JPH04164458A - Warming/humidifying device for respirator - Google Patents

Abstract

PURPOSE:To prevent heat damage of a suction pipe due to overheat of the middle part of a heater element by constructing the tip of the heater element situated at the downstream end of the suction pipe so that it has a higher heat emission than the other parts. CONSTITUTION:To the downstream end of a suction pipe 5 consisting of a coil, a ring-shaped fixing member 11 made of tetrafluoroethylene resin is fitted by pressure through utilization of its resilience. In this suction pipe 5, the tip 9a of a heat wire 9 extended while equipped with such a slack as capable of admitting elongation and contraction of the pipe 5 is folded back being wound on the fixing member 11, and the tip 9a is detained with the downstream end of the suction pipe 5 with the aid of member 11. The number of turns of the heat wire 9 wound at the tip 9a shall be possible smallest, for example 8, so as not to give direct thermal affection to a temp. sensor 10 situated downstream. The heat wire 9 emits more heat at the tip 9 than the other parts to generate linear temp. distribution over the heat wire 9, and the respiratory gas can be heated effectively over the whole length of the suction pipe 5 without causing excessive heating of respiratory gas in the middle part of the suction pipe 5.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a heating humidifier for a respiratory device that is provided to heat and humidify breathing gas in a respiratory device that forcibly or voluntarily supplies breathing gas to a patient. Regarding equipment.

(Prior Art) Conventionally, as shown in FIG. 3, this type of device includes a humidifier 1 interposed in the intake circuit of a respiratory organ, and a chamber heated by a heat plate 3 on the main body 2 of the humidifier 1. It is known to heat and humidify breathing gas using distilled water in a humidifier 1, and to supply this gas to a connection port 6 for a patient, such as a mouthpiece, through an intake pipe 5 on the downstream side of the humidifier 1.

In the figure, 7 is a branch pipe to which a connection port 6 is attached, and includes an inlet part 7a for connecting the intake pipe 5 and an outlet part 7b for connecting the exhalation pipe 8.

By the way, even if breathing gas is heated and humidified by the humidifier 1, the temperature of the breathing gas may drop when it passes through the intake pipe 5, and the moisture contained in the breathing gas may condense in the intake pipe 5. ,
In order to prevent this, in the above-mentioned one, in the intake pipe 5,
A heat wire 9 made of a heating wire covered with silicone rubber or the like as an electric heating body is extended in the longitudinal direction of the protection pipe 5 by folding back one turn, and a temperature sensor lO is provided at the inlet portion 7a of the branch pipe 7.
A signal from the main body 2 is inputted to a controller built in the main body 2, and the controller controls the energization of the heat wire 9 as a feedback 11aL, so that the temperature of the breathing gas at the inlet portion 7a is maintained at the set temperature.

(Problem to be Solved by the Invention) When the heat wire 9 is extended as described above, heat transfer from the tip and tail portions of the heat wire 9 located at the downstream end and upstream end of the intake pipe 5 causes As shown by line a in FIG. 2, the temperature distribution of the heat wire 9 shows a mountain-shaped temperature distribution where the middle part is high temperature, and the breathing gas is excessively heated in the middle part of the intake pipe 5, and energy is lost. causing loss,
Furthermore, there is a possibility that the intake pipe 5 may be damaged by heat due to overheating of the intermediate portion of the heat wire 9.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a device that can eliminate the above-mentioned problems by suppressing the temperature rise in the intermediate portion of an electric heating element extending into an intake pipe.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes an electric heating element that prevents dew condensation in the intake pipe on the downstream side of a humidifier that heats and humidifies breathing gas. In the case where the intake pipe extends in the longitudinal direction, the amount of heat generated at the tip of the electric heating element located at the downstream end of the intake pipe is made higher than that at other parts.

(Function) By increasing the amount of heat generated at the tip of the electric heating element, the temperature at the tip becomes higher, and the temperature distribution of the electric heating element when breathing gas flows is as shown by line b in Figure 2. Since a linear temperature distribution is exhibited, breathing gas is not heated excessively in the middle part of the intake pipe, and heat loss in the intake pipe due to overheating of the middle part of the electric heating element is also prevented.

Incidentally, the heat generation amount at the tip may be increased by changing the material of the tip of the electric heating element, but when using a heat wire as the electric heating element, the wire density is increased by winding or bundling the heat wire at the tip. By increasing the temperature, the amount of heat generated at the tip can be easily increased.

In addition, the intake pipe is generally constructed of a flexible pipe in order to have flexibility and stretchability, and when the distance between the tip of the heat wire and the temperature sensor changes due to expansion and contraction of the intake pipe, the temperature sensor Feedback control based on the signal becomes unstable, but if you provide a fixing member that is locked to the downstream end of the intake pipe and wrap the tip of the heat wire around it, the tip of the heat wire will become unstable. The linear density is increased, and the tip portion can be locked to the downstream end portion of the intake pipe via the fixing member, and the distance between the heat wire tip portion and the temperature sensor is maintained approximately constant even when the intake pipe expands and contracts. Stable feedback control becomes possible.

(Example) FIG. 1 shows an example of the apparatus of the present invention. The same members as in the prior art described above are given the same reference numerals as in FIG.

In this embodiment, a ring-shaped fixing member 1 made of polytetrafluoroethylene resin is attached to the downstream end portion of the intake pipe 5 made of a flexible pipe.
1 is press-fitted and locked using its elasticity, and the intake pipe 5
The distal end portion 9a of the heat wire 9, which is extended with a slack that allows expansion and contraction of the protection tube 5, is wound around the fixing member 11 and folded back, and the distal end portion 9a is connected to the intake pipe through the fixing member 11. It was locked at the downstream end portion of 5.

The tube and fixing member 11 may have any shape and material as long as it can be wound with the heat wire 9 at a required linear density and has heat resistance.

The number of windings of the tip portion 9a of the heat wire 9 is set to the minimum necessary number, for example, 8 turns, in order to prevent a direct thermal effect on the temperature sensor 10 on the downstream side.

The heat plate 3 of the humidifier 1 responds to a signal from a temperature sensor (not shown) provided at the outlet so that the gas temperature at the outlet of the chamber 4 connected to the upstream end of the intake pipe 5 reaches a set temperature, for example, 35°C. Based on this, the heat wire 9 is feedback-controlled by a controller in the main body 2, and the heat wire 9 is controlled by a temperature sensor 10 provided at the inlet portion 7a of the branch pipe 7 so that the temperature of the gas supplied from the intake pipe 5 reaches a set temperature, for example, 37°C.
Feedback control is performed by the controller based on signals from the controller.

Here, since the distal end portion 9a of the heat wire 9 is wound to increase the linear density, the amount of heat generated at the distal end portion 9a is higher than that of other parts, and the temperature distribution of the heat wire 9 is as described above. As explained in the function section, the distribution becomes linear as shown by line b in FIG. Gas can be heated efficiently.

Furthermore, even if the intake pipe 5 expands or contracts, the tip portion 9a of the heat wire 9 is locked to the downstream end portion of the intake tube 5 via the fixing member 11, so that the gap between the tip portion 9a and the temperature sensor 10 is The distance does not change much, and feedback control based on the signal from the temperature sensor 10 can be performed stably.

(Effects of the Invention) As is clear from the above description, according to the invention of claim 1, by increasing the amount of heat generated at the tip of the electric heating element extending into the intake pipe, the temperature distribution of the electric heating element becomes linear. This has the effect of preventing excessive heating of the breathing gas in the middle part of the intake pipe, reducing energy loss, and also preventing heat loss of the intake pipe due to overheating of the middle part of the electric heating element. Furthermore, when a heat wire is used as the electric heating body, the heat generation amount at the tip can be easily increased by increasing the linear density at the tip of the heat wire as in the invention of claim 2; According to the invention, the distal end portion of the heat wire is locked to the downstream end portion of the intake pipe, so that the distance between the downstream temperature sensor of the intake pipe and the distal end portion of the heat wire is kept constant regardless of expansion and contraction of the intake pipe. This has the effect of stably performing feedback control based on the signal from the temperature sensor.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an example of the device of the present invention, FIG. 2 is a graph showing the temperature distribution of a heat wire, and FIG. 3 is a diagram of a conventional device. 1... Humidifier 5... Intake pipe 9... Heat wire 9a... Tip portion 11... Fixing member Fig. 1 Fig. 2 Fig. 3 Fig. 2

Claims (1)

[Scope of Claims] 1. An electric heating element extending in the longitudinal direction of the intake pipe to prevent dew condensation within the intake pipe on the downstream side of a humidifier that heats and humidifies breathing gas, 1. A heating and humidifying device for respiratory organs, characterized in that the distal end portion of the electric heating element located at the downstream end of the intake pipe has a higher calorific value than other portions. 2. The heating and humidifying device for respiratory organs according to claim 1, wherein the electric heating body is made of a heat wire, and the linear density of the tip portion of the heat wire is increased. 3. The heating and humidifying device for respiratory organs according to claim 2, wherein the heat wire is wound around a fixing member that is fixed to the downstream end of the intake pipe to increase the linear density at the tip.