A medical valve having an open mode that permits fluid flow, and a closed mode that prevents fluid flow, the medical valve configured to be used in-line and in fluid communication with a pressure transducer, the medical valve comprising: a housing having a housing wall, an inlet and an outlet, the housing having an interior contact surface at and/or between the inlet and/or the outlet; a resilient valve element within the housing interior configured to control fluid flow through the inlet, the resilient valve element having a body comprising: a proximal portion forming a normally closed aperture configured to open when actuated by a medical device, a distal portion, and a central portion between the proximal portion and the distal portion, the central portion having a wall with an interior surface that defines a fluid chamber in the open mode and in the closed mode, the wall having a plurality of gland projections extending radially outwardly, at least one of the plurality of gland projections and the contact surface of the housing configured to maintain compressive contact to apply a radially inwardly compressive force on the resilient valve element when the valve is in the closed mode and thereby increase the stiffness of the wall to reduce waveform distortion as measured by the pressure transducer, the plurality of gland projections on the wall being spaced apart in a circular array around the central axis to form an interrupted ring, the interrupted ring forming interstices between gland projections, the housing wall having ribs, on an inner surface of the housing wall, that correspond to the interstices, at least one of the pluralities of gland projections being distal of the normally closed aperture. a housing having a housing wall, an inlet and an outlet, the housing having an interior contact surface at and/or between the inlet and/or the outlet; a resilient valve element within the housing interior configured to control fluid flow through the inlet, the resilient valve element having a body comprising: a proximal portion forming a normally closed aperture configured to open when actuated by a medical device, a distal portion, and a central portion between the proximal portion and the distal portion, the central portion having a wall with an interior surface that defines a fluid chamber in the open mode and in the closed mode, the wall having a plurality of gland projections extending radially outwardly, at least one of the plurality of gland projections and the contact surface of the housing configured to maintain compressive contact to apply a radially inwardly compressive force on the resilient valve element when the valve is in the closed mode and thereby increase the stiffness of the wall to reduce waveform distortion as measured by the pressure transducer, the plurality of gland projections on the wall being spaced apart in a circular array around the central axis to form an interrupted ring, the interrupted ring forming interstices between gland projections, the housing wall having ribs, on an inner surface of the housing wall, that correspond to the interstices, at least one of the pluralities of gland projections being distal of the normally closed aperture. a proximal portion forming a normally closed aperture configured to open when actuated by a medical device, a distal portion, and a central portion between the proximal portion and the distal portion, the central portion having a wall with an interior surface that defines a fluid chamber in the open mode and in the closed mode, the wall having a plurality of gland projections extending radially outwardly, at least one of the plurality of gland projections and the contact surface of the housing configured to maintain compressive contact to apply a radially inwardly compressive force on the resilient valve element when the valve is in the closed mode and thereby increase the stiffness of the wall to reduce waveform distortion as measured by the pressure transducer, the plurality of gland projections on the wall being spaced apart in a circular array around the central axis to form an interrupted ring, the interrupted ring forming interstices between gland projections, the housing wall having ribs, on an inner surface of the housing wall, that correspond to the interstices, at least one of the pluralities of gland projections being distal of the normally closed aperture.