Wound drainage system

A low vacuum wound drainage apparatus comprising:

• a high vacuum bottle having an outlet port and connector means;
• a wound drainage line having a first end for connection to said outlet port of said bottle via said connector means whereby suction is applied to a second patient end of said drainage line;
• and
• a regulating valve for continuously regulating the vacuum in said wound drainage line to provide a reduced vacuum at said drainage line second end, said valve comprising a valve body, a valve spool arranged for sliding reciprocal movement within said valve body so as to periodically open and close said valve to provide said continuous regulation in said drainage line, a first side of said valve spool exposed to ambient atmospheric pressure, said spool being spring loaded by a spring, the spring rate of said spring selected to control the degree of vacuum reduction from said high vacuum bottle to said second patient end of said drainage line such that a spring return force on a second side of said spool begins to act against the external atmospheric pressure acting on the opposite side of said spool when the vacuum in the patient end of said wound drainage line is at the desired level, a side of said body having a high vacuum port such that movement of said spool into said body, against the force of said spring, cuts off said high vacuum port from the inside of said valve body, and hence interrupts the flow path from said high vacuum bottle to a second port in said valve body, said valve body second port being connected to said drainage line second end and a sealing means between said valve spool and said valve body.

A flexible wound drainage tube, comprising:

• a first section adapted to be connected to a high vacuum bottle;
• a second section to be applied to a wound;
• and
• a regulating valve interconnecting said first and second sections which acts to continuously provide a lower vacuum in the second section than that provided in the first section from the high vacuum bottle, said valve comprising:
• a valve spool slidingly located within a valve body and held by a spring, said valve body including a patient line port and a high vacuum port, said patient line port being connected to said second section and said high vacuum port being connected to said first section, the spring rate and the cross-sectional area of said valve spool being selected to control the degree of vacuum reduction from the high vacuum of said bottle to said patient end of said wound drainage line, the return force of said spring and the pressure at said patient end of said wound drainage line acting on a first side of said spool and the external atmospheric pressure acting against a second opposite side of said spool, the forces acting on the opposite sides of said spool being equal when the vacuum in said wound drainage line at said patient end thereof is the required low vacuum.