Device for non-invasively measuring blood pressure and pulse rate, especially at humans.

p0001The invention is directed to a process for the bloodless measurement of blood pressure and pulse rate, particularly in humans. In humans, usually the blood pressure is measured using a cuff that is placed in the elbow of a patient to the arm and then long inflated until the flow of blood through the arteries is interrupted. The pressure required is determined by means of a manometer. Then the pressure is slowly reduced until the blood can flow unthrottled again. This pressure also is measured by the pressure gauge. the pressure measurement underlying states of the artery are determined with reference to the flow noise of the blood through the artery by a doctor using a stethoscope.

p0002The pulse rate is determined by simply counting the individual heartbeats during a previous time interval. The measurements by the known method can be performed by trained personnel and occupy a significant portion of the doctor scheduled for the care of a patient time. The equipment required and the procedure itself call especially in children produced mistrust which must first be distracted by additional time by the physician.

p0003The object of the invention is to provide a solution while avoiding the disadvantages described to provide a method and means, even by untrained personnel, in particular also by the patient himself can be performed with both the blood pressure and the pulse in the shortest time. One of many patients felt to be particularly unpleasant applying pressure on the cuff is avoided and thus the process, among other things for children to be particularly suitable, and the blood pressure measuring means to make use of peripherals possible.

p0004This object is according to the invention in a method of the type indicated achieved in that the measurement is made by detecting the arteries movement from outside of the body.

p0005The advantage of the invention is that the sizes to be detected can be reduced in substantially the arteries movement, so that a corresponding measurement in a much shorter time and significantly simplified can be carried out. The detection of the arteries movement can also be performed by untrained personnel. Another decisive advantage lies in the fact that it can be carried out over longer periods without interruption and that just about long-term measurements detectable burden on the patient can be remedied by measures of interference from outside.

p0006In an embodiment of the invention provides that after detection of arterial movement, the signal thus obtained with a pressure and / or directional and / or heart rate signal is converted. Pressure and / or directional signals can be displayed with a known technique in simple electrical variables. These variables are then herkömmmlicher technology to process further, especially with small computers, which are usually available today in any doctor's office or even available at a variety of potential patients are already available.

p0007The invention also provides that a sensor is directly actuated via a mechanical or fluidic coupling of the arteries movement. About such couplings is achieved that possible sources of error, for example, are reduced or eliminated by the arm movement of the person, so that only the real arteries movement can be used as underlying process variable, and depending on the computer model also provides additional information for further processing of the signal can be used , Such variables can be eg the real ruling ambient pressure at the measuring point, the body temperature of the patient, if necessary, the eye pressure u. The like. More.

p0008In a particular embodiment, the invention provides that the sensor over a predeterminable offset pressure applied to the artery and the measurement of offset pressure and the carried out in the sensor pulses to calculate the blood pressure is used.

p0009It has been shown that the application of a preliminary pressure (offset printing) on ​​the gauge relative for example to the patient's forearm measurement simplistic, because this value can be predetermined from the outside and the sensor then relative to its known application pressure further reports the arteries movement and thus a signal is generated which can be used directly to determine the blood pressure.

p0010Another type of compensation is that at least two sensors are provided in a measuring circuit, wherein a sensor to be measured artery and at least one of the further sensors is applied to a pulse-neutral region of the body surface, whereby also in this case the sensors with predetermined contact pressures to the body surface of the person to be measured can be pressed.

p0011The invention also provides that a computer an extreme value and / or a Fourieanalyse the course of the arteries movement with possibly an averaging, a simultaneous determination of heart rate, a correction value calculation, a determination of an average correction value, with a storage of the readings and / or is carried out with an expression of the values ​​determined in digital or analog representation of a printer.

p0012These procedures make the processing modes of a computer is for the intended here inventive purpose. Evaluations of these innovative approaches are explained below based on computer drawings.

p0013Other advantages are that can determine the blood pressure values ​​of the patient from the extreme values, without requiring the detection of flow noises. Also can exclude an averaging of the effect of different sources of error. The synchronous detection of the pulse rate also allows for not only a mean value formation, but also enables the compensation of measurement errors for a certain time, which depends on the pulse frequency, wherein the storage and if necessary optical reproduction by expression of the measured values ​​for the diagnostician the necessary information provides.

p0014In a product essential to the invention embodiment provides that a blood pressure / pulse measurement is carried out continuously and / or that the determined values ​​are used to control and / or to control a drug pump.

p0015As Bereis indicated above, a particular advantage of the invention is that can be measured continuously for extended periods of blood pressure and pulse rate and kind of the pressure or pulse. This makes it possible to the patient directly attributable to a medication pump that supplies the patient with the necessary medicines at faults occur. Thus, it is possible for example to carry a corresponding device approximately in the manner of a wristwatch, wherein the blood pressure and pulse detection means is associated with the corresponding artery and in the same unit a small pump for the injection of drugs is installed.

p0016The invention therefore also provides a device for performing the method, which is characterized in that the pressure sensor is designed as an electronic part and an elastic bearing has in a housing. Electronic Pressure Transducers are already in different designs available. Essential is the special positioning of these components for the present purpose. The elastic bearing in a housing, it can be a silicone material or a similar material here for example, to make the measurement largely by foreign influences independently allows.

p0017In an embodiment, therefore, the invention also provides that the pressure sensor is connected to an amplifier, an A / D converter and a computer system, the latter optionally having a display device and / or a printer. In this circuit essentially conventional components such as an amplifier and an analog / digital converters are used, and. Like., It has been shown in experiments that these control structures are particularly useful.

p0018The invention also provides that the pressure sensor can be pressed through a sleeve or the like. With a predetermined or predeterminable offset printing in the area of ​​an artery in the body. The associated benefits were previously described. The predeterminable offset printing used the computer to compensate for errors, so that it is ensured that the be transmitted through the arteries to the motion transducer pulse is directly convertible to the blood pressure.

p0019It can be advantageous if the pressure sensor in a housing predeterminable spring force on the skin surface can be pressed, it can be provided in a further development that the springs applied on one side of the elastic bearing means of the sensor with, for example, a silicone body and fixed with its other side or turn is elastically disposed on the housing of the pressure transducer. These designs are used in particular for error compensation.

p0020As already indicated above, such a device is particularly suitable to control a drug pump, so that the invention also provides that the arithmetic unit comprises means for controlling and / or regulation of such a drug pump.

p0021The invention is described, for example, reference to the drawings, this shows in<ul><li>Fig. 1 shows the location of a pressure sensor on the radial artery,</li><li>FIG. 2 is a similar arrangement with a differential pressure transducer,</li><li>Fig. 3 shows an embodiment of a pressure sensor,</li><li>Fig. 4 shows another embodiment of a pressure sensor,</li><li>Fig. 5 is a pressure sensor in the section,</li><li>Fig. 6 is a pressure transducer in plan,</li><li>Fig. 7 is a block diagram of the measuring device as well as in</li><li>Fig. 8 the pressure / pulse trajectory of a patient at rest,</li><li>Fig. 9 shows the same curve of a patient, after a short load,</li><li>Fig. 10 Pressure / pulse profile of a person and creating an upper arm cuff at slow applying an appropriate pressure in the cuff and in</li><li>FIG. 11 is an enlargement of the right part of the curve in Fig. 10.</li></ul>

p0022At a in Fig. L and 2 only schematically reproduced human arm 1 with an artery 2, a pressure sensor is placed 3 and fixed there with a hint of reproduced sleeve 4 by applying a forward (offset) its loading.

p0023Is recognizable by a blood pressure fluctuation corresponding change in shape of the artery 2 (shown in phantom in Fig. 1) is applied an alternating pulse to the underside 5 of the pressure sensor 3, which is indicated by the double arrow. These changing condition will be registered by the pressure sensor 3 is converted into electrical signals via an amplifier 7 to an A /_D (Analog / digital) converter converted and a computer 9 supplied, whose results can be printed out if necessary via a connected printer there 10th

p0024The detailed construction of pressure transducers 3 in conjunction with Figures 3 - 6 described in more detail below..

p0025In FIG. 2, a modified type is shown: Here two pressure sensors 3 and 3a are provided, wherein one of the pressure sensor 3, is arranged in the vicinity of the artery 2, while the pressure transducer 3a is positioned in one of its pulsation largely undisturbed neighboring area. Both pressure transducers are placed again by means of a collar 4 around the forearm of a person, which is also referred to herein at 1. With a corresponding circuit, the differing signals from the pressure sensor 3 and the pressure sensor 3a may be used to compensate the respective measuring values, so as to achieve the highest possible measurement accuracy.

p0026In Figs. 5 and 6, the introduced pressure transducer in pressure sensor 3 is described in more detail. In a housing 7, an electronic sensor 8 is housed in a silicone composition. 9 The electrical connections are designated by 10. An opening 11 serves to equalize the atmospheric pressure (Fig. 5).

p0027The method of installation of such a sensor 8 is 3 and 4 reflect the Fig. In different versions. There, the sensor 8 is cast in silicone bed 9 within a 12 closed by a fixed cover housing. 7 The special feature in this case in a spring bearing of a spring 13 which is clamped between two spring pistons 14 and 14a. This can be for example a predeterminable offset printing in the housing 7 simulate in order to compensate measurement errors.

p0028In Fig. 4 an alternative embodiment is shown with all the same components bear the same reference numeral. The main difference here is the design of the cover of the housing. 7 This cover consists of an elastic diaphragm 15, which in turn serves to further incorrect compensation.

p0029In FIG. 8 the pressure waveform of a patient is shown in the rest position, wherein in Fig. 9 of the pulse profile of the same patient is shown after short load. Here, note that the amplitude scale was constructed made approximately the same, while it clearly differs in reality. The curves show not only the typical pressure curve, but reveal the diagnostician even more details by the special curve design.

p0030This is the case also for the two Fig. 10 and 11, in which the imprints of the artery is shown on the upper arm, as measured by a pressure transducer at the radial artery. Here the significant pressure drop is not only recognizable, but in increasing the sloping curve of FIG. 10 in Fig. 11 also details the pulse behavior.

p0031Essential for the invention is that one to the pressure sensor and the electronic monitoring of the values _Medikamentenpumpe 16 (Fig. 7) is made possible. It is thus possible, for example, a sick patient when thresholds are stored setpoints supply a damping or stimulating drug directly from the outside.