DE1566075C3 - Arrangement for measuring the blood inflow volume in vascular areas - Google Patents

Description

A b b. 4, the output voltage is the quotient of the change in resistance and the total resistance and thus proportional to the blood flow.

Since the electrically active length of the mercury column does not exactly correspond to the circumference, it must The measurement result depends on the length of the electrically inactive spacer - in the example given so the chain - to be corrected. This correction can e.g. B. according to the number of links between End piece and hook are carried out.

1 sheet of drawings

Claims (3)

1 2 must, the blood flow is internationally customary in patent claims: Milliliters / 100 milliliters of tissue · minute. This size can be calculated using the formula above from the 1. Determine the arrangement for measuring the blood inflow quotient change in circumference / circumference,
volume in vascular areas according to method 5 For the measurement of changes in the circumference of verder vein occlusion plethysmography, which were investigated or on humans, Glaser developed a device for generating a venous (Klinische Wochenschrift, 18, 1156 [1939]) and blockade and a device for measuring of the later described by Whitney (J. Physiol., London, 121, 1 circumference or the change in circumference of a [1953]) a method which consists of an elastic limb section, thereby using rubber hose marked with mercury that The part used to record the measured values is placed around the extremity to be examined (Fig. 1.1) using sliders. The electrical resistance of the enclosed (Fig. 1.2) separated from the skin, which is a closed mercury column, is proportional to the enlargement of the contact surface and ther- its length and thus to the circumference of the extremity. cause mixed isolation. 15 The method used so far shows three main 2. Arrangement according to claim 1, wherein the defects. The specific resistance of the mercury reading (Scope) with the help of a with mercury is temperature dependent. When creating a silver-filled elastic tube into a tube on an extremity with a body analog electrical resistance converted to temperature of 37 degrees arises in mercury and then with means known per se, such as an undefined temperature, which is between the z. B. a Wheatstone bridge, measured body temperature and the air temperature, is, characterized in that the elastic by this relatively slow ■ adjustment arises Hose is pulled through the slider. a drift during the measurement. The second after 3. Arrangement according to claim 2, wherein the part consists in the friction between the hose and electrical measuring device, e.g. B. Wheat skin. Various authors therefore recommended mass-made stone ash Bridge with additional equipment that took such. B. powder to even one To be able to change the volume directly in milliliters / 100 muli measurement. The third disadvantage liter of tissue is displayed or registered, thereby cutting the tube into the tissue, characterized in that the measuring device is the subject of the invention an arrangement for Quotient of change in resistance and weight. 30 Measurement of the increase in circumference of limbs and total resistance of the filled with mercury thus the volume increase with venous blockage, Hose captured. which avoids the disadvantages described. The idea of the invention is the friction between Avoid skin and hose and keep a temperature 35 thermal insulation between limbs and hose to bring about as well as to enlarge the contact surface. The measurement of the unit of time in a limb. The invention is to be based on an execution Mass section of the inflowing amount of blood is an example to be explained in A b b. 1 shown is a diagnostic aid for occlusive diseases. The elastic tube 1 forms a loop, and circulatory disorders. A very old Me- 40 so that the measuring distance is doubled. He is through The method for carrying out this measurement is the slider 2 pulled through, which is made of a material Vein occlusion plethysmography (B ro which and are manufactured that have a low thermal conductivity Rüssel, J. Physiol. 32, 157 [1905], Hewlett and the lowest possible friction between and van Zwalu wenbu rg, Heart 1, 87 [1909]). see hose and glider allows. The final With this method, the venous drainage is in the 45 pieces 3 and 4 are used for electrical connection, The section of the limb to be examined blocked the lock and the calibration. Because mercury and the increase in volume as a result of the arteries is a danger, an overstretching protection provides len inflow of blood measured. To measure that the hoses are unlikely to tear the increase in volume will be different ratios. For this purpose, the sliders 2 (Fig. 1) driving used. In water plethysmography 50 additional holes through which one or more (Abramson: Circulation in the extremeties, inextensible ropes are pulled around the allowable Academic Press, New York and London [1967], strain gauges are longer than the mercury Greenfield, Meth. Med. Res. 8, 293 [I960]) tubing. Another embodiment a? the corresponding limb section in an overstretching protection shows A b b. 2. Take over here with water-filled rigid shell embedded and the 55 men inlaid bars the end limit. A white Water displacement determined. Analogous to this, the possibility of reducing the dangers of mercury zv. The air plethysmography (G r a f and W e s t e r s t e η, eliminate, is based on the mercury tubes Acta physiol. Scand. 46, 1 [1959]). Replace one with inextensible ropes and attach it to one third option is to measure the scope and place a capacitive, inductive or resistive the increase in circumference, since 60 converters can be used mathematically. lets that for an extremity limited in length, the above-described sensor converts as Actual section the relationship imagines lengths or changes in length in electrical Resistance values or changes in resistance Change in volume _ ₂ change in circumference These are usually measured with a measuring bridge Total volume Total circumference ⁶ 5 (Fig. 3) recorded (1 = measuring sensor, 2 = setting regulator 3 = display or registration of the measured value) is applicable. As for the assessment of the blood influx, the measuring device is also supplemented by an addition the supplied tissue volume can be taken into account circuit, z. B. by a voltage divider nacl