US20020007125A1 - Method and apparatus for more precisely determining mean left atrial pressure - Google Patents
Method and apparatus for more precisely determining mean left atrial pressure Download PDFInfo
- Publication number
- US20020007125A1 US20020007125A1 US09/855,935 US85593501A US2002007125A1 US 20020007125 A1 US20020007125 A1 US 20020007125A1 US 85593501 A US85593501 A US 85593501A US 2002007125 A1 US2002007125 A1 US 2002007125A1
- Authority
- US
- United States
- Prior art keywords
- balloon
- pressure
- left atrial
- signal
- corrected
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
- 230000001746 atrial effect Effects 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims abstract description 16
- 230000010355 oscillation Effects 0.000 claims abstract description 30
- 210000005246 left atrium Anatomy 0.000 claims abstract description 17
- 210000003238 esophagus Anatomy 0.000 claims abstract description 11
- 238000012546 transfer Methods 0.000 description 7
- 230000000747 cardiac effect Effects 0.000 description 6
- 230000010363 phase shift Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000003534 oscillatory effect Effects 0.000 description 2
- 230000000241 respiratory effect Effects 0.000 description 2
- 208000024172 Cardiovascular disease Diseases 0.000 description 1
- 241001522296 Erithacus rubecula Species 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 206010003119 arrhythmia Diseases 0.000 description 1
- 230000006793 arrhythmia Effects 0.000 description 1
- 239000008280 blood Substances 0.000 description 1
- 210000004369 blood Anatomy 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000000004 hemodynamic effect Effects 0.000 description 1
- 208000015181 infectious disease Diseases 0.000 description 1
- 210000005240 left ventricle Anatomy 0.000 description 1
- 230000008855 peristalsis Effects 0.000 description 1
- 210000003800 pharynx Anatomy 0.000 description 1
- 230000037452 priming Effects 0.000 description 1
- 210000001147 pulmonary artery Anatomy 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000002792 vascular Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
- A61B5/021—Measuring pressure in heart or blood vessels
- A61B5/0215—Measuring pressure in heart or blood vessels by means inserted into the body
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
- A61B5/026—Measuring blood flow
- A61B5/0285—Measuring or recording phase velocity of blood waves
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/03—Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure ; Measuring pressure in body tissues or organs
- A61B5/036—Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure ; Measuring pressure in body tissues or organs by means introduced into body tracts
- A61B5/037—Measuring oesophageal pressure
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7235—Details of waveform analysis
- A61B5/7253—Details of waveform analysis characterised by using transforms
- A61B5/7257—Details of waveform analysis characterised by using transforms using Fourier transforms
Definitions
- the present invention relates generally to an apparatus and method for noninvasive monitoring of one or more cardiac performance parameters, and more particularly to a method and an apparatus determining mean left atrial pressure.
- the diagnosis and care of patients with cardiovascular disease critically depends on information about the pumping ability of the heart.
- the priming pressure of the left ventricle of the heart typically obtained by measurement of left atrial pressure, indicates, when abnormal, a mismatch between volume capacity of the vascular system and the circulatory blood volume.
- the mean left atrial pressure as determined above may be used in conjunction with the effects of aortic pressure on an inflated balloon to noninvasively and more comprehensively provide cardiac performance information.
- the wave form of the balloon pressure oscillations is subjected to fast Fourier transform analysis to apply a catheter transfer function to each of the component waves thereof to correct the amplitudes thereof, and a corrected wave form reconstructed from the corrected component waves.
- FIG. 1 is a partial left lateral sectional view of the human body taken along the mid-sagittal plane and showing a balloon-containing catheter in accordance with the present invention within the esophagus and adjacent the left atrium of the heart.
- FIG. 2 is a pressure trace of an unfiltered signal of balloon pressure with respiratory and cardiac-effected oscillations when the balloon is adjacent the left atrium, as the balloon is gradually inflated.
- FIG. 3 is a pressure trace of mean balloon pressure for the pressure trace of FIG. 2.
- FIG. 4 is a pressure trace of amplified cardiac signal on a steady baseline which signal is derived from the balloon pressure trace of FIG. 2 and covers the same time period as that of FIGS. 2 and 3.
- FIG. 5 is a graph of an electrocardiogram taken taken simultaneously with the pressure traces of FIGS. 2, 3, and 4 .
- catheter apparatus including a hollow catheter 20 comprising a length of flexible tubing 22 having a bore or lumen 23 and on one end of which is attached a balloon 24 for flow communication with the lumen 23 for pressurization of the balloon and for sensing the pressure thereof.
- a balloon 24 for flow communication with the lumen 23 for pressurization of the balloon and for sensing the pressure thereof.
- an electrode 21 may be positioned just above the balloon 24 for obtaining an esophageal electrocardiogram and an electrical lead 25 , within a second catheter 27 , provided thereto.
- FIG. 1 There is also illustrated in FIG. 1 the placement of the balloon 24 within the esophagus 26 of a human body for the purpose of sensing the mean pressure of the left atrium 28 of the heart 30 .
- the catheter 20 is inserted balloon first through nasal passage 32 , pharynx 34 , then into the esophagus 26 .
- the balloon may be alternatively inserted through the mouth. As shown in FIG. 1
- the outer wall of the left atrium 28 is adjacent and essentially in direct contact with the outer wall of the esophagus 26 , and advantage is taken of this relationship to determine mean left atrial pressure by means of the balloon 24 thusly inserted non-invasively into the esophagus 26 and positioned therealong adjacent the left atrium so as to be sufficiently affected thereby to sense left atrial pressure, as will be discussed in greater detail hereinafter.
- the catheter apparatus is described in greater detail in my aforesaid prior patents and, in the interest of brevity, will not be repeated here.
- balloon 24 and determinations of mean left atrial pressure obtained therewith may be used in conjunction with a second balloon which senses aortic pressure for providing various cardiac performance parameters noninvasively and comprehensively, as described in my aforesaid parent '442 patent.
- FIGS. 2 to 5 are illustrations of four electronic displays or tracings used to record and display the absolute balloon pressure wave form 108 (FIG. 2), the mean balloon pressure wave form 110 (FIG. 3), the differential signal 112 (FIG. 4) with added gain from a signal processor (not shown), and a simultaneous electrocardiogram 114 (FIG. 5).
- Vertical line 116 in each of FIGS. 2 to 5 represents the same point in time.
- the absolute balloon pressure wave form is preferably filtered or otherwise processed to remove low frequency artifacts such as from respiration or peristalsis to derive wave form 112 .
- the sensing balloon 24 is pressurized.
- the gradual filling of the sensing balloon 24 causes the pressure therein to increase at a generally slow steady rate which, in accordance with the oscillometric principle, is affected by the atrial pressure causing oscillations therein as well as respiratory waves (which as discussed above should be filtered out).
- the mean balloon pressure approaches the mean left atrial pressure
- the left atrial pressure oscillations superimposed on the balloon pressure signal increase in intensity or amplitude until the balloon pressure signal resonates maximally, i.e., reaches a peak amplitude, when the mean balloon pressure approximates the mean left atrial pressure.
- the balloon pressure oscillates maximally when its expansion has increased the pressure in the tissue surrounding the left atrium to the point where the mean tissue pressure equals the mean left atrial pressure.
- the wave form 112 is an oscillating signal of varying amplitude on a steady baseline. These oscillations, derived from the absolute balloon pressure signal, are in response to the driving pressure of the left atrium. By noting the peak resonant amplitude of the wave form 112 (FIG. 4) and comparing it to the simultaneous mean balloon pressure 110 (FIG. 3), an approximation of the mean left atrial pressure can be determined.
- the mean balloon pressure approximates the mean left atrial pressure when the oscillations of wave form 112 are at a peak, i.e., the peak or highest amplitude oscillations in the wave form 112 occur at the time 116 the balloon pressure is equal to mean left atrial pressure.
- An approximation of mean left atrial pressure is thus determined from the example of FIGS. 2 to 5 to be a pressure, illustrated at 128 , of about 3 cm water.
- mean left atrial pressure As determined by the above technique has tended to be over-estimated, i.e., showing a greater mean left atrial pressure than the actual mean left atrial pressure. It is believed that this may be due to distortions in amplitudes of the signal 112 as a result of the distance (for example, 180 cm) over which the signal 112 must travel in the tubing 22 to be processed.
- the signal 112 of balloon pressure oscillations is subjected to fast Fourier transform analysis and corrected to eliminate such distortions.
- any repetitive wave form such as signal 112 is the sum of simple harmonic wave forms.
- the component wave forms, each having a different frequency, of the signal 112 are identified along with their amplitudes (the signal is separated into its component wave forms), for example, a fundamental sine wave having a frequency of 1 Hertz and a sin wave having a frequency of 6 Hertz and ⁇ fraction (1/20) ⁇ of the amplitude of the fundamental and perhaps other wave forms.
- Each frequency may undergo a different amount of distortion in the specific tubing 22 so that, for example, the 1 Hertz frequency wave form may have its amplitude reduced by only a small amount while the 6 Hertz frequency wave form may have its amplitude reduced by a much larger amount.
- a series of wave forms of different frequencies are transmitted through the tubing 22 and the input or source amplitude of each wave form is compared to the output amplitude measured at the end of the tubing to derive a transfer function for the amplitude for each frequency. If desired, a transfer function may also be derived for phase shift for each frequency.
- the transfer function for its frequency to provide a corrected amplitude for each frequency component.
- the transfer function may be 120%, i.e., the amplitude is increased by 20%, while for a 6 Hertz wave form, the transfer function may be 180%, i.e., the amplitude is increased by 80%.
- a similar process may be followed for phase shift.
- An equation may be developed for the transfer function for amplitude and, if desired, phase shift, at any given frequency, and this regression equation applied to each frequency component.
- a corrected signal more precisely representative of the true left atrial pressure wave form is formed by using inverse fast Fourier transform analysis, i.e., by adding together the amplitude-corrected wave forms.
- the application of fast Fourier transform analysis has resulted in increased amplitudes for higher frequency components as compared to lower frequency components, which means that the peak would be expected to occur earlier and therefore at a lower pressure in some instances.
- the application of the above fast Fourier transform process to balloon signals similar to signal 112 should result in the peak amplitude occurring at an earlier point (lower pressure) than the location of the peak when the signal is not subjected to fast Fourier transform analysis, which is consistent with the observation that the mean left atrial pressure has sometimes tended to be estimated to be higher than the true mean left atrial pressure.
- the corrected peak may perhaps be located as illustrated at 118 in FIGS. 2 to 5 .
- the balloon pressure oscillation signal 112 is suitably processed, in accordance with principles commonly known to those of ordinary skill in the art to which this invention pertains, in a suitably programmed general purpose computer, illustrated at 36 , to derive the corrected balloon pressure oscillation signal which provides the corrected peak 118 .
- My aforesaid parent '442 patent discloses using the peak of a corresponding portion of the left atrial pressure signal, i.e., the “a” wave portion, for determining mean left atrial pressure, i.e., measuring the balloon pressure when the amplitude of the corresponding portions is at a peak.
- the above fast Fourier transform process may be applied to such a signal portion.
- signal of balloon pressure oscillations is meant to include, heart sounds passing through the inflated balloon and recorded by a microphone, as discussed in my aforesaid U.S. Pat. Nos. 5,697,375 and 5,921,935.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Cardiology (AREA)
- Engineering & Computer Science (AREA)
- Heart & Thoracic Surgery (AREA)
- Physiology (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Vascular Medicine (AREA)
- Biomedical Technology (AREA)
- Physics & Mathematics (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Measuring And Recording Apparatus For Diagnosis (AREA)
Abstract
Description
- This is a continuation-in-part of pending application Ser. No. 09/625,329, filed Jul. 25, 2000, which is a division of application Ser. No. 09/097,252, filed Jun. 12, 1998 (now U.S. Pat. No. 6,120,442), which claims priority of U.S. provisional patent application Ser. No. 60/049,459, filed Jun. 12, 1997. These prior applications are hereby incorporated herein by reference.
- The present invention relates generally to an apparatus and method for noninvasive monitoring of one or more cardiac performance parameters, and more particularly to a method and an apparatus determining mean left atrial pressure.
- The diagnosis and care of patients with cardiovascular disease critically depends on information about the pumping ability of the heart. For example, the priming pressure of the left ventricle of the heart, typically obtained by measurement of left atrial pressure, indicates, when abnormal, a mismatch between volume capacity of the vascular system and the circulatory blood volume.
- Since the early 1970's, the flow-directed pulmonary artery balloon catheter (a.k.a. the Swan-Ganz catheter) has been the standard for bedside hemodynamic monitoring. It yields cardiac output by thermodilution as well as an estimate of mean left atrial pressure. However, under certain conditions, the pressure readings may not faithfully reflect left atrial pressure (R. RAPER et al, “Misled by the Wedge”,Chest, March 1986, pp. 427-434). This invasive technique is personnel intensive and costly since the catheter must be inserted and used in a critical care area or operating room, and it has been associated with infection, arrhythmias, and death (E. ROBIN et al, “The Cult of the Swan-Ganz Catheter”, Annals of Internal Medicine, Sept. 1985, vol. 103, pp. 445-449). Its use is further limited since it only provides non-automated intermittent measurements, and the catheter should, for safety reasons, only be left in the patient for a few days.
- My U.S. Pat. Nos. 5,048,532; 5,181,517; 5,263,485; 5,398,692; 5,551,439; 5,570,671; 5,697,375; and 5,921,935, the disclosures of all of which patents are incorporated herein by reference, disclose noninvasive methods and apparatus which includes a catheter containing an inflatable balloon insertable into the esophagus for placement adjacent the left atrium, and associated equipment for making determinations of mean left atrial pressure. When the inflated balloon is adjacent the left atrium and receiving pressure waves therefrom, the balloon pressure oscillates. As the balloon pressure is gradually increased, the balloon oscillations reach a peak or point of maximum oscillatory amplitude. As discussed in my prior patents, this peak is believed to occur when the balloon pressure is equal to the mean left atrial pressure. Thus, a determination of mean left atrial pressure may be made by noting the balloon pressure at the oscillatory peak.
- As discussed in the parent patent to this application, the mean left atrial pressure as determined above may be used in conjunction with the effects of aortic pressure on an inflated balloon to noninvasively and more comprehensively provide cardiac performance information.
- While the above technique for determining mean left atrial pressure has been shown experimentally to be accurate, there have nevertheless been instances where the mean left atrial pressure as determined by the above technique has tended to be over-estimated, i.e., showing a greater mean left atrial pressure than the actual mean left atrial pressure.
- It is accordingly an object of this invention to noninvasively and more precisely determine mean left atrial pressure.
- In order to noninvasively and more precisely determine mean left atrial pressure, in accordance with the present invention, the wave form of the balloon pressure oscillations is subjected to fast Fourier transform analysis to apply a catheter transfer function to each of the component waves thereof to correct the amplitudes thereof, and a corrected wave form reconstructed from the corrected component waves.
- The above and other objects, features, and advantages of this invention will become apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings wherein the same reference numerals denote the same or similar parts or items throughout the several views and in which a preferred embodiment of this invention is illustrated.
- FIG. 1 is a partial left lateral sectional view of the human body taken along the mid-sagittal plane and showing a balloon-containing catheter in accordance with the present invention within the esophagus and adjacent the left atrium of the heart.
- FIG. 2 is a pressure trace of an unfiltered signal of balloon pressure with respiratory and cardiac-effected oscillations when the balloon is adjacent the left atrium, as the balloon is gradually inflated.
- FIG. 3 is a pressure trace of mean balloon pressure for the pressure trace of FIG. 2.
- FIG. 4 is a pressure trace of amplified cardiac signal on a steady baseline which signal is derived from the balloon pressure trace of FIG. 2 and covers the same time period as that of FIGS. 2 and 3.
- FIG. 5 is a graph of an electrocardiogram taken taken simultaneously with the pressure traces of FIGS. 2, 3, and4.
- Referring to FIG. 1, there is illustrated generally at19 catheter apparatus including a
hollow catheter 20 comprising a length offlexible tubing 22 having a bore orlumen 23 and on one end of which is attached aballoon 24 for flow communication with thelumen 23 for pressurization of the balloon and for sensing the pressure thereof. If desired, anelectrode 21 may be positioned just above theballoon 24 for obtaining an esophageal electrocardiogram and anelectrical lead 25, within asecond catheter 27, provided thereto. - There is also illustrated in FIG. 1 the placement of the
balloon 24 within theesophagus 26 of a human body for the purpose of sensing the mean pressure of theleft atrium 28 of theheart 30. Thecatheter 20 is inserted balloon first throughnasal passage 32,pharynx 34, then into theesophagus 26. If desired, the balloon may be alternatively inserted through the mouth. As shown in FIG. 1, the outer wall of theleft atrium 28 is adjacent and essentially in direct contact with the outer wall of theesophagus 26, and advantage is taken of this relationship to determine mean left atrial pressure by means of theballoon 24 thusly inserted non-invasively into theesophagus 26 and positioned therealong adjacent the left atrium so as to be sufficiently affected thereby to sense left atrial pressure, as will be discussed in greater detail hereinafter. The catheter apparatus is described in greater detail in my aforesaid prior patents and, in the interest of brevity, will not be repeated here. - It should of course be understood that
balloon 24 and determinations of mean left atrial pressure obtained therewith may be used in conjunction with a second balloon which senses aortic pressure for providing various cardiac performance parameters noninvasively and comprehensively, as described in my aforesaid parent '442 patent. - FIGS.2 to 5 are illustrations of four electronic displays or tracings used to record and display the absolute balloon pressure wave form 108 (FIG. 2), the mean balloon pressure wave form 110 (FIG. 3), the differential signal 112 (FIG. 4) with added gain from a signal processor (not shown), and a simultaneous electrocardiogram 114 (FIG. 5).
Vertical line 116 in each of FIGS. 2 to 5 represents the same point in time. As discussed in my aforesaid prior patents, the absolute balloon pressure wave form is preferably filtered or otherwise processed to remove low frequency artifacts such as from respiration or peristalsis to derive wave form 112. - While not wishing to be bound by theory here or elsewhere in this specification, the following is believed to occur as the
sensing balloon 24 is pressurized. The gradual filling of thesensing balloon 24 causes the pressure therein to increase at a generally slow steady rate which, in accordance with the oscillometric principle, is affected by the atrial pressure causing oscillations therein as well as respiratory waves (which as discussed above should be filtered out). As the mean balloon pressure approaches the mean left atrial pressure, the left atrial pressure oscillations superimposed on the balloon pressure signal increase in intensity or amplitude until the balloon pressure signal resonates maximally, i.e., reaches a peak amplitude, when the mean balloon pressure approximates the mean left atrial pressure. Thereafter, as the mean balloon pressure continues to increase, the amplitude of oscillations due to the left atrial pressure decreases. More specifically, the balloon pressure oscillates maximally when its expansion has increased the pressure in the tissue surrounding the left atrium to the point where the mean tissue pressure equals the mean left atrial pressure. - The wave form112 is an oscillating signal of varying amplitude on a steady baseline. These oscillations, derived from the absolute balloon pressure signal, are in response to the driving pressure of the left atrium. By noting the peak resonant amplitude of the wave form 112 (FIG. 4) and comparing it to the simultaneous mean balloon pressure 110 (FIG. 3), an approximation of the mean left atrial pressure can be determined. Thus, in accordance with the oscillometric principle, the mean balloon pressure approximates the mean left atrial pressure when the oscillations of wave form 112 are at a peak, i.e., the peak or highest amplitude oscillations in the wave form 112 occur at the
time 116 the balloon pressure is equal to mean left atrial pressure. An approximation of mean left atrial pressure is thus determined from the example of FIGS. 2 to 5 to be a pressure, illustrated at 128, of about 3 cm water. - While the above technique for determining mean left atrial pressure has been shown experimentally to be accurate, there have nevertheless been instances where the mean left atrial pressure as determined by the above technique has tended to be over-estimated, i.e., showing a greater mean left atrial pressure than the actual mean left atrial pressure. It is believed that this may be due to distortions in amplitudes of the signal112 as a result of the distance (for example, 180 cm) over which the signal 112 must travel in the
tubing 22 to be processed. - In order to noninvasively and more precisely provide a non-distorted signal of balloon pressure oscillations to determine mean left atrial pressure, in accordance with the present invention, the signal112 of balloon pressure oscillations is subjected to fast Fourier transform analysis and corrected to eliminate such distortions. In accordance with Fourier's theorem, any repetitive wave form such as signal 112 is the sum of simple harmonic wave forms. By use of fast Fourier transform analysis, which is a technique commonly known to those of ordinary skill in the art to which this invention pertains, the component wave forms, each having a different frequency, of the signal 112 are identified along with their amplitudes (the signal is separated into its component wave forms), for example, a fundamental sine wave having a frequency of 1 Hertz and a sin wave having a frequency of 6 Hertz and {fraction (1/20)} of the amplitude of the fundamental and perhaps other wave forms.
- Each frequency may undergo a different amount of distortion in the
specific tubing 22 so that, for example, the 1 Hertz frequency wave form may have its amplitude reduced by only a small amount while the 6 Hertz frequency wave form may have its amplitude reduced by a much larger amount. In order to determine for thetubing 22 how much distortion each frequency component undergoes, a series of wave forms of different frequencies are transmitted through thetubing 22 and the input or source amplitude of each wave form is compared to the output amplitude measured at the end of the tubing to derive a transfer function for the amplitude for each frequency. If desired, a transfer function may also be derived for phase shift for each frequency. - In accordance with the present invention, to the amplitude of each component wave form of signal112 is applied the transfer function for its frequency to provide a corrected amplitude for each frequency component. For example, for a 1 Hertz wave form, the transfer function may be 120%, i.e., the amplitude is increased by 20%, while for a 6 Hertz wave form, the transfer function may be 180%, i.e., the amplitude is increased by 80%. If desired, a similar process may be followed for phase shift. An equation may be developed for the transfer function for amplitude and, if desired, phase shift, at any given frequency, and this regression equation applied to each frequency component.
- Finally, a corrected signal more precisely representative of the true left atrial pressure wave form is formed by using inverse fast Fourier transform analysis, i.e., by adding together the amplitude-corrected wave forms.
- In the specific application using tubing similar to
tubing 22, the application of fast Fourier transform analysis has resulted in increased amplitudes for higher frequency components as compared to lower frequency components, which means that the peak would be expected to occur earlier and therefore at a lower pressure in some instances. The application of the above fast Fourier transform process to balloon signals similar to signal 112 should result in the peak amplitude occurring at an earlier point (lower pressure) than the location of the peak when the signal is not subjected to fast Fourier transform analysis, which is consistent with the observation that the mean left atrial pressure has sometimes tended to be estimated to be higher than the true mean left atrial pressure. For example, the corrected peak may perhaps be located as illustrated at 118 in FIGS. 2 to 5. - Referring to FIG. 1, the balloon pressure oscillation signal112 is suitably processed, in accordance with principles commonly known to those of ordinary skill in the art to which this invention pertains, in a suitably programmed general purpose computer, illustrated at 36, to derive the corrected balloon pressure oscillation signal which provides the corrected
peak 118. - My aforesaid parent '442 patent discloses using the peak of a corresponding portion of the left atrial pressure signal, i.e., the “a” wave portion, for determining mean left atrial pressure, i.e., measuring the balloon pressure when the amplitude of the corresponding portions is at a peak. The above fast Fourier transform process may be applied to such a signal portion.
- By “signal of balloon pressure oscillations”, as used herein and in the claims, is meant to include, heart sounds passing through the inflated balloon and recorded by a microphone, as discussed in my aforesaid U.S. Pat. Nos. 5,697,375 and 5,921,935.
- Although the invention has been described in detail herein, it should be understood that the invention can be embodied otherwise without departing from the principles thereof, and such other embodiments are meant to come within the scope of the present invention as defined by the appended claims.
Claims (3)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/855,935 US6432059B2 (en) | 1997-06-12 | 2001-05-15 | Method and apparatus for more precisely determined mean left atrial pressure |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US4945997P | 1997-06-12 | 1997-06-12 | |
US09/097,252 US6120442A (en) | 1997-06-12 | 1998-06-12 | Method and apparatus for noninvasive determination of cardiac performance parameters |
US09/625,329 US6238349B1 (en) | 1997-06-12 | 2000-07-25 | Method and apparatus for noninvasive determination of cardiac performance parameters |
US09/855,935 US6432059B2 (en) | 1997-06-12 | 2001-05-15 | Method and apparatus for more precisely determined mean left atrial pressure |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/625,329 Continuation-In-Part US6238349B1 (en) | 1997-06-12 | 2000-07-25 | Method and apparatus for noninvasive determination of cardiac performance parameters |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020007125A1 true US20020007125A1 (en) | 2002-01-17 |
US6432059B2 US6432059B2 (en) | 2002-08-13 |
Family
ID=27367542
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/855,935 Expired - Lifetime US6432059B2 (en) | 1997-06-12 | 2001-05-15 | Method and apparatus for more precisely determined mean left atrial pressure |
Country Status (1)
Country | Link |
---|---|
US (1) | US6432059B2 (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080033415A1 (en) * | 2006-03-17 | 2008-02-07 | Rieker Gregory B | Method and apparatus to prevent esophageal damage |
CN100367909C (en) * | 2004-12-25 | 2008-02-13 | 安徽医科大学第一附属医院 | Computer vision esophageal varices pressure measuring instrument |
US20100049062A1 (en) * | 2007-04-11 | 2010-02-25 | Elcam Medical Agricultural Cooperative Association | System and method for accurate placement of a catheter tip in a patient |
WO2012015923A1 (en) * | 2010-07-27 | 2012-02-02 | The University Of Vermont And State Agricultural College | Methods and apparatus for noninvasive assessment of the left atrial and left ventricular diastolic function |
US20120172732A1 (en) * | 2010-12-31 | 2012-07-05 | Volcano Corporation | Lumen Based Pressure Sensing Guidewire System with Distortion Correction |
US20160113589A1 (en) * | 2014-10-23 | 2016-04-28 | Samsung Electronics Co., Ltd. | Biosignal processing method and apparatus |
US20180168517A1 (en) * | 2016-12-16 | 2018-06-21 | Tanita Corporation | Biological information processing device, biological information processing method, and recording medium |
US10349847B2 (en) | 2015-01-15 | 2019-07-16 | Samsung Electronics Co., Ltd. | Apparatus for detecting bio-information |
US10357165B2 (en) | 2015-09-01 | 2019-07-23 | Samsung Electronics Co., Ltd. | Method and apparatus for acquiring bioinformation and apparatus for testing bioinformation |
US10405806B2 (en) | 2015-03-06 | 2019-09-10 | Samsung Electronics Co., Ltd. | Apparatus for and method of measuring blood pressure |
US10568527B2 (en) | 2014-09-03 | 2020-02-25 | Samsung Electronics Co., Ltd. | Apparatus for and method of monitoring blood pressure and wearable device having function of monitoring blood pressure |
US10820858B2 (en) | 2016-10-12 | 2020-11-03 | Samsung Electronics Co., Ltd. | Apparatus and method for estimating biometric information |
Families Citing this family (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6050936A (en) | 1997-01-02 | 2000-04-18 | Myocor, Inc. | Heart wall tension reduction apparatus |
US7883539B2 (en) | 1997-01-02 | 2011-02-08 | Edwards Lifesciences Llc | Heart wall tension reduction apparatus and method |
US6406420B1 (en) | 1997-01-02 | 2002-06-18 | Myocor, Inc. | Methods and devices for improving cardiac function in hearts |
US6183411B1 (en) | 1998-09-21 | 2001-02-06 | Myocor, Inc. | External stress reduction device and method |
US6332893B1 (en) * | 1997-12-17 | 2001-12-25 | Myocor, Inc. | Valve to myocardium tension members device and method |
US6260552B1 (en) | 1998-07-29 | 2001-07-17 | Myocor, Inc. | Transventricular implant tools and devices |
US6723038B1 (en) | 2000-10-06 | 2004-04-20 | Myocor, Inc. | Methods and devices for improving mitral valve function |
US6702835B2 (en) | 2001-09-07 | 2004-03-09 | Core Medical, Inc. | Needle apparatus for closing septal defects and methods for using such apparatus |
US6776784B2 (en) | 2001-09-06 | 2004-08-17 | Core Medical, Inc. | Clip apparatus for closing septal defects and methods of use |
US20060052821A1 (en) | 2001-09-06 | 2006-03-09 | Ovalis, Inc. | Systems and methods for treating septal defects |
ES2310609T3 (en) | 2001-09-07 | 2009-01-16 | Mardil, Inc. | METHOD AND APPARATUS FOR THE EXTERNAL STABILIZATION OF THE HEART. |
US6764510B2 (en) | 2002-01-09 | 2004-07-20 | Myocor, Inc. | Devices and methods for heart valve treatment |
US7247134B2 (en) | 2002-11-12 | 2007-07-24 | Myocor, Inc. | Devices and methods for heart valve treatment |
US7112219B2 (en) | 2002-11-12 | 2006-09-26 | Myocor, Inc. | Devices and methods for heart valve treatment |
US7527599B2 (en) * | 2005-06-17 | 2009-05-05 | The Research Foundation Of State University Of New York | Method of determining cardiac indicators |
US8579936B2 (en) | 2005-07-05 | 2013-11-12 | ProMed, Inc. | Centering of delivery devices with respect to a septal defect |
US7846179B2 (en) | 2005-09-01 | 2010-12-07 | Ovalis, Inc. | Suture-based systems and methods for treating septal defects |
WO2019050937A1 (en) * | 2017-09-05 | 2019-03-14 | Mayo Foundation For Medical Education And Research | Trans-esophageal tonometry |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5048532A (en) * | 1989-09-18 | 1991-09-17 | State University Of New York | Method and apparatus for measuring blood pressure |
US5263485A (en) * | 1989-09-18 | 1993-11-23 | The Research Foundation Of State University Of New York | Combination esophageal catheter for the measurement of atrial pressure |
-
2001
- 2001-05-15 US US09/855,935 patent/US6432059B2/en not_active Expired - Lifetime
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100367909C (en) * | 2004-12-25 | 2008-02-13 | 安徽医科大学第一附属医院 | Computer vision esophageal varices pressure measuring instrument |
US8454588B2 (en) | 2006-03-17 | 2013-06-04 | The Board Of Trustees Of The Leland Stanford Junior University | Method and apparatus to prevent esophageal damage |
US20080033415A1 (en) * | 2006-03-17 | 2008-02-07 | Rieker Gregory B | Method and apparatus to prevent esophageal damage |
US20100049062A1 (en) * | 2007-04-11 | 2010-02-25 | Elcam Medical Agricultural Cooperative Association | System and method for accurate placement of a catheter tip in a patient |
US8715195B2 (en) | 2007-04-11 | 2014-05-06 | Elcam Medical Agricultural Cooperative | System and method for accurate placement of a catheter tip in a patient |
WO2012015923A1 (en) * | 2010-07-27 | 2012-02-02 | The University Of Vermont And State Agricultural College | Methods and apparatus for noninvasive assessment of the left atrial and left ventricular diastolic function |
US20120172732A1 (en) * | 2010-12-31 | 2012-07-05 | Volcano Corporation | Lumen Based Pressure Sensing Guidewire System with Distortion Correction |
US9247909B2 (en) * | 2010-12-31 | 2016-02-02 | Volcano Corporation | Lumen based pressure sensing guidewire system with distortion correction |
US10568527B2 (en) | 2014-09-03 | 2020-02-25 | Samsung Electronics Co., Ltd. | Apparatus for and method of monitoring blood pressure and wearable device having function of monitoring blood pressure |
US20160113589A1 (en) * | 2014-10-23 | 2016-04-28 | Samsung Electronics Co., Ltd. | Biosignal processing method and apparatus |
US10349847B2 (en) | 2015-01-15 | 2019-07-16 | Samsung Electronics Co., Ltd. | Apparatus for detecting bio-information |
US10405806B2 (en) | 2015-03-06 | 2019-09-10 | Samsung Electronics Co., Ltd. | Apparatus for and method of measuring blood pressure |
US10357165B2 (en) | 2015-09-01 | 2019-07-23 | Samsung Electronics Co., Ltd. | Method and apparatus for acquiring bioinformation and apparatus for testing bioinformation |
US10820858B2 (en) | 2016-10-12 | 2020-11-03 | Samsung Electronics Co., Ltd. | Apparatus and method for estimating biometric information |
US11666277B2 (en) | 2016-10-12 | 2023-06-06 | Samsung Electronics Co., Ltd. | Apparatus and method for estimating biometric information |
US20180168517A1 (en) * | 2016-12-16 | 2018-06-21 | Tanita Corporation | Biological information processing device, biological information processing method, and recording medium |
US10667763B2 (en) * | 2016-12-16 | 2020-06-02 | Tanita Corporation | Processing device, method, and recording medium for graphical visualization of biological information |
Also Published As
Publication number | Publication date |
---|---|
US6432059B2 (en) | 2002-08-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6432059B2 (en) | Method and apparatus for more precisely determined mean left atrial pressure | |
US5921935A (en) | Method and apparatus utilizing heart sounds for determining pressures associated with the left atrium | |
US5181517A (en) | Method and apparatus for the measurement of atrial pressure | |
US5263485A (en) | Combination esophageal catheter for the measurement of atrial pressure | |
CA2294998C (en) | Noninvasive monitoring of cardiac performance | |
US6120459A (en) | Method and device for arterial blood pressure measurement | |
US5570671A (en) | Method for positioning esophageal catheter for determining pressures associated with the left atrium | |
Chen et al. | Continuous estimation of systolic blood pressure using the pulse arrival time and intermittent calibration | |
US6648828B2 (en) | Continuous, non-invasive technique for measuring blood pressure using impedance plethysmography | |
EP0651970A1 (en) | Method and apparatus for assessing cardiovascular performance | |
US20070167852A1 (en) | Method and Apparatus for Measuring Blood Volume, and Vital Sign Monitor Using the Same | |
CN107233087A (en) | A kind of Woundless blood pressure measuring device based on photoplethysmographic feature | |
JPH09164121A (en) | Method and device to determine overarm artery pressure wave based on finger blood pressure wave being measured by noninvasive method | |
Aaslid et al. | Accuracy of an ultrasound Doppler servo method for noninvasive determination of instantaneous and mean arterial blood pressure. | |
Corazza et al. | Technologies for hemodynamic measurements: past, present and future | |
JP3289898B2 (en) | Method and apparatus for measuring atrial pressure | |
AU665747B2 (en) | Method and apparatus for the measurement of atrial pressure | |
WO1999039634A1 (en) | Method and device for arterial blood pressure measurement | |
WO1993000037A1 (en) | Method and apparatus for the measurement of atrial pressure | |
EP0957755B1 (en) | Apparatus for determining pressures associated with the left atrium | |
JP4131735B2 (en) | Method and apparatus for determining pressure associated with the left atrium | |
Patterson et al. | Impedance cardiographic measurement of the physiological response to the Valsalva manoeuvre | |
LOUSHIN et al. | 16 Mechanical Aspects | |
Dennish et al. | Accuracy of an Ultrasound Doppler Servo Method for Noninvasive Determination of Instantaneous and Mean Arterial Blood Pressure |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: RESEARCH FOUNDATION OF STATE UNIVERSITY OF NEW YOR Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HICKEY, DONALD D.;REEL/FRAME:011811/0780 Effective date: 20010514 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
REIN | Reinstatement after maintenance fee payment confirmed | ||
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20140813 |
|
FEPP | Fee payment procedure |
Free format text: PETITION RELATED TO MAINTENANCE FEES GRANTED (ORIGINAL EVENT CODE: PMFG); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY Free format text: PETITION RELATED TO MAINTENANCE FEES FILED (ORIGINAL EVENT CODE: PMFP); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
PRDP | Patent reinstated due to the acceptance of a late maintenance fee |
Effective date: 20150227 |
|
FPAY | Fee payment |
Year of fee payment: 12 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |