JPH0356742B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a warmer for intravenous fluids, transfused blood, etc. This invention relates to an infusion warmer that warms infusions, etc.

[Conventional technology]

Infusion fluids such as electrolytes, nutrients, and blood are usually kept at about 4℃.
When injecting the infusion into a patient, the infusion is heated to a temperature close to body temperature. There are methods for heating this infusion solution, such as heating the vial containing the infusion solution or heating the infusion fluid delivery tube. There is a device that heats a heating bag having an infusion flow path by sandwiching it between a heating device having a heating plate. In this invention, temperature sensors are provided at three locations at the inlet, middle, and outlet of the infusion flow path, and the amount of heating of the two heating plates is controlled based on the detected temperatures. However, the rate of infusion into patients is not constant;
Taking blood pressure, heart condition, etc. into consideration, the time for injecting one 500 ml vial is determined to be between 1 and 3 hours, but sometimes it takes 4 to 5 hours. Therefore, it would be more desirable for the infusion warmer to be able to control the temperature of the injected infusion by taking into account not only the temperature of the infusion but also the flow rate of the infusion.

[Problem that the invention seeks to solve]

The present invention is an infusion warmer that heats a heating bag having a flat infusion flow path that meanders from side to side between heating plates, in which the heating amount of the heating plate is controlled based on the temperature of the infusion and the flow rate of the infusion. The purpose is to provide an infusion warmer that can be used.

[Means for solving problems]

The infusion warmer of the present invention heats a heating bag having a flat infusion flow path meandering left and right between heating plates. A first temperature sensor for measuring the temperature at the inlet of the infusion flow path and a second temperature sensor separated by a certain distance from this first temperature sensor are provided in the first heating part. A second heating section that heats most of the infusion flow path is provided between the heating section and the second heating section that heats most of the infusion flow path, and a third heating section that measures the temperature of the infusion heated by the second heating section. A temperature sensor is provided, and a third heating section is provided that heats the outlet portion of the infusion flow path with a thermally insulating band interposed between the second heating section and the temperature detected by the first and second temperature sensors. A control means is provided for controlling the second and third heating sections based on the flow rate and temperature of the infusion solution and the temperature detected by the third temperature sensor.

[Effect]

The infusion warmer of the present invention is provided with a first heating part that heats the inlet linear part of the infusion flow path with a constant amount of heat, and a first temperature sensor that measures the temperature of the inlet of the infusion flow path in this heating part. Since the second temperature sensor is provided at a certain distance, the temperature of the infusion liquid injected into the warmer is detected, and the inlet straight section is heated with a certain amount of heat, so the temperature between the first temperature sensor and the second temperature sensor is detected. The flow rate of the infused fluid is detected based on the temperature difference between the two temperature sensors. In other words, the cross section of the flow path of the heating bag is constant, and the time for the infusion to reach the second temperature sensor after passing through the first temperature sensor is proportional to the flow rate of the infusion, and the time for the infusion to pass through this period is proportional to the flow rate of the infusion. The temperature at which the infusion is heated by the first heating section should be proportional to the temperature, and if the temperature difference is large, the flow rate will be small, and conversely, if the temperature difference is small, the flow rate will be large. The flow rate can be detected based on the temperature difference between the second temperature sensors. In addition, a second heating section that heats most of the infusion flow path is provided between the first heating section and the heat insulating zone, and a second heating section is provided between the second heating section and the infusion channel with a heat insulating zone in between. Since a third heating section that heats the outlet of the flow path and a third temperature sensor that measures the temperature of the infusion heated by the second heating section are provided, the first temperature sensor and the second temperature sensor are provided. Based on the temperature and flow rate of the infusion fluid detected by the temperature sensor and the temperature detected by the third temperature sensor, the amount of heating of the heating section is determined by the control means that controls the second and third heating sections. can be controlled. That is, the temperature of the infusion flowing into the infusion flow path is known by the first temperature sensor, and the flow rate of the infusion is detected based on the temperature difference between the first temperature sensor and the second temperature sensor, so that the infusion cannot be heated. The heating amounts of the second and third heating sections can be set from the target temperature. In addition, since the heating results in the second and third heating sections can be known from the third and fourth temperature sensors, it is possible to correct the heating amounts of the second and third heating sections based on the results. be. As a result, the infusion fluid injected into the warmer flows out while being accurately controlled at the desired temperature, no matter how the temperature and flow rate change.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an embodiment of the infusion warmer of the present invention, FIG. 2 is a plan view with the lid removed, and FIG.
5 is a plan view of the heating bag, FIG. 4 is a partial side sectional view of the heating bag, and FIG. 5 is a block diagram of an embodiment of the present invention.

In FIG. 1, the main body 10 of the infusion warmer is box-shaped, and a heating plate and a temperature sensor are arranged on the front surface 12, and a power supply circuit, a heater, and a control section are housed inside the box. Power cord 14 from the main unit
is pulled out and an outlet 16 is attached to the tip. The lid 18 is rotatably attached to the surface edge of the main body 10 with a hinge 20, and the heating bag 4 is attached between the lid 18 and the surface 12.
It can be closed by sandwiching 2.

As shown in FIG. 2, the surface 12 of the main body is provided with a first heating plate 22 at a location where the linear portion 47 of the first inlet of the infusion flow path 48 of the heating bag contacts when the heating bag 42 is attached. It is being This first heating plate 22
includes a first temperature sensor 24 and a second temperature sensor 2.
6 are spaced apart from each other by an appropriate distance and surrounded by a heat insulating band 28. A second heating plate 32 is provided with the first heating plate 22 and the thermally insulating band 30 separated from each other. This second heating plate 32 has a size that heats most of the heating bag, and a third temperature sensor 34 is installed at the location where the flow end of the infusion flow path 48 heated by this second heating plate exits. Installed. The third heating plate 36 is attached to the second heating plate 32 with a thin heat insulating band 38 in between, and the outlet portion of the infusion flow path 48 of the heating bag 42 is heated. A fourth temperature sensor 40 is attached to the third heating plate at a location where the outlet of the infusion flow path 48 hits, and is adapted to display the temperature of the infusion flowing out from the warmer.

The heating bag 42 is made by adhering an upper membrane 44 and a lower membrane 46 made of thin plastic film to form an infusion passage 48, as shown in FIGS. 3 and 4. Prior to adhesion, the lower membrane 46 is inflated downward by vacuum forming or projection molding in the area where the infusion flow path 48 will be formed, to create a flat space with a thickness of about 1 mm. Adhesive lines 50 between the channels extend alternately from left and right to opposite sides in parallel, and the infusion channel 48 is passed through the heating bag 42 from top to bottom while meandering. An inlet pipe 52 is attached to the upper inlet of the infusion channel 48, and an outlet pipe 54 is attached to the lower outlet. Also, the second
The width of the middle portion 56 of the infusion flow path, which is in contact with the heating plate, is widened to ensure sufficient heat exchange.

The temperature of the infusion is controlled as shown in the block diagram of FIG.
The A/D-converted temperature signals detected by the temperature sensor 4 and the second temperature sensor 26 are input to a subtracter 58, and the temperature difference signal thereof is input to a multiplier 60. Since the input temperature difference signal is proportional to the flow rate, the multiplier 60 multiplies it by a constant constant to calculate the flow rate, and the data is input from the multiplier 60 to the CPU 62 . On the other hand, the temperature of the third temperature sensor 34 is input to the comparator 64, and the comparison value with the set temperature is input to the CPU 62. Further, a signal is input from the first temperature sensor 24 to the CPU. The CPU 62 performs predetermined calculations based on inputs from the multiplier 60, the first temperature sensor 24, and the comparator 64, and then controls the second heating section drive circuit 66 and the third heating section drive circuit 68, respectively. Since the signal is sent, the amount of heat generated by the second heating plate 32 and the third heating plate 36 is controlled.

In this embodiment, a fourth temperature sensor is provided at the infusion outlet of the third heating section to display the temperature, so that the operation of the infusion warmer can be confirmed, making it convenient and possible to confirm safety. In addition, the infusion flow path of the heating bag used in this example was widened and the flow rate was slowed down at the part where the second heating plate, which heats most of the heating bag, touches. Infusion fluid can be heated efficiently.

〔Effect of the invention〕

As explained above, the infusion warmer of the present invention detects not only the temperature but also the flow rate of the infusion flowing through the infusion channel of the heating bag attached to the infusion warmer, and controls the heating plate based on the temperature and flow rate. Since the calorific value can be controlled, there is an excellent effect that the temperature of the infusion can be accurately controlled by following changes in the flow rate of the infusion.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the infusion warmer of the present invention, Fig. 2 is a plan view of the top of the main body, Fig. 3 is a plan view of the heating bag, and Fig. 4 is a partial side of the heating bag. Cross section, 5th
The figure is a block diagram showing the configuration of one embodiment of the control means of the present invention. 22...First heating plate, 24...First temperature sensor, 26...Second temperature sensor, 28...Heat insulation band, 32...Second heating plate, 34...Third temperature Sensor, 36... Third heating plate, 38... Heat insulation band, 42... Warming bag, 48... Infusion flow path.

Claims (1)

[Claims] 1. In an infusion warmer that heats a heating bag with a heating bag having an infusion flow path meandering from side to side, a first heating section is provided that heats the inlet straight part of the infusion flow path of the heating bag with a constant amount of heat, A first temperature sensor for measuring the temperature at the entrance of the infusion flow path of the heating bag is provided in the first heating section, and a second temperature sensor is provided at a certain distance from the first temperature sensor, and thermal insulation is provided between the first temperature sensor and the first heating section. A second heating section that heats most of the heating bag is provided across the band, a third temperature sensor is provided that measures the temperature of the infusion heated by the second heating section, and the second heating section is provided with a third temperature sensor that measures the temperature of the infusion heated by the second heating section. a third heating section that heats the outlet section of the infusion flow path with a heat insulating band between the third heating section and the third heating section;
control means for controlling the second and third heating sections based on the flow rate and temperature of the infusion solution detected by the first and second temperature sensors and the temperature of the infusion solution detected by the third temperature sensor; An infusion warmer characterized by: