Sensor apparatus systems, devices and methods
A sensor apparatus and sensor apparatus system for use in conjunction with a cassette, including a disposable or replaceable cassette. In some embodiments, the cassette includes a thermal well for permitting the sensing of various properties of a subject media. The thermal well includes a hollow housing of a thermally conductive material. In other embodiments, the cassette includes sensor leads for sensing of various properties of a subject media. The thermal well has an inner surface shaped so as to form a mating relationship with a sensing probe. The mating thermally couples the inner surface with a sensing probe. In some embodiments, the thermal well is located on a disposable portion and the sensing probe on a reusable portion.
1. A dialysis apparatus comprising a cassette for sensing liquid in the dialysis apparatus, the cassette comprising a housing having a plurality of fluid paths, each fluid path including
a sensor element comprising a well for transmitting temperature and permitting conductivity sensing of fluid passing along the fluid path, wherein the well is adapted for interconnection with a sensor,
wherein a first fluid flow path of the housing is configured to receive a liquid via a first port and to expel the liquid via a second port located vertically above the first port, and wherein a third port above the first and second ports is arranged to vent gas that escapes from the liquid moving from the first port to the second port.
2. A dialysis apparatus comprising a cassette for sensing liquid in the dialysis apparatus, the cassette comprising a housing having a plurality of fluid paths, each fluid path including
a sensor element comprising a well for transmitting temperature and permitting conductivity sensing of fluid passing along the fluid path, wherein the well is adapted for interconnection with a sensor,
wherein a first fluid path of the housing is configured to receive a first mixture of water and a bicarbonate buffer solution, and a second fluid path of the housing is configured to receive a second mixture of completed dialysate comprising the first mixture and an acid or electrolyte concentrate; wherein each fluid path comprises a conductivity sensing probe extending into the fluid path and spaced apart from the well.
3. The dialysis apparatus of claim 2 , wherein each sensor is mounted onto and electrically connected with a printed circuit board having an edge connector through which sensor information may be transmitted from the sensors to a system controller.
4. The dialysis apparatus of claim 2 , wherein the housing comprises a top plate and a base, the top plate being sealingly engaged with the base to define the volumes of the fluid paths, wherein sensor elements of each sensor penetrate the top plate to extend into the fluid paths.
5. The dialysis apparatus of claim 2 , wherein the sensor is a thermistor.
6. The dialysis apparatus of claim 2 , wherein said well comprises a hollow housing of a thermally and electrically conductive material, said housing having an outer surface and an inner surface, said inner surface of a predetermined shape so as to form a mating relationship with a sensing probe, wherein said mating thermally and electrically couples the inner surface with the sensing probe.
7. The dialysis apparatus of claim 2 , wherein each fluid path comprises a conductivity sensing probe extending into the fluid path and spaced apart from the well.
8. The dialysis apparatus of claim 2 , wherein the well is configured to make contact with fluid in the fluid path.
9. The dialysis apparatus of claim 8 , wherein the well is coupled to the cassette using at least one of press fit connection, flexible tabs, adhesive, ultrasonic weld, and a retaining plate and fastener.
10. A dialysis apparatus comprising a cassette for sensing liquid in the dialysis apparatus, the cassette comprising a housing having a plurality of fluid paths, each fluid path including
a sensor element comprising a well for transmitting temperature and permitting conductivity sensing of fluid passing along the fluid path,
wherein a first fluid flow path of the housing is configured to dialysate solution that is flowing to a dialyzer, and a second fluid flow path of the housing is configured to receive dialysate solution directed to drain or to a heating apparatus; wherein each well of the plurality of fluid paths is adapted for interconnection with a thermistor.
11. The dialysis apparatus of claim 10 , wherein the plurality of fluid paths each further comprises a conductivity sensing probe extending into the fluid path.