameter of the vessel, a Doppler sensor adapted to provide signals to the computing device indicative of a velocity of the blood through the vessel, and an ECG sensor adapted to provide signals to the computing device indicative of a plurality of electrical stimuli that cause the heart to pump. The computing device uses signals from the optical sensor, the Doppler sensor, and the ECG sensor to compute parameters including oxygen saturation of the blood, blood flow, blood pressure, heart rate, and cardiac output.

Description

INTEGRATED HEART MONITORING DEVICE AND METHOD OF USING SAME
CLAIM OF PRIORITY
This application claims priority from U.S. Pat. Appl. No. 12/1 19,315, entitled OPTICAL SENSOR APPARATUS AND METHOD OF USING SAME," U.S. Pat. Appl. No. 12/1 19,339, entitled "DOPPLER MOTION SENSOR APPARATUS AND METHOD OF USING SAME," U.S. Pat. Appl. No. 12/1 19,325, entitled "INTEGRATED HEART MONITORING DEVICE AND METHOD OF USING SAME," U.S. Pat. Appl. No. 12/1 19,462, entitled "METHOD AND SYSTEM FOR MONITORING A HEALTH CONDITION," all filed on May 12, 2008, and U.S. Pat. Appl. No. 12/206,885, entitled "DOPPLER MOTION SENSOR APPARATUS AND METHOD OF USING SAME," filed on September 9, 2008, all by the same inventor hereto, and all applications incorporated herein by reference in their entirety. FIELD OF THE INVENTION
The present invention relates to sensing devices and, more specifically, to devices for monitoring cardiac behaviour. BACKGROUND AND SUMMARY OF THE INVENTION
Cardiovascular disease is a large, growing health problem world wide. Some studies indicate that approximately 15% of the Western World suffers from one or more cardiovascular disease. In the United States, nearly 25% of the population is affected, resulting in more than six million hospitalizations every year.
Various devices exist for monitoring certain parameters relating to cardiac performance. In some instances, in vivo parameters of a patient may need to be monitored over a period of time; for example, such monitoring may be necessary in a subject who has occasional irregular cardiac beats. Heart arrhythmias are changes in the normal sequence of electrical impulses that cause the heart to pump blood through the body. As such abnormal heart rhythms may only occur sporadically, continuous monitoring may be required for detection. By providing continuous monitoring, medical personnel determine if there is a tendency for production of sustained irregular beats in a life-endangering fashion. Medical personnel also use the monitoring results to establish a proper course of treatment.
One prior art device that measures heart rate is the "Reveal" monitor by Medtronic (Minneapolis, MN, USA). This device comprises an implantable heart monitor used, for example, in determining if syncope (fainting) in a subject is related to a heart rhythm problem. The Reveal monitor continuously monitors the rate and rhythm of the heart for up to 14 months. After waking from a fainting episode, the subject places a first recorder device external to the skin over the implanted Reveal monitor and presses a button to transfer data from the monitor to the recorder. The subject gives the first recorder to a physician who provides the subject with a second recorder to use for continued data acquisition. The physician then analyzes the information stored on the first recorder to determine whether abnormal heart rhythm has been recorded. The use of the recorder is neither automatic nor autonomic, and therefore requires either the subject to be conscious or another person's intervention.
Another known type of implantable monitoring device is a transponder-type device, in which a transponder is implanted in a patient and is subsequently accessed with a hand-held electromagnetic reader in a non-invasive manner. An example of the latter type of device is described in US Patent 5,833,603.
In many circumstances, medical personnel are interested in collecting a variety of different types of data relating to the behaviour of the heart and the condition of the patient. Moreover, as mentioned above, it is desirable to obtain as much relevant data as possible without requiring the patient to visit health care provider. Relevant information may include the oxygen saturation level of blood flowing through the aorta, blood pressure, heart rate, blood flow, stroke volume, cardiac output, the electrical activity of the heart (for generating electrocardiogram (ECG) data), and body temperature.
An integrated heart monitoring device for acquiring signals and transmitting data is disclosed herein. In one embodiment of the invention, the monitoring device includes an optical sensor assembly including a plurality of photon emitters and a plurality of photon detectors for detecting a plurality of optical signals. The emitters and detectors face the aorta. A computing device operates the plurality of emitters and detectors and processes the plurality of optical signals to obtain optical measurement values representing the location and size of the aorta and the oxygen saturation of the blood flowing through the aorta.
The monitoring device further includes a Doppler sensor for emitting and detecting a plurality of ultrasonic waves. The computing device also operates the Doppler sensor and, with the aid of the optical measurement values obtained using the optical sensor assembly, processes the plurality of ultrasonic waves to obtain Doppler measurement values representing heart rate, blood flow, stroke volume, blood pressure, and cardiac output.
The monitoring device further includes an ECG sensor for detecting the electrical signals which cause the heart to pump. Additionally, the monitoring device includes a temperature sensor for measuring the temperature of the patient. An energy storage device powers the computing device, the various sensors, and a communication device which is configured to transmit the collected data, or information relating to the collected data, according to a predetermined schedule or upon the occurrence of an event, such as abnormal data or a request for data from an external device. The sensors, the computing device, the communication device, and the energy storage device are enclosed in a housing, which may be worn by the patient or implanted.
By integrating the plurality of sensors and other components mentioned above, embodiments of the present invention permit a single device, mounted at one location on the patient's body, to accurately measure a comprehensive set of parameters relating to the behaviour of the heart, including cardiac output. Moreover, the integrated monitoring device described herein may perform analyses of the parameters and perform functions in response to the "on-board" analyses, as opposed to other sensing devices that export raw data for analysis by another device. As indicated above, the integrated monitoring device according to embodiments of the invention also communicates with other devices, wirelessly or otherwise, providing information and receiving commands and data. As such, the monitoring device collects, analyzes, and communicates data without any human intervention.
The features of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings.
Brief Description of the Drawings:
Figure 1 A is a schematic side view of a monitoring device according to one embodiment of the invention.
Figure 1 B is an outwardly-facing view of the monitoring device of Figure 1.
Figure 1 C is a perspective view of the monitoring device of Figure 1. Figure 2 is a schematic side view of the monitoring device of Figure 1 and a vessel.
Figure 3 is a schematic side view of a Doppler sensor according to one embodiment of the invention.
Figure 4 is a conceptual view of fluid flowing through a vessel.
Figure 5 is a schematic representation of a temperature sensing circuit.
Figure 6 is a conceptual view of a computing device according to one embodiment of the present invention.
Figure 7 is a conceptual view of a system adapted to transmit and receive communication signals from the monitoring device of Figure 1.
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate embodiments of the invention in several forms and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
The embodiments discussed below are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
Fig. 1A depicts an integrated monitoring device according to one embodiment of the present invention. The monitoring device 1 generally includes a plurality of components including an optical sensor assembly 2, a Doppler sensor 60, an ECG sensor including probes 5OA and 5OB (hereinafter collectively referred to as ECG sensor 50), a temperature sensor 70, a computing device 20, a communication device 30, and an energy storage device 40, each of the components mounted on a board 80 and being in electronic communication with computing device 20. The components are enclosed in a housing 90.
Throughout this application, references made to optical sensor assembly 2 refer to the optical sensor assembly 2 described in the Optical Sensor Apparatus application incorporated herein by reference above. Also, references to the Doppler sensor 60 refer to the Doppler sensor 60 described in the Doppler Motion Sensor application incorporated by reference above. The full description of optical sensor assembly 2 and Doppler sensor 60 will not be repeated in this application.
In one embodiment according to the invention, monitoring device 1 is adapted to measure the physiological behaviour of a patient's heart. By "patient" it is meant a person or animal. Although the invention disclosed herein is described in the medical context, the teachings disclosed herein may be applicable in other contexts where compact data acquisition assemblies are desirable to perform measurements over time.
In one embodiment according to the invention, monitoring device 1 is implanted subcutaneously in the patient's body. It should be understood, however, that monitoring device 1 may be implanted at different locations using various implantation techniques. For example, monitoring device 1 may be implanted within the chest cavity beneath the rib cage. Housing 90 may be formed in the shape of a circular or oval disc, with dimensions roughly the same as two stacked quarter dollar coins. More specifically, housing 90 may be approximately three centimetres in diameter and approximately one centimetre thick. Of course, housing 90 may be configured in a variety of other shapes and sizes, depending upon the application. Housing 90 may include four outwardly projecting loops 92, shown in Figs. 1 B and 1 C, for receiving sutures in order to fix the assembly subcutaneously within the patient's body. More or fewer loops 92 may be provided depending upon the shape of housing 90. When so fixed, optical sensor assembly 2, Doppler sensor 60, ECG sensor 50, and temperature sensor 70 are positioned facing inwardly while an energy coupler 42, which is described with particularity below, faces outwardly.
In another embodiment of a monitoring device 1 according to the invention, monitoring device 1 is integrated with an implanted cardiac device such as a pacemaker, a Cardiac Resynchronization Therapy (CRT) device, an implantable cardioverter defibrillator (ICD), etc. In such an embodiment, monitoring device 1 may communicate with the implanted cardiac device and provide information from the implanted cardiac device as well as from its own sensors to external devices in the manner described in the System for Monitoring application incorporated herein by reference above. As many implanted cardiac devices are currently well- understood and routinely prescribed, integration of monitoring device 1 into such other devices may provide an effective means for achieving market acceptance. The above-described integration may be achieved by combining the components of monitoring device 1 and the cardiac device. If the cardiac device includes a computing device, for example, the algorithms that carry out the functions according to the invention may be incorporated with the computing device of the cardiac device instead of adding a second computing device. In a similar manner, energy storage and communication devices may be combined to avoid duplication and lower cost. In one embodiment, some components of monitoring device 1 are included within housing 90 and some components are included with the cardiac device. The cardiac device and the components in housing 90 are operably connected.
In another embodiment, monitoring device 1 is positioned externally to the patient's body. A support member is provided to support monitoring device 1 externally to the body. The support member may be permanently or temporarily coupled to monitoring device 1. In one embodiment, the support member comprises an adhesive layer for adhesively coupling the support member to the patient's body. In another embodiment, the support member comprises a belt, which may be elastic, for holding monitoring device 1 against the patient's body.
Monitoring device 1 may be implanted or positioned on the patient with the aid of an external mapping system such as an ultrasound machine. Proper placement ensures that the aorta is located within the sensing range of the various sensors of monitoring device 1. For example, monitoring device 1 may be positioned on the chest or back of the patient in a location that reduces interference by the ribs of the measurements acquired in the manner described herein.
1. OPTICAL SENSOR
As described in full detail in the Optical Sensor Apparatus application, optical sensor assembly 2, among other things, senses the oxygen saturation level of the patient's blood conveyed through the aorta. Sensing assembly 2 emits beams of electromagnetic energy in the infrared (IR) range of the electromagnetic spectrum and detects IR signals reflected from haemoglobin in the aorta, which is the iron- containing oxygen-transport metalloprotein in red blood cells.
Fig. 2 illustrates the relationship between the aorta 3 conveying blood 4 having haemoglobin in red blood cells 5 and a pair of photocells, emitter 101 and detector 201 , included in emitter array 100 and detector array 200 of sensor assembly 2, respectively. Emitter array 100 may include sixteen emitters 101 -1 16 (only emitter 101 is shown) and detector array 200 may include sixteen detectors 201 -216 (only detector 201 is shown), each being paired with an emitter. Sensor assembly 2 and arrays 100, 200 may be selected from the 8572 family of optical sensors manufactured by Motorola. Emitter 101 emits a beam of photons, including photon 101 ', some of which pass through aorta 3, and others of which are reflected off of red blood cells 5, including photon 101 '. As described in the Optical Sensor Apparatus application, computing device 20 controls the operation of emitter 101 and measures the time required for detector 201 to detect the reflected beam, and interprets signals provided by detector 201 to determine the power or intensity of the reflected beam. This information, along with the known characteristics of the emitted beam, permits computing device 20 to determine a variety of characteristics of aorta 3 and blood 4.
According to one embodiment of the invention, computing device 20 processes signals received from detector array 200 to calculate the time required for the emitted beam to travel from the emitter, to the aorta 3, and to the detector as a reflected beam. As the speed of the beam is known and the distance between the emitter and detector is known, a simple calculation yields the distance from monitoring device 1 to the aorta 3. Computing device 20 also uses the signals from detector array 200 to determine the power of the reflected beam received by each detector in detector array 200. These power values are then used to determine the diameter of aorta 3 using the methods and principles described in the Optical Sensor Apparatus application.
It should be understood that in determining the diameter of the aorta in the manner described above, each of emitters 101 -1 16 are activated individually, in rapid succession. In one embodiment of the invention, the beams are emitted individually in a row-by-row scanning fashion, beginning with emitter 101 , which is followed sequentially until emitter 1 16 is activated. In other embodiments, other sequences are followed.
As indicated above, optical sensor assembly 2 also provides monitoring device 1 with the ability to determine the oxygen saturation level of blood carried by the aorta. When making an oxygen saturation measurement, sensing device 1 activates all emitters 101 -116 of emitter array 100 simultaneously. Having already determined the size and location of the aorta as described above, the expected size or area of the reflected beam received by detector array 200 may be computed by computing device 20. The intensity or power of the reflected beam is, however, unknown prior to this measurement. Detector array 200 receives the reflected beam and provides a signal indicating the intensity of the reflected beam. As the intensity of the emitted beam is known, the intensity measurement of the reflected beam permits computation of the oxygen saturation percentage of the blood in the aorta. Under normal operating conditions, monitoring device 1 may perform an oxygen saturation measurement once or twice per day.
In one embodiment, monitoring device 1 also calculates cardiac pulse. As discussed previously, detectors 201 -216 produce power signals representative of iron content in blood. As the heart pumps oxygenated blood through the aorta, the power signals fluctuate. A plurality of power signals may be obtained in rapid succession to capture the power measurement fluctuation. More specifically, by performing many oxygen saturation measurements (e.g., ten times per second), over a period of time (e.g., fifteen seconds), the saturation measurements will exhibit a pattern or periodicity that represents the beating of the heart. Computing device 20 may determine a curve to fit the saturation measurements, such as a sinusoidal curve, which corresponds directly to the cardiac cycle. Computing device 20 may determine the frequency of peak values of the curve to determine its period. Each period represents a cardiac cycle. By multiplying the number of cardiac cycles in the sample period (e.g., fifteen seconds) by an appropriate factor, computing device 20 may determine pulse rate in terms of cardiac cycles per minute. In one embodiment, computing device 20 stores cardiac pulse values as normal reference values and detects an abnormal or irregular cardiac rhythm by comparing cardiac pulse values to reference values.
2. DOPPLER SENSOR
In an embodiment where monitoring device 1 includes Doppler sensor 60, aorta diameter and location provided by optical sensor assembly 2 may be used to calculate the velocity of blood flowing through the aorta, the volume of blood flowing through the aorta, the patient's blood pressure, and the cardiac output. These parameters may be used to calculate and diagnose an abnormal condition relating to cardiac output. As is fully described in the Doppler Motion Sensor application referenced above, one embodiment of Doppler sensor 60 includes three transducers for insonating the aorta and receiving reflected ultrasonic waves. The velocity of the blood in the aorta is determined by directing the ultrasonic waves towards the blood at a known angle, measuring the frequency shift of the reflected ultrasound energy, and then calculating the velocity of the blood. More specifically, the Doppler frequency shift is proportional to the component of the velocity vector that is parallel to the insonifying wave. The velocity v of the blood is determined by the following equation: v = U c /(2 f cos θ) where c is the velocity of sound in blood, f is the frequency of the insonifying wave, θ is the angle between the wave and the velocity vector, and fd is Doppler frequency shift.
Doppler sensor 60, which may be a continuous wave sensor or a pulsed wave sensor, measures frequency shift by comparing phase shifts between subsequently received waves according to principles that are well known in the art. As the distance between Doppler sensor 60 and the aorta has already been determined by optical sensor assembly 2, and the speed of sound through tissue is known, the frequency shift permits computing device 20 to determine the actual velocity of blood in the aorta.
Fig. 3 illustrates Doppler sensor 60 including linear array transducers A, B and C according to one embodiment of the invention. Each of transducers A, B and C is operably connected with a driver device (not shown) that powers the transducer. Transducers A, B and C are disposed at an angle relative to each other. Transducers B and C are disposed at a 45 degree angle relative to transducer A and at 90 degrees relative to each other. Other relative angles among the transducers may be used. Each of transducers A, B and C may be driven at a different frequency to distinguish the source of the reflected waves received by Doppler sensor 60. For convenience, each transducer in a linear array is referred to herein as a transducer segment. In the embodiment shown, each linear array transducer comprises five transducer segments. Transducer segments may be operably connected to be activated separately or concurrently. Separate activation of one or more transducer segments is desirable to limit power consumption.
As shown, transducer A includes segments A1 -A5, transducer B includes segments B1 -B5, and transducer C includes segments C1 -C5. Each segment may transmit and receive ultrasonic energy in the form of waves. The arrows originating at each segment and projecting perpendicularly to the segment represent the direction of waves transmitted by each segment. Further, arrows 72, 74, and 76 represents the directions of waves produced by transducers A, B and C, in aggregate, respectively. In one embodiment, one or more segments of transducer A are energized at a frequency of 5 Mhz, one or more segments of transducer B are energized at a frequency of 4.5 Mhz, and one or more segments of transducer C are energized at a frequency of 5.5 Mhz. Frequency selection is a function of the distance between the transducer and the target fluid and is selected accordingly. A reflected wave may be measured at each segment of a linear array transducer. Each segment may be energized sequentially and may be energized a plurality of times.
The Doppler shift, or frequency shift, is proportional to the component of the velocity vector parallel to the impinging wave. Since the Doppler shift depends from the cosine of the angle θ between the wave and the velocity vector, and the cosine function ranges between 0 and 1 , signals produced by waves oriented parallel to the velocity vector produce selected signals and, as the angle θ increases, it becomes increasingly more difficult to determine the Doppler shift from those signals. As is fully described in the Doppler Motion Sensor application, the K-shape arrangement of transducers A, B, C ensures that at least one of the transducers is oriented at an acceptable angle θ. Three transducers enable Doppler sensor 60 to obtain a sufficient number of signals even when the relative position of Doppler sensor 60 and aorta 3 change slightly with time or other factors such as a patient's activity level and posture. When broad waves are transmitted, reflected waves may be received by each transducer. However, since waves have frequencies corresponding to each transmitting transducer, Doppler sensor 60 is able to select which signals to filter based on the relative position of the corresponding transmitting transducer and its transmission frequency.
As discussed previously, the calculation of blood velocity requires knowledge of the incident angle θ between the emitted waves and aorta 3. Incident angle and other data characterizing the relative position of aorta 3 and Doppler sensor 60 may be obtained in various ways. Once obtained, it may be stored in memory 26 (see Fig. 6) as reference values. In one embodiment, the relative position data is provided to computing device 20 by optical sensor assembly 2. With this information, computing device 20 computes a blood velocity value by comparing the frequency of the transmitted and the received waves according to well known frequency-shift and angle algorithms or tables. The velocity of the blood flowing through the aorta is different depending upon which portions of the blood are being measured. According to well-understood principles of fluid dynamics, fluid flowing near the outer wall of a vessel flows more slowly than fluid flowing through the central axis of the vessel because of shear
5 stresses between the fluid and the outer wall. The distance and diameter measurements provided by optical sensor apparatus 2 permit computing device 20 to determine, from the measurements of Doppler sensor 60, the location of aorta 3 within the reflected wave detected by Doppler sensor 60. Each of the five velocity measurements in each of the three sets of measurements taken in the manner o described in the Doppler Motion Sensor application is averaged to determine an approximate overall blood flow through aorta 3 and to account for the velocity profile across the diameter of aorta 3. The sets of velocity measurements are taken at the maximum (systolic) and minimum (diastolic) flow conditions of the cardiac cycle. Accordingly, by averaging the five velocity measurements for each of the three sets
5 of maximum flow measurements, and averaging the three results from those calculations, computing device 20 determines an average maximum flow measurement. An average minimum flow measurement is computed in a similar fashion. Finally, the average minimum and average maximum blood flow measurements are averaged to determine the mean blood flow for the patient.
O Next, computing device 20 may compute stroke volume by simply multiplying the mean blood flow measurement described above by the area of aorta 3 (i.e., mean blood flow * πr2), where r is the radius of aorta 3. Of course, the radius of aorta 3 is simply one half of the aorta diameter, which is determined using optical sensor assembly 2 in the manner described above.
5 3. ECG SENSOR
ECG sensor 50 is, in one embodiment of the invention, a single lead device including an anode probe 5OA and a cathode probe 5OB (collectively referred to herein as "ECG sensor 50"). ECG sensor 50 uses probes 5OA, 5OB to detect changes in voltage of the electrical impulses provided to the heart muscles. As is
0 well understood in the art, these electrical signals which trigger heart beats normally start at the top of the heart in the right atrium, and travel from the top of the heart to the bottom. They cause the heart muscle to contract as they travel through the heart. As the heart contracts, it pumps blood out to the rest of the body. By monitoring the electrical activity of the heart over time, ECG sensor 50 permits computing device 20 to determine how fast the heart is beating (i.e., pulse) by determining the number of cardiac cycles per minute (or fraction of a minute). The pulse measurement may be used with the stroke volume discussed above to determine cardiac output. More specifically, the stroke volume measurement may be multiplied by the number of strokes per minute (i.e., pulse) to determine the total volume of blood displaced per minute (i.e., cardiac output).
In one embodiment of the invention, the pulse measured by ECG sensor 50 is compared to the pulse measured by optical sensor assembly 2 as described in the Optical Sensor Apparatus application. If the measurements differ by more than a predetermined amount, the ECG pulse measurement may be discarded under the assumption that electrical interference or some other disturbance caused errors in the detected signals. In this manner, optical sensor assembly 2 functions as a backup pulse measurement device for ECG sensor 50.
ECG sensor 50 provides voltage measurements to computing device 20, which in turn processes the data by filtering out frequencies outside the known range of frequencies generated by the heart's electrical activity. ECG sensor 50 is also mounted within housing 90 in a manner and location that electrically isolates ECG sensor 50 from the other electronic components of monitoring device 1 to minimize the electrical interference caused by those other electronic devices. In one embodiment of the invention, the output of ECG sensor 50 is passed through a band pass filter having a lower cut-off frequency and an upper cut-off frequency. Additionally, computing device 20 may further process the data to produce a smooth ECG trace by applying any of a number of suitable digital smoothing functions.
The output of ECG sensor 50 also permits computing device 20 to identify the maximum and minimum blood flow through the aorta, which are used in the stroke volume and cardiac output calculations described above. Additionally, It shows the heart's rhythm (steady or irregular) and where in the body the heart beat is being recorded. It also records the strength and timing of the electrical signals as they pass through each part of the heart.
Referring now to Fig. 4, ECG sensor 50 and Doppler sensor 60 are used in combination to determine the blood pressure of the patient directly from the aorta 3. One skilled in the art may, using the ECG trace provided by ECG sensor 50, determine with accuracy the maximum blood flow position of the cardiac cycle and the minimum blood flow position. Doppler sensor 60 facilitates determination of the speed or velocity of blood in aorta 3 under the maximum and minimum blood flow conditions in the manner described above. Computing device 20 converts the velocity measurements under each condition into pressure measurements using the known internal surface area of aorta 3 (determined from the diameter measurements facilitated by optical sensor assembly 2) according to principles dictated by Bernoulli's equation. These pressure measurements reflect the dynamic pressure of the blood flowing through aorta 3 under the maximum and minimum flow conditions. More specifically, at Ti of Fig. 4, the dynamic pressure PDi corresponds to the pressure determined from the velocity measurements taken under maximum blood flow conditions. At T2, PD2 corresponds to the pressure determined from the velocity measurements taken under minimum blood flow conditions. It is well known that the total pressure of a fluid flowing through a vessel is the sum of the dynamic pressure and the static pressure. In the case of the aorta 3, the static pressure (depicted as force arrows directed outwardly against the outer wall of the aorta 3) under maximum flow conditions (PSi) directly corresponds to the systolic blood pressure measurement and the static pressure under minimum flow conditions (PS2) directly corresponds to the diastolic blood pressure measurement.
The systolic and diastolic blood pressure measurements may be derived by further computing the total pressure (PT) of blood flowing through aorta 3 and taking advantage of the fact that the total pressure through the aorta at Ti (i.e., PTi) must be the same as the total pressure at T2 (i.e., PT2). Total pressure is derived by computing the change in pressure from the minimum flow conditions to the maximum flow conditions. This change or acceleration, in conjunction with the stroke volume and the known elasticity of aorta 3, permits computing device 20 to determine total pressure according to well known principles in the art. Thus, at time Ti, the equation PTi = PSi + PDi may be solved for PSi and at time T2, the equation PT2 = PS2 + PD2 may be solved for PS2. As indicated above, PSi and PS2 are the systolic and diastolic blood pressure measurements, respectively.
It should be understood that although the blood pressure computation described above refers to determining blood pressure in aorta 3, the same process may be carried out to determine blood pressure in the pulmonary artery, assuming the pulmonary artery is within the sensing range of monitoring device 1. As described in the Optical Sensor Apparatus application, monitoring device 1 distinguishes between the pulmonary artery and aorta 3 by measuring the oxygen saturation of both, and determining which vessel carries blood with higher oxygen saturation. That vessel must be aorta 3. In another embodiment of the invention, monitoring device 1 instead identifies the vessel with lower oxygen saturation as the vessel of interest (i.e., the pulmonary artery). The location and size of the pulmonary artery is then determined in the same manner as described with reference to aorta 3. With the geometry of the pulmonary artery defined, the pressure of the blood flowing through the pulmonary artery is measured as described above with reference to aorta 3.
In one embodiment of the invention shown in Fig. 1 A, housing 90 includes a connector 85 to permit connection of additional ECG leads. Connector 85 is electrically coupled to ECG sensor 50 and other components of monitoring device 1 through board 80. When additional ECG leads are connected to connector 85, connector 85 passes signals from the additional leads to ECG sensor 50. As is known in the art, the additional leads may be affixed to various locations on the chest, back, arms, or legs of the patient, and each lead includes a receiver for detecting electrical activity. As indicated above, connector 85 may also function as a I/O port for monitoring device 1 , permitting downloading of data to a docking station 304 and uploading of data and instructions during a programming operation.
4. TEMPERATURE SENSOR
A variety of different devices may function as temperature sensor 70. Temperature sensor 70 is, in one embodiment of the invention, a readily available resistance temperature detector (RTD). In general, temperature sensor 70 may include a metallic component (wire wound or thin film) with the physical property of an electrical resistance which varies with changes in temperature. Typically, the higher the temperature in the environment of temperature sensor 70, the greater the electrical resistance across the metallic component of temperature sensor 70. Temperature sensors having a platinum metallic component may be desirable because of the nearly linear relationship between resistance and temperature platinum exhibits over a fairly wide temperature range. Of course, one skilled in the art could readily adapt a temperature sensor having a non-linear temperature/resistance curve, so long as the sensor's behaviour over the temperature range of interest is suitably repeatable.
As shown in Fig. 5, temperature sensor 70 is coupled to a constant current source 100, which is also located within housing 90. Current source 100 maintains a constant current through temperature sensor 70 as the resistance of temperature sensor 70 changes with temperature. Accordingly, the voltage across temperature sensor 70 (VT) changes in direct proportion to the changes in temperature. More specifically, according to Ohm's law, Voltage = current * resistance. With a constant current source, changes in resistance due to temperature changes are detected as changes in Vτ. In one embodiment of the invention, Vτ is passed through analog-to- digital converter 22, which is read by computing device 20. Computing device 20 then determines the measured temperature and stores the temperature measurement in memory 26.
It should be understood that although Fig. 5 depicts a constant-current, voltage measurement circuit for use in conjunction with temperature sensor 70, a variety of different circuits could readily be adapted for use with temperature sensor 70, including circuits that measure changes in current passing through temperature sensor 70.
Temperature sensor 70 is mounted within housing 90 such that the temperature sensitive component of temperature sensor 70 is adjacent the outer surface of housing 90, and substantially thermally isolated from any thermal energy that may be created by the operation of the other electronic components mounted within housing 90. In this way, temperature sensor 70 is positioned to detect temperature changes in the body of the patient (either when monitoring device 1 is implanted or when it is worn by the patient) as opposed to changes in temperature of the electronics of monitoring device 1. It should be understood, however, that temperature sensor 70 may also be calibrated to compensate for changes in detected temperature due to thermal energy from monitoring device 1 . Memory 26 of computing device 20 includes a look-up table relating the digital voltage across temperature sensor 70 to temperature, according to the specified operational characteristics of temperature sensor 70. Computing device 20 periodically reads the digital voltage signal, accesses the look-up table in memory 26, and determines the current body temperature of the patient. The temperature is stored in memory 26 and may be transmitted from monitoring device 1 in the manner described below with reference to communication device 30.
2. COMPUTING DEVICE
Computing device 20 comprises a plurality of components. While components are described herein as if they were independent components, the components may be combined in a single device such as an application specific integrated circuit. As shown in Fig. 6, computing device 20 includes an A/ D converter 22 (which also converts optical signals to digital signals), a processor 24, a memory 26, a program 28, inputs 23, and outputs 25. Memory 26 may include, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology. A/ D converter 22, processor 24 and memory 26 may be constructed in an integrated circuit. The integrated circuit may further include emitter array 100, detector array 200, and communication device 30.
Program 28 represents computer instructions directing processor 24 to perform tasks responsive to data. Program 28 resides in memory 26. Data, including reference data and measurement data, also resides in memory 26. Reference data may be stored in ROM or it may be stored in RAM so that it may be modified over time, either in response to external inputs or in response to characteristics of measurement data collected over time. Protocols for responding to measurement values may also be provided. Protocols may be stored in permanent memory or may be stored in non-permanent memory such as RAM and are described in further detail in the System for Monitoring application reference above.
Computing device 20 may be configured to cause communication device 30 to transmit an alert if an abnormal condition is detected, particularly a condition determined to be a serious or dangerous condition according to a prescribed protocol. The alert may be used to actuate an alarm or to alert the patient to take remedial action. A remedial action may be terminating or reducing physical activity. The alert may also provide global positioning (GPS) information to an emergency service. Referring to Fig. 7, the abnormal condition, when found to be present, may also be displayed on a computer 36 and/or transmitted via communication device 30 to a caregiver. The alert may comprise a text message or a code corresponding to the condition. Computing device 20 may also initiate a new measurement cycle and measure on a continuous basis in response to the detection of an abnormal condition.
Computing device 20 may also initiate a treatment. Monitoring device 1 may receive, through communication device 30, an external command to perform a treatment in response to the alert. Optionally, based on the protocol, an abnormal condition may also be used to direct a device adapted to provide treatment to deliver such treatment. Treatment may include, for example, an electric shock or a drug delivery.
Parameter values and/or other information may be communicated to an external device. The parameter values may be stored in memory 26 and transmitted wirelessly by communication device 30. The communication signal from communication device 30 may be activated on a periodic basis (e.g., once per day, once per week, etc.), in response to an abnormal condition, in response to an externally received command, whenever memory usage exceeds a predetermined amount, or whenever the energy storage level is determined to be low, the latter two conditions established to prevent data loss as a result of memory overflow or energy loss. It should also be understood that monitoring device 1 may include communication devices in addition to communication device 30. For example, where communication device 30 is a cellular modem, monitoring device 1 may also include a backup Bluetooth or RF communication device. Such a backup device may be desirable in situations where, after one or more attempts, it becomes apparent that the cellular modem is unable to transmit information (e.g., due to low available power, poor network coverage, etc.). In such a situation, computing device 20 may activate the backup communication device to transmit information or an alert to an alternate external receiving device.
Alternatively or in addition to the above-described transmissions, computing device 20 may be programmed to respond to requests for data received by communication device 30 (e.g., from a health care provider) by causing communication device 30 to transmit the requested data or information representing the requested data.
The communication signal may be received by equipment near the patient to alert the patient to the condition, or received remotely (such as over a network) by a healthcare provider, relative, or other predetermined recipient. Further description of a networked system including at least some of the principles of the present invention is provided in the System for Monitoring application reference above.
3. COMMUNICATION DEVICE
In one embodiment of the invention, communication device 30 is a two-way communication device, e.g. via the cellular telephone system and/or the GPS satellite system, such as NOKIA model number KNL1 147-V. In an alternate embodiment, communication device 30 is capable of transmitting information, but does not receive information or commands. As shown in Fig. 1 A, communication device 30 includes an antenna 32 for transmitting and receiving communication signals. The communication signals, represented by symbol 34, travel wirelessly to and from one of a plurality of optional external communication devices.
Referring again to Fig. 7, an external communication device may be a computer 302 or any electronic device capable of wirelessly receiving a communication signal, such as telephone 306 which is exemplified as a cellular phone. By communication signal is meant a signal that has one or more of its characteristics set or changed to encode information in the signal. By way of example, and not limitation, communication signals include acoustic, RF, infrared, other wireless media, and combinations of any of the above. An external communication device may also be a relay unit located externally of the patient's body, e.g. clipped to the patient's belt. The relay unit may include a receiver for receiving the transmissions from communication device 30, and a transmitter for retransmitting the communication signal to another external communication device. The relay unit may also be stationary and hardwired for connection to the internet or direct connection to a healthcare provider's computer. Likewise, the relay unit may receive a communication signal from a healthcare provider and transmit the signal to communication device 30.
4. ENERGY STORAGE DEVICE
Referring again to Figs. 1A-1 C, a system for recharging energy storage device 40 may be provided in one embodiment according to the invention. Computing device 20 receives energy from energy storage device 40. Energy storage device 40 includes an energy storage component such as a battery. Optionally, monitoring device 1 may also include an energy coupler for receiving energy from an external source to charge energy storage device 40.
One example of an energy coupler is an electromagnetic device, such as induction coils 42, for receiving external electromagnetic signals 44 and converting such signals into electrical energy for recharging the energy storage component. An external electromagnetic device 46 generates electromagnetic signal 44 which is received and converted into electrical energy by energy storage device 40. Energy storage device 40 may provide a charge signal to computing device 20. Computing device 20 may compare the charge signal to a reference charge signal and initiate a low charge communication signal for alerting the patient and/or healthcare providers. Alternatively, a detector, such as a voltage sensor, may be used to monitor the charge of energy storage device 40 and provide a signal to computing device 20 when the charge falls below a threshold. Electromagnetic device 46 may be placed near monitoring device 1 to charge energy storage device 40.
Energy may instead, or additionally, be provided in the form of ultrasonic vibrations. For example, a piezoelectric transducer may be included in monitoring device 1 . An ultrasonic vibration may be provided externally. The transducer generates electricity when driven by ultrasonic vibrations. As indicated herein, energy or power may also be provided to monitoring device 1 through connector 85.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains. For example, it should be understood that each of or some of optical sensor assembly 2, Doppler sensor 60, ECG sensor 50, and temperature sensor 70 may be modular in design. As such, a plurality of different Doppler sensors 60, for example, may be produced to have different performance characteristics (e.g., different output frequencies). Depending upon the application, any of the plurality of the sensors may be installed in monitoring device 1 to achieve the desired performance. Once monitoring device 1 is equipped with the selected sensors, computing device 20 may be programmed to adapt the various algorithms to accommodate the selected sensors. In this manner, a basic monitoring device 1 including computing device 20, communication device 30, etc., may be "custom" built with any of a variety of sensors and programmed to operate with the selected sensors.
As another example, it should be understood that while optical sensor assembly 2, Doppler sensor 60, and temperature sensor 70 are described herein as being activated to obtain measurements relatively infrequently (at least under normal conditions) to conserve power, as battery technology improves, the frequency of activation of these sensors may be increased. Also, where monitoring device 1 is worn externally, connector 85 may be used to supply power to monitoring device 1 , thereby eliminating the power consumption concern and permitting frequent, or even continuous, operation of these sensors.

Claims

What is claimed is:
1. A device for monitoring the heart of a patient, including: a housing; a computing device mounted within the housing; an optical sensor mounted within the housing and adapted to provide signals to the computing device indicative of a distance from the optical sensor to a vessel carrying blood, as well a diameter of the vessel; a Doppler sensor mounted within the housing and adapted to provide signals to the computing device indicative of a velocity of the blood through the vessel; and an ECG sensor mounted within the housing and adapted to provide signals to the computing device indicative of a plurality of electrical stimuli that cause the heart to pump; the computing device using signals from the optical sensor, the Doppler sensor, and the ECG sensor to compute parameters including oxygen saturation of the blood, blood flow, blood pressure, heart rate, and cardiac output.
2. The device of claim 1 , further including a temperature sensor mounted within the housing and adapted to provide signals to the computing device indicative of a temperature of the patient.
3. The device of claim 1 , further including a communication device mounted within the housing, the communication device being coupled to the computing device and configured to transmit information relating to the parameters.
4. The device of claim 1 , wherein the housing is configured for subcutaneous implantation.
5. The device of claim 1 , wherein timing of the operation of the Doppler sensor based on the signals from the ECG sensor.
6. The device of claim 1 , wherein the optical sensor assembly includes an emitter array and a detector array.
7. The device of claim 1 , further including a connector mounted to the housing, the connector being adapted to couple to ECG leads.
8. The device of claim 7, wherein the connector is configured to enable one of programming of the computing device and downloading information relating to the parameters.
9. A monitoring device for measuring parameters indicative of behavior of the heart of a patient, the device including: a plurality of sensors mounted within a implantable housing, the plurality of sensors including an optical sensor for measuring oxygen saturation of blood flowing through an aorta, a Doppler sensor for measuring a velocity of the blood, an ECG sensor for measuring electrical activity of the heart, and a temperature sensor for measuring a temperature of the patient; a communication device mounted within the housing, the communication device being configured to wirelessly transmit information relating to the measured parameters; and a computing device that executes a program to determine, based on signals from the plurality of sensors, blood pressure and cardiac output.
10. The monitoring device of claim 9, further including a rechargeable battery mounted within the housing to power the plurality of sensors, the communication device, and the computing device.
1 1 . The monitoring device of claim 9, wherein the computing device activates the Doppler sensor at a first stage in a cardiac cycle corresponding to a maximum blood flow condition through an aorta, and at a second stage in the cardiac cycle corresponding to a minimum blood flow condition through the aorta.
12. The monitoring device of claim 1 1 , wherein the computing device activates the Doppler sensor at the first stage and the second stage based on information received from the ECG sensor.
13. The monitoring device of claim 1 1 , wherein the computing device activates the Doppler sensor a plurality of times at the first stage to obtain a plurality of first measurements, and a plurality of times at the second stage to obtain a plurality of second measurements, the computing device averaging the plurality of first measurements and the plurality of second measurements.
14. The monitoring device of claim 9, wherein the housing includes a plurality of loops to facilitate implantation.
15. The monitoring device of claim 9, wherein the optical sensor emits infrared beams toward the aorta and detects infrared beams reflected from red blood cells flowing through the aorta.
16. The monitoring device of claim 9, wherein the optical sensor includes an emitter array having a plurality of emitter cells and a detector array having a plurality of detector cells.
17. The monitoring device of claim 16, wherein all of the emitter cells emit beams simultaneously during the oxygen saturation measurement.
18. The monitoring device of claim 16, wherein the computing device activates each of the plurality of emitter cells individually and processes signals received from the detector cells to determine a distance from the optical sensor to the aorta and the diameter of the aorta.
19. The monitoring device of claim 9, wherein the Doppler sensor includes three transducers arranged in a K shape.
20. The monitoring device of claim 19, wherein each of the transducers emit waves of differing frequencies.
21 . The monitoring device of claim 9, wherein the monitoring device is integrated with an implanted cardiac device.
22. A device for determining characteristics of blood and a vessel carrying the blood, the device including: an optical sensor configured to measure the size and location of the vessel using IR beams; a Doppler sensor configured to measure a velocity of the blood moving through the vessel; and a housing enclosing the optical sensor and the Doppler sensor.
23. The device of claim 22, wherein the vessel is an aorta.
24. The device of claim 22, wherein the vessel is a pulmonary artery.
25. The device of claim 22, further including an ECG sensor enclosed within the housing and configured to measure electrical impulses provided to a heart.
26. The device of claim 22, further including a computing device coupled to the optical sensor and the Doppler sensor, the computing device executing a program to determine the pressure of the blood as the blood moves through the vessel.
27. The device of claim 22, wherein the computing device further determines cardiac output.
28. The device of claim 22, further including a temperature sensor enclosed within the housing.
29. The device of claim 22, wherein the optical sensor is further configured to measure oxygen saturation of the blood.
PCT/IB2009/006088 2008-05-12 2009-05-12 Integrated heart monitoring device and method of using same WO2009138883A2 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CA2722662A CA2722662A1 (en) 2008-05-12 2009-05-12 Integrated heart monitoring device and method of using same
EP09746178A EP2282671A4 (en) 2008-05-12 2009-05-12 Integrated heart monitoring device and method of using same
JP2011509042A JP5591794B2 (en) 2008-05-12 2009-05-12 Device for monitoring a patient's heart
CN2009801223131A CN102202568A (en) 2008-05-12 2009-05-12 Integrated heart monitoring device and method of using same
IL209212A IL209212A (en) 2008-05-12 2010-11-09 Device for monitoring the heart of a patient

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
US12/119,339 2008-05-12
US12/119,462 2008-05-12
US12/119,325 2008-05-12
US12/119,339 US20080287800A1 (en) 2006-12-10 2008-05-12 Doppler motion sensor apparatus and method of using same
US12/119,315 2008-05-12
US12/119,325 US8298148B2 (en) 2005-12-08 2008-05-12 Integrated heart monitoring device and method of using same
US12/119,315 US8442606B2 (en) 2006-12-10 2008-05-12 Optical sensor apparatus and method of using same
US12/119,462 US9037208B2 (en) 2005-12-08 2008-05-12 Method and system for monitoring a health condition
US12/206,885 US20090048518A1 (en) 2006-12-10 2008-09-09 Doppler motion sensor apparatus and method of using same
US12/206,885 2008-09-09

Publications (2)

Publication Number Publication Date
WO2009138883A2 true WO2009138883A2 (en) 2009-11-19
WO2009138883A3 WO2009138883A3 (en) 2011-09-01

Family

ID=41170098

Family Applications (4)

Application Number Title Priority Date Filing Date
PCT/IB2009/006082 WO2009138882A2 (en) 2008-05-12 2009-05-12 Doppler motion sensor apparatus and method of using same
PCT/IB2009/006088 WO2009138883A2 (en) 2008-05-12 2009-05-12 Integrated heart monitoring device and method of using same
PCT/IB2009/006078 WO2009138880A2 (en) 2008-05-12 2009-05-12 Optical sensor apparatus and method of using same
PCT/IB2009/006081 WO2009138881A2 (en) 2008-05-12 2009-05-12 Method and system for monitoring a health condition

Family Applications Before (1)

Application Number Title Priority Date Filing Date
PCT/IB2009/006082 WO2009138882A2 (en) 2008-05-12 2009-05-12 Doppler motion sensor apparatus and method of using same

Family Applications After (2)

Application Number Title Priority Date Filing Date
PCT/IB2009/006078 WO2009138880A2 (en) 2008-05-12 2009-05-12 Optical sensor apparatus and method of using same
PCT/IB2009/006081 WO2009138881A2 (en) 2008-05-12 2009-05-12 Method and system for monitoring a health condition

Country Status (6)

Country Link
EP (4) EP2282671A4 (en)
JP (4) JP5591794B2 (en)
CN (4) CN102202568A (en)
CA (4) CA2722593A1 (en)
IL (4) IL209212A (en)
WO (4) WO2009138882A2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102564857A (en) * 2012-01-18 2012-07-11 复旦大学 Device for measuring nonlinear mechanical property of blood vessel
CN102755152A (en) * 2011-04-27 2012-10-31 深圳市迈迪加科技发展有限公司 Cardiac function monitoring instrument
CN102755151A (en) * 2011-04-27 2012-10-31 深圳市迈迪加科技发展有限公司 Heart function monitoring method
US9867222B2 (en) 2013-03-12 2018-01-09 Fujitsu Limited Wireless communication system, wireless communication method, transmission device, control method, and recording medium
US10964393B2 (en) 2014-05-22 2021-03-30 Semiconductor Energy Laboratory Co., Ltd. Method for operating a semiconductor device having a memory circuit with an OS transistor and an arithmetic circuit
US20220265197A1 (en) * 2019-06-18 2022-08-25 Huawei Technologies Co., Ltd. ECG Detection Method and Wearable Device

Families Citing this family (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102958448B (en) * 2010-08-06 2015-01-21 株式会社日立医疗器械 Medical image diagnostic device and cardiac measurement value display method
CN102293643B (en) * 2011-05-23 2014-07-02 陕西鸿远科技有限公司 Implanted physiological data measurement device
EP2526856A1 (en) 2011-05-26 2012-11-28 Koninklijke Philips Electronics N.V. Fever detection apparatus
JP6335122B2 (en) * 2011-10-21 2018-05-30 インキューブ ラブズ, エルエルシー Implantable oxygen saturation measuring device and method of use
JP5940652B2 (en) * 2012-04-27 2016-06-29 パイオニア株式会社 Physical condition monitoring apparatus and method
JP5946904B2 (en) * 2012-04-27 2016-07-06 パイオニア株式会社 Physical condition monitoring apparatus and method
JP2013252423A (en) * 2012-05-08 2013-12-19 Seiko Epson Corp Cardiac output monitor device and cardiac output measurement method
CN107495949A (en) * 2012-07-05 2017-12-22 微创医学科技有限公司 Direct deployment system and method
EP2882355A1 (en) 2012-08-13 2015-06-17 Mor Research Applications Ltd. Radial artery device
AU2013316101B2 (en) * 2012-09-17 2018-03-08 Donald A. Rhodes Technique for determining optimum treatment parameters
EP2928364A4 (en) 2013-01-28 2015-11-11 Valencell Inc Physiological monitoring devices having sensing elements decoupled from body motion
US9636070B2 (en) * 2013-03-14 2017-05-02 DePuy Synthes Products, Inc. Methods, systems, and devices for monitoring and displaying medical parameters for a patient
CN103932737A (en) * 2014-04-28 2014-07-23 刘树英 Cardiovascular blood flow velocity sensor
CN104013389B (en) * 2014-06-18 2016-01-20 香港应用科技研究院有限公司 For searching for the method and apparatus of artery position
EP3217863B1 (en) * 2014-11-13 2024-07-03 Vanderbilt University Device for hemorrhage detection and guided resuscitation and applications of same
KR102358589B1 (en) * 2015-02-12 2022-02-03 파운드리 이노베이션 앤드 리서치 1 리미티드 Implantable devices and related methods for monitoring heart failure
US9696199B2 (en) * 2015-02-13 2017-07-04 Taiwan Biophotonic Corporation Optical sensor
US20160317050A1 (en) * 2015-04-28 2016-11-03 Federico Perego Costa Hemodynamic parameter (Hdp) monitoring system for diagnosis of a health condition of a patient
EP3307171B1 (en) * 2015-06-10 2021-08-11 Koninklijke Philips N.V. Ultrasound imaging apparatus
KR101785788B1 (en) * 2015-06-12 2017-11-06 한국 한의학 연구원 Computing system and method for providing classifying of mibyou using analyzing result respiratory gas
WO2016205824A1 (en) 2015-06-19 2016-12-22 Neural Analytics, Inc. Transcranial doppler probe
JP2019506205A (en) * 2015-12-31 2019-03-07 ウェア2ビー リミテッド Apparatus, system, and method for non-invasive monitoring of physiological measurements
EP3399920B1 (en) 2016-01-05 2020-11-04 Neural Analytics, Inc. Integrated probe structure
CN108778140A (en) * 2016-01-05 2018-11-09 神经系统分析公司 System and method for determining clinical indication
US11589836B2 (en) 2016-01-05 2023-02-28 Novasignal Corp. Systems and methods for detecting neurological conditions
CN108778107B (en) * 2016-03-04 2021-08-03 皇家飞利浦有限公司 Device for vessel characterization
CN106073754A (en) * 2016-05-16 2016-11-09 天津工业大学 A kind of portable cardiac monitoring device of low-power consumption
CN105994004A (en) * 2016-05-19 2016-10-12 上海应特宠企业管理有限公司 Pet real-time monitor system
CN106037643A (en) * 2016-05-19 2016-10-26 上海应特宠企业管理有限公司 Implanted chip and system for continuously detecting mammal signs
WO2017208645A1 (en) * 2016-05-31 2017-12-07 国立大学法人九州大学 Flow volume measuring device, flow volume measuring method, pressure measuring device, and pressure measuring method
US10182729B2 (en) * 2016-08-31 2019-01-22 Medtronics, Inc. Systems and methods for monitoring hemodynamic status
CN108332780B (en) * 2017-01-10 2020-11-10 派克汉尼芬公司 Optically powered sensor calibration data storage module
CA3096680A1 (en) 2018-04-10 2019-10-17 Cerenetex, Inc. Systems and methods for the identification of medical conditions, and determination of appropriate therapies, by passively detecting acoustic signals
US12004846B2 (en) 2018-04-10 2024-06-11 Cerenetex, Inc. Non-invasive systems and methods for the improved evaluation of patients suffering from undiagnosed headaches
EP3840633A1 (en) * 2018-08-24 2021-06-30 LAMEGO, Marcelo Malini Monitoring device and system
CN109431485A (en) * 2018-11-06 2019-03-08 天津大学 A kind of velocity of blood flow detection device applied in foley's tube
AU2019384549B2 (en) * 2018-11-20 2024-09-19 Veris Health Inc. Vascular access devices for monitoring patient health
US11464440B2 (en) 2019-04-10 2022-10-11 Autem Medical, Llc System for prognosticating patient outcomes and methods of using the same
CN110339427B (en) * 2019-05-30 2021-12-14 努比亚技术有限公司 Infusion monitoring method, wearable device and computer-readable storage medium
CN110495864B (en) * 2019-08-02 2022-04-05 深圳市德胜医疗科技有限公司 Method and device for measuring human blood vessel blood flow contraction force and relaxation force

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5833603A (en) 1996-03-13 1998-11-10 Lipomatrix, Inc. Implantable biosensing transponder
JP2006204432A (en) 2005-01-26 2006-08-10 Seiko Instruments Inc Biological information measuring apparatus
US20060241460A1 (en) 2005-02-14 2006-10-26 Fumio Kimura Blood rheology measurement device and blood rheology measurement method
US20070088214A1 (en) 2005-10-14 2007-04-19 Cardiac Pacemakers Inc. Implantable physiologic monitoring system
WO2007066343A2 (en) 2005-12-08 2007-06-14 Dan Furman Implantable biosensor assembly and health monitoring system

Family Cites Families (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4770177A (en) * 1986-02-18 1988-09-13 Telectronics N.V. Apparatus and method for adjusting heart/pacer relative to changes in venous diameter during exercise to obtain a required cardiac output.
US5115133A (en) * 1990-04-19 1992-05-19 Inomet, Inc. Testing of body fluid constituents through measuring light reflected from tympanic membrane
US5218962A (en) 1991-04-15 1993-06-15 Nellcor Incorporated Multiple region pulse oximetry probe and oximeter
CA2103166C (en) 1991-05-16 2003-10-28 Britton Chance Lateralization spectrophotometer
US5370114A (en) 1992-03-12 1994-12-06 Wong; Jacob Y. Non-invasive blood chemistry measurement by stimulated infrared relaxation emission
US5544649A (en) * 1992-03-25 1996-08-13 Cardiomedix, Inc. Ambulatory patient health monitoring techniques utilizing interactive visual communication
US5558092A (en) * 1995-06-06 1996-09-24 Imarx Pharmaceutical Corp. Methods and apparatus for performing diagnostic and therapeutic ultrasound simultaneously
US5995860A (en) * 1995-07-06 1999-11-30 Thomas Jefferson University Implantable sensor and system for measurement and control of blood constituent levels
US5606972A (en) * 1995-08-10 1997-03-04 Advanced Technology Laboratories, Inc. Ultrasonic doppler measurement of blood flow velocities by array transducers
US6511426B1 (en) * 1998-06-02 2003-01-28 Acuson Corporation Medical diagnostic ultrasound system and method for versatile processing
AU7383100A (en) * 1999-09-17 2001-04-17 Endoluminal Therapeutics, Inc. Sensing, interrogating, storing, telemetering and responding medical implants
JP2001087249A (en) * 1999-09-27 2001-04-03 Sanyo Electric Co Ltd Blood component measuring device
JP4607308B2 (en) * 2000-10-03 2011-01-05 シスメックス株式会社 Noninvasive living body measurement apparatus and method
US20060100530A1 (en) * 2000-11-28 2006-05-11 Allez Physionix Limited Systems and methods for non-invasive detection and monitoring of cardiac and blood parameters
JP2002172095A (en) * 2000-12-06 2002-06-18 K & S:Kk Pulse measurement device
EP1317902B1 (en) * 2001-12-10 2005-11-09 Kabushiki Gaisha K-and-S Biological data observation apparatus
US6985771B2 (en) * 2002-01-22 2006-01-10 Angel Medical Systems, Inc. Rapid response system for the detection and treatment of cardiac events
JP2003218805A (en) * 2002-01-25 2003-07-31 Tama Tlo Kk Power and signal transmission device using ultrasonic waves
US6609023B1 (en) * 2002-09-20 2003-08-19 Angel Medical Systems, Inc. System for the detection of cardiac events
DE60331455D1 (en) * 2002-10-04 2010-04-08 Microchips Inc MEDICAL DEVICE FOR THE CONTROLLED MEDICAMENTAL ADMINISTRATION AND HEART CONTROL AND / OR HEART STIMULATION
US7010337B2 (en) * 2002-10-24 2006-03-07 Furnary Anthony P Method and apparatus for monitoring blood condition and cardiopulmonary function
JP2004148070A (en) * 2002-10-29 2004-05-27 Tse:Kk Detector of a pluralty of components in blood
US6931328B2 (en) * 2002-11-08 2005-08-16 Optiscan Biomedical Corp. Analyte detection system with software download capabilities
US7035684B2 (en) * 2003-02-26 2006-04-25 Medtronic, Inc. Method and apparatus for monitoring heart function in a subcutaneously implanted device
US6944488B2 (en) * 2003-04-30 2005-09-13 Medtronic, Inc. Normalization method for a chronically implanted optical sensor
US7303530B2 (en) * 2003-05-22 2007-12-04 Siemens Medical Solutions Usa, Inc. Transducer arrays with an integrated sensor and methods of use
JP4272024B2 (en) * 2003-09-16 2009-06-03 浜松ホトニクス株式会社 Optical biological measurement device
JP4412644B2 (en) * 2003-10-29 2010-02-10 セイコーインスツル株式会社 Cardiodynamic measurement device
JP4460316B2 (en) * 2004-01-27 2010-05-12 日本電信電話株式会社 Biological information measuring device and health management system
US7637871B2 (en) * 2004-02-26 2009-12-29 Siemens Medical Solutions Usa, Inc. Steered continuous wave doppler methods and systems for two-dimensional ultrasound transducer arrays
JP2006026394A (en) * 2004-06-15 2006-02-02 Sysmex Corp Noninvasive organism measuring apparatus
US20060129038A1 (en) 2004-12-14 2006-06-15 Zelenchuk Alex R Optical determination of in vivo properties
US7747301B2 (en) 2005-03-30 2010-06-29 Skyline Biomedical, Inc. Apparatus and method for non-invasive and minimally-invasive sensing of parameters relating to blood
WO2006123282A1 (en) * 2005-05-18 2006-11-23 Koninklijke Philips Electronics N.V. Cannula inserting system
JP2006325766A (en) * 2005-05-24 2006-12-07 Sharp Corp Biological signal measuring instrument
JP2007020735A (en) * 2005-07-13 2007-02-01 Toshiba Corp Biological light measuring device
CN100445488C (en) * 2005-08-01 2008-12-24 邱则有 Hollow member for cast-in-situ concrete moulding
US20070142727A1 (en) * 2005-12-15 2007-06-21 Cardiac Pacemakers, Inc. System and method for analyzing cardiovascular pressure measurements made within a human body
US8078278B2 (en) * 2006-01-10 2011-12-13 Remon Medical Technologies Ltd. Body attachable unit in wireless communication with implantable devices
GB0607270D0 (en) 2006-04-11 2006-05-17 Univ Nottingham The pulsing blood supply
US7559899B2 (en) * 2006-04-12 2009-07-14 Salutron, Inc. Power saving techniques for continuous heart rate monitoring
US7539532B2 (en) * 2006-05-12 2009-05-26 Bao Tran Cuffless blood pressure monitoring appliance
TW200744529A (en) * 2006-06-09 2007-12-16 Avita Corp Medical measuring device with long distant transmission function

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5833603A (en) 1996-03-13 1998-11-10 Lipomatrix, Inc. Implantable biosensing transponder
JP2006204432A (en) 2005-01-26 2006-08-10 Seiko Instruments Inc Biological information measuring apparatus
US20060241460A1 (en) 2005-02-14 2006-10-26 Fumio Kimura Blood rheology measurement device and blood rheology measurement method
US20070088214A1 (en) 2005-10-14 2007-04-19 Cardiac Pacemakers Inc. Implantable physiologic monitoring system
WO2007066343A2 (en) 2005-12-08 2007-06-14 Dan Furman Implantable biosensor assembly and health monitoring system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2282671A4

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102755152A (en) * 2011-04-27 2012-10-31 深圳市迈迪加科技发展有限公司 Cardiac function monitoring instrument
CN102755151A (en) * 2011-04-27 2012-10-31 深圳市迈迪加科技发展有限公司 Heart function monitoring method
CN102564857A (en) * 2012-01-18 2012-07-11 复旦大学 Device for measuring nonlinear mechanical property of blood vessel
CN102564857B (en) * 2012-01-18 2015-07-29 复旦大学 Device for measuring nonlinear mechanical property of blood vessel
US9867222B2 (en) 2013-03-12 2018-01-09 Fujitsu Limited Wireless communication system, wireless communication method, transmission device, control method, and recording medium
US10964393B2 (en) 2014-05-22 2021-03-30 Semiconductor Energy Laboratory Co., Ltd. Method for operating a semiconductor device having a memory circuit with an OS transistor and an arithmetic circuit
US11488668B2 (en) 2014-05-22 2022-11-01 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and healthcare system
US20220265197A1 (en) * 2019-06-18 2022-08-25 Huawei Technologies Co., Ltd. ECG Detection Method and Wearable Device

Also Published As

Publication number Publication date
WO2009138880A2 (en) 2009-11-19
CN102046085B (en) 2013-12-25
IL209211A (en) 2014-06-30
IL209213A (en) 2014-06-30
WO2009138881A3 (en) 2010-05-14
JP5591794B2 (en) 2014-09-17
JP5405564B2 (en) 2014-02-05
EP2285288A4 (en) 2012-11-28
WO2009138883A3 (en) 2011-09-01
JP5650104B2 (en) 2015-01-07
CN102046069A (en) 2011-05-04
IL209212A (en) 2014-06-30
EP2282671A4 (en) 2012-11-21
EP2282673A2 (en) 2011-02-16
JP5497008B2 (en) 2014-05-21
CA2722662A1 (en) 2009-11-19
CN102202568A (en) 2011-09-28
CN102065773B (en) 2014-04-09
JP2011526498A (en) 2011-10-13
IL209211A0 (en) 2011-01-31
WO2009138882A3 (en) 2010-04-08
CN102046085A (en) 2011-05-04
JP2011519704A (en) 2011-07-14
CA2722659A1 (en) 2009-11-19
WO2009138882A4 (en) 2010-05-27
EP2285288A2 (en) 2011-02-23
IL209212A0 (en) 2011-01-31
WO2009138881A2 (en) 2009-11-19
CA2722593A1 (en) 2009-11-19
WO2009138881A4 (en) 2010-07-15
IL209210A (en) 2014-06-30
IL209213A0 (en) 2011-01-31
IL209210A0 (en) 2011-01-31
JP2011519703A (en) 2011-07-14
CA2722616A1 (en) 2009-11-19
JP2011521678A (en) 2011-07-28
EP2282671A2 (en) 2011-02-16
EP2282667A4 (en) 2012-11-21
WO2009138880A3 (en) 2010-01-07
CN102065773A (en) 2011-05-18
EP2282667A2 (en) 2011-02-16
WO2009138882A2 (en) 2009-11-19

Similar Documents

Publication Publication Date Title
US8298148B2 (en) Integrated heart monitoring device and method of using same
EP2282671A2 (en) Integrated heart monitoring device and method of using same
US6409675B1 (en) Extravascular hemodynamic monitor
US6527729B1 (en) Method for monitoring patient using acoustic sensor
US20090048518A1 (en) Doppler motion sensor apparatus and method of using same
US11957504B2 (en) Patient monitoring and treatment systems and methods
US6600949B1 (en) Method for monitoring heart failure via respiratory patterns
US6942622B1 (en) Method for monitoring autonomic tone
US6480733B1 (en) Method for monitoring heart failure
WO2018136135A1 (en) Non-invasive blood pressure measurement using ultrasound
EP4287930A1 (en) Cardiovascular monitoring system
CN211187185U (en) Combined type physiological detection device
WO2023013720A1 (en) Biological information measuring apparatus and biological information processing system
US20050245981A1 (en) Pacemaker evaluation method and apparatus

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200980122313.1

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09746178

Country of ref document: EP

Kind code of ref document: A2

WWE Wipo information: entry into national phase

Ref document number: 2722662

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 2011509042

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2624/MUMNP/2010

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 2009746178

Country of ref document: EP