Field of the Invention
This invention relates to a system and method for purging a negative pressure wound therapy system.
Description of the Related Art
The referenced shortcomings are not intended to be exhaustive, but rather are among many that tend to impair the effectiveness of previously known techniques in purging a negative pressure wound therapy (NPWT) system. However, those mentioned here are sufficient to demonstrate that the methodologies appearing in the art have not been satisfactory and that a significant need exists for the techniques described and claimed in this disclosure.
Advanced NPWT devices and systems use multiple fluid channels to provide therapeutic negative pressure, transport wound products (liquid and solid) and monitor the applied negative pressure close to the wound site (via additional tubing lumens, typically). During this process several problems can be encountered, which can cause therapy to be interrupted or accuracy to be compromised.
For example, the therapy line may be blocked by highly viscous fluids, solid matter, or wound products coagulating in the line due to long residency time when flow is restricted under low leak conditions. In addition, the wound pressure sensing line may be blocked by wound fluid and/or instillation fluid.
Current practice in some advanced NPWT products is to periodically vent the wound pressure sensing line to atmosphere (near the pump/sensor end of the line), which allows the vacuum in the wound dressing to pull a short burst of air into the wound and thus attempt to clear a blockage in the sensing lumen(s). However, when instillation therapy is used in conjunction with NPWT, there can be little or no vacuum at the wound site. Moreover, there is a tendency for practitioners to over-fill the wound with instillation fluid, which can drive instillation fluid up the wound pressure sensing lines and thereby prevent accurate sensing of wound pressure until the fluid in the wound pressure sensing lumen(s) is removed. Wound pressure sensing is accurate only if there is a clear air path between the sensor and wound site, and wound pressure sensing will be degraded if there are slugs of fluid in the sensing lines.