US20120053541A1 - Negative pressure wound therapy system and a feedback control method for the same - Google Patents

Abstract

A negative pressure wound therapy system creates a negative pressure environment in the opening of a wound-dressing unit and a positive pressure environment in the collecting bag. Then a positive pressure detecting procedure is proceeded in the positive pressure environment and a negative pressure detecting procedure is proceeded in the negative pressure environment. The detecting results are sent to determine whether a micro pump is stopped.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a negative pressure wound therapy system and a feedback control method for the same, especially to a therapy system creating negative pressure in the wound environment to promote healing in wounds.
• 2. Description of the Prior Arts
• Negative pressure wound therapy utilizes wound sheets, soft suction pads, or biocompatibility pore materials to attach on the wounds and connects to a vacuum pump. The vacuum pump creates negative pressure in the wound to extract the pus and infection subjects and to draw the healthy tissue fluid so that a moist therapy environment is maintained. Therefore, the blood circulation around the wound is promoted to accelerate wound healing.
• One of the conventional negative pressure wound therapy systems has a rigid collector connecting to a front end of the vacuum pump to extract the pus and the infection subjects into the rigid collector. A negative pressure sensor detects the negative pressure in the collector to determine whether the traditional system is operated normally. However, since the vacuum pump is connected to the rear end of the rigid collector, the pump is further from the wound so that the pump needs more power to create negative pressure in the wound and to extract the pus and the infection subjects from the wound.
• Another conventional negative pressure wound therapy system solves the above problem. The collector is connected to the rear end of the vacuum pump. The vacuum pump is directly connected to the wound sheet attached on the wound so that the vacuum pump uses less power. However, the collector does not have the same negative pressure environment as the wound. Therefore, the negative pressure sensor is not useful to detect.
• To overcome the shortcomings, the present invention provides a negative pressure wound therapy system and a feedback control method for the same to mitigate or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
• The main objective of the present invention is to provide a negative pressure wound therapy system and a feedback control method for the same. The system creates a negative pressure environment in the opening of a wound-dressing unit and a positive pressure environment in the collecting bag. Then a positive pressure detecting procedure is proceeded in the positive pressure environment and a negative pressure detecting procedure is proceeded in the negative pressure environment. The detecting results are sent to determine whether a micro pump is stopped.
• Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of a negative pressure wound therapy system in accordance with the present invention;
• FIG. 2 is a block diagram shown the connection of the negative pressure wound therapy system inFIG. 1;
• FIG. 3 is a perspective view of a wound-dressing unit of the negative pressure wound therapy system;
• FIG. 4 is an exploded perspective view of the negative pressure wound therapy system inFIG. 1;
• FIG. 5 is an exploded perspective view of a sensor assembly and an actuator of the negative pressure wound therapy system inFIG. 1;
• FIG. 6 is a partial perspective view of the actuator of the negative pressure wound therapy system inFIG. 1;
• FIG. 7 is a flow chart shown test mode of a feedback control method in accordance with the present invention for the negative pressure wound therapy system inFIG. 1; and
• FIG. 8 is a flow chart shown operating mode of the feedback control method for the negative pressure wound therapy system inFIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• With reference toFIG. 1, a negative pressure wound therapy system in accordance with the present invention comprises acontroller10, asensor assembly20, anactuator30, acollector40 and a wound-dressing unit50.
• With reference toFIGS. 1 and 2, thecontroller10 comprises amicroprocessor11, apower supply unit12 and acontrol panel13. Thepower supply unit12 electrically connects to themicroprocessor11, provides electricity and may be a battery set, or may be a power converter connected to an external power source. Thecontrol panel13 is attached to an outer surface of thecontroller10 and electrically connects to themicroprocessor11 and thepower supply unit12.
• Thesensor assembly20 comprises anegative pressure sensor21, apositive pressure sensor22 and arelief valve23. Therelief valve23 adjusts the pressure of the system and may apply an intermittent mode.
• Theactuator30 comprises amicro pump31.
• Thecollector40 comprises acollecting bag41 and a liquid absorber42. Theliquid absorber42 is mounted in thecollecting bag41.
• With reference toFIG. 3, the wound-dressing unit50 comprises awound sheet51 and aconduit52. Thewound sheet51 has anopening511. Theconduit52 is attached securely to thewound sheet51 and is connected to the opening511 and has afilter strip521. Thefilter strip521 is made of biocompatibility materials and keeps solid chips such as tissue fragment from flowing into theconduit52. In a preferred embodiment, theconduit52 is attached securely to thewound sheet51 by ultrasonic welding.
• With reference toFIGS. 2 and 4, the negative pressure wound therapy system in accordance with the present invention comprises electrical connection and fluid connection to connect aforementioned elements.
• Thecontroller10 is electrically connected to thesensor assembly20, and thesensor assembly20 is electrically connected to theactuator30. Detachable electrical wire set forms the electrical connection. For example, anelectrical wire61 with aplug62 protrudes out from thesensor assembly20. Thecontroller10 has acorresponding socket63. Theplug62 is plugged detachably into thesocket63 to form the electrical connection.
• A fluid connection is formed between thepump inlet311 of themicro pump31 and theconduit52. A fluid connection is formed between thepump outlet312 of themicro pump31 and the entry end of thecollecting bag41. A check valve is mounted in theentry end411 of thecollecting bag41 to keep the liquid in thecollecting bag41 from flowing back to infect the wound. Detachable fluid tube set forms the fluid connections. For example, afirst tube64 with afluid connector65 protrudes out from themicro pump31 and asecond tube64 with afluid connector65 protrudes out from theconduit52. Thefluid connectors65 detachably connect to each other to form the fluid connection.
• A fluid connection is formed between thepositive pressure sensor22 and the detectingend412 of thecollecting bag41. A fluid connection is formed between thenegative pressure sensor21, therelief valve23 and theconduit52, especially through thepump inlet311 of themicro pump31. Detachable tube set forms the fluid connections. For example, atube64 with afirst fluid connector65 protrudes out from thepositive pressure sensor22. Asecond fluid connector65 is mounted on the detectingend412 of thecollecting bag41. Thefluid connectors65 detachably connect to each other to form the fluid connection.
• With reference toFIGS. 5 and 6, in a preferred embodiment thesensor assembly20 has a first connectinginterface201, and theactuator30 has a second connectinginterface301. The first connectinginterface201 has a firstelectrical connector202 and a firstfluid connector203. The second connectinginterface301 has a secondelectrical connector302 and a secondfluid connector303. Themicro pump31 is electrically connected to the secondelectrical connector302. The connectinginterfaces201,301 are connected detachably to each other. The firstelectrical connector202 is connected to the secondelectrical connector302. The firstfluid connector203 is connected to the secondfluid connector303. Afluid division66 may be a manifold and comprises afirst passage661 and asecond passage662. Thefirst passage661 connects thepump inlet311 of themicro pump31 and theconduit52. Thesecond passage662 connects the secondfluid connector303 and theconduit52.
• Furthermore, filters70 are mounted in the detectingend412 of the collectingbag41 and the secondfluid connector303 of theactuator30 to keep the infections from flowing into thesensor assembly20.
• With the aforementioned electrical connections and the fluid connections being detachably, the elements are available to detach from each other to be repaired independently.
• When the system as described is operated, thewound sheet51 covers the wound of the patient with theopening511 facing the wound. The user actuates themicro pump31 through thecontrol panel13. Themicro pump31 creates a negative pressure environment in the wound through the fluid connections and extracts the pus and infection subjects from the wound. The pus and infection subjects pass through theactuator30 and are collected in the collectingbag41.
• The system as described has following advantages.
• 1. Since all of the components connect to each other by detachable electrical wire sets and detachable tube sets, each component is available to be disassembled and repaired independently.
• 2. The components have different lifespan. For example, thecollector40 and the wound-dressing unit50 directly contact the infections so that thecollector40 and the wound-dressing unit50 need to be replaced frequently while thecontroller10, theactuator30 and thesensor assembly20 can be used for a long time. Therefore, the detachable connections are convenient for users to disassemble and replace each component.
• 3. When the user moves between different places such as hospital and home, the detachable connections allow the user only bring some of the components to move. For example, the user only carries thecontroller10, thesensor assembly20 and theactuator30, and leaves thecollectors40 and the wound-dressingunits50 at different places, and vice versa. Therefore, the user only needs to carry part of the system.
• 4. In the fluid connections, theactuator30 is located in front of the collectingbag41. Themicro pump31 is directly connected to the wound sheet attached on the wound so that the micro pump uses less power.
• To ensure the system as described is operated safely, a feedback control method in accordance with the present invention for the system as described comprises a test mode and an operating mode.
• With reference toFIG. 7, when the system as described is started, the system enters the test mode. Themicro pump31 inflates the fluid connections in the system. Then thepositive pressure sensor22 detects whether the positive pressure at the detectingend412 of the collectingbag41 is normal. When the fluid connections are not connected properly, the positive pressure is abnormal. If the positive pressure is abnormal, the system outputs an alarm signal. Then the test mode is ended. When the fluid connections are connected properly, the positive pressure is normal. If the positive pressure is normal, the system enters the operating mode.
• With reference toFIG. 8, when the system enters the operating mode, themicro pump31 creates a negative pressure environment in the wound through theopening511 of thewound sheet51 and extracts the pus and infection subjects from the wound. Then the collectingbag41 is accordingly formed as a positive pressure environment. Then the positive pressure detecting procedure and negative pressure detecting procedure are started.
• The positive pressure detecting procedure detects the positive pressure in the collectingbag41. Thepositive pressure sensor22 detects whether the positive pressure in the collectingbag41 is normal. When the fluid connections between the collectingbag41 and other elements are disconnected, or an external overload is applied to the collectingbag41, or the collectingbag41 is full of liquid, the positive pressure of the detectingend412 of the collectingbag41 is abnormal. If the positive pressure is abnormal, thepositive pressure sensor22 sends a signal to themicroprocessor11 to stop themicro pump31 and send an alarm signal to notify the user. Therefore, the pus and the infection subjects are prevented from leaking out of the fluid connections or the collectingbag41 is prevented from breaking because of overload or being full. Then the operating mode is ended. If the positive pressure is normal, thepositive pressure sensor22 keeps processing the positive pressure detecting procedure.
• The negative pressure detecting procedure detects the negative pressure in the wound. Thenegative pressure sensor21 detects whether the negative pressure in theopening511 of thewound sheet51 is normal. When the fluid connections is obstructed or is disconnected, the negative pressure is abnormal. If the negative pressure is abnormal, thenegative pressure sensor21 sends a signal to themicroprocessor11 to stop themicro pump31 and send an alarm signal to notify the user. If the negative pressure is normal, thenegative pressure sensor23 keeps processing the positive pressure detecting procedure.
• With the aforementioned modes, the system as described is operated safely.
• Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims (18)

What is claimed is:

1. A feedback control method for a negative pressure wound therapy system that the system has a wound-dressing unit and a collecting bag communicating with the wound-dressing unit, the method comprising an operating mode, which comprises acts of:

(a) creating a negative pressure environment in an opening of a wound-dressing unit and a positive pressure environment in the collecting bag;

(b) proceeding a positive pressure detecting procedure in the positive pressure environment and proceeding a negative pressure detecting procedure in the negative pressure environment; and

(c) sending the detecting results to determine whether the operating mode is ended.

2. The feedback control method as claimed inclaim 1, wherein before step (a) further comprises an act of applying a micro pump between the wound-dressing unit and the collecting bag to creating the negative pressure environment and extracting the fluid in the opening.

3. The feedback control method as claimed inclaim 2, wherein positive pressure detecting procedure further comprises acts of:

detecting the positive pressure in a detecting end of the collecting bag by a positive pressure sensor; and

determining whether the positive pressure is normal; if the positive pressure is abnormal, the micro pump is stopped and the operating mode is ended; if the positive pressure is normal, the micro pump is kept operating and back to the act of the detecting positive pressure.

4. The feedback control method as claimed inclaim 2, wherein negative pressure detecting procedure further comprises acts of:

detecting the negative pressure in the opening of the wound-dressing unit by a negative pressure sensor; and

determining whether the negative pressure is normal; if the negative pressure is abnormal, the micro pump is stopped and the operating mode is ended; if the negative pressure is normal, the micro pump is kept operating and back to the act of the detecting negative pressure.

5. The feedback control method as claimed inclaim 3, wherein negative pressure detecting procedure further comprises acts of:

detecting the negative pressure in the opening of the wound-dressing unit by a negative pressure sensor; and

determining whether the negative pressure is normal; if the negative pressure is abnormal, the micro pump is stopped and the operating mode is ended; if the negative pressure is normal, the micro pump is kept operating and back to the act of the detecting negative pressure.

6. The feedback control method as claimed inclaim 2 further comprising a test mode before proceeding the operating mode, wherein the test mode comprises acts of:

inflating fluid connections in the system by the micro pump;

detecting the positive pressure in a detecting end of the collecting bag by a positive pressure sensor; and

determining whether the positive pressure is normal; if the positive pressure is abnormal, an alarm signal is output and the test mode is ended; if the positive pressure is normal, the test mode is end and the operating mode is entered.

7. The feedback control method as claimed inclaim 3 further comprising a test mode before proceeding the operating mode, wherein the test mode comprises acts of:

inflating fluid connections in the system by the micro pump;

detecting the positive pressure in the detecting end of the collecting bag by the positive pressure sensor; and

determining whether the positive pressure is normal; if the positive pressure is abnormal, an alarm signal is output and the test mode is ended; if the positive pressure is normal, the test mode is end and the operating mode is entered.

8. The feedback control method as claimed inclaim 4 further comprising a test mode before proceeding the operating mode, wherein the test mode comprises acts of:

inflating fluid connections in the system by the micro pump;

detecting the positive pressure in the detecting end of the collecting bag by the positive pressure sensor; and

determining whether the positive pressure is normal; if the positive pressure is abnormal, an alarm signal is output and the test mode is ended; if the positive pressure is normal, the test mode is end and the operating mode is entered.

9. The feedback control method as claimed inclaim 5 further comprising a test mode before proceeding the operating mode, wherein the test mode comprises acts of:

inflating fluid connections in the system by the micro pump;

detecting the positive pressure in the detecting end of the collecting bag by the positive pressure sensor; and

determining whether the positive pressure is normal; if the positive pressure is abnormal, an alarm signal is output and the test mode is ended; if the positive pressure is normal, the test mode is end and the operating mode is entered.

10. A negative pressure wound therapy system comprising:

a controller;

a sensor assembly electrically connected to the controller and comprising a negative pressure sensor and a positive pressure sensor to detect pressure, and comprising a relief valve;

an actuator comprising a micro pump electrically connected to the sensor assembly;

a collector comprising a collecting bag;

a wound-dressing unit having an opening;

a first fluid connection connecting between the sensor assembly and the collecting bag;

a second fluid connection connecting between the sensor assembly and the wound-dressing unit;

a third fluid connection connecting between the wound-dressing unit, the actuator and the collecting bag, wherein the actuator is located between the wound-dressing unit and the collecting bag in the third fluid connection;

whereby the micro pump creates a negative pressure environment in the opening through the third fluid connection and extracts the fluid from the opening of the wound-dressing unit, and the fluid passes the actuator to flow into the collecting bag, and the collecting bag is defined as a positive pressure environment.

11. The negative pressure wound therapy system as claimed inclaim 10 further comprising:

a first detachable electrical wire set connecting between the sensor assembly and the controller;

a second detachable electrical wire set connecting between the sensor assembly and the micro pump;

a first detachable tube set connecting between a pump inlet of the micro pump and the sensor assembly;

a second detachable tube set connecting between a detecting end of the collecting bag and the sensor assembly;

a third detachable tube set connecting between an inlet end of the collecting bag and a pump outlet of the micro pump;

a fourth detachable tube set connecting between the wound-dressing unit and the sensor assembly; and

a fifth detachable tube set connecting between the wound-dressing unit and the pump inlet of the micro pump, wherein

the first fluid connection is formed by the second detachable tube set;

the second fluid connection is formed by the fourth detachable tube set; and

the third fluid connection is formed by the first, third and fifth detachable tube sets.

12. The negative pressure wound therapy system as claimed inclaim 11, wherein

the wound-dressing unit comprises

a wound sheet, where the opening of the wound-dressing unit is formed through; and

a conduit attached securely to the wound sheet, connected to the opening and having a filter strip made of biocompatibility materials;

the fourth detachable tube set connects between the conduit and the negative pressure sensor and the relief valve; and

the fifth detachable tube set connects between the conduit and the pump inlet of the micro pump.

13. The negative pressure wound therapy system as claimed inclaim 12 further comprising a fluid division, wherein

the sensor assembly has a first connecting interface having a first electrical connector and a first fluid connector; and

the actuator has a second connecting interface connected detachably to the first connecting interface and having

a second electrical connector electrically connected to the micro pump connected to the first electrical connector; and

a second fluid connector connected to the first fluid connector;

the fluid division comprises

a first passage connecting the pump inlet of the micro pump and the conduit; and

a second passage connecting the second fluid connector and the conduit.

14. The negative pressure wound therapy system as claimed inclaim 12, wherein the fifth detachable tube set comprises a first tube with a fluid connector protruding out from the micro pump and a second tube with a fluid connector protruding out from the conduit, and the fluid connectors detachably connect to each other.

15. The negative pressure wound therapy system as claimed inclaim 13, wherein the fifth detachable tube set comprises a first tube with a fluid connector protruding out from the micro pump and a second tube with a fluid connector protruding out from the conduit, and the fluid connectors detachably connect to each other.

16. The negative pressure wound therapy system as claimed inclaim 15, wherein the second detachable tube set comprises a tube with a first fluid connector protruding out from the positive pressure sensor and a second fluid connector mounted on the detecting end of the collecting bag, and the fluid connectors detachably connect to each other.

17. The negative pressure wound therapy system as claimed inclaim 16 further comprising two filters respectively mounted in the detecting end of the collecting bag and the second fluid connector of the actuator to keep the infections from flowing into the sensor assembly.

18. The negative pressure wound therapy system as claimed inclaim 17 further comprising check valve mounted in an entry end of the collecting bag to keep the liquid in the collecting bag from flowing back.

Images