Apparatus and method for controlling tissue oxygen and promoting tissue viability for wound healing

Abstract

The application relates to devices and methods for controlling tissue oxygen and promoting tissue viability for wound healing. Specifically, a wound treatment system includes a housing. A processor is located in the housing. A pressure monitoring system is coupled to the processor. A power delivery system is located in the housing and coupled to the processor. An oxygen concentrator is located in the housing and coupled to the power delivery system. The oxygen concentrator includes a plurality of oxygen outlets. The processor is configured to: receive pressure information from the pressure monitoring system, the pressure information indicating a pressure in a confined airflow closure provided by a dressing and positioned adjacent a wound site; and using the pressure information to control power provided from the power delivery system to the oxygen concentrator to control an oxygen flow generated by the oxygen concentrator and provided to the restricted airflow enclosure via one of the plurality of oxygen outlets.

Description

[0001] This application is a divisional application of an application with application date of December 7, 2016, application number 201680071641.3, and invention name “Device and method for controlling tissue oxygenation and promoting tissue vitality in wound healing”. Technical Field

[0002] Embodiments disclosed herein relate to tissue treatment systems, and in particular, tissue oxygenation systems for accelerating the healing of damaged tissue and promoting tissue vitality. The tissue oxygenation systems described herein can be used to treat skin ulcers caused by diabetes, venous stasis, postoperative infection, gangrenous lesions, bedsores, infected stumps, skin grafts, burns, frostbite, and / or a variety of other wounds and physical conditions known in the art. Background Art

[0003] When tissue is damaged, a wound is formed and the healing process begins. The term "wound" may include, but is not limited to, chronic wounds, traumatic wounds, wounds resulting from surgery, and / or other wounds known in the art. Restoring optimal metabolic function of the cells of the tissue in a wound requires the availability of oxygen at all stages of wound healing, and the more layers of tissue that are damaged, the greater the risk of complications during the wound healing process.

[0004] Difficult-to-heal wounds encounter obstacles to the wound healing process and often experience delays in one or more wound healing stages. One of the most common contributing factors to delays in the healing process of venous leg ulcers, diabetic foot ulcers, and bedsores is the problem of chronic wound ischemia. Chronic wound ischemia is a pathological condition that limits blood supply, oxygen delivery, and blood demand for adequate tissue oxygenation, which inhibits normal wound healing.

[0005] Implementing the standard of care for treating difficult-to-heal wounds typically involves the use of advanced wound dressings or a combination of advanced wound dressings that provide a dressing treatment system. The advanced dressing is placed on the wound site and / or around the surrounding unbroken skin to provide wound site closure. Advanced wound dressings typically include materials with properties for promoting moist wound healing, managing wound secretions, and helping to control wound bioburden. Typical material components in the combination additionally include properties for providing limited moisture permeability. The lower the moisture permeability of the dressing or the greater the occlusion of the dressing, the lower the amount of ambient air and corresponding oxygen available to the wound. 100% oxygen applies a partial pressure of 760 mm Hg. Ambient air contains about 21% oxygen, thereby applying an oxygen partial pressure of about 159 mm Hg. Typical advanced wound dressings or wound dressing systems that include lower moisture permeability materials affect the oxygen available to the wound site, thereby limiting the oxygen partial pressure of the closed wound site to about 10-60 mm Hg. Thus, fresh air is only provided to the wound site when the dressing is changed, and the dressing may remain covered for up to seven days before a dressing change is required. The moisture vapor permeability properties of advanced wound dressings that provide a wound environment with reduced oxygen are therefore not conducive to reestablishing optimal metabolic function of the cells of the tissue in the wound, which would benefit from having oxygen available at all stages of wound healing.

[0006] Prior art methods for tissue oxygenation of difficult-to-heal wounds generally include intermittent or continuously applied local high-pressure oxygen. Intermittent local high-pressure oxygen is a method of tissue oxygenation including a sealed extremity or partial body chamber and a connected large-flow pure oxygen source. The affected limb or affected body area is placed in a sealed extremity chamber or partial body chamber so that the oxygen source supplied to the chamber can provide the patient with up to 100% oxygen locally at a flow rate that can exceed 300 liters per hour so that the interior of the chamber is pressurized to up to 1.05% normal atmospheric pressure, thereby increasing the available oxygen for cell treatment at the affected wound site. During the application of oxygen, the oxygen partial pressure applied in the local or partial body chamber can reach 798mm Hg, and local high-pressure oxygen can be applied for about 90 minutes. The prior art also teaches a variety of methods for intermittently applying local high-pressure oxygen. A partial body chamber for treating sacral wounds has been described in U.S. Pat. No. 4,328,799 granted to LoPiano (1980), wherein oxygen is applied to the interior of the chamber from a fixed supply tank via a connected pipeline. A similar method of applying topical high-pressure oxygen is described in U.S. Pat. No. 5,478,310 to Dyson-Cantwell (1995), in which oxygen is applied from a fixed supply tank to the interior of a disposable extremity chamber via connected tubing. These and similar methods of applying intermittent topical high-pressure oxygen are restrictive, cumbersome, can only intermittently supply oxygen to the affected area without systematic application, and can only be applied in minimal increments (about 5%) of atmospheric pressure. The effectiveness of oxygen therapy at the wound site is therefore often minimal, as evidenced by the lack of commercial success of topical high-pressure oxygen extremity chambers.

[0007] U.S. Pat. No. 5,578,022 to Scherson (1996) and U.S. Pat. No. 5,788,682 to Maget (1998) both describe disposable devices that utilize the transmission of gas in ionic form through an ion-specific membrane to apply supplemental oxygen directly to a wound. These devices are described as battery-powered disposable oxygen-making bandages and methods of direct application to a wound. Both devices include electrochemical oxygen generation using a variation of the same 4-electron formula originally developed for NASA in U.S. Pat. No. 3,489,670 to Maget (1970). The amount of oxygen that can be applied to the wound is typically 3 ml per hour. Specific oxygen flow rates are generated by means of corresponding specific pre-selected battery sizes and specific specified amperages, and these disposable devices are described as "on or off". The prior art also describes disposable devices that do not have a means for sensing temperature changes in the oxygen environment of the wound site, and does not provide a means for delivering a variable or adjustable oxygen flow rate without requiring the patient to obtain and apply a new device with a new battery with a specific amperage. Other limitations are associated with the use of fixed, non-variable oxygen flow rates.

[0008] No prior art tissue oxygenation device provides continuous oxygen adjustability to a patient's wound to create a controlled hyperoxic and hypoxic wound environment for damaged tissue to accelerate wound healing and promote tissue vitality. Specifically, there is no prior art teaching of continuous oxygen adjustability based on actual flow rate, partial pressure at the wound site, and, in favorable circumstances, temperature, pH, and / or other local conditions at the wound site. Summary of the invention

[0009] Embodiments disclosed herein include improved tissue oxygenation devices and wound monitoring systems. Those embodiments generally include oxygen delivery, microporous catheters for placement at or near the wound bed, and wound dressings covering the catheter and wound site to provide a restricted airflow closure. The catheter may have a plurality of holes located at or near the distal end of the catheter and may include a substantially flat, elastic, oxygen-permeable band or membrane portion connected to the distal end of the catheter. The catheter may be elastic with an anti-kink lumen. The catheter may include a temperature sensor. The catheter may include a pressure sensor. The catheter may include an oxygen partial pressure sensor. The proximal end of the catheter is connected to an oxygen source. The proximal end of the catheter may have a port Luer-type locking mechanism for airtight sealing during the application of oxygen and removal from the oxygen source during the application of the dressing. The oxygen source is in communication with the proximal and distal ends of the catheter and may be provided by an electrochemical oxygen concentrator supplied by AC or DC and a power management device using a power management scheme. According to embodiments of the present disclosure, a variable electrochemical oxygen concentrator is used to meet the changing target parameters of the wound site by varying the oxygen flow rate. The oxygen flow rate is regulated by the system periodically or continuously monitoring the wound pressure and, where advantageous, temperature environment. In addition, the system can monitor the catheter pressure and adjust the oxygen flow rate according to a target set point. Regulating the oxygen flow in response to changes in monitored wound site oxygen and target oxygen pressure and, where advantageous, wound site temperature, humidity, pH or perfusion provides a controlled hyperoxic wound environment that can shorten the healing process. The monitoring system of the present invention can additionally provide an alarm when the pressure, temperature, humidity, pH, perfusion or flow rate is out of range.

[0010] In some cases, excessive oxygen pressure (i.e., greater than 22 mm Hg) can block arterial circulation and cause local tissue circulation to decrease and in some cases cause local tissue damage. Embodiments of device design can address how the device controls oxygen pressure so that the pressure does not exceed a safe limit. Unlike conventional local oxygen chambers for extremities, the present invention does not create a sealed oxygen-rich environment in the chamber into which the patient's limb is inserted. Instead, oxygen can be generated by a proton exchange membrane within a portable device and delivered to the wound site via a microporous catheter at a rate of 3 ml / hour to 100 ml / hour. Because the wound site is only covered by an occlusive wound dressing rather than inserting the entire limb into a sealed chamber, the oxygen pressure at the site and around the limb will never exceed normal atmospheric pressure.

[0011] In some embodiments, the device may have a backlit display terminal or touch screen liquid crystal display, a data entry keypad or device function control buttons, a wound or housing temperature monitoring system, a wound or device moisture monitoring system, a battery and oxygen pressure alarm system, a digital camera, a patient data input and memory system, a data port, wireless data acquisition and / or other components discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A more complete understanding of the present disclosure and its advantages may be obtained by referring to the following description made in conjunction with the accompanying drawings:

[0013] Figure 1 is a perspective view illustrating one embodiment of a tissue oxygenation system.

[0014] Figure 1A It is used to treat multiple wounds of the patient. Figure 1 and 1A A front view of one embodiment of a tissue oxygenation system.

[0015] Figure 1B is a cross-sectional view of one embodiment of a wound site showing a wound site that can be used Figure 1 The distal tip of the oxygen delivery catheter of the tissue oxygenation system.

[0016] Figure 2 Yes Description Figure 1A A side perspective view of one embodiment of a distal tip of an oxygen delivery catheter showing a generally flat, elastic, oxygen permeable band or membrane portion attached to the oxygen delivery catheter.

[0017] Figure 2A Yes Description Figure 1A An end view of one embodiment of an oxygen delivery catheter.

[0018] Figure 3 Yes Description Figure 2A A side view of one embodiment of a distal tip of an oxygen delivery catheter.

[0019] Figure 4 Yes Description can be used Figure 1 A perspective view of one embodiment of a handheld controller for a tissue oxygenation system.

[0020] Figure 5 Yes Description Figure 1 Schematic diagram of one embodiment of a tissue oxygenation system.

[0021] Figure 6 Yes Description can be used Figure 1 A top plan view of one embodiment of an electrolyzer / concentrator for a tissue oxygenation system.

[0022] Fig. 6A Yes Description Figure 6 A side plan view of one embodiment of an electrolyzer / concentrator.

[0023] Figure 6B Yes Description Figure 6 An exploded perspective view of one embodiment of an electrolyzer / concentrator.

[0024] Figure 7 This means that Figure 1 A flow chart of one embodiment of a method of controlling tissue oxygenation for use with a tissue oxygenation system.

[0025] Although the embodiments of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown in the drawings and described in detail herein by way of example. However, it should be understood that the description of specific embodiments herein is not intended to limit the present disclosure to the specific forms disclosed, but is intended to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the present disclosure as defined by the appended claims. DETAILED DESCRIPTION

[0026] Several embodiments of a tissue oxygenation system for promoting healing and tissue vitality of damaged tissue will now be described in detail with reference to the drawings.

[0027] Figure 1 1 is a perspective view of several components of a tissue oxygenation system of the present disclosure for providing oxygen to a wound. The illustrated embodiment includes a monitoring unit 10, an electrochemical oxygen concentrator 11, an oxygen delivery conduit 12, a moisture-absorbent dressing 14, and a vapor-permeable dressing 16. The oxygen delivery conduit 12 may be connected (at Figure 1 ) to the monitoring unit 10. In one embodiment, the monitoring unit 10 is provided in a portable, relatively small, lightweight housing and can be worn separately by the patient in a pocket, attached to a belt, and / or otherwise carried in various ways known in the art.

[0028] Monitoring unit 10 may include within housing 13: any or all of microprocessors 58 (see Figure 4 and 5), power management system 52, one or more pressure sensors 30a or pressure sensor interfaces, one or more temperature sensors 32a or temperature sensor interfaces, one or more flow rate sensors 54 or flow rate sensor interfaces, input port 62, and user access port 66. Monitoring unit 10 may additionally include within housing 13: any or all of one or more pH sensors 34a or pH sensor interfaces, one or more perfusion sensors 36a or perfusion sensor interfaces, and one or more humidity sensors 38a or humidity sensor interfaces. Electrochemical oxygen concentrator 11 may be disposed within housing 13. Microprocessor 58 may be used to control power; collect various readings from flow rate sensor 54, pressure sensor 30a, pH sensor 34a, perfusion sensor 36a, humidity sensor 38a, and temperature sensor 32a included within housing 13 or coupled to corresponding interfaces in housing 13; control ion purification of ambient air for delivery to conduit 12 by electrochemical oxygen concentrator 11; and provide information on an information display of monitoring unit 10. The microprocessor 58 can be wirelessly connected to the computer via the user access port 66 and the input port 62. and / or other wireless technologies known in the art, and / or using other communication systems to receive data, which includes information related to a specific patient, reprogramming information in the event of a system malfunction of the device, and / or any other information that would be apparent to a technician in the art possessing the present disclosure.

[0029] As in Figure 1A and 2 As further seen in the figure, the distal tip 17 of the catheter 12 may include or be coupled to a soft, elastic, oxygen-permeable band or membrane portion 29 that may be placed on or near an injured tissue or wound site 20 on a patient's limb 19 and covered with a hygroscopic dressing 14, which is further covered by a permeable occlusive dressing 16 having a reduced vapor pressure.

[0030] In one embodiment, oxygen may be delivered to the wound site 20 via a kink-resistant conduit 12 connected at its proximal end 15 to an outlet of an oxygen concentrator in the housing 13 of the monitoring unit 10. Furthermore, in some embodiments, the oxygen concentrator in the housing 13 of the monitoring unit 10 may include a plurality of oxygen outlets, and a plurality of kink-resistant conduits 12 may be connected at their proximal ends 15 to respective outlets of the oxygen concentrator, with their respective distal ends 17 placed on or near a plurality of different damaged tissues or wound sites 20 of the patient and covered by a permeable occlusive dressing 16 with reduced vapor pressure, such as Figure 1B As shown. Figure 1BOnly two wound sites on the patient are shown to be treated, but a technician in the field with the present disclosure should recognize that any number of wounds can be treated in a similar manner, such as by increasing the oxygen output of the oxygen concentrator, providing more oxygen concentrators in the housing 13 of the monitoring unit 10, etc.

[0031] like Figure 2 As shown, in one embodiment, a soft elastic oxygen permeable flat strip or membrane 29 may be connected at the distal end 17 of each catheter 12. Sensor wires 30 and 32 may extend through the lumen of each catheter 12 to communicate with any of the sensors or sensor interfaces discussed above included within the housing 13 of the monitoring unit 10. For example, the sensor wires 30 and 32 may communicate with the temperature sensor 32, the oxygen partial pressure sensor 30, the flow rate sensor 54, the humidity sensor 38a, the pH sensor 34a, the perfusion sensor 36a, and / or other sensors positioned at each wound site and provide the information to the microprocessor 58. In other embodiments, the sensor wires may be eliminated and the temperature, pressure, flow rate, pH, perfusion, humidity, and / or other wound environment measurements may be measured at each outlet of the oxygen concentrator within the monitoring unit housing.

[0032] like Figure 2A As shown, in some embodiments, catheter 12a may include several lumens, sensors, and / or other subsystems that may be required to effectively monitor wound treatment. Specifically, Figure 2A An end view of catheter 12a is shown, and depicts a length of catheter 12A that is capable of connecting to the output side of either outlet of electrochemical oxygen concentrator 11 housed within monitoring unit 10. Such catheter length allows the monitoring unit to be worn separately while oxygen is continuously delivered to wound site 20. The lumen or hole 18a of the catheter may have Figure 2AThe star-shaped configuration of the tube 18a can prevent kinking of the catheter and / or allow oxygen flow when the catheter 12a is bent, but other configurations of the lumen 18a may also provide similar benefits. An oxygen partial pressure sensor 19a, which can be placed at or near the wound site, can be placed in the catheter 12A and communicate with a pressure monitoring system and / or a microcontroller to allow oxygen flow rate adjustment, visual pressure display, out-of-range alarms, and / or other benefits that should be obvious to a person skilled in the art. A temperature sensor 21a, which can also be placed at or near the wound site, can be placed in the catheter 12a and communicate with a temperature monitoring system and / or a microcontroller to allow visual display of temperature, out-of-range alarms, to allow appropriate adjustment of oxygen via the microprocessor 58, and / or provide other benefits that should be obvious to a person skilled in the art. In addition, a pH sensor, perfusion sensor and / or humidity sensor, which may also be placed at or near the wound site, may be similarly positioned within conduit 12a and in communication with a pH monitoring system, a perfusion monitoring system, a humidity monitoring system and / or a microcontroller to allow for visual display of pH, perfusion, relative humidity, out-of-range alarms to allow for proper adjustment of oxygen via microprocessor 58, and / or to provide other benefits that should be apparent to a person skilled in the art.

[0033] Figure 3 1 is a side view of one embodiment of the distal end of the catheter 12a, which may include a plurality of holes 23 formed along the side of the distal end of the catheter 12a to assist in oxygen delivery to the wound. In use, oxygen may be provided to the wound site via the catheter 12a in a flow F and may enter the wound bed via the plurality of holes 23. Oxygen may also flow through the distal end of the star-shaped lumen 18a, but in some embodiments, the plurality of holes at the distal end of the catheter 12a can allow an increased flow of oxygen to the wound site 20.

[0034] Figure 1AA wound site 20 is shown with the distal end 17 of the oxygen delivery conduit 12 having an oxygen distribution band 29 placed over or near the wound site 20, although in some embodiments, the band 29 may be placed centrally over the wound site for optimal delivery of oxygen to the damaged tissue. In some embodiments, the wound may be saturated with close to 100% O2. A hygroscopic dressing 14 may be placed at the wound site to cover the band end of the oxygen delivery conduit 12 and the wound site. A person skilled in the art having the present disclosure will appreciate that a variety of hygroscopic dressings that provide typical standard of care regimens for difficult-to-heal wounds are capable of being used with the oxygen delivery conduit 12 as discussed above. A reduced moisture permeability dressing 16 may then be used to cover the hygroscopic dressing 14, the band end of the conduit 12, and the wound site 20 to create a restricted airflow closure. In some embodiments, the reduced moisture permeability dressing 16 may be transparent and may be considered an occlusive dressing. An occlusive dressing may be used to trap oxygen over the wound site to create and maintain an oxygen-rich environment. In some embodiments, the local partial pressure of oxygen at the wound site 20 may be increased from a low range of 10 to 60 mm Hg to an oxygen-rich environment range of 200 to 760 mm Hg, and the increased available oxygen may be metabolized at the cellular level to promote growth factor increase, epithelialization, granulation tissue, glucosaminoglycan production, collagen synthesis, and / or other wound healing factors known in the art. In one embodiment, the oxygen partial pressure at the wound site may be communicated to a pressure monitoring system and / or microprocessor in the housing 13. The oxygen partial pressure sensor may supply data to the microprocessor 58 so that the microprocessor 58 may be used to control the flow of electricity (amperage) to the concentrator 11, which in turn may cause the concentrator to increase or decrease its O2 production to change the O2 flow rate to the wound site. In some embodiments, the oxygen partial pressure sensor may be a conductivity sensor, but other systems for measuring this pressure may be used and still fall within the scope of the present disclosure.

[0035] Figure 4 is a perspective view of a handheld controller that may house components of a tissue oxygenation system of the present disclosure, and Figure 5is a schematic diagram of those components. In use, the monitor housing 13 can inhale ambient air 50 having about 21% oxygen via the air inlet 40 by means of an electrochemical process. The ambient air 50 can then pass through the ion exchange oxygen concentrator 11, which is used to concentrate the oxygen in the ambient air 50 to create a gas flow of 99% pure oxygen. The power management system 52 can control the current supplied to the ion exchange oxygen concentrator 11, so that the oxygen flow rate conforms to the amount of current supplied to the ion exchange oxygen concentrator 11, that is, increasing the current will increase the electrochemical process and thus increase the corresponding oxygen flow rate to the wound site 20, and reducing the current will reduce the electrochemical process and thus reduce the corresponding oxygen flow rate to the wound site. In some embodiments, the power management system 52 may include a lithium battery (e.g., 3.7v) and a regulator to change the current within a range of about 20 mA to about 140 mA, while in other embodiments, the range may be about 7 mA to about 70 mA. In some embodiments, this range of current variation may produce an O2 flow rate in the range of about 3.0 ml / hr to about 20.0 ml / hr, while in other embodiments the range may be about 3.0 ml / hr to about 10.0 ml / hr.

[0036] The concentrated O2 then exits the housing via the oxygen delivery port 54. The proximal end 15 of the oxygen delivery conduit 12 is connected to the oxygen delivery port 54 with a Luer-type lock fitting or other fittings known in the art to maintain an airtight seal with the conduit 12 and allow the conduit 12 to deliver the concentrated O2 to the wound site.

[0037] like Figure 2 and 5 As shown, the pressure sensor 30a or 19a in the conduit 12 or 12a and, in some embodiments, the temperature sensor 32a / 21a are in communication with the microprocessor 58. In addition, the pH sensor 34a, the perfusion sensor 36a, and / or the humidity sensor 38a may also be in communication with the microprocessor 58. The microprocessor 58 may be in communication with the power management system 52 to adjust the oxygen flow rate to the wound site (as sensed by the sensor 54) according to a programmed algorithm to best meet the patient's changing oxygen wound healing requirements. In one embodiment, if multiple conduits 12 or 12a are connected between the oxygen concentrator and multiple wound sites (such as Figure 1B ), the microprocessor 58 may communicate with the power management system 52 to adjust the oxygen flow rate to each individual wound site (sensed by the corresponding sensor 54) according to a programmed algorithm to best meet the varying oxygen wound healing requirements of each wound of the patient, which may be different and thus may require different oxygen flow rates and / or other processing features that should be apparent to a person skilled in the art having the present disclosure.

[0038] See instead Figure 6, 6A and 6B, showing an electrochemical oxygen generator / concentrator 11. In the illustrated embodiment, the unique design of the concentrator provides a more robust pumping unit. For example, sometimes the oxygen delivery conduit may become kinked or blocked, and in the prior art concentrator, the result of any slight back pressure will be that the concentrator will rupture. The concentrator of the embodiment disclosed herein does not rupture when the outlet is blocked. In addition, the system is configured to provide an alarm to inform the patient that the oxygen flow / pressure is out of range, thereby allowing the patient to check the delivery conduit. If multiple conduits are provided to multiple wound sites, the system can provide an alarm to inform the patient which of those conduits includes an oxygen flow / pressure that is out of range, thereby allowing the patient to check which of the multiple delivery conduits triggered the alarm. When the oxygen flow is blocked, an audio alarm will sound and in some embodiments, a visual warning light will light up. For example, the alarm may sound for two minutes. In one embodiment, the alarm can be silenced by pressing a mute button on the monitoring housing, which can be used to silence the audio alarm for fifteen minutes while the user troubleshoots the system, which may include checking for a kink in the catheter or an object pressing against the catheter or an obstruction that may have occurred at the wound site under the dressing.

[0039] Figure 6 is a top plan view of concentrator 11 showing cathode plates 70 covering anode disks 72. Fig. 6A is a side view of concentrator 11. Each of the charged plates may include a carbon backed metallized substrate having a 0.85 square inch titanium mesh plated on a woven fiber carbon film, which may provide a fully covered area for directing the charge to the concentrator 11. Oxygen transfer membrane ( TURF® is a registered trademark of DuPont and is a sulfonated tetrafluoroethylene copolymer that is well known in the art as a proton conductor for proton exchange membranes (PEMs).

[0040] Figure 6B is an exploded perspective view of the concentrator 11. The PEM membrane 74 can be fully compressed between the cathode 70 and the anode 72 by a torque screw type fastener. The elbow 80 can be connected to the anode disk 72. Electrical contact and transfer to the plate can be completed by connecting the copper strip to the titanium mesh substrate. The applied compressive force can provide the necessary adhesion to the surfaces of the two metals. The strip can then be connected to the charged plate with epoxy resin.

[0041] Ambient air may enter the concentrator via an inlet 82 covered by a filter membrane 84 that allows water vapor and gases to pass through while preventing contaminants from entering the concentrator. The concentrated O2 may then be exhausted out of an exhaust valve 80 that communicates with an exhaust port 54 in the housing 13.

[0042] Figure 7 A flow chart showing a method of controlling tissue oxygenation using the system discussed above. When the monitoring unit 10 is turned on or activated at box 90, the microprocessor 58 calibrates all sensors and PEM cells at box 92. Because each PEM cell and each sensor has its own specific functional characteristics, the embodiments described herein calibrate the sensors and cells to ensure accurate flow rates.

[0043] If the calibration is successful at box 94, the microprocessor can then obtain the desired flow rate from the user at box 95. In one embodiment, the desired flow rate can be obtained remotely from a caregiver (e.g., the patient's doctor or nurse) or the manufacturer of the monitoring unit 10. The microprocessor can then calculate the current output from the PEM to set the desired flow rate at box 96. The microprocessor can then receive input from the flow rate sensor 54 and determine whether the set flow rate has been reached at box 97, and if not, the processor can try again to change the current to the sensor and PEM battery. If the set flow rate is reached at box 97, the microprocessor can enter PID control mode at box 98. The flow rate can then be adjusted according to the input from the pressure monitoring system and the flow sensor. The microprocessor can also display the flow rate and temperature (when appropriate) on the monitor display screen 68. In proportional control mode, the microprocessor can continuously test the actual flow rate using a feedback loop that focuses on changes in sensor and PEM battery efficiency to ensure that it is maintained at box 99.

[0044] In one embodiment, the flow rate can be adjusted to a set upper limit, which can provide a relatively high flow rate. For example, the flow rate can be set to such a relatively high level to treat a whole limb or a part of the patient's body, which may require a flow rate of more than hundreds of milliliters per hour. In such embodiments, a flow rate of 100 milliliters per hour may be sufficient for most applications, but it is envisioned that a higher flow rate is within the scope of the present disclosure. In an embodiment where multiple catheters are used to deliver oxygen to multiple wound sites, the flow rate of any specific catheter to a specific wound site can be set to be different from the flow rate of the catheter to other wound sites, and can be based on wounds and / or wound features. To obtain a higher flow rate, the monitoring unit 10 may have a larger battery or PEM battery to provide a longer operating time between recharging. For example, the monitoring unit 10 may have enough batteries to operate for 24 hours without recharging. In addition, in the case of a desired higher output flow rate (for example, for larger wounds, multiple wounds, etc.), multiple PEM batteries or batteries can be placed in parallel to obtain such flow rates.

[0045] In some embodiments, a humidity pack may be provided within the housing 13 along with the concentrator 11. In some instances, the humidity pack may be inserted into the monitoring unit 10 when low humidity (e.g., below a threshold) is detected, or may be present within the housing 13 and activated only when low humidity is detected, or may alternatively be always active to maintain a desired humidity within the housing 13. In some embodiments, the monitoring unit 10 may monitor the humidity of the air reaching the fuel cell (i.e., PEM cell), and may alert the user when the humidity is below a level that may affect the function or efficiency of the device. For example, when the humidity drops too low, the PEM cell may dry out and effectively degrade, which may require additional power to achieve the same flow rate. Therefore, if the humidity is too low, the flow rate may be reduced because there is a limit on how much power can be used to compensate for the low humidity, and a humidity pack may be used to ensure appropriate humidity in the housing to prevent such situations from occurring.

[0046] In some embodiments, the humidity pack may be provided as a stand-alone module, and in some instances may be connected to a battery pack. In some embodiments, the humidity pack is disposable and disposable after use. In other embodiments, the humidity pack may be refilled by adding water to the humidity pack. For example, a refillable humidity pack may include a separate refill chamber from which water is drawn as needed to refill the humidity pack. Thus, a monitoring or warning system may be included in the device to warn the user via audio and / or visual signals when the humidity is below a threshold, and the warning system may also use graphical, audio or text instructions to assist the user with the steps of replacing or refilling the humidity pack as discussed above, or with any related troubleshooting as needed.

[0047] In some embodiments the battery of monitoring unit 10 within housing 13 is replaceable, while in other embodiments the battery of monitoring unit 10 within housing 13 may be refillable.

[0048] In some embodiments, the processor of the monitoring unit 10 is capable of recording and reporting data to the manufacturer, caregiver, and or any other entity related to the patient, the device, the use of the device, and / or any other information generated as discussed above. For example, the monitoring unit 10 may record and report any or all of the following: patient compliance with unloading, patient compliance with changing wound dressings, compliance with proper connection of the catheter to the dressing, compliance with applying the dressing to the wound, and / or other compliance information known in the art. In addition, the patient's activity level may be recorded. Still further, status information of the monitoring unit 10 may be recorded and reported, such as the time and duration that the monitoring unit 10 is powered on, whether the device is properly charged, the performance of the device (e.g., efficiency, flow output, or other characteristics), environmental conditions (e.g., humidity or temperature), device location (e.g., determined using a global positioning satellite (GPS), Bluetooth, Wi-Fi, etc.), and / or other device status information known in the art.

[0049] In one embodiment, a report alert based on the data record may be sent to the patient, the caregiver, the manufacturer of the device, and / or other entities as needed. In some embodiments, the report alert may be sent according to the severity of the recorded information. For example, for problems that cannot be corrected by the patient, such as device performance warnings, an alert may be sent only to the manufacturer of the device, who may be able to intervene when there are signs that the device may be damaged and needs to be replaced. Similarly, if the wound experience affects the patient or the patient's behavior, such as compliance with unloading or dressing changes, an alert may be sent to the patient and the caregiver, allowing the patient or caregiver (or both) to intervene earlier to ensure the best results. In some embodiments, if the patient complies with the caregiver or device recommendations, a congratulatory or encouraging notification or alert may be sent to the patient to strengthen and ensure the patient's future compliance. Thus, any information recorded and / or reported can be analyzed by the device or another system to determine whether an alert or other report should be sent to any entity.

[0050] According to some embodiments, the wound monitoring system or monitoring unit may include communication capabilities provided by a communication device 70, such as a GSM or LTE cellular communication device. In addition, the wound monitoring system or monitoring unit having the communication device 70 may include a Wi-Fi (e.g., 802.11a / b / c / d / n) communication device. The wound monitoring system or monitoring unit may also include near field communication or other radio frequency communication capabilities, such as Bluetooth, to enable short-range data transmission between the wound monitoring system or monitoring unit and other devices, such as a patient's or a caregiver's mobile phone or other computing system.

[0051] The wound monitoring system or monitoring unit may include various power control features implemented by the power management system 52. In one embodiment, the monitoring unit, once activated, may remain on and may require a specific override from the patient to shut down the device. For example, the specific override may include a button that is different from the button used to activate the device to shut down the device. In another example, the monitoring unit may require confirmation from the patient to shut down the device. In another example, the monitoring unit may require the patient to press the off button for a period of time (e.g., two seconds) before the device will shut down. Although some examples have been provided, it is contemplated that various other power control features are within the scope of the present disclosure.

[0052] Other control features may also be included in some embodiments of the wound monitoring system or monitoring unit. In one embodiment, if the system includes a communication device that connects the system to a network, the wound monitoring system can be remotely turned on, off, and controlled in various ways. For example, the wound monitoring system can be remotely shut down to enforce a payment requirement that allows use of the device, such as if a patient associated with the device has not yet provided sufficient fees for the device or the ongoing rental of the device. In another example, if the device is reported as lost or stolen, the wound monitoring system can be remotely shut down. In some embodiments, the manufacturer or caregiver of the device may require regular communication with the wound monitoring system to ensure compliance or authorization for continued use. For example, if too much time has passed since previous communication with the device, the device can be remotely disabled as a precautionary measure. In another example, the device can also be remotely restarted or power cycled for troubleshooting by a technician or manufacturer.

[0053] In some embodiments, the wound monitoring system or monitoring unit further includes a relative humidity sensor capable of assisting in monitoring relative humidity levels, which in some cases can be used to trigger various other events, such as activating a humidity pack, sending diagnostic data or performance data collected by the device, requesting assistance from a caregiver or manufacturer, providing a warning signal to the patient, caregiver or manufacturer, and / or other alarms or events known in the art.

[0054] In some embodiments, the monitor display screen 68 can provide additional information such as feedback information to the patient or caregiver. For example, the feedback information can include automatic warnings from the device, such as low battery warnings, blockage warnings, low humidity warnings, etc.; information from the manufacturer, such as server-side feedback, or customer service feedback, such as positive reinforcement for compliance with instructions, warnings of potential problems (e.g., when the catheter or dressing is not connected properly), non-compliance warnings, and / or other feedback information known in the art.

[0055] In some embodiments, in addition to the temperature sensor that can be provided in the catheter as discussed above, additional components, devices or sensors can be used for temperature sensing or detection. For example, thermocouples, thermistor Wheatstone bridges and / or other temperature measurement subsystems can be provided in the monitoring unit 10 or coupled to the monitoring unit 10. Such temperature measurement subsystems can be incorporated into the wound dressing, the outside of the housing and / or coupled to the patient at a distance from the wound site. For example, an independent temperature measurement subsystem can be placed directly in the wound bed, inserted into the wound channel, or placed on the dressing material, such as in the non-adhesive layer of the dressing. In addition, for an independent temperature measurement subsystem, a symbol or other indication can be made in the memory of the device about the location of the temperature measurement subsystem to allow tracking and reporting of potential temperature excursions of the wound site that can be measured according to different positions of the temperature measurement subsystem. In some embodiments, the microprocessor or other component of the device may include the ability to detect different types of dressings or temperature measurement subsystems that have been connected to the device.

[0056] In some embodiments, the temperature measurement subsystem may be provided in the form of a flat strip, a small ball, a rod, or other temperature measurement subsystem configurations known in the art. Such temperature measurement subsystems may be used to generate temperature measurement sensor data, which may be used to monitor changes in the average temperature of a wound over time, which in some cases may indicate changes in the healing status of the wound. For example, infection or new capillary growth may be apparent from temperature changes. Temperature data may also be used to monitor patient compliance, such as whether a dressing or temperature measurement sensor is properly placed on the wound (or whether it is placed on the wound), how often the dressing is changed, whether the patient frequently opens the dressing to check the wound, and / or other compliance-related events known in the art. In one embodiment, data from the temperature measurement sensor may be combined with data from any of the other sensors discussed above (e.g., perfusion data, pH data, pressure data, etc.) to refine the analysis of patient compliance, wound status, and / or other factors.

[0057] In some embodiments, additional components, devices or sensors other than those discussed above may be used to detect pH levels. For example, the provision of a pH sensor may be independent of a wound dressing and incorporated into a wound dressing. Such a pH sensor may be placed directly in the wound bed, inserted into a wound channel, or placed on a dressing material, such as in a non-adhesive layer. In some embodiments, symbols or other indications may be made in the memory of the device regarding the positions of different pH sensors to permit tracking of potential offsets caused by different positions of the pH sensor. For example, if a pH sensor is incorporated into a wound dressing, the type of dressing and the type of pH sensor may be entered into the memory of the device. In some embodiments, the device may include the ability to detect different types of dressings or pH sensors that have been connected to the device.

[0058] In some embodiments, the pH sensor can be provided in the form of a flat strip, a small ball, a rod, or other pH sensor configurations known in the art. The pH sensor data can be used to monitor changes in the pH level of the wound over time, which can indicate changes in the healing status of the wound. For example, pH changes can indicate new capillary growth or infection. In addition, data from the pH sensor can be used to monitor patient compliance, such as whether the dressing or pH sensor is properly placed on the wound (or whether it is placed on the wound). For example, the pH sensor may require liquid to function and may provide different output results when the wound is dry. Data from the pH sensor can also be used to determine the frequency of wound cleaning, and / or can be combined with data from temperature, perfusion or pressure probes or sensors to further refine the determination of patient compliance or wound condition analysis.

[0059] In some embodiments, additional components, devices, or sensors may be used to monitor perfusion levels. Perfusion monitoring may include methods for detecting the relative and / or absolute amount of blood flowing into the wound, and in some embodiments, may additionally include detecting the relative and / or absolute oxygen saturation of tissue in the wound bed. For example, a perfusion monitoring sensor may include a reflective photoplethysmograph. Similar to the temperature monitoring sensor and pH sensor described above, a perfusion monitoring sensor may be independent of a wound dressing and incorporated into a wound dressing. For example, an independent perfusion monitoring sensor may be placed directly in the wound bed, inserted into a wound channel, or placed on a dressing material, such as in a non-adhesive layer. In addition, symbols or other indications may be made in the memory of the device regarding the locations of different perfusion monitoring sensors to permit tracking of potential perfusion excursions in the wound site due to different locations of the perfusion monitoring sensors. In one embodiment, a microprocessor or other component of the device may include the ability to detect different types of dressings or perfusion monitoring sensors that have been connected to the device.

[0060] In some embodiments, the perfusion monitoring sensor may have the form of a flat strip, a small ball, a rod, or other perfusion monitoring sensor configuration known in the art. Perfusion monitoring sensor data can be used to monitor changes in wound perfusion over time, which in some cases can indicate changes in the healing status of the wound. For example, infection or new capillary growth can be apparent based on perfusion changes. Perfusion data can also be used to monitor patient compliance, such as whether the dressing or perfusion monitoring sensor is properly placed on the wound (or placed on the wound), the frequency of dressing changes, whether the patient opens the dressing to check the wound, and / or other compliance-related events. In some embodiments, data from the perfusion monitoring sensor can be combined with data from other sensors, such as temperature data, pH data, or pressure data discussed above to further refine compliance determinations or wound condition analysis.

[0061] Thus, with the aid of the data entry keypad 64 and function control buttons 65, the wound monitoring system allows patient data and treatment instructions to be communicated between the device and the caregiver or patient for processing. The data port 66 can be used to upload or download data. The monitoring system allows the collection and monitoring of key medical parameters to assist the caregiver in managing patient care and potentially accelerate the healing process with the increased access to more data. Available patient data and device functions are displayed on the device function display screen 68 and visually and audibly alerted when appropriate. A digital camera 69 can also be used to assist in the monitoring process to visually track the progress of wound closure.

[0062] Although illustrative embodiments have been shown and described, various modifications, variations and substitutions are contemplated in the foregoing disclosure, and in some cases some features of the described embodiments may be employed without corresponding use of other features. It is appropriate, therefore, that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.

Claims

1. A wound treatment system, comprising: shell; a processor located in the housing; a pressure monitoring system coupled to the processor; a power delivery system located in the housing and coupled to the processor; an oxygen concentrator located in the housing and coupled to the power delivery system, wherein the oxygen concentrator includes a plurality of oxygen outlets; wherein the processor is configured to: receiving pressure information from the pressure monitoring system, the pressure information indicating a pressure within a restricted airflow closure provided by the dressing and positioned adjacent a wound site; and The pressure information is used to control power provided from the power delivery system to the oxygen concentrator to control a flow of oxygen generated by the oxygen concentrator and provided to the restricted flow enclosure via one of the plurality of oxygen outlets.

2. The system according to claim 1, further comprising: a humidity pack coupled to the housing, a humidity monitoring system coupled to the processor; wherein the processor is configured to: receiving humidity information from the humidity monitoring system, the humidity information indicating humidity within the restricted airflow enclosure of the housing; using the humidity information to control the humidity provided from the humidity pack to the oxygen concentrator; and The humidity information is used to control power provided from the power delivery system to the oxygen concentrator to control a flow of oxygen generated by the oxygen concentrator and provided to the restricted flow enclosure via one of the plurality of oxygen outlets.

3. The system according to claim 1, further comprising: a temperature sensor coupled to the processor, wherein the processor is configured to receive temperature information from the temperature sensor, the temperature information indicating a temperature of the wound site, and determine whether the oxygen flow from the oxygen concentrator is at a desired oxygen flow level.

4. The system according to claim 1, further comprising: a pH sensor coupled to the processor, wherein the processor is configured to receive pH information from the pH sensor, the pH information indicating a pH value of the wound site, and determine whether the oxygen flow from the oxygen concentrator is at a desired oxygen flow level.

5. The system of claim 1, further comprising: a perfusion sensor coupled to the processor, wherein the processor is configured to receive perfusion information from the perfusion sensor, the perfusion information indicating perfusion of the wound site, and determine whether the oxygen flow from the oxygen concentrator is at a desired oxygen flow level.

6. The system of claim 1, wherein the plurality of oxygen outlets comprises at least two oxygen outlets, and wherein the processor is configured to: controlling a flow of oxygen generated by the oxygen concentrator and provided to the restricted flow enclosure via a first oxygen outlet at a first level; and A flow of oxygen generated by the oxygen concentrator and provided to a second restricted flow enclosure via a second oxygen outlet at a second level different from the first level is controlled.

7. The system of claim 1, further comprising: A battery pack is coupled to the housing.

8. The system of claim 1, further comprising: A communication interface is provided wherein the processor is configured to control power provided from the power delivery system to the oxygen concentrator in response to instructions received via the communication interface.

9. The system of claim 1, further comprising: An alarm system is coupled to the pressure monitoring system, wherein the processor is configured to activate the alarm system in response to an out-of-range indication from the pressure monitoring system.

10. The system of claim 1, further comprising: A delivery conduit includes a first end coupled to the oxygen outlet and a second end configured to be positioned in the restricted gas flow enclosure adjacent the wound site.

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