Abstract: A syringe pump operated by a stepping motor to repetitively fill and empty a syringe cartridge over a plurality of operational cycles of successive fill stroke and pump stroke periods. The motor is driven by drive pulses from a digital pulse generation and control system, the pulse frequency establishing a predetermined fixed rate of fill during the fill stroke and being preselected, in accordance with desired output flow rate, to establish the rate at which the syringe is emptied during the pump stroke. The drive pulse rate during a fill stroke exceeds the maximum pulse rate during a pump stroke and, in order to maintain a proportional relationship between the preselected pumping rate and the actual pumping rate over each complete cycle of successive fill and pump strokes, the drive pulse frequency during each pump stroke is automatically increased to compensate for the time lost during each fill stroke.

Abstract: Apparatus for fluid flow control in a parenteral administration system, utilizing a syringe pump operated by a motor to repetitively fill and empty a disposable syringe cartridge over a plurality of operational cycles of successive fill and pump stroke periods. The syringe cartridge has no valves, and the apparatus repetitively and sequentially opens and closes, by means of an external pair of tube pinchers, a pair of intake and output I.V. tubes communicating with the inlet and outlet nipples of the syringe cartridge.

Abstract: A motor driven syringe pump utilizing a disposable syringe cartridge. The syringe cartridge has no valves, and the apparatus repetitively and sequentially opens and closes, by means of an external pair of tube pinchers, a pair of intake and output I.V. tubes communicating with the inlet and outlet nipples. The cartridge includes a molded plastic cylinder having inlet and outlet nipples, a plastic piston and piston rod, and a rubber sealing cap defining a conical piston face, a pair of piston sealing rings and a sealing boot. The pair of sealing rings enhance axial alignment and stability, while the sealing boot prevents air or bacterial intake through the bottom of the cylinder during repetitive strokes. The plastic cross-sections are selected to provide maximum strength for minimum material employed. The interior cylinder chamber is sloped to drive out gas through the outlet nipple. An integral tab on the cylinder provides an operator handle for mounting and removing the syringe.

Abstract: A digital system wherein a wide variety of different electromechanical output control devices, e.g., stepping motor pump or solenoid actuated I.V. tube pincher, is driven by electrical output pulses of varible frequency and pulse width from a digital pulse generation and control system, the frequency and pulse width of the output pulses being selected and controlled by the system to establish drop flow rates with digital precision over an extremely wide dynamic range. Pulse width is determined by the relative states of a pair of digital counters in a digital memory, frequency being determined by a high, preferably non-integral, multiple of the desired drop flow rate. The equivalent of negative pulse width in the digital memory can be effectively utilized to expand the effective dynamic range of the memory for specified types of electromechanical output devices. A start up subsystem temporarily presets the initial pulse rate and speeds up early regulation.

Abstract: Apparatus for fluid flow control in a parenteral administration system, utilizing a syringe pump operated by a motor to repetitively fill and empty a syringe cartridge over a plurality of operational cycles of successive fill stroke and pump stroke periods. The apparatus repetitively and sequentially opens and closes a pair of intake and output I.V. tubes communicating with a syringe, the tubes alternating opened and closed states, one tube always being open while the other is closed, by means of a pair of L-shaped pivotal tube pinchers, one pincher controlling each I.V. tube, each pincher being normally spring biased to the tube clamping shut-off state. The tube pinchers are alternately pivoted to a non-clamping, tube-open position by a spring biased, intermittent motion, reciprocating slide bar under the control of a reversible, rotating cam, the cam being driven by the same motor as that used to drive the piston of the syringe through its fill and pump strokes.

Abstract: A parenteral administration system, utilizing a syringe pump operated by a motor to repetitively fill and empty a disposable syringe cartridge over a plurality of operational cycles of successive fill and pump stroke periods. The syringe cartridge has no valves, and the apparatus repetitively and sequentially opens and closes, by means of an external pair of tube pinchers, a pair of intake and output I.V. tubes communicating with the inlet and outlet nipples. The disposable syringe cartridge includes a molded plastic cylinder having inlet and outlet nipples, a plastic piston and piston rod, and a rubber sealing cap defining a conical piston face, a pair of piston sealing rings and a sealing boot. The pair of sealing rings enhance axial alignment and stability, while the sealing boot prevents air or bacterial intake through the bottom of the cylinder during repetitive strokes. The plastic cross-sections are selected to provide maximum strength for minimum material employed.

Abstract: An electronic method and apparatus for measuring temperatures by means of a thermistor in one arm of an electrical bridge, bridge output being varied by the on and off duty cycle of a shunting impedance selectively switched into and out of the balancing arm of the bridge in accordance with the relative states of a counting display register and a cyclically scanned counting register, the display register state being altered by gated pulses, under the control of bridge output, to provide a digital indication of measured temperature. Bridges of both the nulling and non-nulling types are disclosed using either a dual ramp integrator or conventional detector acting upon bridge output to provide an impedance measurement subsystem independent of reference supply voltage and also enabling non-linear analog to digital conversion to compensate for a non-linear thermistor temperature vs. thermistor resistance characteristics, without sacrificing measurement sensitivity.