FIELD OF THE INVENTION

The present invention relates to systems for treating wounds by the application of negative pressure, and to devices for use in such systems. More particularly, the present invention relates to a wound drainage system with a reservoir suitable for drainage under negative pressure during post-operative procedure with the options to employ and operate one or more catheters simultaneously.

BACKGROUND OF THE INVENTION

It is often desirable to drain fluids from a wound as it assists in quicker healing by removing pus, blood, serum, bile or other biological fluids from a wound which may accumulate and in itself become a focus of infection. Removal of these fluids can promote proper healing and reduce the threat of infection, thus reducing the amount of time spent in the hospital. Various types of wound drainage systems are used to collect drainage fluids from body wounds, such as surgical wound, in order to promote healing. In many cases, a manually operated suction pump having a collapsible drainage fluid collection chamber which is connected to a suction catheter is used. After being collapsed, the collection chamber expands effecting a negative pressure for promoting the flow of drainage fluid from the wound to the chamber.

The prior art wound drainage systems, however, have several shortcomings in meeting the patient's needs. Such systems tend to experience substantial rapid decrease from maximum negative pressure to a minimum negative pressure during the expansion of the reservoir from the compressed to the normal rest position. Such systems also not provide to employ and operate the drainage systems with one or more catheters simultaneously. Moreover, systems in the prior art, face the problems in that they do not provide a closed sterile environment while still permitting easy clearing of drainage catheters. They also cannot be stored in the activated position.

Thus, several systems and techniques have been proposed, however, there exists a constant need for a wound drainage system which is more versatile and easier to use by health care workers or patient attending personnel and one that is relatively less costly to manufacture and assemble.

SUMMARY AND OBJECTS OF THE INVENTION

The invention relates to systems for treating wounds by the application of negative pressure, and to devices for use in such systems. More particularly, the present invention relates to a wound drainage system with flexible reservoir suitable for drainage under negative pressure during post-operative procedure with the options to employ and operate one or more catheters simultaneously. The present invention provides a portable wound drainage system which is easy to use and economical.

Accordingly, this invention relates to a wound drainage device for draining fluids from a portion of the body, said device comprising a reservoir having an upper cover and lower cover sealed in a fluid tight sealing engagement by a flexible sidewall, one or more vacuum assist means comprising at least one drain cap and at least one non-return valve assembly further comprising a suction connector, at least one drainage tube connected to the said suction connector, at least one Y-connector connected to the said drainage tube capable of employing one or more catheters simultaneously; and constant force expansion means for automatically expanding the passive reservoir from its collapsed state such that a substantially constant level of negative pressure is created within the passive reservoir so as to provide for the removal of fluids from the wound at a substantially constant rate of suction throughout the range of evacuation, said expansion means including vacuum assist means and constant force resilient members.

Another aspect of this invention relates to a method of drawing fluids from a portion of the body by use of the wound drainage device, the method comprises the steps of attaching one end of the drainage tube to the suction connector of the non-return valve assembly, inserting the other end into the wound by means of one or more catheters using a Y-connector, opening the drain cap, placing the device on a surface, applying force on the upper cover such that the reservoir is compressed to a passive state, placing the drain cap to close entry of air while the reservoir is compressed such that upon release of force a vacuum is created in the said reservoir defining a storage space resulting in suction of fluids from the wound at a substantially constant rate of suction.

An object of the present invention is to provide an improved wound drainage suction evacuator system.

Another object of the present invention is to provide a wound drainage system for draining fluids from the wound site on the patient’s body into a flexible reservoir. Fluids that can accumulate in the wound and lead to various complications include blood, serum, pus, bile or other biological fluids.

Another object of the present invention is to provide a wound drainage system utilizing a flexible reservoir and a vacuum assist means to maintain a constant level of vacuum during the post-operative procedure while draining fluids from the wound.

Another object of the present invention is to provide an efficient valve mechanism which allows easy activation and deactivation of the device as the need arises.

Another object of the present invention is to provide a wound drainage system including means to employ and operate one or more catheters simultaneously.

Yet another object of the present invention is to provide a wound drainage system utilizing a flexible reservoir and a vacuum assist means which is of simplified construction, which can be readily and economically manufactured at a low cost, and which will provide a uniform and reliable vacuum level during its use.

The present invention, together with further objects and advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 illustrates a perspective view of the wound drainage device in accordance with the present invention;

FIG. 2 illustrates another perspective view of the wound drainage device in accordance with the present invention;

FIG. 3 illustrates a bottom view of the wound drainage device in accordance with the present invention;

FIG. 4a illustrates an exploded view of the wound drainage device in accordance with the present invention;

FIG. 4b illustrates another exploded view of the wound drainage device in accordance with the present invention;

FIG. 5 illustrates the catheter and trocar in use with the wound drainage device in accordance with the present invention; and

FIG. 6 illustrates the drainage tube in use with the wound drainage device in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, an improved wound drainage device 10 is provided to induce suction by means of a reservoir 24 connected to the drainage tube 42 which is used in draining a wound. The said reservoir 24 acts as an air tight sterile reservoir 24 in which the withdrawn fluid can be collected. The present invention provides a portable device 10 which is disposable for preventing infections caused due to body fluids.

Referring now to the drawings and particularly to Figs. 1, 2 and 3, wound drainage devices 10 is shown which includes a reservoir 24 defining a space for storage of fluids having an upper cover 18 and lower cover 30 connected by a flexible sidewall 32. The upper cover 18 is sealed in a fluid tight sealing engagement with an upper sheet 20 and the lower cover 30 is likewise sealed in a fluid tight sealing engagement with a lower sheet 28. The upper 20 and lower sheets 28 are preferably made of durable elastomeric plastic material such as polyvinyl chloride or a suitable resilient synthetic plastic. The device 10 may be grasped in hands and squeezed to collapse the walls 32 and reservoir 24. When the hand pressure or compressive force is released, the resiliency of the sidewalls 32 of the reservoir 24 return the wound drainage device 10 to its predetermined normal or molded shape illustrated in the drawings. When the device 10 is released from the collapsed condition such as being in a passive state, the reservoir 24, of course, expands to an active state causing a negative pressure or partial vacuum in the reservoir 24.

Thus, the device 10 is provided with constant force expansion means for automatically expanding the passive reservoir 24 from its collapsed state such that a substantially constant level of negative pressure is created within the passive reservoir 24 so as to provide for the removal of fluids from the wound at a substantially constant rate of suction throughout the range of evacuation, said expansion means including vacuum assist means 40 and constant force resilient members 26. The resilient members 26 are provided in the space created by the said reservoir 24 to hold the said upper cover 18 and the said lower cover 30 at a distance and being secured to the said reservoir 24.

Further, the wound drainage device 10 is provided with the vacuum assist means 40 which comprises a drain cap 12 and a non-return valve assembly 22 and is provided with a non-return valve-gasket 16. During the discharge of drainage fluid from the patient to the reservoir 24, the non-return valve-gasket 16 prevents fluid from flowing from the reservoir 24 into the catheter and patient. The non-return valve assembly 22 is further provided with a suction connector 14 as shown in Figs. 1 and 2.

As shown in Figs. 4a and 4b, the vacuum assist means 40 is fixed preferably on the upper cover 18 of the reservoir 24. The lower cover 30 is sealed with the lower sheet 28 and reservoir 24 is attached to the said lower sheet 28. The reservoir 24 defining a space for storage is provided with one or more resilient members 26 which hold the upper cover 18 and the lower cover 30 of the reservoir 24 at a fixed distance. The resilient members 26 assist in the compression and expansion of the reservoir 24 and in developing the vacuum in the reservoir 24.

The non-return valve assembly 22 is provided on the upper cover 18 which provides a communication between the interior of the reservoir 24 and the drainage tube 42. The drainage tube 42 is connected to the suction connector 14. As shown in Fig. 6, a pinch clamp 44 may be mounted on the drainage tube 42 to control/regulate/stop the flow of liquid or fluids.

The non-return valve assembly 22 operates in a manner such that it allows gases or fluids to flow into the reservoir 24 but does not permit gases or fluids to flow out of the reservoir 24 in the reverse direction hence ensuring a sterile environment inside the reservoir 24 by disallowing entry of air into the reservoir 24. This also eliminates back flow of fluids once suction is complete. The non-return valve assembly 22 is further provided with a suction connector 14 which allows connecting to it various specification sizes or kinds of suction tube.

Referring to Fig. 5, one or more catheters with a distal end which is inserted into the wound site of the patient are provided. The catheter 34 is inserted into the patient’s body by means of a trocar 36. Trocar 36 is a rod-shaped, stainless steel surgical instrument having a blade portion at one end, usually with a three-sided point designed to be inserted into a vein, artery, bone marrow or body cavity and the catheter 34 at the other end.

The wound drainage device 10 can also be provided with support straps 48. The support strap 48 is used for convenient support adjacent to the patient and/or could be carried with the patient.

The amount of negative pressure in the reservoir 24 is directly related to the extent the reservoir 24 is compressed. That is, the more compressed, the greater the negative pressure. When the pressure is released and the reservoir 24 returns to its normal position, the negative pressure decreases from a maximum to a minimum.

The reservoir 24 is advantageously made of resilient elastomeric plastic material having high elastic recovery characteristics, such as polyethylene or other appropriate plastic material. This assists in developing and maintaining a uniform vacuum such that when the reservoir 24 is compressed from a normal rest position and then released a vacuum is developed within it as the resilient members 26 return to the normal rest position. This vacuum in combination with the vacuum created within the reservoir 24 is used to draw fluids from the body into the reservoir 24.

Preferably the reservoir 24 will be made of a transparent plastic and will have integrated markings or scales thereon. The user will therefore be able to visibly inspect the proper operation of the device 10. Additionally, he can measure the amount of fluid collected upon holding the reservoir 24. Thus, such markings or scale, not shown, can be provided on the sidewall 32 portion or any other suitable portion of the reservoir 24 to permit measurement of the volume of the liquid content being stored in the said reservoir 24. The upper cover 18 and lower cover 30 portion of the reservoir 24 are much thicker in comparison to the flexible sidewalls 32. The flexible sidewalls 32 are thinner to allow the reservoir 24 to be compressed and expanded. The thickened upper 18 and lower 30 covers act to restrain the vacuum assist means 40 so that it can be firmly operated without the possibility of protruding through the surface which could happen if the upper 18 and lower 30 covers were too thin. The thickened upper 18 and lower 30 covers thus act as pressure plates to distribute the force applied against the upper 18 and lower 30 cover of the reservoir 24.

The reservoir 24 can be fabricated of relatively inexpensive plastic materials. The vacuum assist means 40 as shown in Fig. 4 can be fabricated from a single molded piece of plastic and the like materials which could be easily assembled on the wound drainage device 10. The vacuum assist means 40 could be fabricated from other materials as well and does not necessarily have to be fabricated in one piece.

The reservoir 24 is adapted to be compressed and to expand to develop a vacuum on expansion. The reservoir 24 is provided with a non-return valve assembly 22 and suction connector 14 to which a drainage tube 42 can be attached.

As shown in Fig. 5, the distal end of the drainage tube 42 can be further attached to a catheter 34 which is provided with a plurality of perforations 52 (not shown) to allow fluid and other matter from within the patient to drain through catheter lumen, then into the drainage tube 42 and finally into the reservoir 24. The suction end of the drainage tube 42 is connected to the reservoir 24. The distal end of the drainage tube 42 is attached to a Y-connector. The Y-connector 50 allows for addition of one or more catheters 34 to be used with the wound drainage device 10. The Y-connector 50 is configured of such a shape which facilitates addition of various specification size of catheters 34 allowing it to grippingly engage the interior wall of the catheters 34.

A vacuum pressure can be created in the reservoir 24 by use of a drain cap 12, compressing upper 18 and lower cover 30 together against the force of the resilient member 26. The resilient member 26 will bias upper 18 and lower 30 cover apart, thereby creating a vacuum in drainage tube 42 lumen. Thus, the resilient member 26 within the reservoir 24 is adapted to be compressed and to expand to develop a vacuum on expansion.

The wound drainage device 10 for draining fluids out of a wound defines a reservoir 24 wherein one or more resilient member 26 such as spring like structures are contained in the space created by the reservoir 24 which hold the upper 18 and lower 30 cover of the reservoir 24 together. As mentioned, in the preferred embodiment, the resilient member 26 is a constant force coiled metal spring as shown in Figs. 4a and 4b having helical structure. The coil springs having a dimension where the diameter of a coil at a proximal end thereof forming helical structure descends to a lower diameter of a coil at a distal end thereof. Such springs are desirable since they have the feature of providing a nearly constant force throughout their range of expansion. In this manner, the device 10 provides a substantially constant suction throughout the range of evacuation, a feature found by most medical practitioners to be quite desirable in such devices. Furthermore, such resilient members 26 render the device 10 insensitive to orientation so that no particular orientation of the device 10 is required.

The method of drawing fluids from a portion of the body by use of the wound drainage device 10, the method comprises the steps of attaching one end of the drainage tube 42 to the suction connector 14 of the non-return valve assembly 22,
inserting the other end into the wound by means of one or more catheters 34 using a Y-connector 50, opening the drain cap 12, placing the device 10 on a surface, applying force on the upper cover 18 such that the reservoir 24 is compressed to a passive state, placing the drain cap 12 to close entry of air while the reservoir 24 is compressed such that upon release of force a vacuum is created in the said reservoir 24 defining a storage space resulting in suction of fluids from the wound at a substantially constant rate of suction.

The assembled device 10 can be attached to a patient in a convenient manner. With the catheter 34 inserted in the patient and with its lower end connected to the connector 14, the wound drainage device 10 is hand squeezed to collapse to a passive state. In this state, the resilient sidewalls 32 and reservoir 24 discharge air from the reservoir through the vacuum assist means 40 to the atmosphere. Under these conditions, the catheter 34 connects the wound in fluid communication with the device 10 reservoir 24, which reservoir is tending to expand and effect a negative pressure or partial vacuum in the device 10 and wound. This negative pressure facilitates the flow of drainage fluid from the wound to the device 10 reservoir 24.

The device 10 is further provided with one or more slidable locks 46 (not shown) which help to hold the upper 18 and lower 30 cover of the reservoir 24 in the pre-compressed position. The vacuum assist means 40 comprises a non-return valve assembly 22 fitted into the upper cover 18 of the reservoir 24. The upper cover 18 of the reservoir 24 and the lower cover 30 are therefore held together in a pre-compressed position such that the person using the device does not need to apply any pressure to compress the device to activate a vacuum. The said resilient member 26 disposed within the space created in the reservoir 24 holding the upper 18 and the lower 30 cover of the reservoir 24 is expandable such that controlled unlocking of the said slidable locks 46 leads to release of force on the resilient member 26 such as the spring like structure creating a vacuum inside the cavity of the reservoir 24 resulting in controlled suction of the fluids. Controlled suction of fluids from the wound ensures less damage to body tissues.

Thus, the present invention provides numerous advantages over the presently available wound suction evacuator systems. The present invention provides wound drainage device with 10 improved novel means which assist in developing uniform and constant vacuum during its draw cycle, can be stored in the activated state, is easily operated, and is small and light in weight. The invention also provides improved wound drainage device 10 suitable for drainage under negative pressure during post-operative procedure with the options to employ and operate one or more catheters 34 simultaneously. Advantageously the wound drainage device 10 is substantially rigid thereby avoiding the possibility of inadvertent compression by a patient rolling over onto the device 10.

It can also be seen by the above description that a relatively low cost and reliable wound drainage system 10 is provided. The reservoir 24 can be formed by relatively simple inexpensive molding techniques, and the entire structure can be made from relatively small number of parts, which can be easily fabricated and assembled.

Although, the invention has been described with reference to certain specific embodiments and examples, it would be appreciated by those skilled in the art that the invention may be embodied in many forms without departing from the broader spirit and scope of the invention as set forth in the invention. Thus, variations of preferred embodiments as disclosed may become apparent to those of ordinary skill in the art upon reading the foregoing description. It is therefore contemplated that the foregoing disclosure will cover any such modifications or embodiments that fall within the true scope of the present invention.

Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. The specification and drawings, therefore, are to be regarded in an illustrative rather than a restrictive manner without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

List of reference numerals:

10 wound drainage device
12 drain cap
14 suction connector
16 non-return valve gasket
18 upper cover
20 upper sheet
22 non-return valve assembly
24 reservoir
26 resilient member
28 lower sheet
30 lower cover
32 flexible sidewall
34 catheter
36 trocar
38 connector portion
40 vacuum assist means
42 drainage tube
44 pinch clamp
46 slidable lock
48 support strap
50 Y-connector
52 perforations

Claims:
WE CLAIM:

1. A wound drainage device (10) for draining fluids from a wound site on a patient’s body, said device (10) comprising:
a reservoir (24) having an upper cover (18) and a lower cover (30) sealed in a fluid tight sealing engagement by a flexible sidewall (32);
one or more vacuum assist means (40) comprising a drain cap (12), and a non-return valve assembly (22) provided with a non-return valve gasket (16) and a suction connector (14);
a drainage tube (42) connected to said suction connector (14);
a Y-connector (50) connected to said drainage tube (42) capable of employing one or more catheters (34) simultaneously; and
constant force expansion means for the removal of fluids from the wound at a substantially constant rate of suction throughout the range of evacuation, said expansion means including said vacuum assist means (40) and constant force resilient member (26) wherein said resilient member (26) includes at least one coiled spring; and
at least one slidable lock to hold said upper cover (18) and lower cover (30) in a pre-compressed position providing a controlled unlocking of said slidable lock leading to release of force on said resilient member (26) .

2. The wound drainage device (10) as claimed in claim 1, wherein said vacuum assist means (40) fixed preferably on the upper cover (18) of said reservoir (24).

3. The wound drainage (10) device as claimed in claim 1, wherein said coil spring having a helical structure assisting in compression and expansion of said reservoir (24) and in developing the vacuum in said reservoir (24).

4. The wound drainage device (10) as claimed in claim 3, wherein said coil spring having a dimension where the diameter of a coil at a proximal end thereof forming helical structure descends to a lower diameter of a coil at a distal end thereof.

5. The wound drainage device (10) as claimed in claim 1, wherein said lower cover (30) sealed in a fluid tight sealing engagement with a lower sheet (28) and said reservoir (24) attached to said lower sheet (28).

6. The wound drainage device (10) as claimed in claim 1, wherein said Y-connector (50) configured of a shape which facilitates addition of various specification size of catheters (34) allowing it to grippingly engage the interior wall of said catheters (34).

7. The wound drainage device (10) as claimed in claim 1, wherein said upper cover (18) and the lower cover (30) of the reservoir (24) differs in configuration thickness in comparison to the flexible sidewall (32).

8. The wound drainage device (10) as claimed in claim 1, wherein said catheter (34) comprises plurality of perforations (52) to allow fluid and other matter from within the patient to drain through catheter lumen into the drainage tube (42) and finally into said reservoir (24).

9. The wound drainage device (10) as claimed in claim 1, wherein said reservoir (24) advantageously made of resilient elastomeric plastic material having high elastic recovery characteristics, such as polyethylene or other appropriate plastic materials.

10. The wound drainage device (10) as claimed in claim 1, wherein said reservoir (24) provided with markings and/or scales to facilitate measurement of the volume of the liquid content being stored in the drainage device (10).