JPS63241316A - Method for horizontally stopping receiving tray of apparatus performing weighing under rocking - Google Patents

Abstract

PURPOSE:To stop a receiving tray in a horizontal state, by stopping the rocking of a load cell immediately before the wt. of the receiving tray detected by the rocking load cell increases to reach the max. value. CONSTITUTION:A rocking mechanism 5 is driven after a power switch is closed but before an object 3 to be weighed is placed on the upper surface of a receiving tray 4 to reciprocally rock a load cell 6 and the max. value and min. value of the receiving tray 4 detected by the load cell 6 are recorded to calculate the difference between both values. Then, the moment the wt. of the receiving tray 4 detected by the load cell 6 increases to become slightly smaller than the value obtained by adding the aforementioned difference to the aforementioned min. value, that is, immediately before the measured value of the load cell 6 reaches the aforementioned max. value, the rocking mechanism 5 is stopped. By this method, the receiving tray 4 slightly rocking by inertia can be stopped in a horizontal state.

Description

[Detailed Description of the Invention] a1 Purpose of the Invention (Field of Application in Industry A) The present invention is applicable to cases where a certain amount of blood is collected from a blood donor during blood donation performed at a blood center or a mobile blood collection vehicle. etc.

(Prior Art) Blood for use in blood transfusions is often obtained through blood donation at blood centers or on the street.

In blood donation, the amount of blood donated per person is determined (
200cc or 400cc), Jitsugan Sho 61-176
Various quantitative blood sampling devices are in use, such as the quantitative blood sampling device disclosed in US Pat.

FIG. 2 shows an example of such a quantitative blood sampling device.

The quantitative blood collection device shown in FIG. 2 has a blood collection bag 3, which has a tube 2 connected to one end and a blood collection needle connected to the other end, placed inside a box-shaped container 1 provided with a lid that can be freely sealed. A receiving tray 4 for the above-mentioned blood collection, a swinging mechanism 5 for swinging the receiving tray 4, a load cell 6 for detecting the weight of blood stored in the blood collection bag 3 placed on the receiving tray 4, and a swinging mechanism 5 for the above-mentioned swinging mechanism 5. It has a controller that controls operation and stop as well as continuation and stop of the blood collection work based on the weight detected by the load cell 6, and is further provided with a vacuum pump to evacuate the inside of the vessel 1. It is something.

When blood is collected using the quantitative blood collection device described above, the procedure is as follows.

When a blood collection needle is inserted into the donor's arm and the quantitative blood collection device is started, blood is deposited from the blood collection needle into the tray 4 inside the container 1 via the tube 2 connected to the blood collection needle due to the donor's blood pressure. The blood flows into blood collection bag 3. If necessary, blood can be collected in a short time by operating a vacuum pump to create a negative pressure inside the vessel 1.

When the quantitative blood sampling device is started, the swinging mechanism 5 built into the quantitative blood sampling device operates, and the saucer 4 that is linked to the swinging mechanism 5 swings.

As the saucer 4 swings, the blood collection bag 3 placed on top of the saucer 4 also swings.
The anticoagulant contained therein and the blood that has flowed into the blood collection bag 3 are stirred and mixed, and the blood collected in the blood collection bag 3 is prevented from coagulating.

The load cell 6 detects the weight of blood stored in the blood collection bag 3, and when the weight of the blood detected by the load cell 6 reaches the weight stored in advance in the controller, the quantification is performed. The blood sampling device is stopped to complete the blood sampling operation.

(Problems to be Solved by the Invention) However, in the quantitative blood sampling device as described above, the following disadvantages occur.

That is, in order to obtain an accurate amount of blood to be collected, the weight of the tray 4 and the weight of the guarantee bag 3 must be subtracted from the weight detected by the load cell 6.

Among these, the weight of the receiving tray 4 is always constant, so it is sufficient to store this value in advance in the controller that controls the operation of the blood sampling device. There are differences even with those for CC use, and it also varies depending on the material, amount of anti-caking agent added inside, etc., so measurements must be taken each time.

For this reason, in the case of a quantitative blood sampling device as shown in FIG. 2, it is necessary to measure the weight of the blood sampling bag 3 to be used before starting the blood sampling operation, and subtract this weight from the measured value of the load cell 6 as a tare weight. It becomes necessary.

However, the weight detected by the word cell 6 that is swung by the 11-force mechanism 5 changes depending on the attitude (inclination direction, inclination angle) of the load cell 6. In the case of the posture, it is necessary to measure the weight of the blood collection bag 30.

Weight measurement using the load cell 6 can be performed accurately only when the tray 4 provided above the load cell 6 is horizontal.Moreover, when the tray 4 is horizontal,
Since it may be easy to place objects to be weighed, such as the blood collection bag 3, on the top surface of this saucer 4, it is preferable that the saucer 4 be horizontal at the beginning of blood sampling and other weighing operations. Since the posture of the tray 4 at the end of a measuring operation such as blood sampling is not particularly determined, it is necessary to control the posture of the tray 4 at the beginning of a measuring operation such as blood sampling.

The horizontal stopping device of the present invention for weighing while swinging solves the above-mentioned problems.

b1 Structure of the Invention (Means for Solving the Problem) As described above, the method for horizontally stopping the receiving tray of the device for weighing while swinging according to the present invention is to A device that performs weighing while swinging has a load cell that is oscillated back and forth, and a tray whose lower surface is connected to the upper surface of the other end of the load cell and on which an object to be weighed is placed. This method involves stopping the machine in a horizontal position before starting.

In the method of the present invention used for the above purposes,
After turning on the power switch and before placing the object to be weighed on the top surface of the tray, the rocking mechanism is driven to swing the load cell back and forth, and the load cell detects the load cell as it moves back and forth. Record the maximum and minimum weights of the trays and find the difference.

That is, due to this reciprocating rocking, the value measured by the load cell 6 changes between the maximum value ■□8 and the minimum value V mln, as shown in range A in FIG. By repeating the above (preferably about 3 times as shown in FIG. 1), the difference in the measured value of the load cell 6 that changes with the rocking
V raax −V mtn ) is determined.

After finding the difference in the measured values of the load cell 6 that change with the reciprocating rocking as described above, observe the weight of the saucer 4 detected by the load cell 6, as shown in range B in Fig. 1. At the same time, the load cell 6 continues to swing.

As shown at point 0 in FIG. 1, the weight obtained from this observation increases and becomes slightly smaller than the above minimum value Vmln plus the above difference, that is, the measured value of the load cell 6 Immediately before reaching the maximum value ■□8, a signal is sent to the swing mechanism 5 for reciprocating the load cell 6 to stop its operation.

In response to this signal, the swing mechanism 5 stops its operation,
The receiving tray 4 for placing the object to be measured, such as the blood collection bag 3, also stops, but the receiving tray 4 does not stop after the swinging mechanism 5 receives the signal for stopping the operation described above until it actually stops. Due to the inertia caused by the inertia, the load cell 6 and the saucer 4 slightly oscillate.

For this reason, as mentioned above, a signal is sent to the swing mechanism 5 for reciprocating the load cell 6 to stop its operation immediately before the measured value of the load cell 6 reaches the maximum value V□8. By sending , the saucer 4 can be stopped in a horizontal state.

The amount of inertia operation performed from when the swing mechanism 5 receives the signal for stopping the operation until it actually stops varies depending on the weight of the load cell 6 and the saucer 4, the swing speed, etc. The timing of issuing a signal for stopping operation is determined by design considerations according to these conditions, but normally, the measured value of the load cell 6 is within the minimum value V1n and the difference (Vm
The moment the value reaches the sum of about 90% of (ax-Vln),
Issues a signal to stop operation.

As described above, if the receiving tray 4 for placing the object to be measured such as the blood collection bag 3 is stopped in a horizontal state, the second
As shown in the figure, an object to be measured, such as a blood collection bag 3, is placed on the upper surface of this tray 4, and measurement operations such as blood collection are started. By placing the object to be measured, such as the blood collection bag 3, on the upper surface of the saucer 4 in this way, the measured value of the load cell 6 increases by 7w in FIG. 1. Since this increment VW is the weight of the object to be weighed, such as the blood collection bag 3, it is used as a tare weight and is subtracted from subsequent measurement values, as described above.

C1 Effects of the Invention Since the method of horizontally stopping the receiving tray of the device that performs weighing while swinging according to the present invention is configured as described above, it is possible to accurately determine the weight of blood, etc. stored in the blood collection bag. It becomes possible to accurately collect a certain amount of blood, etc.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between time and output voltage of the load cell when implementing the horizontal stopping method of the present invention,
FIG. 2 is a longitudinal sectional view showing the structure of a quantitative blood sampling device used to carry out the present invention. 1: Instrument body, 2: Tube, 3: Blood collection bag, 4: Receiver,
5: Swing mechanism, 6: Load cell. Patent applicant: Chiyoda Manufacturing Co., Ltd. Agent: Koyama Structure (and 1 other person) Figure 1 Figure 2

Claims (1)

[Claims] Measuring while rocking, comprising a load cell that is reciprocated by a rocking mechanism connected to the lower surface of one end, and a tray whose lower surface is connected to the upper surface of the other end of the load cell, and on which the object to be weighed is placed. This is a method in which the tray of a device that performs weighing is stopped in a horizontal state before starting weighing work, and after turning on the power switch and before placing the object to be weighed on the top surface of the tray, the swing mechanism is The load cell is driven to swing back and forth, and the maximum and minimum values of the weight of the tray detected by the load cell are recorded as the load cell moves back and forth, and the difference between them is determined. As the load cell continues, the weight of the tray detected by this load cell is observed, and at the moment when the weight obtained by this observation increases and becomes slightly smaller than the above minimum value plus the above difference, the swing mechanism A method of horizontally stopping the receiving tray of a device that performs weighing while swinging, sending a signal to stop its operation.