WO2012027912A1

WO2012027912A1 - Negative pressure wound therapy system capable of detecting air leakage rate

Info

Publication number: WO2012027912A1
Application number: PCT/CN2010/077046
Authority: WO
Inventors: 隗刚; 菅冀祁; 黄锦旺; 李佳
Original assignee: 惠州市华阳多媒体电子有限公司
Priority date: 2010-09-03
Filing date: 2010-09-17
Publication date: 2012-03-08
Also published as: CN101966364A

Abstract

A negative pressure wound therapy system capable of detecting air leakage rate includes: a liquid collection bottle(5) for collecting wound exudates; a negative pressure wound therapy device(8) consisted of a negative pressure source(6) and a controller(7); a wound kit for filling a wound and sealing the wound, which communicates with the liquid collection bottle(5) via a connecting tube(4). The system also includes an exudates volume detection unit(9) for detecting the volume of wound exudates in the liquid collection bottle(5); said controller(7) calculates air leakage rate according to the volume of wound exudates, an environment temperature and a negative pressure change of the negative pressure source(6). The negative pressure wound therapy system capable of detecting air leakage rate can measure current air leakage rate, and enable medical staff or users to know the degree of air leakage intuitively, and then to examine related connection parts to reduce the degree of air leakage.

Description

Negative Pressure Wound Treatment System for Detecting Air Leakage Rate This application claims to be submitted to the China Patent Office on September 3, 2010, application number 201010274065.7, and the invention titled "Negative Pressure Wound Treatment System with Detectable Air Leakage Rate", China Priority of the patent application, the entire contents of which are incorporated herein by reference.

The invention relates to the technical field of negative pressure wound treatment equipment, in particular to a negative pressure wound treatment system capable of detecting air leakage rate. Background technique

Negative pressure wound therapy equipment, called "Native" in the United States, is called NPWT. Its principle is to promote wound healing by applying negative pressure to the wound. According to the clinical results of the United States in the past 10 years, the device has a good healing effect on various acute and chronic wound treatments.

Generally, a negative pressure wound treatment system includes a negative pressure wound treatment device, a wound site kit, and a container for collecting exudate at the wound (herein referred to as a container for the collection bottle). Among them, the wound kit is used to close the wound and create a negative pressure space. The negative pressure wound treatment device is used to create the required negative pressure of the wound, and the negative pressure wound treatment device consists of a negative pressure source and a controller. Referring to Figure 1, a common negative pressure wound treatment system is shown. Within the dashed box is a negative pressure wound treatment device 8; reference numeral 1 shows the skin tissue around the human wound; the filler 2 at the wound covers the wound of the human body; a wound closure 3 is placed above the filler 2 at the wound, The wound is closed, and the wound filler 2 is connected to the liquid collecting bottle 5 through the connecting tube 4, thereby guiding the exudate from the wound into the liquid collecting bottle 5, and collecting the exudate from the wound through the collecting bottle 5, The other end of the liquid bottle 5 is connected to the negative pressure source 6, and the negative pressure source 6 provides a negative pressure to supply the wound exudate to the liquid collecting bottle 5; the negative pressure source 6 is connected to a controller 7, and is controlled by the controller 7. The control of the negative pressure source 6 is achieved.

Since the vacuum therapy device, the liquid collection bottle, and the wound are connected by the gas path, the gap at the joint and the resulting air leakage are inevitable. When the air leak is serious, the device can't even pump air to the set negative pressure value. At this time, the device alarm prompt is needed, so that the user or the medical staff of the negative pressure wound treatment system can promptly check the cause of the malfunction and eliminate the malfunction. When the air leak rate is still high but the equipment can still pump When the gas reaches the set negative pressure value, the start interval of the equipment air pump will be short at this time, the air pump starts frequently, the power consumption is large for the system, and the service life of the air pump is reduced, which also makes the negative pressure treatment equipment more noisy. Large, affecting the patient's normal rest and care. Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a negative pressure wound treatment system that can detect a leak rate, which can detect a leak rate, so that a user or a medical professional can intuitively understand the degree of air leak.

In order to solve the above technical problem, the present invention provides a negative pressure wound treatment system capable of detecting a leak rate,

a wound kit that fills the wound and closes the wound, communicating with the collection via a connecting tube; also includes:

The wound exudate volume detecting module detects the volume of the wound exudate in the collecting bottle; the controller calculates the leak rate according to the wound exudate volume, the ambient temperature, and the negative pressure change of the negative pressure source.

Preferably, the controller further includes a display interface that displays a numerical value of the air leak rate or a graph characterizing a leak rate.

Preferably, the display interface is an LED interface or an LCD interface.

Preferably, the controller further includes an alarm device, and the controller compares the calculated air leakage rate with a preset threshold value to determine whether an alarm signal is issued, and the alarm device alarms when receiving the alarm signal.

Preferably, when the calculated air leakage rate is greater than a preset threshold, the controller sends an alarm signal, and the alarm device alarms.

Preferably, the alarm device emits sound and/or light upon an alarm.

Preferably, a temperature sensor is further included to obtain an ambient temperature.

Preferably, the wound exudate volume detecting module comprises:

a transmitting unit that emits an electromagnetic wave or an acoustic wave signal to the liquid collecting bottle;

The receiving unit receives the electromagnetic wave or sound wave signal reflected or refracted by the liquid collecting bottle; and the detecting control unit determines whether there is a wound exudate at the position of the detecting module according to whether the receiving unit receives the electromagnetic wave or the acoustic wave signal. Preferably, the wound exudate volume detecting module is plural, and is disposed at the same distance along the longitudinal interval of the liquid collecting bottle.

Preferably, the wound exudate volume detecting module is disposed on a transmission mechanism, and the driving mechanism is coupled to a driving mechanism.

The negative pressure wound treatment system capable of detecting the leak rate of the present invention detects the volume of the wound exudate in the liquid collecting bottle by setting the wound exudate volume detecting module; the controller is calculated according to the volume of the exudate and the ambient temperature The air leakage rate is obtained. Therefore, the present invention can directly detect the air leakage rate of the system, and is convenient for medical personnel or other users to intuitively understand the degree of air leakage.

Further, a display unit is provided, which displays a numerical value of the air leakage rate or a graphic indicating the size of the air leakage rate, which is more convenient and intuitive to use.

Further, an alarm device is further provided, and when the air leakage rate is greater than a preset threshold, the alarm device alarms, so as to promptly remind the medical staff, the medical staff can timely check the relevant connection portion to reduce the air leakage rate, thereby avoiding energy waste. Improve the service life of the air pump and avoid the noise caused by air leakage. DRAWINGS

1 is a schematic structural view of a conventional negative pressure wound treatment system;

Figure 2 is a schematic view of the gas volume in the liquid collection bottle and the volume of the wound exudate;

3 is a schematic structural view of a first embodiment of a negative pressure wound treatment system capable of detecting a leak rate according to the present invention;

Figure 4 is a schematic diagram showing the gas leakage rate;

Figure 5 is a schematic view of the optical path of the Α portion of Figure 1;

Figure 6 is a schematic diagram of the optical path when there is no exudate in a liquid collecting bottle in the first embodiment;

7 is a schematic diagram of an optical path when a clear exudate is present in a liquid collection bottle in the first embodiment; FIG. 8 is a wound exudate volume detecting module in the second embodiment of the negative pressure wound treatment system capable of detecting a leak rate according to the present invention; Schematic diagram of cooperation with the transmission mechanism and the drive mechanism.

In the figure, the relevant reference numerals are as follows:

1 wound, 2 wound filling, 3 wound closure, 4 connecting tube, 5 - collecting bottle, 6 - negative pressure source, 7 - controller, 8 - negative pressure wound treatment equipment, 9 wound exudate volume detection Module, 91-launch unit, 92-receiver unit, 10-screw, 11 motor, 12-display Face, 13 - alarm device, 14 an exudate. detailed description

The principles utilized in this application are as follows:

The relationship between the amount of gas (molar number, set to n), pressure P, volume V, and temperature (Kelvin) T in a sealed container is: PV = nRT, where R is a constant.

This formula is stable near normal temperature, while the normal operating temperature range for negative pressure wound therapy devices is usually between 0-40 degrees Celsius, which is between 273 Kelvin and 313 Kelvin. That is to say, this formula is very stable in this temperature range. At the same time, when operating in this temperature range, the temperature of the gas in the enclosed space and the ambient temperature at which the vacuum therapy device is placed can be considered to be consistent. Among them, the ambient temperature can be measured immediately, and it can also be set to a constant under certain circumstances during a certain period of time.

The volume of gas controlled by the vacuum therapy system is:

The volume of gas in the liquid collection bottle VI;

Volume of gas in the trachea at the collection bottle and wound and volume of gas at the wound V2

The volume of gas V3 in the vacuum therapy device and between the vacuum therapy device and the collector tube connection tube, the total volume V in the vacuum therapy system is:

V= V1+ V2 + V3

Among them, V2 and V3 are relatively stable, because after a negative pressure wound therapy device is finalized, both V2 and V3 have been customized, and the sum can be fixed. Therefore, only the volume of the VI will vary with the amount of wound exudate in the collection bottle.

Set the volume of the liquid collection bottle to V5, and the volume of the exudate in the liquid collection bottle is V4, then the gas volume in the liquid collection bottle is: vi= V5—V4, see Figure 2;

Among them, for a custom liquid collection bottle, the volume V5 is constant, so the VI decreases with the increase of V4.

The leak rate in a space is measured by the decrease in the number of moles of gas in the space over a certain time interval.

Assume that within the time gap t, the negative pressure of the negative pressure wound treatment system drops from P1 (corresponding to the number of moles nl, PI is absolute) to P2 (corresponding to the number of moles n2, P2 is the absolute value), indicating the gas in the closed space of the system. The content is reduced by N: N=nl

Because: n =

RT

RT ;

P ₂ (V ₅ -V ₄ +V ₂ +V ₃ )

n ₂

RT ;

(ρ, -ρ, χν, -ν, +ν, +ν,)

N =

RT; the leak rate is L, as indicated by the above, then L is:

L = N/t

_L= (P _l -P ₂ )(V ₅ -V ₄ +V ₂ +V)

― RTt.

Therefore, the leak rate L can be completely quantified. From this formula, it can be seen that the leak rate can be measured as long as the volume of the wound exudate in the collecting bottle is measured.

Based on the above calculation formula, the present invention will be described in detail below through specific embodiments with reference to the accompanying drawings:

Embodiment 1

The default air leak rate threshold can be set according to the actual situation. When the calculated air leak rate is higher than the threshold value, the user or the medical staff is prompted to check whether the system has insufficient connection or the like, which may involve air leakage.

Referring to FIG. 3, the negative pressure wound treatment system capable of detecting the air leak rate in the embodiment includes: a liquid collection bottle 5 for collecting wound exudate;

Negative pressure wound treatment device 8, including a negative pressure source 6 and a controller 7;

a wound kit for filling a wound and closing the wound, including a wound filler 2, a wound closure 3, and a wound filler 2 connected to the collection bottle 5 through a connecting tube 4;

There are also four wound exudate volume detecting modules 9 on the side wall of the liquid collecting bottle 5;

a sensor (not shown) to obtain an ambient temperature; The controller 7 calculates a corresponding air leakage rate based on the volume of the permeate, the ambient temperature, and the amount of change in the negative pressure of the negative pressure source.

The controller 7 is connected to a display interface 12, and the display interface 12 can directly display the value of the leak rate. As shown in FIG. 4, a graph indicating the size of the leak rate can also be displayed, where B represents the size of the leak rate threshold, C It represents the current air leakage rate. Therefore, it can be known from the position where the current C is greater than the position where B is located, and it can be known that the air leakage rate is about or not.

The display interface is an LED display interface. Of course, other display interfaces, such as an LCD interface, are also available.

The controller 7 is further connected to an alarm device 13, and the controller compares the calculated air leakage rate value with a preset threshold value. When the threshold value is greater than the threshold value, an alarm signal is sent, and the alarm device 13 emits a sound and a warning light. Remind medical staff or users to inspect the relevant connections and reduce the rate of air leaks.

Wherein, each wound exudate volume detecting module 9 comprises:

The transmitting unit 91 emits an electromagnetic wave or an ultrasonic signal to the liquid collecting bottle 5, and is disposed on one side of the liquid collecting bottle 5;

The receiving unit 92 receives the electromagnetic wave or ultrasonic signal refracted by the liquid collecting bottle 5, and is disposed on the other side of the liquid collecting bottle 5 opposite to the emitting unit 91 so that there is no wound exudate at the position of the liquid collecting bottle 5 , just received electromagnetic waves or ultrasonic signals that have been transmitted through the refraction.

The detection control unit determines whether the receiving unit receives the electromagnetic wave or the ultrasonic signal, and if not, determines that the wound exudate volume detecting module is located at the wound exudate.

The electromagnetic wave used in the present embodiment is infrared rays. As another embodiment, visible light, ultraviolet light, laser light or other electromagnetic signals may be used, and ultrasonic waves, infrasound waves or other sound wave signals may be used.

Wherein, the liquid collecting bottle 5 is provided with four gear positions for characterizing the level of the wound exudate liquid, and each gear position corresponds to an exudate volume detecting module 9, according to the receiving of the exudate volume detecting module 9. The unit 92 receives the infrared signal or not, determines whether there is exudate here, and then determines the height of the wound exudate liquid level in the liquid collecting bottle 5 by the number of receiving units 92 capable of receiving the infrared signal, and then combines the set. The bottom area of the liquid bottle can be used to calculate the volume of exudate in the liquid collection bottle.

The working principle of the wound exudate volume detecting module 9 of the present invention will be described below. Referring to FIG. 5, the transmitting unit 91 emits an infrared ray S1, which is oscillated through the side wall 51 of the liquid collecting bottle 5 into the inner region 52 of the liquid collecting bottle 5, and then ejected from the other side of the side wall 51 of the liquid collecting bottle 5, The receiving unit 92 receives the infrared ray S1 that is refracted, and the other part of the infrared ray is reflected into the reflected light S2.

Referring to Fig. 6, Fig. 6 is a schematic view of the optical path when there is no wound exudate at the corresponding position in the liquid collecting bottle, and the infrared ray when there is no wound exudate at the liquid collecting bottle 5 between the transmitting unit 91 and the receiving unit 92 Optical path ^1 further analysis:

Let α, β, γ, Θ be infrared rays incident on the outer surface of the outer casing of the liquid collecting bottle 5, into the outer casing of the liquid collecting bottle 5, and onto the inner surface of the outer casing of the liquid collecting bottle 5, and when injected into the inner cavity of the liquid collecting bottle 5, infrared rays and The angle between the normals. Let δ be the angle formed by the point where the infrared rays are incident on the outer surface of the casing 5 and the line connecting the points from the inner surface to the center line of the section of the liquid collection bottle 5. Set the liquid bottle 5 with a radius of R and a wall thickness of h.

Let the liquid bottle 5 have a refractive index of nl, and the refractive index in air is about 1, by the law of refraction: sina = nlsinp- nlsiny = sine, shell ' J α θ. Similarly, θ, =α, can be obtained. Θ and θ are the two base angles of the isosceles triangle, so 0 = 0, and ' J α = θ = θ, = α,.

Thereby, the angle ε between the infrared ray S11 incident on the outer surface of the outer casing of the liquid collecting bottle 5 and the infrared ray S13 emitted from the inner surface is mainly caused by the incident point of the infrared ray on the outer surface of the outer casing of the liquid collecting bottle 5 and the emission from the inner surface. The deflection determination of the arc normal at two points can be approximated:

ε= δ ~ h tanp/R=h/R tan[arcsina I nl]

The angle between the infrared ray S12 incident on the inner surface of the liquid collection bottle 5 and the infrared ray S13 on the outer surface of the outer casing of the liquid collection bottle 5 is also δ. The angle between the infrared ray S11 and the infrared ray S13 should be 2 ε = 2 δ 2h / R tan (arcsina / nl).

When h«R, δ is negligible, the infrared ray S11 incident on the outer surface of the outer casing of the liquid collecting bottle 5 is substantially parallel to the infrared ray S13 on the outer surface of the outer casing of the liquid collecting bottle 5.

Therefore, as shown in Fig. 6, the receiving unit 92 and the transmitting unit 91 are disposed on the same horizontal line, and the receiving unit can receive the refracted infrared rays, and therefore, it is judged that there is no wound exudate.

For the same reason, the infrared light path when there is a transparent wound exudate at the liquid collecting bottle 5 between the transmitting unit 91 and the receiving unit 92 can be further analyzed. Referring to FIG. 7, FIG. 7 shows the wound in the corresponding position in the liquid collecting bottle. Light path diagram for exudate:

Let the refractive index of the exudate be η2, then the law of refraction: Sina = n2 sinB = n2 sinB' = sina'.

The angle between the infrared ray S 1 1 incident on the outer surface of the liquid collection bottle 5 and the infrared ray S 12 emitted from the inner surface ε:

ε = (α-θ) +δ = [a-arcsin(sina / η2 ) ]+δ - [a-arcsin(sina / η2 )] + h/R tan(arcsina / nl);

When h«R, δ is negligible, the angle ε: ε a-arcsin(sina I n2 );

The angle between the infrared S l l and the infrared S 13 should be: 2ε ~ 2 [a-arcsin(sina / n2 )] ; Example: When a=30. That is, τιΙ 6 radians, and 4叚 set the exudate refractive index close to water, which is n2=1.33. Then the angle between the infrared S 11 and the infrared S 13 should be: 2ε - 0.276 radians, that is, 15.8°.

That is, when there is exudate in the liquid collecting bottle 5, the angle between the incident and outgoing rays can be changed by about 15.8°. Therefore, referring to Fig. 7, the receiving unit 92 does not receive infrared light, and therefore, it is possible to judge that there is wound exudate in the liquid collecting bottle 5.

With this feature, the position of the receiving unit 92 is set so that it can receive the emitted light only when the liquid collecting bottle 5 has no exudation, and cannot be received when the liquid collecting bottle 5 has the wound exudate. Light, the liquid position in the liquid collection bottle 5 can be judged, and the liquid volume in the liquid collection bottle 5 can be calculated.

Embodiment 2

The difference between this embodiment and the first embodiment is that:

1. Only one wound exudate volume detecting module 9 is provided, and the transmitting unit and the receiving unit are assembled together. Referring to Fig. 8, the wound exudate volume detecting module 9 is set on a screw 10 which is vertically extended on a center line. The center line of the screw 10 is parallel to the up-and-down direction of the liquid collecting bottle 5; preferably, the wound exudate volume detecting module 9 is restrained in the circumferential direction of the center line of the screw 10, and can only move in the direction of the center line of the screw 10. One end of the screw 10 is connected to the motor 11, and under the driving of the motor 11, the screw 10 rotates around its center line, thereby driving the wound exudate volume module 9 to move down the center line of the screw 10, to the liquid collecting bottle 5 Whether the wound has exudate is detected at the corresponding position.

Wherein, the screw 10 can also be replaced by any other transmission mechanism such as: gear set, belt, and leather wheel; as long as the wound exudate volume detecting module 9 can be moved in the vertical direction with respect to the liquid collecting bottle 5, The purpose of detecting the amount of liquid in the corresponding position of the liquid collection bottle 5 can be achieved. When the motor 11 is in operation, the wound exudate volume detecting module 9 is moved up and down by the screw rod 10. When the receiving unit jumps between the inability to detect the infrared signal, the wound exudate volume detecting module 9 determines that the position at this time corresponds to the liquid level, and then determines the liquid collecting bottle 5 according to the stroke of the motor. The liquid level is calculated to calculate the amount of wound exudate in the liquid collection bottle 5.

2. The temperature sensor is not set in this embodiment, and the average ambient temperature value is taken directly for a certain period of time.

In each of the above embodiments, when there is no liquid at the position where the wound exudate volume detecting module 9 is located in the liquid collecting bottle 5, the receiving unit 92 can receive an electromagnetic wave signal or an acoustic wave signal in the wound exudate volume detecting module 9 When there is a liquid at the position, the receiving unit 92 cannot receive the electromagnetic wave signal or the acoustic wave signal; further, when the receiving unit 92 does not receive the electromagnetic wave signal or the acoustic wave signal, it is determined that the position of the wound exudate volume detecting module 9 is lag. There is liquid. According to the above description, it is also possible to determine in the opposite manner that the position of the wound exudate volume detecting module 9 is stagnation liquid. For example, when the electromagnetic wave signal or the acoustic wave signal can pass through the liquid collection bottle 5 and the liquid, the receiving unit 92 can receive the electromagnetic wave signal or the acoustic wave signal when there is liquid at the position where the wound exudate volume detecting module 9 is located. When the position of the wound exudate volume detecting module 9 is no liquid, the receiving unit 92 can not receive the electromagnetic wave signal or the acoustic wave signal, and then according to whether the receiving unit 92 receives the electromagnetic wave signal or the acoustic wave signal, the wound exudate volume detecting module is determined. The position of 9 is stagnation of liquid, thereby achieving the purpose of detecting the amount of liquid in the liquid collection bottle 5. In addition, it is also possible to determine that the position of the wound exudate volume detecting module 9 is stagnation liquid, etc., depending on the strength of the received electromagnetic wave signal or the acoustic signal.

The above is only a preferred embodiment of the present invention, and it should be noted that the above-described preferred embodiments are not to be construed as limiting the scope of the invention, and the scope of the invention should be determined by the scope of the claims. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and scope of the invention.

Claims

Rights request

1. A negative pressure wound treatment system capable of detecting a leak rate, comprising:

Liquid collection bottle, collecting wound exudate;

The negative pressure wound treatment device is composed of a negative pressure source and a controller;

a wound kit, filling the wound and closing the wound, communicating with the collecting bottle through a connecting tube; and further comprising:

2. The negative pressure wound treatment system of claim 1, wherein the controller further comprises a display interface for displaying a value of the air leak rate or a graph characterizing a leak rate. .

3. The negative pressure wound treatment system for detecting a leak rate according to claim 2, wherein the display interface is an LED interface or an LCD interface.

4. The negative pressure wound treatment system of claim 1, further comprising an alarm device, wherein the controller compares the calculated air leak rate with a preset threshold value. It is judged whether an alarm signal is issued, and when the alarm device receives the alarm signal, it will alarm.

The negative pressure wound treatment system for detecting a leak rate according to claim 4, wherein when the calculated air leakage rate is greater than a preset threshold, the controller issues an alarm signal and the alarm device alarms.

A negative pressure wound treatment system for detecting a leak rate according to claim 4, wherein said alarm means emits sound and/or light upon an alarm.

7. The negative pressure wound treatment system for detecting a leak rate according to claim 1, further comprising a temperature sensor for obtaining an ambient temperature.

8. The negative pressure wound treatment system of claim 1, wherein the wound exudate volume detecting module comprises:

The receiving unit receives the electromagnetic wave or sound wave signal reflected or refracted by the liquid collecting bottle; the detecting control unit determines whether the receiving unit receives the electromagnetic wave or the sound wave signal according to whether the receiving unit receives the electromagnetic wave or the sound wave signal Whether there is wound exudate at the location of the module.

9. The negative pressure wound treatment system for detecting a leak rate according to claim 1, wherein the wound exudate volume detecting module is plural, and the same distance is spaced along the longitudinal direction of the liquid collecting bottle. Settings.

The negative pressure wound treatment system for detecting a leak rate according to claim 1, wherein the wound exudate volume detecting module is disposed on a transmission mechanism, and the transmission mechanism is coupled to a driving mechanism.