Apparatus for controlling the flow of intravenous fluid to a patient

In combination for controlling the rate of flow of intravenous fluid to a patient,

• first means defining an inlet line,
• second means spaced from the first means and defining an outlet line,
• the first and second means being spaced by a cavity, and
• third means disposed in the cavity and defining a sealed passage of adjustable volume for the flow of fluid from the first means into the second means, the first means and the second means being disposed on the same side of the passage defined by the third means,
• the third means including resilient means disposed in the cavity for controlling the flow of fluid through the passage in accordance with the constraint of the resilient means and further including adjustable means disposed against the resilient means to control the flow of fluid through the passage,
• a button disposed in the passage to block the flow of fluid through the passage between the inlet and outlet lines, and
• at least one channel in the button to cooperate with the diaphragm in providing a controlled flow of fluid between the inlet and outlet lines.

In combination for controlling the rate of flow of intravenous fluid to a patient,

• a cassette,
• means defining a passage in the cassette for the flow of fluid,
• resilient means defining in the cassette a particular boundary of the passage for controlling the size of the passage in accordance with variations in force exerted against the resilient means,
• means disposed in the cassette and defining an inlet to the passage and an outlet from the passage,
• manually operable control means extending through the cassette from a position outside of the cassette into direct engagement with the resilient means for producing an adjustable force against the resilient means in a direction to limit the size of the passage in accordance with such manual operation,
• a housing constructed to support the cassette,
• means disposed on the housing and settable to any desired rate of fluid flow, and
• means disposed in the housing and operatively coupled to the control means and to the settable means and responsive to any setting of the settable means for overriding any manual positioning of the control means to position the control means in accordance with such setting.

In combination for controlling the flow of fluid from a source to a patient,

• a housing,
• an inlet line in the housing,
• an outlet line in the housing,
• a cavity in the housing in communication with the inlet and outlet lines,
• a resilient diaphragm disposed in the cavity to define a particular boundary of a passage extending between the inlet and outlet lines,
• means extending into the cavity from a position external to the housing and coupled to the diaphragm to constrain the diaphragm in accordance with the operation of the coupling means,
• a button disposed between the inlet and outlet lines and blocking the passage against the flow of fluid between the inlet line and the outlet line, and
• means operably associated with a particular one of the button, the diaphragm and the coupling means and cooperating with at least another one of the button, the diaphragm and the coupling means to define a channel for a controlled flow of fluid through the inlet line, the passage and the outlet line.

In combination for controlling the flow of fluid from a source to a patient,

• means providing settings of desired rates of fluid flow,
• means for providing for the flow of the fluid from the source to the patient,
• means for sensing the rate at which the fluid flows from the source to the patient,
• means responsive to the settings of the desired rate of fluid flow and to the sensings of the actual rate of flow fluid for producing error signals having characteristics representing any differences in the desired and actual rates,
• means including an adjustably positioned member for controlling the rate of flow of the fluid through the control means in accordance with the adjustable positioning of the member,
• means for removably receiving the control means, and
• means responsive to the error signal, with the control means disposed in the receiving means, for adjusting the positioning of the member to minimize the error signal.

In combination for controlling the flow of fluid from a source to a patient,

• means providing settings of desired rates of fluid flow,
• means for providing for the flow of the fluid from the source to the patient,
• means for sensing the rate at which the fluid flows from the source to the patient ,
• means responsive to the settings of the desired rate of fluid flow and to the sensings of the actual rate of fluid flow for producing error signals having characteristics representing any differences in the desired and actual rates,
• housing means,
• the flow means including a cassette removably disposed in the housing means for controlling the flow of fluid from the source,
• means including an adjustably positioned member included in the cassette for controlling the rate of flow of the fluid through the control means and the cassette in accordance with the adjustable positioning of the member, and
• means responsive to the error signal for adjusting the positioning of the adjustably positioned member in a direction to minimize the error signal.

In combination for controlling the rate of flow of fluid to a patient,

• means for providing for a source of fluid,
• means defining an inlet line from the source and an outlet line to the patient,
• means disposed between the inlet line and the outlet line for defining a passage communicating with the inlet and outlet lines,
• a button disposed in the passage in blocking relationship to the flow of fluid through the passage between the inlet and outlet lines,
• there being at least one channel in the external surface of the button,
• resilient means disposed in the passage at a position facing the button for controlling the size of the passage in accordance with the positioning of the resilient means in the passage relative to the button, and
• adjustably positioned means disposed in coupled relationship to the resilient means for constraining the resilient means to control the size of the passage in accordance with adjustments in the positioning of the adjustably positioned means.

In combination for controlling the flow of fluid from a source to a patient,

• a housing,
• an inlet line in the housing,
• an outlet line in the housing,
• a cavity in the housing in communication with the inlet and outlet lines,
• a resilient diaphragm disposed in the cavity to define a particular boundary of a passage extending between the inlet and outlet lines,
• means extending into the cavity from a position external to the housing and coupled to the diaphragm to constrain the diaphragm in accordance with the operation of the coupling means, and
• a plurality of means disposed in the passage and cooperative with the diaphragm for controlling the flow of fluid through the passage between the inlet and outlet lines in accordance with the constraint of the diaphragm,
• each of the means in the plurality being provided with parameters relative to the other means in the plurality to inhibit the flow of fluid through the passage with a different constraint of the diaphragm relative to the diaphragm constraint inhibiting the flow of fluid through the passage as a result of the operation of the other means in the plurality.