JPH0420624B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a urine volume measurement mechanism that integrally measures and displays the urine volume per unit time of a patient to whom an extracorporeal circulation circuit is connected, and based on the measured value,
The present invention relates to an artificial heart-lung machine that can safely maintain the physiological state of a patient by adjusting the rotational speed of a blood pump and the head of a blood removal volume measurement/head adjustment tank manually or by a control mechanism.

Generally, in open heart surgery, a rotary pump (blood pump) is used to take over the work of the patient's heart.
The patient's blood is then circulated outside the body using an artificial heart-lung machine combined with an oxygenator (oxygen supply device), which also takes over the function of the lungs. In the extracorporeal circulation of blood using this artificial heart-lung machine, the amount of urine excreted by the patient is a very important index as a measurable amount for understanding the hemodynamics of peripheral blood vessels. This is because, as is well known, urine is produced by the kidneys, and in the above extracorporeal circulation, the circulation of blood to the kidneys can be considered to be at the same level as the so-called peripheral circulation. be.

That is, blood feeding using an artificial heart-lung machine is different from natural blood feeding, and blood feeding using a rotary pump cannot be said to be normal blood feeding for a living body. Blood is circulated using this abnormal blood supply method, and the amount of urine produced by the kidneys is measured in order to understand the state of blood circulation. That is, in order to obtain the same amount of blood feeding as the natural blood feeding (circulatory blood feeding to the heart that is normally performed in living organisms) using a blood feeding means using a rotary pump, a predetermined blood feeding amount, that is, a rotary pump, is required. A predetermined rotational speed of the pump must be ensured, and whether the amount of blood delivered when extracorporeal blood circulation is performed using a rotary pump is approximately the same as the amount of blood delivered normally to the living body. must be confirmed.

By the way, it is important to maintain a constant urine output in order to prevent renal failure, and maintaining a constant urine output means that the renal blood flow is maintained. This is thought to mean that the required amount of blood is maintained in other organs, so the urine volume measurements serve as an indicator for determining whether or not extracorporeal circulation is adequate.

As mentioned above, there is a close relationship between the amount of blood pumped and the amount of urine excreted that is normally carried out in living organisms. , the amount of urine excreted from the living body is measured, and from this urine output measurement value, it can be determined whether or not blood delivery using a rotary pump is appropriate, and the amount of blood delivered by the rotary pump can be adjusted based on the results. The goal is to maintain the normal state of the organism.

Here, one of the factors governing urine production is blood pressure. In order for a certain amount of blood to flow, the blood pressure must be set according to that blood flow, and that blood flow can be obtained.Of course, a certain amount of blood flow,
If blood pressure cannot be maintained, urine production will be difficult. For example, urine production that does not maintain a blood pressure of 50 m/mHg is not normal.

Therefore, in the case of blood transfer using a rotary pump,
In order to maintain a blood pressure that allows urine to be produced, it is necessary to ensure a constant amount of blood supply, that is, a constant number of rotations of the rotary pump, and to ensure that the amount of blood supplied by the rotary pump is appropriate for the living body. In order to calculate the blood volume, it is sufficient to make the amount of urine produced to be the same as the normal amount of the living body.To do this, look at the amount of urine excreted and calculate the amount of urine excreted based on the amount of urine excreted in normal times. It becomes necessary to adjust the amount of blood delivered by the rotary pump in order to maintain approximately the same amount of discharge.

Furthermore, during extracorporeal blood circulation, the amount of venous blood removed changes due to bleeding during cardiac surgery, blood accumulation in the peripheral circulatory system, and the like. For example, if blood pools in the peripheral vascular system, the amount of venous blood returning to the vena cava will decrease, and the amount of blood induced into the extracorporeal circulation device (the amount of blood removed) will decrease accordingly. It is also necessary to adjust the amount of blood removed by vertically adjusting the blood volume measurement/head adjustment tank. In addition, in order to maintain a constant arterial pressure, a certain flow rate of blood must be delivered to the living body, but even if the same flow rate of blood is delivered to the living body, the blood loss state of the living body exceeds a certain limit. If this occurs, the arterial pressure remains in a low state, and it is difficult to raise the arterial pressure even if the blood flow is increased. In this state, venous pressure is also reduced. Therefore, it is necessary to adjust the amount of blood removed from this point as well. By the way, as an example, blood pressure is 60
m/mHg, the amount of urine produced is about 100c.c./1Hr.

Therefore, conventional methods have been used to measure the patient's urine output per unit time, and depending on the deviation of the measured value from the standard urine output, the rotational speed of the blood pump in the heart-lung machine and the blood removal volume measurement and head adjustment tank. The head of the body is adjusted to maintain a safe physiological state. In practice, the above-mentioned fluctuation in urine volume causes the measured value to be smaller than the standard urine volume value (estimated from the patient's normal urine volume). Therefore, specific adjustments are made using the following two methods. One is when the amount of blood circulating is low, in which case the rotational speed of the blood pump is increased to increase the amount of circulating blood. The other case is when the circulating blood volume is sufficient but the blood pressure is low. In this case, the head of the blood loss measurement and head adjustment tank is lowered to increase the blood removal resistance and increase the blood pressure.

By the way, in the conventional urine volume measurement mechanism, for example, a halumbag with a measuring scale is hung below the operating table, an introduction tube is connected to this bag, and the urine volume in the halumbag is read at regular intervals. The device is installed separately from the heart-lung machine, and its display (scale) is located in a location where it is difficult to confirm urine volume (read the scale).

As a result, the person who reads the urine volume and the person who adjusts the heart-lung machine must be placed separately, which increases the number of operators, and the work efficiency does not improve even though the number of operators increases. situation.

This invention was made in view of the above circumstances,
A urine volume measurement mechanism that measures and displays the patient's urine volume is installed in a conventional heart-lung machine, and based on the measured value, the rotation speed of the blood pump in the heart-lung machine and the amount of blood removed are measured and the head is adjusted. Not only can the head of the tank be adjusted manually or by a control mechanism to safely maintain the physiological state of the patient during extracorporeal circulation, but it also simplifies the adjustment operation based on urine volume measurements. This made it possible to reduce the number of personnel involved.

The present invention will be explained below with reference to the drawings.
FIG. 1 shows an embodiment of the present invention, and reference numeral 1 in the figure indicates a urine volume measuring mechanism. This urine volume measuring mechanism 1 is provided integrally with the heart-lung machine 2 and is composed of a detection section 3, a control section 4, and a display section 5.

The detection unit 3 is connected to a urine drainage tube 7 attached to the patient 6, and includes, for example, a urine storage container that stores urine discharged by the urine drainage tube 7, and a sensor that detects the amount of urine in this urine storage container. has
The cumulative amount of urine in the urine storage container can be detected over time by the sensor, and the detected value is converted into an electrical signal and supplied to the control section 4.

The control unit 4 receives the detection signal from the detection unit 3, calculates the urine volume per unit time (urine flow rate) based on this, and displays this urine volume measurement value on the display unit 5.
The system is configured so that calculations and control operations as shown in FIG. 2 are performed based on this urine volume measurement value. That is, the above-mentioned standard urine volume value is input to this control unit 4, and the first
Then, it is determined whether the urine volume measurement value is larger or smaller than this standard urine volume value. When the urine volume measurement value is smaller than the standard urine volume value, if the circulating blood volume of the circulating blood volume measuring device (to be described later) at that point is smaller than the pre-input setting value, the roller of the heart-lung machine 2 A signal A that increases the rotational speed of the pump (blood pump) 8 is supplied from the control unit 4 to the rotational drive unit of the roller pump 8, and conversely, when the circulating blood volume is larger than the above set value, the heart-lung machine shown in FIG. 1 is activated. A signal B for reducing the head from the patient's heart to the liquid level in the blood removal reservoir 13 in the blood removal amount measurement and head adjustment tank 9 of the device 2 is sent from the control unit 4 to the head of the blood removal amount measurement and head adjustment tank 9. The adjustment drive is supplied.

As shown in FIG. 3, the blood removal amount measurement/head adjustment tank 9 includes a lifting device 12 provided below the bed 11, and a blood removal reservoir (blood reservoir) attached to the lifting device 12 so as to be vertically movable. )13 and
A blood tube 14 that guides blood from the patient 11a on the bed 11 to the blood removal reservoir 13; a blood tube 15 attached to the bottom of the blood removal reservoir 13 so as to communicate with the blood removal reservoir 13; A blood pump (roller pump) 16 connected to a blood tube 1 is used to remove blood from a patient 11a on a bed 11.
4, the scale 13a for measuring blood volume
The control section 4 sends an output electric signal according to the circulating blood volume of the circulating blood volume measurement device into the blood removal reservoir 13 having a blood removal amount measurement and head adjustment tank 9. A drive unit (not shown) is applied to the lifting device 1 by the head adjusting drive unit.
By moving the blood removal reservoir 13 up and down via the blood removal reservoir 13, the height 17 from the heart of the patient 11a to the liquid level in the blood removal reservoir 13 can be adjusted. The circulating blood volume measurement value of the circulating blood volume measuring device is transmitted from the circulating blood volume measuring device in which the heart-lung machine 2 is installed to the control unit 4.
is configured so that it is always input.

As shown in FIG. 4, the circulating blood volume measuring device has one end 3 connected to the patient's superior vena cava or inferior vena cava.
1 of the central venous pressure gauge 34, which is formed of a U-shaped tube 33 with the other end 32 located higher than 1.
A pressure conversion mechanism 35 is connected to the other end 32 of the double tube 33, a calculation mechanism 36 is electrically connected to the pressure conversion mechanism 35, and the calculation mechanism 36 is electrically connected to the control section 4 of the urine volume measurement mechanism 1. The central venous pressure obtained based on the blood introduced into this U-shaped tube 33 through one end 31 of the U-shaped tube 33 is converted into an electrical signal according to the central venous pressure by a pressure conversion mechanism 35. The calculation mechanism 36 is converted based on the electrical signal.
The amount of circulating blood per unit time is calculated, and the amount of circulating blood is converted into an electrical signal and sent to the control section 4.
It was designed to be output to .

The converted output electric signal of the circulating blood volume output to the control unit 4 is displayed on a display unit provided in the control unit 4, and this display unit The rotation speed of the blood pump 16 is also displayed.

In the circulating blood volume measuring device, the U-shaped tube 3
The height from one end 31 of 3 to the upper end surface 33a of blood introduced into this U-shaped tube 33 is the central venous pressure 33.
b, and the air pressure generated between the upper end surface 33a of the blood in the U-shaped tube 33 and the pressure conversion mechanism 35 is converted into an electrical signal by the pressure conversion mechanism 35. ing.

According to the artificial heart-lung machine with a urine volume measurement and adjustment mechanism configured as described above, the following excellent effects can be obtained.

() Since the urine volume display section 5 is integrally provided in the heart-lung machine 2, it becomes very easy to read the urine volume as needed.

() Even when any of the above is observed in the urine volume measurement value, the cause of the abnormality (whether the circulating blood volume is inappropriate or the blood pressure is inappropriate) can be determined immediately and appropriate measures can be taken automatically. patient safety is ensured.

() As described above, since the detection of abnormal urine output and its adjustment operation are performed automatically, the number of personnel operating the heart-lung machine during extracorporeal circulation can be significantly reduced while maintaining safety.

In addition, in the above embodiment, the urine volume measuring mechanism is composed of a detection section, a control section, and a display section, and the amount of circulating blood,
Although the blood pressure can be adjusted automatically, the urine volume measuring mechanism is composed of a detection section and a display section, and the measured value is confirmed by the operator of the device, while the display section provided in the control section 4 The operator confirms the circulating blood volume display and the rotation speed display of the roller pump, and from these, the operator can adjust the rotation of the roller pump 8 or adjust the amount of blood removed from the patient's heart into the blood removal reservoir 13 using the blood removal amount measurement/head adjustment tank 9. The adjustment operation of the head to the liquid level may be performed manually. In this way, when a decrease in urine output occurs due to factors other than changes in circulating blood volume and blood pressure, other measures such as drug injection can be taken as needed.

As explained above, according to the present invention, a blood reservoir having a scale and capable of measuring the amount of blood removed by the scale is provided so as to be movable up and down, and the blood pressure can be adjusted by the up and down movement of the reservoir. In a heart-lung machine, which allows blood to be drawn from a patient into the blood reservoir of the volume measurement and head adjustment tank, and which is capable of sending blood to the patient via a heart-lung machine using a blood pump, a central venous pressure gauge is installed from the patient's vein. The central venous pressure obtained by introducing blood into the central venous pressure gauge is converted into an electrical signal corresponding to the central vein by a pressure conversion mechanism attached to the central venous manometer, and outputted, and communicated to the pressure conversion mechanism based on the electrical signal. a circulating blood volume measuring device that calculates the circulating blood volume per unit time using a calculation mechanism configured to calculate the circulating blood volume and outputs the circulating blood volume as an electrical signal; and a urine storage unit that stores the urine taken out from the patient via the urine drainage tube. a container, a detection sensor that detects the amount of urine in the urine storage container, a display section that is provided near the vertical movement operation section of the blood pump and the blood removal amount measurement/head adjustment tank and that displays the amount of urine, and the detection sensor. Calculate the amount of urine per unit time based on the detection signal of When the circulating blood volume calculated by the circulating blood volume measuring device is smaller than the preset value when the value is smaller than the standard urine volume value, the circulating blood volume calculated by the circulating blood volume measuring device is lower than the preset value. An output electrical signal is applied to the drive unit of the blood pump to increase the amount of blood sent by the blood pump, and when the circulating blood volume calculated by the circulating blood volume measuring device is larger than the set value, the circulating blood volume is increased. An output electrical signal corresponding to the circulating blood volume of the blood volume measuring device is applied to the head adjustment drive section of the blood removal amount measurement and head adjustment tank, and the head adjustment drive section measures the blood removal amount and adjusts the head from the patient's heart. Since the configuration includes a urine volume measuring mechanism equipped with a control unit that can reduce the drop to the liquid level in the blood reservoir of the tank depending on the drop at that time, the rotation speed of the blood pump of the heart-lung machine The head of the blood loss measurement/head adjustment tank can be easily adjusted, the physiological state of the patient during extracorporeal circulation can be safely maintained, and the number of personnel operating the device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of a control section constituting this invention,
FIG. 3 is a schematic configuration diagram for explaining the mechanism of the blood removal amount measurement and head adjustment tank, and FIG. 4 is a schematic configuration diagram for explaining the mechanism of the circulating blood volume measuring device. 1... Urine volume measuring mechanism, 2... Artificial heart-lung machine, 8
...Blood pump, 9 Blood loss measurement and settling adjustment tank.

Claims (1)

[Scope of Claims] 1. A blood removal amount measurement and head drop, in which a blood reservoir having a scale and capable of measuring the amount of blood removed by the scale is provided so as to be movable up and down, and blood pressure can be adjusted by the up and down movement of the blood reservoir. In a heart-lung machine that allows blood to be drawn from a patient into the blood reservoir of a regulating tank and to be sent to the patient via an oxygenator by a blood pump, blood is transferred from the patient's veins to the central venous manometer. The central venous pressure obtained by introducing the central venous pressure is converted into an electrical signal corresponding to the central venous pressure by a pressure conversion mechanism attached to the central venous manometer and output, and the electrical signal is communicated to the pressure conversion mechanism based on the electrical signal. a circulating blood volume measuring device that calculates the circulating blood volume per unit time using a calculation mechanism and outputs the circulating blood volume as an electrical signal; and a urine storage container that stores the urine taken out from the patient via the urine drainage tube. a detection sensor for detecting the amount of urine in the urine storage container; a display section for displaying the urine amount provided near the vertical movement operation section of the blood pump and the blood removal amount measurement/head adjustment tank; and detection of the detection sensor. Calculating the urine volume per unit time based on the signal and displaying the calculated value on the display unit, and displaying the circulating blood volume obtained by the circulating blood volume measuring device on the display unit, and calculating the urine volume calculation value. When the circulating blood volume calculated by the circulating blood volume measuring device is smaller than the standard urine volume value and is smaller than a preset value, the output electricity of the circulating blood volume measuring device according to the circulating blood volume is lower than the preset value. applying a signal to a drive unit of a blood pump to increase the amount of blood sent by the blood pump;
When the circulating blood volume calculated by the circulating blood volume measuring device is larger than the set value, the output electric signal corresponding to the circulating blood volume of the circulating blood measuring device is applied to the head of the blood removal volume measurement and head adjustment tank. a control unit configured to apply a signal to an adjustment drive unit so that the head difference from the patient's heart to the liquid level in the blood reservoir of the blood loss measurement and head adjustment layer is made smaller than the current head difference by the head adjustment drive unit; What is claimed is: 1. A heart-lung machine with a urine volume measuring mechanism, comprising: a urine volume measuring mechanism;