SU824987A1 - Device for measuring yield of blood - Google Patents

Description

one

The invention relates to medical technology, namely, hemodynamic recorders with indicators.

A device for measuring blood flow is known, comprising a serially connected sensor, a frequency divider, a time relay and a trigger, a series-connected pulse counter, a register and an indicator, as well as a delay circuit and a matching circuit, the first input of which is connected to the sensor, and the second is the output of the time relay, the trigger output is connected to the register synchronization input and the input of the delay circuit, the output of which is connected to the impulse input of the pulse counter, the counting and control inputs of which are connected respectively to the output dy coincidence circuit and the frequency divider 1.

A disadvantage of the known device is the low measurement accuracy due to the systematic error that occurs when measuring the average frequency of the pulses.

The purpose of the invention is to improve the accuracy of the measurement by reducing the systematic component of the error.

This goal is achieved in that a device containing a series-connected sensor, a frequency divider, a time relay and a trigger, a series-connected pulse counter, a register and an indicator, as well as a delay circuit and a matching circuit, the first input of which is connected to the sensor, and the second with the output of the time relay, the trigger output is connected to the register clock input, and the output of the delay circuit is connected to the counter input pulse counter, a second one is introduced, a time relay, an OR circuit, and a series-connected converter the code frequency, the second frequency divider, the second coincidence circuit, and the second OR circuit, the second input of which is connected to the output of the first matching circuit, and the output to the counting input of the output counter, the control input of which is connected to the output of the first OR circuit, the input is connected to the output of the first frequency divider, and the second input is connected to the output of the trigger and the input of the second time relay, the output of which is connected to the second input of the second coincidence circuit,

L - -.

 the control input of the indicator, the input of the delay and the second synchronization input of the register, the information outputs of which are connected to similar inputs of the code-frequency converter. . The drawing shows the structural diagram of the proposed device for measuring blood flow. The device contains a sensor 1, a circuit 2 of coincidence, controlled by a signal of time relay 3, a sequence of 4 pulses connected, a register 5 and an indicator 6. A frequency divider 7 is connected to the sensor connected to the input of the OR circuit 8 and the time input 3 of which is connected to the second run of coincidence circuit 2 and the input of Trigger 9, the output of which is connected to the first synchronization input of register 5, the second input of OR circuit 8, and the forward dynamic input of time relay U. The time relay output 10 is connected to the second inverse dynamic synchronization input of register 5, the input of the delay circuit 11, the inverted control input of the indicator 6, and the input of the coincidence circuit 12, the second input of which is connected to the output of the frequency divider 13, and the INPUT to the input of the OR circuit 14 connected to the second the input to the output of the circuit 2 is coincident, and the output to the counting input of the counter 4. pulses, the forward dynamic control input of which is connected to the output of the circuit, 8 OR. The output of the delay circuit 11 is connected to the invoice Dynamic zero reset counter ika 4 pulses. The information outputs of the register 5 are connected to the analog inputs of the code-frequency converter 15, the output of which is connected to the input of the frequency divider 13. . The device works as follows. In the initial state, the n (tQ) nQ dividers 7 and 13 of the frequency, the trigger 9, the pulse counter 4 and the register 5 are set to zero, and the signals at the outputs of the circuits 2 and 12 do not match. Pulses with an average frequency n (t) nQ from sensor 1 are continuously fed to the input of a frequency divider 7 with a division factor of N equal to, for example, 1000, To the time point C corresponding to the appearance at the output of the divider 7 of the first pulse, it arrives the number of pulses is 5; i.) At-UeVt (.- eH). % - «(. О о. Where n (tj |) is the average frequency of impulses at the moment of time, is equal, respectively, nCt-t) na-NX. The output pulse of the divider 7 starts a 3-stage relay, for example, performed according to the stand-by single-vibration scheme with a time of quasi-responsive island at, for example, 0.1 s, simultaneously through the circuit 8 OR switches the counting direction of the counter to Addition. Pulses-sensor astro-njje through open at the time & .t the coincidence circuit 2 and the LI circuit 14 arrive at the counting input of the counter 4, which during this time registers the number of pulses equal to | (J.) -, (The trailing edge of the first control pulse of the time relay 3 sets the trigger 9 to one state By the time t. ,, / с: corresponding to the appearance at the output of the divider 7 of the second pulse, the number of pulses J (i (t), where n (t / 2) is the average frequency of the pulses at time t , is equal respectively to n (b2) P (, - 2MYA- The second pulse of the divider 7 starts the relay 3 times and at the same time switches the direction The counting of counter 4 by Subtraction. During the time dt in counter 4, the number of pulses N / equal to r IV - is subtracted. As a result of subtracting, the difference N - (- Njj remains in the counter) is Nth (tl - (. t e) .. ..- MEM, .. (XAt) ... adt) -N-jj-tN-ut The falling edge of the second control pulse of the relay 3 times trigger 9 returns to its original state, and the signal that appears at the inverse trigger output rewrites the contents the counter 4 into the register 5, starts the time relay 10, made, for example, according to the waiting one-shot circuit with a quasistable state time of, for example, 0.1 s, and at the same time through the circuit 8 OR is fed to the control input of the 4-pulse counter, switching it to the Addition mode. In this mode, the counting input of counter 4 through the coincidence circuit 12 open for time At and circuit 14 OR pulses are output from the output of divider 13, the division factor of which is set to 2NAt. Transform

The code-frequency carrier 15 is made according to a scheme with a quadratic conversion characteristic, therefore the frequency of the pulses at the output of the converter 15 is equal to).

Taking into account the division factor of divider 13, the number of pulses arriving at time 4t on the counting input is the account jNt-NgfAi (N-j-Ng /

chica 4 equals lA / At 2N

At the end of time ut signal from the output

time relay 10 is fed to the inverse dynamic input of the synchronization register 5 by writing to it the contents of counter 4, which is

- (VN,) (l-)

GAL + N TSO ,, ir, (MLl Vlatw. 3-2 g-ai J

Claims (1)

- -% F --- F -l -h in the known device, the pulse difference, j is indicated on the digital display as a measurement result, therefore the systematic error is (li, -K, bMutX (PO) 2 2. iMAtI 3. For example, at 0.01, dd), 0025%, with 0.5%; with LD t b, 05, L, 0.0625% Cf 2.5%; WHAT 0.1 0.25% cQ; 5.00%. Thus, the proposed device provides a reduction in the systematic measurement error. Claims An apparatus for measuring blood flow, comprising a series-connected sensor, a time relay frequency divider and a trigger, a pulse counter sequentially on, a register and an indicator, as well as a delay circuit and a matching circuit, the first input of which is connected to the sensor, and the second with the time relay output, the trigger output is connected to the register synchronization input, and the delay circuit output is connected to the counting input % (,). fcM By the same signal, which arrives at the inverse control input of indicator b, digital indication of the measurement result is allowed, which, given the comma (Nut 100), is equal to the measured parameter X / characterizing the blood flow through the test area of the organism. After that, the signal from the output of the delay circuit 11 is fed to the counter input 4 of the counter, setting it to its initial state. The next measurement is similar. The systematic measurement error of the parameter 7i by the device is equal to xatN A hl-fcN pulse pulse, characterized in that, in order to improve measurement accuracy by reducing the system: tical component of the error, a second time relay, an OR circuit and a code-frequency converter connected in series, a second frequency divider, a second coincidence circuit and a second the OR circuit, the second input of which is connected to the output of the first coincidence circuit, and the output of the counting input of the pulse counter, the control input of which is connected to the output of the first OR circuit, which is connected to the output of the first input the frequency input and the second input to the trigger output and the input of the second relay, the output of which is connected to the second input of the second coincidence circuit, the control input of the indicator, the input of the delay circuit and the second synchronization input of the register, the output outputs of which are connected to the similar inputs of the converter code frequency. Sources of information, rintye taken into account when euspertiz 1. Copyright certificateSSSR 603373, cl. A 61 B 5/02, 1976.