Abstract: A frequency selective transient voltage protector (FSTVP) circuit that may be used in connection with a communication line over which POTS and DSL service may be simultaneously provided. The FSTVP circuit attenuates high frequency transient voltages that exceed a predetermined voltage level, while permitting low frequency, generally high voltage signals (e.g., ring signals) and high frequency, low voltage signals (e.g., DSL signals) to pass with little or no attenuation. The FSTVP circuit comprises a frequency selective network (that comprises a frequency discriminator and a voltage discriminator) connected to an overvoltage protection device that shunts any high frequency transient voltages thus protecting devices connected downstream along the communications line from damage. The frequency selective network is tuned to gate the overvoltage protection device when the frequency and voltage of a signal present on the communication line exceed predetermined values.

Abstract: A frequency selective transient voltage protector (FSTVP) circuit that may be used in connection with a communication line over which POTS and DSL service may be simultaneously provided. The FSTVP circuit attenuates high frequency transient voltages that exceed a predetermined voltage level, while permitting low frequency, generally high voltage signals (e.g., ring signals) and high frequency, low voltage signals (e.g., DSL signals) to pass with little or no attenuation. The FSTVP circuit comprises a frequency selective network (that comprises a frequency discriminator and a voltage discriminator) connected to an overvoltage protection device that shunts any high frequency transient voltages thus protecting devices connected downstream along the communications line from damage. The frequency selective network is tuned to gate the overvoltage protection device when the frequency and voltage of a signal present on the communication line exceed predetermined values.

Abstract: A frequency selective transient voltage protector (FSTVP) circuit that may be used in connection with a communication line over which POTS and DSL service may be simultaneously provided. The FSTVP circuit attenuates high frequency transient voltages that exceed a predetermined voltage level, while permitting low frequency, generally high voltage signals (e.g., ring signals) and high frequency, low voltage signals (e.g., DSL signals) to pass with little or no attenuation. The FSTVP circuit comprises a frequency selective network (that comprises a frequency discriminator and a voltage discriminator) connected to an over-voltage protection device that shunts any high frequency transient voltages thus protecting devices connected downstream along the communications line from damage. The frequency selective network is tuned to gate the overvoltage protection device when the frequency and voltage of a signal present on the communication line exceed predetermined values.

Abstract: A system for infusing fluids into the human body includes a peristaltic-type metering apparatus which controls the flow of fluid through a disposable administration set. The metering apparatus includes a control system which allows the volume and rate of flow of the fluid to be infused to be accurately preset by the operator. The control system provides an alarm function in the event of malfunction of the pump or occlusion of the tubing of the administration set, and a minimum pumping rate for maintaining fluid flow through the system after the desired volume of fluid has been infused.

Abstract: Valving configurations between the valve seat in a cassette and the valve members in a controller used to limit the flow rate of an intravenous solution to a patient. The configurations minimize the criticality of the alignment between the components. The cassette forms part of the flow path of the solution on its way to the recipient. The controller's valve member may stretch a membrane in the cassette and cause it to contact a flat surface surrounding the opening through which the fluid must flow. Alternately, the end of the valve member may be appreciably smaller than the opening, pass through it, and stretch the membrane until the latter contacts all of the opening's edge. The membrane meeting the edge of the opening in a closed loop prevents the flow of fluid through it. As a further possibility, the valve member may place the membrane in contact with one or more edges provided between two segments of a straight channel through which the solution flows.

Abstract: A crystal-controlled low-frequency power-conserving circuit for use in a controller operating with a casette to limit the rate of flow of an intravenous solution to a patient. The circuit uses a crystal oscillator operating below the stray frequencies often present in a hospital environment. The CMOS components in the circuit respond to the low frequencies of the oscillator, display no sensitivity to the higher stray frequencies, and consume a minimum of energy. Binary rate dividers reduce the frequency obtained from the oscillator by a positive integral power of two. Cascaded variable binary rate multipliers selectively permit the absorbtion of a least half of the pulses received from the rate divider. The inverted pulses of the binary rate multipliers pass to the S input of a D-type flip-flop. The pulses from the binary divider pass to the C input of the same flip-flop.