Intravascular blood gas sensing system

A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

• the housing adapted and sized to be located outside the body of the patient and having a fluid flow passage therethrough into which blood can be received from said patient, said housing including a first housing component having a first recess and a second housing component having a second recess which confronts the first recess, said second housing component being at least partially received in said first recess so that at least a portion of each of said first and second recesses forms at least a portion of said fluid flow passage and a substantially annular space exists between said first and second housing components;
• adhesive means located at least partially in said substantially annular space and acting to bond said first and second housing components together;
• and
• a sensing element located in said housing in or near said fluid flow passage for providing a signal in response to a compositional parameter of blood.

An assembly for use in measuring a compositional parameter of blood comprising:

• a housing having a fluid flow passage extending therethrough and first and second opposite sides;
• a tube;
• means on said housing for coupling the housing to the tube with the tube in communication with said fluid flow passage whereby blood can be conducted to the fluid flow passage;
• said housing having wall means defining an external recess on said first side of the housing;
• a sensing element carried by said wall means for providing a signal in response to a compositional parameter of the blood;
• signal transmission means for transmitting said signal away from the housing, a portion of said signal transmission means being receivable in said recess;
• and
• coupling means carried by the signal transmission means for engaging said second side of said housing to releasably couple the housing to the signal transmission means.

A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

• a housing adapted and sized to be located outside the body of the patient and having a fluid flow passage extending therethrough, said fluid flow passage being elongated along an axis of elongation and having first and second ports at opposite ends of the fluid flow passage and located along the axis of elongation, said fluid flow passage being capable of receiving blood from the patient through one of said ports;
• a plurality of sensing elements located in said housing along the axis of elongation in or near said fluid flow passage, each of said sensing elements being capable of providing a signal in response to a different compositional parameter of blood;
• and
• said fluid flow passage at or near the location of said sensing element being at least two times as wide as its depth, the depth of said fluid flow passage extending directly outwardly from said sensing element and the wide direction of said fluid flow passage being substantially perpendicular to both the general direction of fluid flow in said fluid flow passage and to the depth of the fluid flow passage.