In-vitro wound surface model testing device for dressing liquid control performance

Abstract

The invention discloses a dressing liquid control performance in-vitro wound surface model testing device, which comprises a dressing liquid performance control model, the top of the dressing liquid performance control model is provided with a breathable layer, and the dressing liquid performance control model is internally filled with a contact wound surface dressing; the liquid feeding device can convey simulation liquid into the dressing liquid performance control model, the contact wound dressing can completely or partially absorb the simulation liquid and form water vapor, and the water vapor can be discharged from the breathable layer; the dressing liquid performance control model is arranged on the balance system, and the balance system can detect the mass of the dressing liquid performance control model and transmit data to the computer; by monitoring the mass of the dressing before and after liquid absorption, the amount of water vapor discharged by evaporation of the dressing within a period of time is calculated, the air permeability of the dressing is reflected through the water vapor amount, and the air permeability of the dressing is tested.

Description

Technical Field

[0001] The invention relates to the field of dressing testing equipment, in particular to an in vitro wound model testing device for dressing liquid control performance. Background Art

[0002] Contact wound dressings refer to medical materials used to cover wounds and wound surfaces. Their function is to temporarily play a part of the skin's barrier function while waiting for the wound surface to re-epithelialize or transition to rebuilding a permanent skin barrier. Currently common dressing products include bandages, infusion patches, absorbent gauze, Fanshilin gauze, polyurethane foam dressings, hydrocolloid dressings, alginate dressings or composite material dressings, etc. In addition to having good liquid absorption, contact wound dressings should also have good water vapor permeability. If the liquid absorbed by the dressing cannot form water vapor and permeate in time, it will accumulate in the dressing for a long time, which is not conducive to the re-epithelialization of the wound surface or the transition to rebuilding a permanent skin barrier.

[0003] At present, the testing equipment for contact wound dressings is mostly used for dressing water absorption test and dressing external water barrier test. In view of this, how to provide a device that can test the liquid absorption and water vapor permeability of contact wound dressings is a technical problem that people in this field urgently need to solve. Summary of the invention

[0004] The purpose of the present invention is to provide an in vitro wound model testing device for liquid control performance of a dressing, so as to solve the problems existing in the prior art and realize the performance testing of liquid absorption and water vapor permeability of contact wound dressings.

[0005] To achieve the above-mentioned purpose, the present invention provides the following scheme: The present invention provides an in vitro wound model testing device for the liquid control performance of a dressing, comprising: a dressing liquid performance control model, the top of the dressing liquid performance control model having a breathable layer, the interior of which is filled with a contact wound dressing; a liquid feeding device, the liquid feeding device can transport simulated liquid into the dressing liquid performance control model, the contact wound dressing can fully or partially absorb the simulated liquid and form water vapor, and the water vapor can be discharged from the breathable layer; a balance system, the dressing liquid performance control model is arranged on the balance system, and the balance system can detect the mass of the dressing liquid performance control model and transmit the data to a computer.

[0006] The beneficial effect of the present invention is that the quality of the dressing before and after liquid absorption is monitored to calculate the amount of water vapor evaporated from the dressing within a period of time, and the air permeability of the dressing is reflected by the amount of water vapor, thereby realizing the test of the air permeability of the dressing.

[0007] Furthermore, in the above technical solution, the liquid feeding device should be provided with a flow meter or other device that can be used to measure the quality of the simulated liquid fed, so as to facilitate the subsequent calculation of the amount of water vapor. The simulated liquid can be a mixed solution of sodium chloride and calcium chloride or 0.9% saline or distilled water.

[0008] Furthermore, the dressing liquid performance control model includes: a dressing cavity, the dressing cavity is hollow inside, the lower layer is paved with a water-absorbing sponge, the upper layer is paved with the contact wound dressing, the bottom of the dressing cavity is provided with a plurality of water-permeable holes, the side of the dressing cavity is provided with a liquid supply hole corresponding to the inner and outer surfaces of the water-absorbing sponge, and the air-permeable layer is arranged at the top of the dressing cavity and communicated with the dressing cavity; an injection needle, the injection needle is inserted into the water-absorbing sponge from the liquid supply hole, and the injection needle is communicated with the liquid supply device; a transparent shell, the transparent shell is arranged below the dressing cavity, the upper opening of the transparent shell corresponds to the position of the water-permeable hole. The injection needle is connected with the liquid supply device, and can continuously deliver simulated liquid into the water-absorbing sponge at a certain liquid supply rate. When the amount of water vapor absorbed and evaporated by the dressing is less than the continuous delivery amount, the excess simulated liquid in the water-absorbing sponge will flow into the transparent shell from the bottom and form liquid accumulation. The amount of liquid accumulation per unit time can represent the liquid absorption capacity and water vapor permeability of the dressing. When the amount of water vapor absorbed and transmitted by the dressing is greater than the continuous delivery amount, there will be no water in the transparent shell. At this time, you can consider increasing the delivery amount of the simulated liquid.

[0009] Further, the dressing cavity and the transparent shell are both arranged horizontally or vertically. When the dressing cavity and the transparent shell are both arranged horizontally, it can be considered that the dressing is arranged on a horizontal wound surface, and the liquid absorption performance and water vapor transmission performance of the dressing are test data under the horizontal wound surface model. When the dressing cavity and the transparent shell are both arranged vertically, it can be considered that the dressing is arranged on a vertical wound surface, and the liquid absorption performance and water vapor transmission performance of the dressing are test data under the vertical wound surface model.

[0010] Furthermore, the transparent shell is provided with exhaust holes through the front and rear surfaces, and the exhaust holes are provided close to the top of the transparent shell. To balance the pressure in the transparent shell, exhaust holes are provided through the front and rear surfaces of the transparent shell. To prevent the simulated liquid in the transparent shell from being lost, the exhaust holes should be provided as close to the top of the transparent shell as possible, and the hole diameter should be as small as possible.

[0011] Furthermore, it also includes a heater and an organic glass box, wherein a base is provided in the organic glass box, the balance system and the dressing liquid performance control model are located in the organic glass box and the balance system is provided on the base, and the heater is provided on the inner side wall of the organic glass box or on the base. It also includes an evaporation container, wherein a support plate is provided near the top of the organic glass box, the evaporation container is provided on the support plate, and the evaporation container contains a humidity regulating solution. The humidity regulating solution is a glycerol aqueous solution. When the dressing is tested for liquid absorption performance and water vapor discharge performance, it is necessary to ensure that the ambient temperature and humidity are fixed. Therefore, the present application uses an organic glass box as a test container, the organic glass box is sealed, and the temperature and humidity in the organic glass box are controlled by a heater and a humidity regulating solution, wherein the humidity regulating solution can form different air humidities at different temperatures and different concentrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a schematic diagram of the structure of the present invention;

[0014] Figure 2 It is a schematic diagram of the structure of the dressing liquid performance control model (horizontal position);

[0015] Figure 3 It is a schematic diagram of the structure of the dressing liquid performance control model (vertical position);

[0016] Among them, 1. Dressing liquid performance control model; 2. Breathable layer; 3. Balance system; 4. Dressing cavity; 5. Absorbent sponge; 6. Injection needle; 7. Transparent shell; 8. Exhaust hole; 9. Organic glass box; 10. Evaporation container; 11. Support plate. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] The present invention provides an in vitro wound model testing device for the liquid control performance of a dressing, comprising: a dressing liquid performance control model 1, the top of the dressing liquid performance control model 1 has a breathable layer 2, the interior of which is filled with a contact wound dressing; a liquid feeding device, the liquid feeding device can transport simulated liquid into the dressing liquid performance control model 1, the contact wound dressing can fully or partially absorb the simulated liquid and form water vapor, and the water vapor can be discharged from the breathable layer 2; a balance system 3, the dressing liquid performance control model 1 is arranged on the balance system 3, the balance system 3 can detect the mass of the dressing liquid performance control model 1 and transmit the data to a computer. In this embodiment, the test area of ​​the dressing is 50cm 2 (diameter is about 79.8mm), and an opening is provided at the contact point with the water-absorbing sponge 5, and the opening area is 10cm 2 , and fixed with a circular clamp of suitable size.

[0020] In this embodiment, a flow meter is provided at the liquid outlet of the liquid feeding device (the mass can be calculated according to the flow rate and the density of the simulated liquid). The liquid feeding device delivers the simulated liquid through an electronic pump, which can provide a flow rate of 0.50 mL / h and an accuracy of ±5%. The accuracy of the balance system 3 is 0.01 g.

[0021] In this embodiment, the dressing liquid performance control model 1 includes: a dressing cavity 4, which is hollow inside, with a water-absorbent sponge 5 laid on the lower layer and a contact wound dressing laid on the upper layer, a plurality of water-permeable holes are opened at the bottom of the dressing cavity 4, and liquid supply holes are opened on the side of the dressing cavity 4 corresponding to the water-absorbent sponge 5 and penetrating the inner and outer surfaces, and the air-permeable layer 2 is arranged at the top of the dressing cavity 4 and connected with the dressing cavity 4; an injection needle 6, which is inserted into the water-absorbent sponge 5 from the liquid supply hole, and the injection needle 6 is connected with the liquid supply device; a transparent shell 7, which is arranged below the dressing cavity 4, and the upper part of the transparent shell 7 is opened and corresponds to the position of the water-permeable holes.

[0022] In this embodiment, the dressing cavity 4 and the transparent shell 7 are both arranged horizontally or vertically. The transparent shell 7 is provided with exhaust holes 8 through the front and rear surfaces, and the exhaust holes 8 are arranged near the top of the transparent shell 7.

[0023] In this embodiment, a heater and an organic glass box 9 are also included. A base is provided in the organic glass box 9. The balance system 3 and the dressing liquid performance control model 1 are located in the organic glass box 9 and the balance system 3 is arranged on the base (in this embodiment, there are four dressing liquid performance control models 1, the two on the left side of the organic glass box 9 are horizontal dressing liquid performance control models 1, and the one on the right side of the organic glass box 9 is a vertical dressing liquid performance control model 1). The heater is arranged on the inner side wall or the base of the organic glass box 9. An evaporation container 10 is also included. A support plate 11 is provided near the top of the organic glass box 9. The evaporation container 10 is arranged on the support plate 11. The evaporation container 10 contains a humidity regulating solution. In some other embodiments, a circulating fan can also be arranged in the organic glass box 9. In this embodiment, a temperature sensor and a humidity sensor are also arranged in the organic glass box 9. The temperature sensor and the humidity sensor are both connected to a computer for feedback of the temperature and humidity in the organic glass box 9. The heater uses an incandescent lamp. The power of the incandescent lamp can be adjusted by a controller to adjust its heat dissipation so that the temperature in the organic glass box 9 is constant. The humidity adjustment solution is a glycerol aqueous solution. Table 1 shows the glycerol aqueous solution concentration corresponding to relative humidity at various temperatures.

[0024] Table 1

[0025]

[0026] Since the concentration of glycerol solution changes with time, the refractive index of glycerol aqueous solution at 25 degrees Celsius can be monitored by using sodium D line (589nm). Adjust the concentration of the glycerol aqueous solution as appropriate.

[0027]

[0028] Where:

[0029] U——Relative humidity, expressed as percentage (%);

[0030] A——Parameter that has an equation relationship with the solution temperature θ(℃):

[0031] A=25.60-0.1950θ+0.0008θ 2

[0032] The required concentration C of the glycerol aqueous solution can be obtained from the formula:

[0033]

[0034] Unless otherwise specified, check the refractive index at least once a week using a refractometer with a test range of 1.330 to 1.470 and a reading of ±0.001. If the refractive index deviates from the expected value by more than 0.002 units, replace the glycerin solution.

[0035] The accuracy of the required relative humidity calculated by this method is ±2%. The refractive index of the glycerol solution maintained under the general standard atmospheric tolerance is shown in Table 2.

[0036] Table 2

[0037]

[0038] Note: In special cases, an environment with (20±2)℃ and (65±10)% relative humidity is required. The value is 1.426±0.016.

[0039] The range of the refractive index of the glycerol solution maintained under strict standard atmosphere tolerance is shown in Table 3.

[0040] Table 3

[0041]

[0042] Note: In special cases, an environment with (20±1)℃ and (65±5)% relative humidity is required. The value is 1.426±0.007.

[0043] The specific test steps are as follows:

[0044] 1. Determine the temperature and humidity of the test environment. The test is carried out at a temperature of (37±1)°C and a relative humidity of (50±2)%. The glycerol aqueous solution uses a glycerol aqueous solution with a mass fraction of 81%. According to Table 1, a glycerol aqueous solution with a mass fraction of 81% at 0°C to 50°C can achieve a relative humidity of 48% to 52%.

[0045] 1. Determine the simulation liquid. Distilled water is used as the simulation liquid.

[0046] 2. Sample dressing preparation: Use appropriate tools to cut a round dressing sample with a diameter slightly larger than 79.8 mm from the dressing to be tested, and weigh the mass of the sample W. to an accuracy of 0.01 g.

[0047] 3. Install the absorbent sponge 5 in the horizontal / vertical dressing chamber 4, and manually drip the wound simulation liquid into the absorbent sponge 5 until the absorbent sponge 5 is saturated, and a drop of liquid is observed dripping from the absorbent sponge 5 (in the vertical dressing chamber 4, you can first confirm that the absorbent sponge 5 is saturated and then set the dressing chamber to be placed vertically).

[0048] 4. Install the prepared dressing sample in the horizontal / vertical body dressing cavity 4 and fix it with a circular clamp, and use a balance to weigh the mass W1 of the horizontal / vertical body dressing liquid property control model 1 at this time.

[0049] 5. Connect the electronic pump to the feeding device, and then connect the electronic pump to the injection needle 6, deliver the simulated liquid to the absorbent sponge 5 at a flow rate of 0.50 mL / h and start timing. Weigh the mass W2 of the horizontal / vertical body dressing liquid performance control model 1 (including the dressing sample) every 3 hours, and calculate the amount of water vapor that has penetrated at this time according to the following formula W e .

[0050] W e =0.5×t×ρ-(W2-W1)

[0051] Where:

[0052] 0.5——Flow rate of the electronic pump, in milliliters per hour (mL / h);

[0053] W e ——The amount of water vapor transmitted, in grams (g);

[0054] t——test time, in hours (h);

[0055] p——the flow rate of the electronic pump, in grams per milliliter (g / mL);

[0056] W1——The mass of the dressing liquid property control model with the dry test sample, in grams (g);

[0057] W2 is the mass of the dressing liquid performance control model with the test sample during the test, in grams (g).

[0058] 6. The test was continued for 3 days. After 3 days, the mass of the horizontal / vertical dressing liquid performance control model 1 (including the dressing sample) was weighed, the dressing sample was removed and the mass W3 of the dressing sample was weighed at this time. The amount of liquid absorbed by the dressing at this time was calculated according to the following W a .

[0059] W a =W3-W0

[0060] Where:

[0061] W a ——The mass of liquid absorbed by the test sample after the test, in grams (g);

[0062] W. ——The mass of the dry test sample, in grams (g);

[0063] W3 is the mass of the test sample after the test, in grams (g).

[0064] At least three tests were performed for each dressing.

[0065] The present invention provides an in vitro wound model testing device for liquid control performance of a dressing, which can detect the amount of liquid absorbed by the dressing and the amount of water vapor discharged after the dressing absorbs liquid, and thus test the liquid absorption performance and water vapor discharge performance of the dressing.

[0066] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0067] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An in vitro wound model testing device for liquid control performance of dressings, characterized in that: include: A dressing liquid property control model (1), wherein the dressing liquid property control model (1) has a breathable layer (2) on the top, and the interior of the breathable layer is filled with a contact wound dressing; a liquid supply device, wherein the liquid supply device is capable of delivering simulated liquid into the dressing liquid property control model (1), the contact wound dressing is capable of fully or partially absorbing the simulated liquid and forming water vapor, and the water vapor is capable of being discharged from the breathable layer (2); A balance system (3), the dressing liquid performance control model (1) is arranged on the balance system (3), and the balance system (3) can detect the mass of the dressing liquid performance control model (1) and transmit the data to a computer.

2. The in vitro wound model testing device for liquid control performance of dressing according to claim 1, characterized in that: The dressing liquid property control model (1) comprises: A dressing cavity (4), wherein the dressing cavity (4) is hollow inside, a water-absorbing sponge (5) is laid on the lower layer, and the contact wound dressing is laid on the upper layer. A plurality of water-permeable holes are provided at the bottom of the dressing cavity (4), and liquid supply holes are provided on the side of the dressing cavity (4) corresponding to the inner and outer surfaces of the water-absorbing sponge (5). The air-permeable layer (2) is arranged on the top of the dressing cavity (4) and is in communication with the dressing cavity (4); an injection needle (6), the injection needle (6) being inserted into the water-absorbing sponge (5) from the liquid feeding hole, the injection needle (6) being connected to the liquid feeding device; A transparent shell (7), wherein the transparent shell (7) is arranged below the dressing cavity (4), and the top of the transparent shell (7) is open and corresponds to the position of the water permeable hole.

3. The in vitro wound model testing device for liquid control performance of dressing according to claim 2, characterized in that: The dressing cavity (4) and the transparent shell (7) are both arranged horizontally or vertically.

4. The in vitro wound model testing device for liquid control performance of dressing according to claim 2, characterized in that: The transparent shell (7) is provided with exhaust holes (8) through the front and rear surfaces, and the exhaust holes (8) are arranged close to the top end of the transparent shell (7).

5. The in vitro wound model testing device for liquid control performance of dressing according to claim 1, characterized in that: It also includes a heater and an organic glass box (9), wherein a base is arranged in the organic glass box (9), the balance system (3) and the dressing liquid performance control model (1) are located in the organic glass box (9) and the balance system (3) is arranged on the base, and the heater is arranged on the inner wall of the organic glass box (9) or on the base.

6. The in vitro wound model testing device for liquid control performance of dressing according to claim 1, characterized in that: It also comprises an evaporation container (10), wherein a support plate (11) is arranged near the top of the organic glass box (9), the evaporation container (10) is arranged on the support plate (11), and the evaporation container (10) contains a humidity regulating solution.

7. The in vitro wound model testing device for liquid control performance of dressing according to claim 6, characterized in that: The humidity adjustment solution is a glycerol aqueous solution.

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