Surgery – Truss – Pad
Patent
1995-03-15
1997-04-15
Sykes, Angela D.
Surgery
Truss
Pad
128774, A61B 502
Patent
active
056200030
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method and apparatus for measuring quantities relating to the cardiac activity and physical condition of a person, including quantities correlating to the stroke volume and cardiac output which relate to the heart rate and a person's weight and cardiac blood circulation, and for using the measuring results for calculating an index representing the physical condition of a person.
The cardiac pulse rate or heart rate HR, whose unit is pulses per minute as measured in conditions of rest and various stresses, provides e.g. a representation of the physical condition of a person being examined. HR increases not only as a result of mental and physical stress but also various illnesses, for example fever. At rest, HR of a person in a good condition is typically lower than HR of a person in a poor condition.
In the evaluation of the cardiac activity, the measurement of HR only provides highly superficial information. It is also important to know the cardiac stroke volume SV, whose unit is liter, and the cardiac output CO, whose unit is liters per minute. CO is obtained for example by multiplying HR and the average SV with each other.
It is prior known to measure HR by recording electric cardiac activity, a so-called ECG-signal, used for identifying e.g. so-called QRS-complexes. The heart rate is obtained by measuring the time between successive QRS-complexes, whereby the inverse value of said time indicates HR. Devices based on this principle are manufactured for athletes and fitness enthusiasts e.g. by Polar Electro OY, Finland. A drawback in these devices is the necessity of attaching electrodes to the body. Neither does the ECG-signal provide any information about SV or CO.
It is also prior known to measure HR by utilizing variations of electrical impedance and light transmission. Light transmission can be measured e.g. from the earlobe and finger. An HR measuring device for athletes based on light transmission is manufactured e.g. by Casio, Japan. A drawback in this type of methods is that a necessary transducer must be in a good optical contact with a person being examined. With persons in poor condition or in a cold environment, the blood circulation in a finger or an ear may be so weak that the required signal cannot be produced. The light transmission variations caused by peripheral blood circulation do not include information about SV or CO. On the other hand, the CO meters based on electrical impedance variation require that several electrodes be attached to the body.
A person being examined in a ballistiocardiographic apparatus lies on a responsive support and mechanical oscillations resulting from cardiac activity are recorded. In principle, the SV and CO values can be calculated from the amplitude of oscillations. In practice, the results have shown a poor absolute accuracy but measurements at different times on one person are relatively well reproducible. An inconvenience in this method is e.g. the provision of a sufficiently responsive bed for a patient in order to obtain sufficiently accurate measuring results.
It is further known to place a pad underneath a person being examined for producing a piezoelectric signal or some other electric quantity for measuring a person's HR. Such measurements do not provide information about the CO or SV values of a person.
The prior known methods and equipment are neither capable of measuring HR, SV and CO values in a simple manner nor of producing simple indices for monitoring the condition of a person.
The present invention provides a solution for eliminating the deficiencies of prior art and for designing equipment which provide information not only about HR but also about the SV and CO values and the weight of a person. The quantities measured by means of methods and equipment of the invention can be used for producing index numbers for monitoring the progress of a person's condition. In order to achieve this, a method of the invention and apparatus based thereon are characterized by what is set forth in the characterizing se
REFERENCES:
patent: 2141246 (1938-12-01), Jacobus et al.
patent: 2219692 (1940-02-01), McDonald
patent: 3076452 (1963-02-01), Rothe
patent: 3465747 (1969-09-01), Rogallo
patent: 4195643 (1980-04-01), Pratt, Jr.
patent: 4299233 (1981-11-01), Lemelson
patent: 4831527 (1989-05-01), Clark
patent: 4836215 (1989-06-01), Lee
Wilbarger, Jr. et al., "Indirect Heart Rate Measuring Device", American Journal of Medical Electronics, Jul.-Sep. 1964, pp. 199 - 200.
Increa Oy
Sykes Angela D.
Winakur Eric F.
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