Patent ID: 7686778

Claim:
A waste balancing system for medical use comprising: a first container containing a fluid waste; a second container containing a replacement fluid; a support supporting the first and second containers in a stacked relationship such that the weight of one of the first and second containers bears on the other of the first and second containers, the first and second containers having flexible walls in direct contact with each other such that said containers form a column of fluid which conforms to the shape and size of the support; and a pressure sensor in pressure communication with at least one of the first and second containers and located at a bottom of the support such that the pressure sensor indicates a height of the column of fluid; a controller connected to control a pump and to receive a signal from said pressure sensor and control a rate of flow of at least one of said fluid waste and said replacement fluid to and from said first and second containers responsively to said signal, such that a constant height of the column of fluid is maintained and thereby maintaining a constant total mass of fluid in both of the first and second containers combined.