Pressure measurement device
View Patent ↗A pressure measurement device isolates liquid, such as blood, from an intermediate fluid, such as air, by means of a diaphragm. The diaphragm is arranged between first and second chambers of respective first and second shells of a pressure pod body. The first shell has first and second ports, which are connected to the first chamber. The second shell has a measurement port with a connector in communication with the second chamber. A pressure transducer with a mating connector is directly connected to the measurement port connector to minimize the sealed volume between the diaphragm and the pressure transducer.
1. A pressure measurement device comprising:
a pressure pod body including:
first and second chambers separated by a flexible diaphragm;
first and second ports in fluid communication with the first chamber, each of the first and second ports being adjacent and having a respective axis and a respective fitting for attaching to a respective tube,
said axes being parallel such that, when each of the first and second ports is connected to the respective tube, the respective tubes are held mutually adjacent and in a parallel orientation; and
a measurement port with an integral connector in fluid communication with the second chamber, the measurement port having a measurement port axis parallel to the first and second port axes;
the measurement port connector being configured to be engaged with a mating connector by displacing the pressure pod body in a direction aligned with the measurement port axis.
2. The pressure measurement device of claim 1 , wherein the measurement port connector includes a luer connector.
3. The pressure measurement device of claim 1 , wherein the measurement port connector is configured such that a pressure transducer can be directly connected thereto so as to define a sealed volume between the pressure transducer and the diaphragm, the sealed volume transferring pressure from the first chamber to the pressure transducer via the diaphragm.
4. The pressure measurement device of claim 3 , wherein said sealed volume is filled with air.
5. The pressure measurement device of claim 1 , further comprising a pressure transducer having the mating connector connected directly to the measurement port connector with no intervening fluid channel, the pressure transducer being attached rigidly to the measurement port connector.
6. The pressure measurement device of claim 1 , wherein a surface of the second chamber facing the diaphragm has a concave shape, the diaphragm conforming to the second chamber surface at a maximum displacement of the diaphragm.
7. The pressure measurement device of claim 1 , wherein the pressure pod body further includes a deflector configured to redirect dynamic pressure of fluid flowing into the first chamber thereby reducing displacement of the diaphragm by the dynamic pressure.
8. A pressure measurement device, comprising:
a first pod body shell having a first port and a second port;
a second pod body shell having a measurement port with a connector;
a diaphragm arranged between the first pod body shell and the second pod body shell so as to define a first chamber with the first pod body shell and a second chamber with the second pod body shell, the first and second chambers being separated by the diaphragm; and
a pressure transducer which is connected directly to the measurement port connector with no intervening fluid channels,
wherein the first and second ports are in fluid communication with the first chamber, and
the measurement port is in fluid communication with and adjacent to the second chamber.
9. The pressure measurement device of claim 8 , further comprising a deflector unit arranged within the first chamber so as to redirect fluid which flows into the first chamber.
10. The pressure measurement device of claim 9 , wherein the deflector unit includes a deflector plate supported in the first chamber so as to dissipate an inlet flow from one of the first and second ports into eddies.
11. The pressure measurement device of claim 8 , wherein the pressure transducer is connected to the measurement port connector so as to define a sealed fluid volume, a volume of the sealed fluid volume is changed between a maximum value and a minimum value by displacing the diaphragm, and a ratio of the maximum value to the minimum value is at least 5.
12. The pressure measurement device of claim 8 , wherein the second pod body shell has a second chamber surface facing the diaphragm, the second chamber surface having a concave shape.
13. The pressure measurement device of claim 8 , wherein the diaphragm is a polyvinyl chloride sheet with a thickness, over at least a major portion thereof, of 10 mil.
14. The pressure measurement device of claim 8 , further comprising a blood tubing set, the first and second ports being connected to respective blood lines of the blood tubing set.
15. A pressure measurement device, comprising:
a pressure pod body having a first shell with a first recess, a second shell with a second recess, and a diaphragm arranged between the first and second shells so as to isolate the first recess from the second recess,
the first shell having inlet and outlet ports communicating with the first recess,
the second shell having a single measurement port with a connecting portion arranged on an exterior surface of the second shell, the single measurement port communicating with the second recess; and
a measurement assembly including a pressure transducer connected releasably to said connecting portion so as to define a sealed volume between the pressure transducer and the diaphragm, the sealed volume transferring pressure from the diaphragm to the pressure transducer,
wherein said pressure pod body is removable from the measurement assembly such that the measurement assembly can be reused with a new pressure pod body.
16. The pressure measurement device of claim 15 , wherein the pressure transducer is mounted on a rigid frame, the pressure pod body being supported at least in part by the connection between the pressure transducer and the connecting portion.
17. The pressure measurement device of claim 15 , wherein the second recess in the second shell has a concave surface facing the diaphragm.
18. The pressure measurement device of claim 15 , further comprising a blood tubing set, the inlet and outlet ports being connected to respective blood lines of the blood tubing set.
19. A pressure measurement device comprising:
a pressure pod body including:
first and second chambers separated by a flexible diaphragm;
first and second ports in fluid communication with the first chamber, each of the first and second ports being adjacent and having a respective axis and a respective fitting for attaching to a respective tube,
said axes being parallel such that, when each of the first and second ports is connected to the respective tube, the respective tubes are held mutually adjacent and in a parallel orientation; and
a measurement port with an integral connector in fluid communication with the second chamber, the measurement port having a measurement port axis parallel to the first and second port axes; and
a frame rigidly supporting a pressure transducer, the pressure transducer having a mating connector configured to connect directly to the measurement port connector such that the pressure pod is rigidly attached to the frame with no intervening fluid channel,
wherein the measurement port connector is configured to be engaged with the mating connector by displacing the pressure pod in a direction aligned with the measurement port axis, and
the mating and measurement port connectors are configured such that the first and second port respective axes extend away from the frame, whereby the pressure pod body and tubes attached to the first and second ports can be manually grasped by wrapping a single human hand therearound.
20. The pressure measurement device of claim 19 , wherein the measurement port connector includes a luer connector.
21. The pressure measurement device of claim 19 , wherein the pressure transducer defines a sealed volume between the pressure transducer and the diaphragm when the mating connector is connected to the measurement port connector, said sealed volume being filled with air.
22. The pressure measurement device of claim 19 , wherein a surface of the second chamber facing the diaphragm has a concave shape, the diaphragm conforming to the second chamber surface at a maximum displacement of the diaphragm.
23. The pressure measurement device of claim 19 , wherein the pressure pod body further includes a deflector configured to redirect dynamic pressure of fluid flowing into the first chamber thereby reducing displacement of the diaphragm by the dynamic pressure.