Apparatuses and methods for inline collection of a fluid specimen

A collection fitting for sampling fluid from a tissue site, the collection fitting comprising:

• a housing having a central passage, a first union configured to be fluidly coupled to a reduced-pressure source, and a second union configured to be fluidly coupled to the tissue site, the first union and the second union in fluid communication with the central passage;
• a plunger disposed in the housing, the plunger comprising a cylindrical body and having a bypass passage comprising an annular recess depending into a sidewall of the cylindrical body, the bypass passage configured to fluidly couple the first union and the second union through the central passage in a bypass position;
• and
• a cap having a boss and an open end extending away from the boss, the boss having a first inlet and a second inlet, the first inlet and the second inlet comprising openings in a sidewall of the boss, and the first inlet including a baffle extending beyond the open end of the cap, the boss configured to be inserted into the central passage and move the plunger within the housing, the first inlet and the second inlet being configured to fluidly couple the first union and the second union in a sampling position and the baffle configured to prevent a liquid from flowing directly between the first inlet and the second inlet.

A system for sampling fluid from a tissue site, the system comprising:

• a housing having a central passage, a first union, and a second union, the first union and the second union in fluid communication with the central passage;
• a plunger disposed in the housing and having a bypass passage comprising an annular recess disposed around a center of the plunger, the bypass passage configured to fluidly couple the first union and the second union through the central passage in a bypass position;
• a cap having a boss and an open end extending away from the boss, the boss having a first inlet and a second inlet, the first inlet and the second inlet comprising openings in a sidewall of the boss, and the first inlet including a baffle extending beyond the open end of the cap, the boss configured to be inserted into the central passage and move the plunger within the housing, the first inlet and the second inlet being configured to fluidly couple the first union and the second union in a sampling position and the baffle configured to prevent a liquid from flowing directly between the first inlet and the second inlet;
• a first tube coupled to the first union;
• a second tube coupled to the second union;
• and
• a specimen container configured to be coupled to the cap, the first inlet and the second inlet being in fluid communication through the specimen container.

A method for sampling fluid from a tissue site, the method comprising:

• providing a collection fitting comprising:
• a housing having a central passage, a first union, and a second union, the first union and the second union in fluid communication with the central passage;
• and
• a plunger disposed in the housing and movable between a sampling position and a bypass position, the plunger having a bypass passage comprising an annular recess disposed around a center of the plunger, the bypass passage configured to fluidly couple the first union and the second union through the central passage in the bypass position;
• fluidly coupling the collection fitting between a reduced-pressure source and the tissue site through the plunger of the collection fitting;
• coupling a cap of a specimen container to the collection fitting proximate to the plunger of the collection fitting, the cap having a boss and an open end extending away from the boss, the boss having a first inlet and a second inlet, the first inlet and the second inlet comprising openings in a sidewall of the boss, and the first inlet including a baffle extending beyond the open end of the cap, the boss configured to be inserted into the central passage and move the plunger, the first inlet and the second inlet being configured to fluidly couple the first union and the second union in the sampling position, and the baffle configured to prevent a liquid from flowing directly between the first inlet and the second inlet;
• moving the plunger out of fluid communication with the reduced-pressure source and the tissue site;
• and
• moving the cap into fluid communication with the reduced-pressure source and the tissue site, bypassing the plunger.