WO2001086474A1 - Determination des parametres de debit sanguin - Google Patents

Determination des parametres de debit sanguin Download PDF

Info

Publication number
WO2001086474A1
WO2001086474A1 PCT/GB2000/001779 GB0001779W WO0186474A1 WO 2001086474 A1 WO2001086474 A1 WO 2001086474A1 GB 0001779 W GB0001779 W GB 0001779W WO 0186474 A1 WO0186474 A1 WO 0186474A1
Authority
WO
WIPO (PCT)
Prior art keywords
parameter
determined
equation
subject
value
Prior art date
Application number
PCT/GB2000/001779
Other languages
English (en)
Inventor
Samuel Nathaniel Olalekan Akinyemi
Original Assignee
Akinyemi Samuel Nathaniel Olal
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
Application filed by Akinyemi Samuel Nathaniel Olal filed Critical Akinyemi Samuel Nathaniel Olal
Priority to AU45946/00A priority Critical patent/AU4594600A/en
Priority to PCT/GB2000/001779 priority patent/WO2001086474A1/fr
Publication of WO2001086474A1 publication Critical patent/WO2001086474A1/fr

Links

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 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
    • A61B5/0205—Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/021—Measuring pressure in heart or blood vessels
    • A61B5/0215—Measuring pressure in heart or blood vessels by means inserted into the body
    • A61B5/02152—Measuring pressure in heart or blood vessels by means inserted into the body specially adapted for venous pressure
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026—Measuring blood flow
    • A61B5/029—Measuring or recording blood output from the heart, e.g. minute volume
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455—Measuring 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
    • A61B5/14551—Measuring 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 for measuring blood gases

Definitions

  • the present invention relates to a method and apparatus that allows the accurate determination of certain parameters of the blood carrying organs, namely the brain, kidneys, lungs, heart, liver, placenta (in the pregnant woman) and blood itself.
  • the parameters include:
  • cardiac output (namely the volume of blood pumped from the heart per minute);
  • right ventricular pressure (namely the pressure in the right ventricle of the heart);
  • intraocular pressure namely the pressure in the eye
  • cation e.g. potassium and sodium
  • anion e.g. chloride
  • plasma and products of metabolism e.g. blood glucose
  • parameters of the subject's blood biochemistry, blood gas and haematology such as those indicated above. These parameters are normally determined from arterial or venous blood samples. These are time consuming to compile, and cause the subject pain. In particular, blood samples are taken and these are transferred to a laboratory for analysis. This analysis may take some considerable time, typically at least 40 minutes. From this analysis, the required parameters are accurately found, however the time lapse between the measurements being taken and the results being available may be unacceptable.
  • these parameters are determined from a limited number of actual measurements of the subject, most of which can be determined non-invasively, and with the minimum of time and pain.
  • the measurements that are taken may include:
  • T total plasma protein concentration
  • Hgb blood haemoglobin concentration
  • oxygen saturation of the subject's blood which may be measured, as a percentage, using a standard oximeter
  • the blood pressure measurements may be made invasively or non-invasively. In some cases, a direct or invasive method is preferred as this gives greater accuracy, and is more sensitive, especially for critically ill subjects compared to non-invasive measurements.
  • the derived factors may include:
  • Dcvp derived central venous pressure
  • An equation or algorithm is used, including some or all of the actual measurements for the subject and the derived factors, for each parameter to be determined.
  • a different equation or algorithm is used for each parameter to be determined.
  • For the determination of the different parameters not all measurements and derived factors are necessarily required, and therefore some may be omitted. However, since it is usually required to determine a number of parameters at the same time from the same measurements, it is advantageous for all measurements to be taken together.
  • Some of the equations or algorithms used are known, for example from the Applicant's earlier International Patent Application WO 92/22871.
  • the prior art problems are overcome by modifying the parameter determined by the standard equation by use of a correction factor k n .
  • the value of k n which will usually be different for different parameters to be determined, is itself determined from a database of values based on the determined correction factor for previous measurements as described in greater detail below.
  • the database may be stored in the memory of a computer.
  • the value k n is itself the parameter.
  • the parameter is determined based on the difference between an actual measurement and a derived measurement when compared with the determined differences of values stored in the database.
  • Figure 1 shows the values stored in a database for a class, and the measurements for a test subject
  • Figure 2 is a schematic drawing showing an apparatus for determining a subject's weight. Formation of a database
  • a particular parameter is determined by a standard method, which is usually an invasive or otherwise undesirable, yet reliable, method, giving a value CFSM.
  • the measurements that are to be used in the determination of the parameter using an equation involving the measurements for a subject according to the present invention are taken.
  • the value of the parameter is determined by the normal equation, giving a result CF 5 .
  • a correction factor, Kc is determined for each test subject for each parameter as CFS /CF 5 . Therefore, Kc is a factor by which the evaluated parameter may be modified to calibrate this to the actual value.
  • All of the measurements for each of the test subjects, and the correction factors for each parameter Kc are stored in a database. For simplicity, there will generally be a separate database for each of the parameters that are to be determined, since the correlation between the measurements of the subjects and the correction factors will differ for different parameters to be determined. The measurements are stored in the database in classes.
  • An initial factor (in a preferred example the plasma total protein concentration T) is used to divide the measurements into a number of schools.
  • the parameter used to divide the measurements into schools is known as the Primary Key Factor.
  • one school is defined as containing those measurements for which the total plasma protein concentration is equal to or less than 4gm/100ml.
  • a second school is defined as containing those measurements for which the total plasma protein concentration is equal to or greater than 4gm/100ml and less than 5gm/100ml.
  • Table 1 An example of how seven schools may be defined is shown in Table 1.
  • Plasma total protein concentration has been found to give particularly good results as this gives a good correlation between the results for sample data and actual subjects.
  • the measurements for subjects falling within the school are ordered based on the determination of a parameter known as the Secondary Key Factor or Class Index, CLa.
  • the Class Index is the value of the parameter to be determined calculated based on the standard (i.e. without correction) equation for that parameter.
  • the parameter to be determined is the cardiac output (CO) of the subject
  • the results may be divided into classes based on the value for cardiac output determined using the standard cardiac output equation, namely:
  • a general quantity used for determination of the Class Index is the quantity Sp for adults and pregnant females and Spk for children, where:
  • Y is the central venous pressure and M is derived by measuring the central venous pressure by a standard method of test subjects, together with the values of S, D and P. Then the measured central venous pressure is
  • M 7.35. It can be assumed that M expresses a conversion ratio required for the change from a Newtonian model to that of a fluid bath such as blood which is non-Newtonian. It is not a constant with a fixed value as it is subject to the Theological changes that occur in the circulation, in health and disease. From this, it has been found that C varies with age, race, sex and geographical location. For adults, when Y is set at OmmHg, C is 3.89. For children (i.e. between 5 and 8 year olds), when Y is set to OmmHg, C is 4.23.
  • the derived factors, Dpv, Dw, Dcvp and Dsr, are determined from the actual measurements of the subject as set out below.
  • Dpv is the derived plasma viscosity, given by the equation
  • Dw is the derived plasma osmolarity, given by the equation
  • Dcvp is the derived central venous pressure.
  • the central venous pressure of a subject is determined based on a prior evaluation of the cardiac output of the subject.
  • a derived cardiac output (Deo) can be calculated for use in determining the derived central venous pressure.
  • the derived cardiac output for an adult or non-pregnant female is given by the equation
  • Dsr is the derived right ventricular pressure in the adult and pregnant female, and is given by the equation:
  • Dsrk is the derived right ventricular pressure in the child, and is given by the equation
  • references to derived right ventricular pressure are references to Dsr for adults and Dsrk for children, and that Dsrk will be substituted for Dsr in equations where the subject is a child.
  • the resulting ordered results are used to define classes, each class having at least a Lower Class Pupil and a Higher Class Pupil.
  • each class may contain only two pupils, a higher class pupil and a lower class pupil, each class may contain more pupils to reduce the number of classes for a given data sample.
  • a correction factor Kc for each set of the stored measurements is stored.
  • the Kc value for the lower class pupil is KcL
  • the Kc value for the higher class pupil is KcH.
  • Kps is determined for some or all of the measurements or derived factors used in the determination of the parameter and the evaluated parameter itself. No Kps value need be determined for the evaluated parameter when this parameter is used as the class index.
  • cardiac output which requires the derived plasma viscosity (Dpv), pulse rate (P), pulse pressure (S-D), plasma total proteins concentration (T), weight, height, blood haemoglobin concentration (Hgb) and derived plasma osmolarity (Dw).
  • the Kps value may be determined for each of these measurements.
  • the Kps value is a ratio of the change in the correction factor, Kc with respect to the change in the value of the factor (either measured or determined) between the lower class pupil and the higher class pupil.
  • the Kps value is determined as:
  • the measurements for the subject are taken.
  • the set of measurements taken of the real subject will include the plasma total proteins concentration T, the blood haemoglobin concentration Hgb, the systolic blood pressure S, the diastolic blood pressure D, the mean arterial blood pressure m, the pulse rate P, the blood oxygen saturation U, and the weight w, height h and temperature Th of the subject.
  • the plasma total proteins concentration and the blood haemoglobin concentration are measurements taken from a small sample of the subject's blood. The remaining measurements are made non-invasively.
  • the school within which the measurement falls is determined. For example, where the schools are determined as being based on a protein total plasma concentration of greater than 4gm/100ml but less than 5gm/100ml and on a protein total plasma concentration of equal to or greater than 5gm/100ml and equal to or less than 6gm/100ml, if the test subject has a total protein plasma concentration of 4.8gm/100ml, the measurements will fall within the 4 to 5gm/100ml school.
  • CLa Class Index
  • the database may include classes defined as Class 1 has CLa values of equal to or less than B, Class 2 has CLa values of greater than B to less than C, Class 3 has CLa values greater than or equal to C. In this case, it is determined whether the CLa value for the measurement falls within the range of class 1 , class 2 or class 3.
  • an initial correction factor, DX for the measurement is determined based on an interpolation of the existing Kc values for the higher and lower class pupils defining the class.
  • DX is determined as:
  • the calculated value DX (DXL or DXH) alone may be used as the correction factor kn for the test subject. However, more accuracy may be obtained by further modification of the DX value. In this case, a tertiary key factor may be used.
  • the value of DX is modified to give a modified value DXh or DXi in accordance with the equation:
  • DX DX + ((QuX - QuL)(Kps I QuL))
  • DX is modified by one of the above equations for each of the tertiary key factors. After all modifications have been made, the resulting DX value is used as the correction factor, kn to adjust the calculated value of the parameter using the standard equation to give the required measurement.
  • FIG. 1 A particular example of the determination of the kn factor will be described with respect to Figure 1.
  • the upper part of this Figure shows the database entry of a class within a school.
  • the school is defined as those results having a plasma total proteins concentration of less than 4gm/L, as shown at 1.
  • the class is defined by the lower class pupil (LCP) having a class index (CLa) shown at 7 of 4.1 L and a higher class pupil (HCP) having a class index of 4.8L.
  • LCP lower class pupil
  • HCP class index of 4.8L
  • Kc (3) for the lower class pupil and the higher class pupil
  • KcL 1.23
  • KcH 0.78
  • Also stored are the values for each of the seven tertiary key factors used, and the associated Kps values (10).
  • the second tertiary key factor is the systolic blood pressure (S).
  • S systolic blood pressure
  • the lower half of the Figure shows the measurements for a test subject with a plasma total protein concentration of less than 4gm/L, and with a Class Index of 4.5L. Such a set of measurements falls within the class and school shown in the upper part of the Figure.
  • DXi DX+((QuX-QuL)(kps/QuL)). Therefore, for the first tertiary key factor, the value of DX will be modified by:
  • the measured value is greater than the value for the higher and lower class pupils, and therefore the equation
  • the offset is:
  • L is the foetal length
  • us is the maternal true blood glucose concentration
  • fe is the maternal serum iron concentration
  • the primary key factor is the plasma total proteins concentration.
  • the secondary key factor is the value Sp (or Spk for children).
  • the tertiary key factors include one or more of the evaluated cardiac output (CO), the derived plasma viscosity (Dpv), the pulse rate (P), the pulse pressure (S-D), the plasma total proteins concentration (T), the body weight (using w 0'425 ), the height (using h ), the blood haemoglobin concentration (using 3Hgb) and the derived plasma osmolarity (Dw). It will be seen that rather than using the actual body weight w, the actual height h and the actual blood haemaglobin concentration Hgb, modified values of these are used.
  • the tertiary key factors are the evaluated central venous pressure, the mean arterial blood pressure (using m 2 ) and the derived cardiac output (Deo).
  • the tertiary key factors are the evaluated right ventricular pressure, the derived plasma viscosity (Dpv), the pulse and pulse pressure product (Pp), the plasma total proteins concentration (T), the weight (using the factor w ' ), the height (using the factor h 25 ), the oxygen saturation, the derived central venous pressure (using the factor Dcvp+C), the derived plasma osmolarity and the haemoglobin concentration (using the factor 3 ⁇ gb).
  • the blood pH is also a tertiary key factor.
  • the left atrial pressure, Yp is determined by the equation:
  • the tertiary key factors are the evaluated left atrial pressure, the systolic blood pressure (using S ), the derived plasma viscosity (Dpv), the pulse and pulse pressure product (Pp), the plasma total proteins concentration (T), the weight (using w '42 ⁇ ), the height (using h 0725 ), the drived plasma osmolarity (Dw) and the haemaglobin concentration (using 3 ⁇ gb).
  • blood pH and oxygen saturation are also used as tertiary key factors.
  • the tertiary key factors used are the evaluated stroke volume, the pulse and pulse pressure product (Pp), the systolic blood pressure (using S ) and the derived central venous pressure (using Dcvp+C).
  • Pulmonary mean arterial blood pressure (PaPm) and pulmonary arterial diastolic blood pressure (PaPd) may be determined using the equations:
  • PaPm k n (DSr - 2Sp)
  • DSr is the derived right ventricular pressure in the adult or pregnant female (substituted for DSrk for children) as described above, and Sp (Spk for children) is the mean systemic filling pressure (as also described above).
  • the tertiary key factors are the evaluated pulmonary mean arterial blood pressure, the derived right ventricular pressure (Dsr) and the mean systemic filling pressure (using 2Sp).
  • the tertiary key factors are the evaluated pulmonary diastolic blood pressure, the difference in the values of the derived right ventricular pressure and the mean systemic filling pressures using (Dsr-2Sp) and (Dsr-2Sp)/3.
  • Mcp Mean pulmonary capillary pressure
  • Mcp k n .— y m - (Dcvp + C) 8
  • m is the mean arterial blood pressure.
  • the tertiary key factors will be the evaluated mean capillary pressure, the mean arterial blood pressure, the derived central venous pressure (using Dcvp+C) and the plasma total proteins concentration (T).
  • Erythrocyte sedimentation rate Ed
  • Ed may be determined by the equation: ' 3 ⁇ gb ⁇
  • the preferred primary key factor is the plasma total proteins concentration and the preferred secondary key factor is the value Sp (or Spk for children).
  • the tertiary key factors include one or more of the plasma total proteins concentration, the weight and the height of the subject, the derived plasma viscosity and derived plasma osmolarity, and the evaluated blood haemoglobin concentration.
  • a correction factor kn is evaluated using the general principles outlined above, to determine the net fluid load or deficit in accordance with the equation:
  • the response of a subject to treatment, and the prognosis of a subject's illness can be monitored by making regular measurements of the serum electrolytes and products of metabolism.
  • the serum electrolyte potassium (K + ), sodium (Na + ), chloride (CI “ ), bicarbonate (HCO3 " ), calcium (Ca ++ ) and magnesium (Mg ++ ) ions and the blood concentration of glucose, urea and creatitnine are used commonly.
  • the uncalibrated concentration of the electrolyte or products of metabolism, Csv is given by the equation:
  • Dw is the derived plasma osmolarity of the test subject as defined above
  • Nv is the ratio of the concentration of the electrolyte or products of metabolism and the serum plasma osmolarity found in healthy subjects.
  • the Nv value is a constant with an empirically determinable value for a given population. There will be variations in the values for male and females, or geographical differences.
  • the normal concentration of potassium ions in plasma is 4.7mmol/L for a healthy adult male with a plasma osmolarity of 300 centipoise, giving a value of Nv of 0.01567 (4.7/300).
  • Nv is 0.4833, where the normal sodium ion concentration in a healthy adult male is 145mmol/L with a plasma osmolarity of 300 centipoise.
  • Nv is 0.01867, where the normal blood glucose concentration in a healthy adult male is 5.6mmol/L with a plasma osmolarity of 300 centipoise.
  • Nv is 0.06 where the normal serum ion concentration in a healthy adult female is 18 ⁇ mol/L with a plasma osmolarity of 300 centipoise.
  • Nv is 0.02967, where the normal blood urea nitrogen concentration in a healthy adult is 8.9mmol/L with a plasma osmolarity of 300 centipoise.
  • Nv 0.4433 where the normal serum creatinine concentration in a healthy adult is 133 ⁇ mol/L with a plasma osmolarity of 300 centipoise.
  • the preferred primary key factor is the plasma total proteins concentration.
  • the secondary key factor is preferably the value Sp (or Spk for children).
  • the tertiary key factors may be one or more of the plasma total
  • Hep hepatic central vein pressure
  • nh is the blood ammonia concentration and st is the serum Transaminase, both evaluated as described with respect to the anion and cation concentration above.
  • Nv for determining blood ammonia concentration is 0.1833 where the normal blood ammonia concentration for a healthy adult is 55 ⁇ mol/L with a plasma osmolarity of 300 centipoise, and where Nv is 0.0015 for the evaluation of serum transaminase concentration, where the normal concentration is 0.45 ⁇ mol.s ⁇ /L with a plasma osmolarity of 300 centipoise, Th is the body temperature, pCO2 is the arterial carbon dioxide tension and pH is the blood pH.
  • the primary key factor is the plasma total proteins concentration
  • the secondary key factor is the value Sp (or SpK for children).
  • the tertiary key factors may include the derived central venous pressure (Dcvp+C), the plasma total proteins concentration (T), the blood ammonia concentration (nh), the serum transaminase (st), the body temperature (Th), the arterial carbon dioxide tension (pCO2), the blood pH, the haemoglobin concentration (3Hgb), the derived plasma viscosity, the derived plasma osmolarity (Dw), and the subject's weight (w 0425 ) and height (h 0'725 ).
  • Intracerebral pressure, lb may be determined using the equation: S 2 .(3Hgb).Dpy.U.er.pHTh.pCQ 2
  • pH is the blood pH
  • Th is the temperature of the body
  • pCO2 is the arterial carbon dioxide tension of the blood
  • Pa ⁇ 2 is the arterial oxygen tension of the blood.
  • the blood pH, the arterial oxygen tension, the arterial carbon dioxide tension, the true blood glucose and the blood urea nitrogen values are calculated as described elsewhere in the present application, and therefore can be found without needing additional blood samples.
  • the primary key factor is preferably the plasma total proteins concentration
  • the secondary key factor is the value Sp (or Spk for children).
  • the tertiary key factors may include one or more of the pulse and pulse pressure product (Pp), the systolic blood pressure (S 2 ), the plasma total proteins concentration (T), the oxygen saturation (U), the body temperature (Th), the weight (w 0'425 ) and height (h ' ) of the subject, the derived plasma viscosity (Dpv), the derived plasma osmolarity (Dw), and the evaluated blood haemoglobin concentration (Hgb), the blood pH, the derived arterial carbon dioxide tension (pCO2), the derived arterial oxygen tension (PaCO2), the derived blood urea nitrogen (BUN) and the derived true blood glucose.
  • the intraocular pressure of the eye is the balance between the rate of secretion of aqueous humour into the posterior chamber of the eye, and the resistance to drainage from the anterior chamber of the eye.
  • the present invention allows the determination of the intraocular pressure Poc, the rate of drainage of aqueous liquor Fo and the pressure in the episcleral veins Pev.
  • c is a constant having an empirical value for the measurement of the resistance to flow along the drainage route, and which is generally accepted in humans to be 0.24 ⁇ Umin.
  • the intraocular pressure, drainage rate and pressure in the episcleral veins are determined using the equations:
  • the plasma total proteins concentration is used as the primary key factor, and the value Sp (or Spk for children) is used as the secondary key factor.
  • the tertiary key factor may include one or more of the pulse and pulse pressure product, the systolic blood pressure (using S ), and the derived central venous pressure (Dcvp+C).
  • the body surface area of a subject, SA can be used to monitor drug administration and to assess the response to treatment and prognosis.
  • Surface area may be calculated using the Dubois equation, namely:
  • a hydraulic bed such as an inflated bladder 21
  • a smooth flat surface 22 As shown in Figure 2, a hydraulic bed, such as an inflated bladder 21 , is provided on a smooth flat surface 22.
  • the subject 27 is placed on the bladder 21 , which induced a pressure in the bladder 21 at a temperature Thf. This pressure is measured using a pressure gauge. From this induced pressure, the weight of the subject may be determined.
  • the evaluated weight, w is proportional to the correction factor DX W , and equal to the factor kn w .
  • the weight, height, age (GE), the pressure induced by the weight of the subject (Pid) and the termperature of the fluid within the hydraulic bed (Thf) are determined and stored in a database.
  • the results are divided into schools using the age of the subject as the primary key factor. The schools are therefore
  • results are divided into classes using the subject's height as the secondary key factor.
  • a correction factor Kc w is stored, the correction factor being the weight of the pupil, i.e. the value of Kc for the higher class pupil is w
  • the value DX W is determined using the general principles outlined above for an interpolation of the correction factors for the existing pupils of the class, namely using one of the equations:
  • Hh is the height of the higher class pupil
  • Lh is the height of the lower class pupil
  • Xh is the height of the test subject.
  • the value of DX is then modified in accordance with the Kps value of the tertiary key factors, namely the measured pressure induced Pid by the weight of the subject and the measured temperature Thf of the fluid within the hydraulic bed.
  • the Kps value is determined in accordance with the equation:
  • kn W is the true evaluated weight of the subject. This result may then be used to determine the surface area of the subject in accordance with the Dubois equation.
  • the expected volume over twenty four hours of urine eV (eVp for subjects with a positive calibrated central venous pressure, eVn for subjects with a negative calibrated central venous pressure) formed in a subject may be
  • the preferred primary key factor is the plasma total proteins concentration
  • the secondary key factor is the value Sp (Spk for children).
  • the tertiary key factors includes one or more of the pulse rate, the body temperature, the weight (w ' ) and height (h ' ) of the subject, the central venous pressure (CVP+C), the arterial carbon dioxide tension, the blood pH, the blood creatinine and the serum potassium.
  • Blood haematocrit, A may be determined from the equation:
  • the plasma total proteins concentration, T may also be evaluated using the equation:
  • the plasma total protein concentration is a value that is usually measured for dividing the results into schools, this is generally not used.
  • Pain index can be determined. This is useful for determining the pain and awareness of a subject undergoing surgery under general anaesthesia. The pain index ranges from 0%, indicating that the subject is dead, to 100% for a pain free and fully orientated subject.
  • the pain index of a subject is normally determined by observation based on a number of standard criteria.
  • DSV1 is the derived stroke volume measurement when the subject is pain free
  • DSV2 is the derived stroke volume measurement when the subject is in pain.
  • the derived stroke volume measurement is evaluated using the equation:
  • a trained observer When compiling the database for pain index, a trained observer scores the value of the degree of pain of the subject in accordance with a special protocol, and this is stored as the Kc value.
  • the factors that are used in assessing the pain response index namely the pulse rate, pulse pressure, derived central venous pressure (using Dcvp+C) and systolic blood pressure (using S ), as well as the pain response index itself, are also stored, and are used as the tertiary key factors.
  • the usual parameters for a subject under test are measured to put the measurements in a class within a school, preferably using the plasma total proteins concentration as the primary key factor and the quantity Sp (or Spk for a child) as the secondary key factor.
  • a value DX is determined based on an interpolation of the Kc values, namely the pain index of the lower class pupil and higher class pupil. This value is then modified based on the interpolation using the Kps values for the tertiary key factors.
  • the resulting value, kn is the pain index, i.e.
  • Pain index (%) kn. Foetal Distress Index.
  • Pain Index Similar principles to those used for determining Pain Index can be used for the determination of foetal distress, Ftd, during pregnancy and parturition.
  • Foetal distress index measurements range from a value of 0, indicating that the foetus is in no distress, to 5, indicating foetal death.
  • Foetal distress is determined by a trained observer who scores the value of the degree of foetal distress based on observations.
  • An indication of foetal distress may be determined using the equation:
  • Sm is the maternal systolic blood pressure
  • Dm is the maternal diastolic blood pressure
  • Dcvpm is the maternal derived central venous pressure
  • Pf is the foetal heart rate
  • the maternal plasma total proteins concentration (T), the blood haemoglobin concentration (Hgb), the systolic blood pressure (S), the diastolic blood pressure (D), the mean arterial blood pressure (m), the pulse rate (P) and the blood oxygen saturation (U), together with the weight (w) and height (h) and the measured foetal heart rate are obtained and stored in the database with the evaluated foetal distress, Ftr, and the observed foetal distress index.
  • results are then placed into a class using the maternal plasma total proteins concentration (T) as the primary key factor and the maternal Sp value as the secondary key factor.
  • T maternal plasma total proteins concentration
  • Kc is stored which gives the recorded foetal distress.
  • This DX value may be modified based on the tertiary key factors, which may include one or more of the maternal pulse and pulse pressure product (Ppm), the maternal pulse rate (Pm), the maternal systolic blood pressure (Sm 2 ), the foetal heart rate (Pf) and the derived central venous blood pressure (Dcvp) and the evaluated foetal distress (Ftr).
  • Ppm maternal pulse and pulse pressure product
  • Pm maternal pulse rate
  • Sm 2 maternal systolic blood pressure
  • Pf the foetal heart rate
  • Dcvp derived central venous blood pressure
  • Ftr the evaluated foetal distress
  • Blood gas measurements including blood oxygen tension, blood carbon dioxide tension and blood pH.
  • the blood gases of the subject namely the oxygen tension, carbon dioxide tension and pH of the blood.
  • Such measurements are usually obtained from analysis of venous and arterial blood taken from the subject. It is especially difficult, and painful, to remove arterial blood from a subject. According to the present invention, it is possible to non-invasively determine the parameters of blood gases.
  • a database is formed of oxygen content of the blood measurements with the associated oxygen tension, carbon dioxide tension and blood pH. In this way, by determining the oxygen content, the oxygen tension, carbon dioxide tension and blood pH can be found.
  • the oxygen content of a subject's blood, OFk is determined using the derived cardiac output value, using the equation:
  • Dcog is the derived cardiac output, Deo, and is itself determined by the equation:
  • the plasma total proteins concentration, blood haemoglobin concentration, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, pulse rate, blood oxygen saturation, weight and height of the subject are measured.
  • the oxygen content of the blood OFk is initially determined in accordance with the above equation.
  • the preferred primary key factor is the plasma total proteins concentration.
  • the preferred secondary key factor is the calculated value Sp (or Spk for children). From the classification of the measurements, the value DX can be determined as described above, based on the interpolation of the correction factors Kc for the lower class pupil and the higher class pupil.
  • the Kps value is determined for each of the oxygen tension, carbon dioxide tension and blood pH based on the derived oxygen content measurements. These Kps values are then used to determine a value for each of the oxygen tension, carbon dioxide tension and the blood pH.
  • the measured value of a factor was compared to the known values of the factor for the lower class pupil and higher class pupil, and an interpolation made to modify the value DX.
  • it is the value of the factor for the test subject that is to be determined, and therefore the reverse process is carried out, namely from a knowledge of the correction factor based on the difference between the calculated value and the actual value, the expected value QuX is determined. This determination is made in accordance with the equations as set out below:
  • OFk falls within the range of the lower class pupil and higher class pupil (i.e. QuL ⁇ OFk ⁇ QuH),
  • QuX QuH - ⁇ (K C H - DX)(Kps I QuH) ⁇
  • QuX QuL + ⁇ (DX - K c L)(Kps I QuL) ⁇
  • OFk is less than the value of both QuL and QuH
  • OFk is greater than the value of both QuL and QuH
  • results for subjects at high altitudes will be different for those at lower altitudes, typically below 3000m and at or above sea level.
  • the subject is under greater than normal atmospheric pressure, for example underwater, and undergoing decompression in hyperbaric pressure chambers, different results may be expected.
  • Suitable apparatus for the implementation of the present invention is based around a microcomputer with a memory storing the database or databases for the parameters to be determined. Preferably there are separate databases for each of the parameters to be determined, although these may be combined.
  • the measurements from the subject under test are input to the microcomputer. This may either be by manual input of the measured parameters, for example through a keyboard. However, it is preferred that the measurements are input directly from the measuring apparatus. For example, an electronic sensor may be provided that determines the pulse rate and blood pressure measurements, and outputs these directly to the computer for processing. Another machine, including a hydraulic bed, may determine the weight and height of the subject, and again can output these determinations to the computer directly.
  • the measurements that come from a sample of the subject's blood may also be analysed by a machine that outputs the results in an electronic form directly to the computer.
  • the computer is then able to take the measurements, derive the derived parameters and calculate the values of the desired parameters using the equations and methods as described above.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Cardiology (AREA)
  • Physiology (AREA)
  • Engineering & Computer Science (AREA)
  • Medical Informatics (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Pulmonology (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Physics & Mathematics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)

Abstract

La présente invention concerne un procédé et un appareil d'évaluation des paramètres de débit sanguin d'un sujet. Une case de données est créée qui conserve les mesures de sujets tests et les facteurs de correction associés. Les mesures correspondant aux différents sujets tests sont divisées en écoles sur la base d'une valeur mesurée ou évaluée, et en classes ordonnées sur la base d'une autre valeur mesurée ou évaluée. L'école et la classe du sujet sont déterminées, et la valeur de correction pour le sujet est déterminée par une interpolation des résultats conservés dans l'école et la classe.
PCT/GB2000/001779 2000-05-09 2000-05-09 Determination des parametres de debit sanguin WO2001086474A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU45946/00A AU4594600A (en) 2000-05-09 2000-05-09 Determination of blood flow parameters
PCT/GB2000/001779 WO2001086474A1 (fr) 2000-05-09 2000-05-09 Determination des parametres de debit sanguin

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/GB2000/001779 WO2001086474A1 (fr) 2000-05-09 2000-05-09 Determination des parametres de debit sanguin

Publications (1)

Publication Number Publication Date
WO2001086474A1 true WO2001086474A1 (fr) 2001-11-15

Family

ID=9884373

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2000/001779 WO2001086474A1 (fr) 2000-05-09 2000-05-09 Determination des parametres de debit sanguin

Country Status (2)

Country Link
AU (1) AU4594600A (fr)
WO (1) WO2001086474A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2377787A (en) * 2001-03-14 2003-01-22 Samuel Nathaniel Olal Akinyemi Determination of blood flow parameters
US9442065B2 (en) 2014-09-29 2016-09-13 Zyomed Corp. Systems and methods for synthesis of zyotons for use in collision computing for noninvasive blood glucose and other measurements
US9554738B1 (en) 2016-03-30 2017-01-31 Zyomed Corp. Spectroscopic tomography systems and methods for noninvasive detection and measurement of analytes using collision computing

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5152297A (en) * 1989-03-08 1992-10-06 Asulab Sa Method and apparatus for establishing the pressure-diameter relationship of an artery by non-invasive measures
WO1992022871A1 (fr) 1991-06-10 1992-12-23 Akinyemi Samuel Nathaniel Olal Mesure non sanglante des parametres du debit sanguin
US5699246A (en) * 1995-09-22 1997-12-16 Schlumberger Technology Corporation Method to estimate a corrected response of a measurement apparatus relative to a set of known responses and observed measurements
US5971934A (en) * 1996-10-04 1999-10-26 Trustees Of The University Of Pennsylvania Noninvasive method and apparatus for determining cardiac output
US5995912A (en) * 1996-04-30 1999-11-30 Imec Vzw Database and method for measurement correction for cross-sectional carrier profiling techniques
WO2000028317A2 (fr) * 1998-11-09 2000-05-18 Le Tri, Nhan Mesure non vulnerante amelioree de parametres du debit sanguin

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5152297A (en) * 1989-03-08 1992-10-06 Asulab Sa Method and apparatus for establishing the pressure-diameter relationship of an artery by non-invasive measures
WO1992022871A1 (fr) 1991-06-10 1992-12-23 Akinyemi Samuel Nathaniel Olal Mesure non sanglante des parametres du debit sanguin
US5699246A (en) * 1995-09-22 1997-12-16 Schlumberger Technology Corporation Method to estimate a corrected response of a measurement apparatus relative to a set of known responses and observed measurements
US5995912A (en) * 1996-04-30 1999-11-30 Imec Vzw Database and method for measurement correction for cross-sectional carrier profiling techniques
US5971934A (en) * 1996-10-04 1999-10-26 Trustees Of The University Of Pennsylvania Noninvasive method and apparatus for determining cardiac output
WO2000028317A2 (fr) * 1998-11-09 2000-05-18 Le Tri, Nhan Mesure non vulnerante amelioree de parametres du debit sanguin

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2377787A (en) * 2001-03-14 2003-01-22 Samuel Nathaniel Olal Akinyemi Determination of blood flow parameters
US9442065B2 (en) 2014-09-29 2016-09-13 Zyomed Corp. Systems and methods for synthesis of zyotons for use in collision computing for noninvasive blood glucose and other measurements
US9448164B2 (en) 2014-09-29 2016-09-20 Zyomed Corp. Systems and methods for noninvasive blood glucose and other analyte detection and measurement using collision computing
US9448165B2 (en) 2014-09-29 2016-09-20 Zyomed Corp. Systems and methods for control of illumination or radiation collection for blood glucose and other analyte detection and measurement using collision computing
US9453794B2 (en) 2014-09-29 2016-09-27 Zyomed Corp. Systems and methods for blood glucose and other analyte detection and measurement using collision computing
US9459203B2 (en) 2014-09-29 2016-10-04 Zyomed, Corp. Systems and methods for generating and using projector curve sets for universal calibration for noninvasive blood glucose and other measurements
US9459202B2 (en) 2014-09-29 2016-10-04 Zyomed Corp. Systems and methods for collision computing for detection and noninvasive measurement of blood glucose and other substances and events
US9459201B2 (en) 2014-09-29 2016-10-04 Zyomed Corp. Systems and methods for noninvasive blood glucose and other analyte detection and measurement using collision computing
US9610018B2 (en) 2014-09-29 2017-04-04 Zyomed Corp. Systems and methods for measurement of heart rate and other heart-related characteristics from photoplethysmographic (PPG) signals using collision computing
US9554738B1 (en) 2016-03-30 2017-01-31 Zyomed Corp. Spectroscopic tomography systems and methods for noninvasive detection and measurement of analytes using collision computing

Also Published As

Publication number Publication date
AU4594600A (en) 2001-11-20

Similar Documents

Publication Publication Date Title
Papaioannou et al. Mean arterial pressure values calculated using seven different methods and their associations with target organ deterioration in a single-center study of 1878 individuals
Carlin et al. Physiological changes of pregnancy and monitoring
CN108185996B (zh) 动脉血管年龄估算模型构建方法和装置
Borden et al. Pulmonary hypertension in chronic pulmonary emphysema
KR101130902B1 (ko) 환자의 수화 및/또는 영양 상태를 측정하는 방법 및 장치
Ellwein et al. Patient-specific modeling of cardiovascular and respiratory dynamics during hypercapnia
US20100228104A1 (en) Cerebral vascular reactivity monitoring
Girandola et al. Effects of water immersion on lung volumes: implications for body composition analysis
Anderson et al. Survival of healthy older people.
Kurmanavicius et al. Reference values of fetal peak systolic blood flow velocity in the middle cerebral artery at 19–40 weeks of gestation
Nyberg et al. Fetal breathing is associated with increased umbilical blood flow
Cesarelli et al. Floatingline estimation in FHR signal analysis
WO2001086474A1 (fr) Determination des parametres de debit sanguin
Holmes et al. Body-density measurement in children: the BOD POD versus Hydrodensitometry
Sanchez-Carrillo et al. Test of a noninvasive instrument for measuring hemoglobin concentration
WO2000028317A9 (fr) Mesure non vulnerante amelioree de parametres du debit sanguin
Ducharme et al. Comparison of supine and vertical bioimpedance measurements in young adults
Vujicic et al. Comparison of clinical assessment and multifrequency bioimpedance analysis as methods of estimating volume status in peritoneal dialysis patients–A single-center experience
Mokarami Pitfalls in interpreting umbilical cord blood gases and lactate at birth
RU2722879C1 (ru) Способ прогнозирования риска преждевременного старения мужчин молодого и среднего возраста
RU2695022C1 (ru) Способ оценки биологического возраста
Farid et al. Ultrasonography measurement of inferior vena cava diameter of blood donors as predictors for early blood loss in tertiary hospital northeastern, malaysia
RU2232988C2 (ru) Способ оценки содержания лейкоцитов, эритроцитов и тромбоцитов в крови с учетом гемоконцентрации
RU2266044C2 (ru) Способ определения психосоматического состояния человека
Gomes Extraction of Information Theory-Based Indices from Fetal-Maternal Heart Rate Simultaneous signals

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AL AM AT AU AZ BA BB BG BR BY CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP