Fluid volume measurement using canister resonance for reduced pressure therapy systems
AssigneeKCI Licensing, Inc.
InventorsJames A. Luckemeyer, Christopher Brian Locke
Life of this patent
Estimating the term…
Abstract
A wound fluid collection system includes a canister adapted to collect bodily fluids from a tissue site. The canister includes an acoustic transducer adapted and positioned to insonify a cavity within the canister, the cavity being defined by a wall of the canister and the bodily fluids collected within the canister. A resonant frequency may be calculated based on a resulting received signal from the insonification. The resonant frequency may indicate a volume of the cavity within the canister. The difference between a known volume of the canister and the calculated volume of the cavity provides the volume of bodily fluid collected in the canister.
Claims11
A reduced pressure treatment system for collecting bodily fluids from a tissue site using reduced pressure, comprising:
- a source of reduced pressure;
- a dressing adapted to be disposed proximate and in fluid communication with the tissue site;
- a canister having walls including sidewalls closed by a lower wall and an upper wall for collecting body fluids from the tissue site, an inlet adapted to be in fluid communication with the dressing, and an outlet disposed in the upper wall over the sidewalls proximate the upper wall and adapted to be in fluid communication with the source of reduced pressure, wherein the bodily fluids have a surface rising as the canister fills from an empty state to a full state while collecting the bodily fluids to define an airspace above the surface within the canister;
- a first acoustic transducer acoustically coupled to one of the sidewalls of the canister, configured to insonify the airspace of the canister at predetermined acoustic frequencies along a first axis of insonification including a first frequency and a second frequency, and adapted to generate a first echo output signal in response to acoustic waves reflected within the airspace by opposing walls;
- and
- a processor in electrical communication with the first acoustic transducer, and adapted to provide input signals to the first acoustic transducer for insonifying the airspace at the predetermined acoustic frequencies, and then for receiving the first echo output signal from the first acoustic transducer to determine a first harmonic frequency being the lowest frequency between the first frequency and the second frequency corresponding to a drop in power required to drive the first acoustic transducer, wherein the first harmonic frequency corresponds to the volume of the airspace.
A system for collecting bodily fluids from a tissue site using reduced pressure, comprising:
- A canister having walls including sidewalls closed by a lower wall and an upper wall defining a cavity for collecting body fluids from the tissue site, the cavity configured to be in fluid communication with the dressing and a source of reduced pressure, wherein the cavity fills from an empty state to a full state while collecting the bodily fluids creating an airspace above the bodily fluids within the cavity;
- a first acoustic transducer acoustically coupled to one of the walls and configured to insonify the airspace at a first frequency and a second frequency along a first axis of insonification and to generate a first echo output signal in response to acoustic waves reflected within the airspace by opposing walls;
- and
- a processor in electrical communication with the first acoustic transducer, the processor adapted to provide input signals to the first acoustic transducer to insonify the airspace and to receive the first echo output signal to determine a first harmonic frequency indicative of the volume of the airspace, the first harmonic frequency being the lowest frequency between the first frequency and the second frequency corresponding to a drop in power required to drive the first acoustic transducer.
Dependencies are inferred from the claim text.