The present invention relates generally to negative pressure wound therapy system and, more particularly, to an exudates canister co-operable with a pump providing a source of negative pressure for the bandage system to collect the exudates and fluid extracted from the negative pressure bandage.
Negative pressure wound therapy involves a bandage system that is applied to the wound site on the patient to create a seal around the perimeter of the bandage system and around a periphery of the wound to be treated. The negative pressure bandage system is provided with a connector that connects to a pump that draws a vacuum on the bandage system to urge any fluid and exudates within the wound site to move toward the pump through a conduit interconnecting the connector and the pump. A canister is connected to the conduit to intercept the fluids and exudates before reaching the pump to collect the fluids and exudates until the canister is filled to a predetermined level. Preferably, the canister can be removed from the pump housing and replaced when filled.
In U.S. Pat. No. 6,139,982, granted to Kenneth W. Hunt, et al on Nov. 7, 2000, a negative pressure wound therapy apparatus is disclosed in which a canister is removably mounted in a pump housing and connected by a conduit to the pump to draw a vacuum on the canister. A separate conduit connects the canister to the negative pressure bandage system to draw the fluids and exudates from the wound being treated into the canister. A filter is provided at the outlet end of the canister where the conduit interconnecting the canister and the pump is located to prevent the introduction of the fluids and exudates collected into the canister from the bandage system into the pump.
U.S. Pat. No. 7,004,915, issued to Thomas A. Boynton, et al on Feb. 28, 2006, discloses a canister that is connected by a first conduit to the negative pressure bandage system and by a second conduit to the pump that asserts a negative pressure on the canister through the second conduit, which vacuum is asserted through the canister to the first conduit and the connected bandage system. The canister incorporates first and second hydrophobic filters at the connection of the second conduit to the canister such that the first hydrophobic is adapted to operate as a fill sensor for the canister and the second hydrophobic filter further inhibits contamination of the pump by the collected fluids and exudates from the wound site. An odor filter is also provided between the first and second hydrophobic filters to counteract the production of malodorous vapors present in the collected wound exudates.
In U.S. Pat. No. 7,611,500, granted on Nov. 3, 2009, to Cesar Z. Lina, et al, the canister includes an outlet that is plugged onto a port supported on the pump housing to connect the canister with the vacuum source. A switch carried on the pump housing closes when the canister is properly seated on the port. The canister incorporates a filter cap that allows the pump to draw air from the canister through the port and assert a vacuum on the negative pressure bandage system. The canister also incorporates a fill sensor in the form of a capacitive sensor that identifies a change in capacitance within the canister corresponding to the fluid level reaching the fill sensor located on the side of the canister near the outlet.
In each of the above-described prior art canisters, the fluids and exudates are drawn from the negative pressure bandage directly into the canister where the fluids and exudates are collected. Typically, the movement of the fluids and exudates is restricted from contaminating the pump by a hydrophobic filter that prevents the fluids and exudates from entering the vacuum line to the pump. The canister is preferably removable from the pump housing and disposed when filled, to be replaced by a new canister. With fill sensors specifically located on the canister, orientation of the canister is highly critical to prevent the fluids from being sensed by the fill sensor.
Many known negative pressure wound therapy systems commercially available are portable devices, meaning that the pump and the canister are sufficiently small as to be capable of being attached to the patient and moved from one location to another as the patient moves about. To ensure that the fluid and exudates that have been removed from the wound site are not able to flow back into the wound site, or back to the bandage over the wound site, canisters are often provided with tilt sensors that are operably connected to the pump and determine the orientation of the canister. When the angle of tilt exceeds a certain allowed maximum, the operation of the vacuum pump is terminated.
It would be desirable to provide a fluid and exudates collection system that is less dependent on orientation of the canister to operate properly. It would also be desirable to provide sensors that would accurately reflect the filling of the canister no matter how the canister is oriented with respect to vertical.
It is an object of this invention to overcome the disadvantages of the prior art by providing a pump for use with negative pressure wound therapy systems and having tilt and fill sensors that indicate when the pump canister is filled with fluid from the wound.
It is another object of this invention to provide tilt and fill sensors for use on a pump having a canister for collecting fluids from a wound being treated with a negative pressure bandage.
It is a feature of this invention that a microprocessor operatively coupled with the tilt and fill sensors to avoid a false indication of a full canister.
It is an advantage of this invention that the negative pressure wound therapy apparatus is less dependent on orientation of the pump for operation.
It is another advantage of this invention that the person being treated with negative pressure wound therapy is more capable of being mobile while being treated.
It is still another advantage of this invention that the tilt sensor can be utilized to provide an indication that a triggering of the fill sensor is not indicative of a filled canister.
It is another feature of this invention that the fill sensor is formed with a pair of spaced sensor pins that provide an indication of a filled canister when liquid in the canister contacts both sensor pins.
It is a still another feature of this invention that the microprocessor ceases operation of the pump when the microprocessor receives a signal from the fill sensor without a signal from the tilt sensor.
It is yet another feature of this invention that the microprocessor pauses the operation of the pump when a signal from the tilt sensor is received.
It is yet another advantage of this invention that the pausing of the operation of the pump can be delayed for a period of time after the tilt signal is received to determine if the tilt signal remains activated.
It is still another feature of this invention that the microprocessor can sound an alarm when the tilt sensor is activated.
It is yet another feature of this invention that the microprocessor can cease operation of the pump when both the tilt and fill sensors are received.
It is still another object of this invention that a pump providing a vacuum to a negative pressure wound therapy bandage which is durable in construction, carefree of maintenance, and simple and effective in use.
These and other objects, features and advantages are accomplished according to the instant invention by providing a pump having a canister for collecting fluids from a negative pressure wound therapy bandage in which the canister incorporates both tilt and fill sensors operatively connected to a microprocessor to control the operation of the pump in drawing fluids from the bandage. The fill sensors include a pair of spaced sensor pins that convey a filled signal when fluid within the canister interconnects the two sensor pins. The tilt sensor is housed within the pump housing. The canister is also formed with an optical sensor that provides an indication of proper alignment of the canister on the pump housing. The optical sensor includes a reflector in the canister that reflects an infrared light emanating from the pump housing. When the light reflection is received properly within the pump housing, the canister is properly aligned and mounted on the pump housing.
The foregoing and other objects, features, and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description that follows, in conjunction with the accompanying sheets of drawings. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the invention.
Referring to
The canister 20 is a hollow structure for collecting and storing the fluids and exudates extracted from the negative wound therapy bandage 34. The canister 20 is detachably supported on the mounting ledge 25 of the pump housing 12 and operatively cooperable therewith to receive a vacuum therefrom and to apply that vacuum to the negative pressure bandage 34 to extract fluids and exudates therefrom. The canister 20 is formed with a latch member 22 at the upper edge thereof to be positionable for engagement with the latch keeper 14 on the pump housing 12. Also, the bottom surface of the canister 20 is formed with a mounting tab 23 that is sized to insert into a positioning slot 24 formed in the housing ledge 25 to secure the canister 20 on the pump housing 12 and to assure that the canister 20 is properly mounted on the pump housing 12.
The canister 20 is provided with a receiver port 26 that is aligned with the vacuum port 13 when the canister 20 is properly mounted on the pump housing 12 so that the pump 10 can draw a vacuum on the canister 20. The canister 20 is also provided with retainer holes 27 that receive retainer tabs 28 formed on the pump housing 12 to stabilize the positioning of the canister 20 on the pump housing 12. The process to mount the canister 20 on the pump housing 12 is shown in
Because of the required connection of the vacuum port 13 within the receiver port 26 to enable proper operation of the negative pressure wound therapy system, the pump housing 12 is provided with an optical sensor 30 that directs an infrared light onto a reflector 33 mounted on the canister 20. If the reflector 33 is not properly aligned, i.e. perpendicular to the optical sensor 30, the infrared light beam will not be reflected back into the infrared optical sensor 30. The pump 10 is operably connected to the optical sensor 30 such that the receipt of a return signal from the reflector 33 is required in order for the pump 10 to be activated. Preferably, the optical sensor 30 will initiate a message on the display screen 15 to alert the user that the canister 20 is or is not properly aligned for operation of the pump 10.
Once the canister 20 is properly seated on the pump housing 12, the pump 10 is free to operate and draw a vacuum through the vacuum port 13 engaged with the receiver port 26 into the canister 20, which is turn is applied to the tubing 35 connected to the inlet port 36 of the canister 20 and extending to the negative pressure bandage 34, as is shown in
The canister 20 is provided with a pair of resister-type fill sensors 38 that project into the interior of the canister 20 and are connected to the microprocessor 51 mounted in the pump housing 12 via the contacts 37, as is depicted in the schematic block diagram of
As can be seen in
As shown in
If at step 41, the tilt sensor 39 has been activated, the process delays activity for eight seconds to provide a safeguard against a false signal due to movement of the canister 20 splashing fluids onto the fill sensors 38. Then at step 44, the process queries whether the tilt sensor 38 has undergone a status change. If at step 44 the tilt sensor 39 has a changed status, the process returns to step 41 to query if the tilt sensor 39 has been activated. If the response to the query at step 44 is in the negative, the process 40 queries the fill sensor 38 at step 46 to see if the fill sensor 38 has been activated. If the fill sensor 38 has not been activated, the process triggers an alarm, preferably both audible and visual, at step 47, to inform the user to reorient the canister 20, while the operation of the pump is paused until the canister has been returned to a vertical orientation.
The process 40 then returns to step 44 to see if the status of the tilt sensor 39 has changed. The alarm will not be disengaged nor the pump returned to operation until the status of the tilt sensor 39 has changed at step 44. If at step 46 the fill sensor 38 has been activated, the alarm is also triggered and the operation of the pump 10 is paused. If after sixty seconds at step 49 the status of the fill sensor has changed, then the process returns to step 41 to determine if the tilt sensor 38 is still activated. If at step 49 both the fill and tilt sensors 38, 39 remain activated, then the process will automatically shut down the pump 10 at step 45.
The impact of the fluid content within the canister 20 when the canister 20 is tilted in various directions is depicted in
Forward and rearward tilt angles are shown in
Referring now to the schematic diagram of the control logic in
The invention of this application has been described above both generically and with regard to specific embodiments. Although the invention has been set forth in what is believed to be the preferred embodiments, a wide variety of alternatives known to those of skill in the art can be selected within the generic disclosure.
This application claims domestic priority on U.S. Provisional Patent Application Ser. No. 61/620,616, filed on Apr. 5, 2012, the content of which is incorporated herein by reference.
Number | Date | Country | |
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61620616 | Apr 2012 | US |