Abstract: An infusion apparatus incorporates a RAM which has a first storage section for storing only one delivery pattern defining an infusion rate and a volume to be infused at the infusion rate, and a PDP storage section for storing a plurality of delivery patterns. In a one-pattern delivery mode, an infusion fluid is delivered according to the only one delivery pattern read out from the first storage section by a CPU. Therefore, infusion is performed at the same rate from the beginning to the end. In a PDP (Program Delivery Profile) mode, an infusion fluid is delivered according to the plurality of delivery patterns read out in sequence from the PDP storage section. Therefore, infusion is performed at various rates. One of the one-pattern delivery mode and the PDP mode is selected by an operator through operation of a mode selector in consideration of factors such as the kind of medication and the condition of the patient.

Abstract: A peristaltic pumping apparatus has a misloaded-tube detector. The detector is constituted of a pair of pressure sensors and a CPU. The pressure sensors are located on both sides of a fluid propelling portion onto which an IV tube containing a solution is loaded. The detector detects a tube misloading by making use of pressure which is applied to one pressure sensor when the tube is displaced onto the pressure sensor and is forced against it by the closing of a door. Each sensor consists of first and second electrodes spaced from each other, a pressure-resistive conductive element attached to the first electrode and spaced from the second electrode and capable of connecting thereto, and a resistor connected to the first and second electrodes. The CPU judges from a resistance value of the pressure sensor as to whether the tube is properly loaded or misloaded or whether the pressure sensor is in an operative state.

Abstract: An infusion apparatus is provided with a clock, a power-on-time counter for counting a period of time in which power is supplied to the infusion apparatus from an AC power source or a backup battery for backing up the AC power source, a pump-on-time counter for counting a period of time in which a pump mechanism operates, and a battery-on-time counter for counting a period of time in which power is supplied to the infusion apparatus from the backup battery. A CPU displays a time value counted by the counters on a display unit. The time value displayed on the display unit indicates the degree of deterioration of charge capability of the backup battery, from which a time for replacing the backup battery and the other parts can be easily perceived.

Abstract: A rotary encoder comprises a rotary plate having a plurality of primary slits defined in the rotary plate in a circular row coaxial with the axis of rotation of the rotary plate. The rotary plate also has at least one reference slit defined therein at a position radially of the circular row of the primary slits. A primary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the circular row of the primary slits intervening therebetween is used to detect the passage of the primary slits therethrough while an auxiliary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the path of travel of the reference slit intervening therebetween is used to detect the passage of the reference slit therethrough.

Abstract: The present invention provides a drive signal for a peristaltic pump motor. A first circuit is provided which generates a first series of pulses at a given frequency. A second circuit is provided which generates a second series of pulses having a frequency higher than the frequency of the first series of pulses. A third circuit is provided which generates a third series of pulses having a frequency between the frequency of the first and second series of pulses. Finally, a circuit is provided which combines the three series of pulses into a drive signal. The drive signal length is determined by the frequency of the first series of pulses. The drive signal further is divided into two sections, an initial pulse stage determined by the frequency of the third series of pulses, and a modulated pulse stage being a series of pulses determined by the frequency of the second series of pulses.

Abstract: A stepping motor driving apparatus includes a stepping motor and a pulse output circuit for outputting drive pulses for driving the stepping motor. A pulse generator generates further pulses which not only have frequency higher than that of the drive pulses but are capable of a variable duty factor at the frequency of the further pulses. A gate circuit receives the drive pulses from the pulse output circuit and the further pulses from the pulse generator so as to output the further pulses of the pulse generator during excitation of the drive pulses such that the stepping motor is driven by the further pulses outputted from the gate circuit.

Abstract: The present invention provides an intravenous administration set 10 having a primary container 22 and a secondary container 24, each containing fluid, and a pump 20. The primary container 22 and secondary container 24 are joined into a single flow path by a Y-site 50. A check valve 42 is provided between the primary container 22 and the Y-site 50. A fluid capacitor 60 is provided on the single flow path between the Y-site 50 and the pump 20 to repenish displaced fluid in the pump 20.

Abstract: An encoder wheel (60) is provided for monitoring a peristaltic pump (20). The encoder wheel (60) provides a plurality of equispaced sectors (62) and a reference sector (66) provided at the outer radius of the encoder wheel (60). A vane slit (68) is provide radially offset from the sectors (62,66). A pair of optical couplers (72,74) are provided to read the sectors (62,66) and the vane slit (68).