RU2131696C1 - Oscillovasometer - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: oscillovasometer is used for diagnostics of diseases of limb vessels. It has compressor, receiver and pneumatic system. The latter includes cuff-receptor with pressure sensor, unit of air quantity control and measurement. Oscillovasometer also includes occlusion cuff, reservoir, valves, and air ducts. Reservoir is provided with hole and valve for communication with atmosphere, and its volume is selected, respectively. EFFECT: obtaining of data on blood flow state in periphery arteries and veins. 1 dwg

Description

 The device relates to the field of medical equipment and is intended for the diagnosis of vascular diseases of the limbs.

 Two close analogues are known: venous-occlusive plethysmograph (1), which allows to obtain a set of medical indicators for blood flow in the extremities (resting blood flow, blood flow at the peak of reactive hypermia, venous capacity, venous outflow velocity) and an oscilloscope (2), which allows to obtain a set of medical parameters by the elastic properties of arterial vessels of limbs (elastic resistance, bulk modulus of elasticity, characteristic impedance, internal effective diameter of arterial vessels, blood pressure and other derivatives).

 These devices have in their design blocks that can become common to both devices, this is a compressor, receiver, ducts, pressure sensors, valves, amplifiers of electrical signals, computers.

 The venous-occlusive plethysmograph, which may be the prototype of the present invention, contains a compressor, a mercury receptor sensor, an air quantity control and measurement unit (valves and pressure sensors), a pressure gauge, an occlusal cuff and a buffer tank.

 However, venous-occlusive plethysmograph does not allow obtaining information about the elastic properties of arterial vessels of the limbs, which leads to the need to use another device to determine the elastic properties of the vessels of the limbs, and this significantly lengthens the study time.

 The objective of the invention is the creation of a device that, along with the determination of the elastic properties of arterial vessels of the extremities (3), obtain data on the state of blood flow in peripheral arteries and veins.

 The new device allows you to expand the amount of medical information by determining blood flow in the vessels of the limbs and the ability to determine additionally another indicator - peripheral vascular resistance; to increase the accuracy of determining blood flow parameters through the use of a pneumatic cuff-receptor, which provides close contact with the studied limb; significantly reduce the total study time.

 This problem is solved by the proposed device design, by attaching to the oscilloscope block for determining blood flow in the extremities, consisting of an occlusal cuff, reservoir, valves, ducts (see drawing).

 To illustrate, a drawing is attached - a schematic diagram of the proposed device, which includes a reservoir - an occlusal cuff - 2, a receiver pressure sensor - 3, a receiver 4, a compressor - 5, a nozzle - 11 and a pneumatic system consisting of a receptor cuff - 8, a pressure sensor - 9, a tank for dosed air discharge - 6, a differential sensor - 7, openings - 10, a nozzle - 12 and air ducts with valves.

 The proposed device comprises a compressor 5, connected, using an air duct and a valve, to a block for determining blood flow and to a receiver 4, in which a pressure sensor for receiver 3 is installed. The block for determining blood flow in turn consists of a tank 1 communicating with the atmosphere through an opening with a valve, and an occlusal cuff 2 connected to the reservoir 1 by means of an air duct provided with a valve. The receiver 4, through the duct with the valve and the nozzle 11, communicates with the pneumatic system of the device. The latter includes a receptor cuff 8 connected by air ducts to a pressure sensor 9 and a differential sensor 7. The differential sensor 7 has two air ducts connecting the supramembrane space of the sensor to the device’s pneumatic system, one of which has a valve, and the other has a nozzle 12. Tank for dosed air discharge 6, through air ducts with valves built into them, communicates with the device’s pneumatic system and atmosphere. The differential sensor 7 with a tank for dosed air discharge 6 and a nozzle 12 form a control unit for the amount of air and its measurement, which has an opening 10 with a valve for communication with the atmosphere.

The device operates as follows:
- On the studied limb impose a smear-receptor 8 and proximal to it - an occlusive cuff 2.

 - Air is pumped into receiver 4 by compressor 5 to such a pressure that, upon subsequent intake of air from receiver 4 into receptor cuff 8, it provides a fairly tight contact between receptor cuff 8 and the limb under study, but does not violate the venous outflow.

 - When connecting the receiver 4 to the pneumatic system of the device, the cuff of receptor 8 is smoothly filled with air through the nozzle 11 until the pressures in the cuff of receptor 8 and receiver 4 are balanced, which is detected by the pressure sensor of receiver 3, after which the receiver is disconnected from the pneumatic system.

 - Air is pumped into receiver 4 by compressor 5 so that after balancing the pressures in receiver 4 and occlusal cuff 2, a pressure is set lower than arterial but higher than venous, which is controlled by the pressure sensor of receiver 3.

 - Simultaneously with the intake of air into the occlusal cuff 2, the absolute value of blood pressure is recorded using the cuff receptor 8, which senses pulsations of the vessels of the limbs and transmits them to the pressure sensor 9; the latter measures and transmits to the recording device the magnitude of these pulsations, which are in direct proportion to the magnitude of blood pressure. At the same time, the pulse increment of blood pressure is measured according to the same principle, but instead of the pressure sensor 9, the differential sensor 7 is involved in the work.

 - After reaching the maximum pressure change under the cuff-receptor 8 from the occlusal cuff 2, the air is quickly discharged into the atmosphere through the reservoir 1. At the same time, the absolute value of blood pressure and its pulse increment under the cuff-receptor 8 continue to be recorded.

 - After balancing the pressure in the occlusal cuff 2 with the atmospheric compressor 5, air is pumped into the receiver 4 to such a pressure that, after a smooth flow of air from the receiver 4 into the pneumatic system through the nozzle 11, would provide a pressure level that obviously exceeds the systolic value. Simultaneously with a gradual increase in pressure in the cuff receptor 8, blood pressure and its pulse increment under the cuff receptor 8 are recorded and a peripheral pulse is recorded. Registration of the peripheral pulse is carried out using a standard pulse sensor, which can be included in the design of the device, and can also be used separately and included in the work simultaneously with the oscilloscope. In this case, pressure is not created in the occlusal cuff 2.

 - After equalizing the pressure in the receiver 4 and the pneumatic system at a level exceeding the systolic pressure, the process of step decompression begins with a metered discharge of air from the pneumatic system at each step of the step decompression and continues to a pressure level in the receptor cuff 8, which provides a sufficiently tight cuff contact -receptor 8 with the studied limb, but does not violate the venous outflow. After that, the pressure drop in the cuff receptor 8 stops. The process of step decompression is carried out using a tank for dosed air discharge 6. At the same time, blood pressure and its pulse increment are recorded under the cuff receptor 8.

 - After the end of the step decompression, the compressor 5 in the occlusal cuff 2 creates a pressure in excess of systolic, and is maintained at this level for two to three minutes.

 - Then, air is quickly discharged from the occlusal cuff 2 to the reservoir 1 to a pressure lower than arterial but higher than the venous pressure, which is regulated by the specially selected volume of the reservoir 1. At the same time, blood pressure and its pulse increment under the cuff-receptor 8 are recorded using a pressure transducer 9 and a differential sensor . 7.

 - Upon reaching the maximum effect determined by the registration of blood pressure and its pulse increment under the cuff-receptor 8, the air from the occlusal cuff 2 is discharged into the atmosphere through the reservoir 1, after which the study is considered completed.

 The remaining air in the pneumatic system of the device is discharged through the hole 10.

 A prototype of the proposed device has been tested, which showed that it meets the requirements for it.

Sources of information
1. Instrumental methods for the study of the cardiovascular system. / Handbook, ed. Vinogradova T.S. - M.: Medicine, 1986, p. 324 - 326.

 2. Instruction manual for venous-occlusive plethysmograph. Venous-Occlusion-Plethysmography. In: "Eurasburger-Berichte zu Themen der Angiologie und Kardiologie", Eurasburg, 1980, S 11.

Claims (1)

 An oscilloscope containing a compressor that communicates through a receiver and duct with an integrated valve and jet, to the device pneumatic system, which includes a receptor cuff equipped with a pressure sensor, and an air quantity control and measurement unit, as well as an occlusal cuff connected to the receiver through the duct with a valve, characterized in that it further has a reservoir connected to the occlusal cuff through the duct with a valve, and the reservoir has an opening with a valve for communication with the atmosphere and its volume is selected in such a way that when air passes from the occlusal cuff to the reservoir, a pressure is set below the arterial, but above the venous.