Monitoring low pressures in high pressure environments

A disposable flow circuit assembly for a medical injection system comprising:

• a sensor subassembly including a substrate, and a pressure sensor mounted on the substrate;
• a protective apparatus extending over the pressure sensor, the protective apparatus comprising:
• a plate including a first side, a second side, opposite the first side, and an opening extending from the first side to the second side, the second side of the plate defining a cavity with the pressure sensor;
• a sleeve extending around an outer perimeter surface of the plate and of the pressure sensor;
• and
• a flexible diaphragm extending over the first side of the plate and defining a compressible cavity with the first side of the plate, the compressible cavity being in fluid communication with the cavity formed between the second side of the plate and the coupled pressure sensor, via the opening of the plate, the diaphragm being formed from a rubber material, and the diaphragm including a central zone, an undulating peripheral zone, and a perimeter edge, the perimeter edge being attached to the sleeve between the sleeve and the outer perimeter surface of the plate, and the peripheral zone including a series of annular corrugations and a series of spoke-like corrugations, each spoke-like corrugation radiating from the central zone to the perimeter edge and intersecting each annular corrugation;
• and
• a cap coupled to the sleeve of the protective apparatus, the cap comprising an inner surface that defines a flow chamber, at least one inlet port for flow into the flow chamber, and an outlet port for flow out from the flow chamber, the flow chamber being located on an opposite side of the diaphragm of the protective apparatus from the compressible cavity.

A manifold connector for use in a medical injection system, the manifold connector comprising an injection channel and an auxiliary channel in fluid communication therewith;

• the injection channel of the manifold connector comprising:
• a wall defining a lumen of the channel and having an aperture formed therethrough, the aperture having a perimeter surface configured to retain a blood pressure-monitoring pressure sensor therein;
• and
• a protective apparatus mounted within the aperture of the wall, the protective apparatus comprising:
• a plate including a first side facing toward the lumen of the channel, a second side, opposite the first side, and an opening extending from the first side to the second, the second side of the plate defining a cavity with the pressure sensor when the pressure sensor is retained in the aperture;
• and
• a flexible diaphragm extending between the first side of the plate and the lumen of the channel, the diaphragm defining a compressible cavity with the first side of the plate, the compressible cavity being in fluid communication with the cavity formed between the second side of the plate and the coupled pressure sensor, via the opening of the plate, the diaphragm being formed from a rubber material, and the diaphragm including a central zone, an undulating peripheral zone, and a perimeter edge, the peripheral zone including a series of annular corrugations and a series of spoke-like corrugations, each spoke-like corrugation radiating from the central zone to the perimeter edge and intersecting each annular corrugation;
• and
• wherein the perimeter edge of the diaphragm is captured between an outer perimeter surface of the plate and the perimeter surface of the aperture formed through the wall of the channel, and a side of the diaphragm, opposite the compressible cavity, is in fluid communication with the lumen of the channel.

A fluid circuit line comprising:

• a wall defining a lumen of the line and having an aperture formed therethrough, the aperture having a perimeter surface configured to retain a pressure sensor therein;
• and
• a protective apparatus mounted within the aperture of the wall, the protective apparatus comprising:
• a plate including a first side facing toward the lumen, a second side, opposite the first side, and an opening extending from the first side to the second, the second side of the plate defining a cavity with the pressure sensor, when the pressure sensor is retained in the aperture;
• and
• a flexible diaphragm extending between the first side of the plate and the lumen, the diaphragm defining a compressible cavity with the first side of the plate, the compressible cavity being in fluid communication with the cavity formed between the second side of the plate and the coupled pressure sensor, via the opening of the plate, the diaphragm being formed from a rubber material, and the diaphragm including a central zone, an undulating peripheral zone, and a perimeter edge, the peripheral zone including a series of annular corrugations and a series of spoke-like corrugations, each spoke-like corrugation radiating from the central zone to the perimeter edge and intersecting each annular corrugation;
• and
• wherein the perimeter edge of the diaphragm is captured between an outer perimeter surface of the plate and the perimeter surface of the aperture, and a side of the diaphragm, opposite the compressible cavity, is in fluid communication with the lumen.

A flow circuit assembly comprising:

• a sensor subassembly including a substrate, and a pressure sensor mounted on the substrate;
• a protective apparatus extending over the pressure sensor, the protective apparatus comprising:
• a plate including a first side, a second side, opposite the first side, and an opening extending from the first side to the second side, the second side of the plate defining a cavity with the pressure sensor;
• a sleeve extending around an outer perimeter surface of the plate and of the pressure sensor;
• and
• a flexible diaphragm extending over the first side of the plate and defining a compressible cavity with the first side of the plate, the compressible cavity being in fluid communication with the cavity formed between the second side of the plate and the coupled pressure sensor, via the opening of the plate, the diaphragm being formed from a rubber material, and the diaphragm including a central zone, an undulating peripheral zone, and a perimeter edge, the perimeter edge being attached to the sleeve between the sleeve and the outer perimeter surface of the plate, and the peripheral zone including a series of annular corrugations and a series of spoke-like corrugations, each spoke-like corrugation radiating from the central zone to the perimeter edge and intersecting each annular corrugation the central zone having a stiffness greater than the peripheral zone, the central zone being aligned over the opening of the plate;
• and
• a cap coupled to the sleeve of the protective apparatus, the cap comprising an inner surface that defines a flow chamber, a pair of inlet ports for flow into the flow chamber, and an outlet port for flow out from the flow chamber, the flow chamber being located on an opposite side of the diaphragm of the protective apparatus from the compressible cavity.