Intravenous infusion counter and alarm apparatus

• US 5,166,667 A
• Filed: 07/02/1991
• Issued: 11/24/1992
• Est. Priority Date: 11/29/1990
• Status: Expired due to Fees

• Current Assignee: Chung H. Jen
• Original Assignee: Chung H. Jen
• Inventors: Jen, Chung H.
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Hofsass, Jeffery A.
• Application Number:
  US07/724,839
• Time in Patent Office: 511 Days
• Field of Search: 340/606, 340/618, 340/619, 340/621, 128/DIG. 13, 604/64, 604/65, 604/253, 73/293
• US Class Current: 340/606
• CPC Class Codes: A61M 5/1689 Drip counters
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

An intravenous infusion counter/alarm for counting the flow of drips, displaying dynamic speed of dripping, and alarming during malfunction, with at least a main body, an adjusting member which can be received by the main body in order to connect to a drip infusion tube, and a control circuit for providing a light source, light sensing unit, and control signals to detect the flow of dripping, to display the dynamic dripping speed, and to actuate an alarm when the flow deviates from a set value.

Claims

1. An intravenous infusion counter/alarm comprising a mechanical part and an electrical part, said mechanical part comprising:

(a) a main body having

(i) a chamber;

(ii) a notch in one side of the main body to enable attachment onto a drip infusion tube;

(iii) an alarm reset switch on the top surface of said main body for shutting off the alarm by sending out a signal (K3);

(iv) a buzzer switch for allowing an operator to reset a buzzer if a malfunction occurs;

(v) a liquid crystal display (LCD) screen showing a flow rate, a caliber of a drip infusion tube, and a drip rate;

(vi) a power button for turning power on and off; and

(vii) a selecting switch for sending out a signal (K2) to set volume per drip according to the caliber of said drip infusion tube; and

(b) an adjusting means received in said main body, said adjusting means having;

(i) a battery chamber for receiving a battery;

(ii) a buzzer for alarming the operator if a malfunction occurs;

(iii) a protruding body extending therefrom into the chamber of said main body;

(iv) a notch disposed thereon which matches the notch in said main body;

(v) a spring which is in the head of the protruding body compressing against the inner wall of said chamber;

(vi) a light emitting diode (LED) and a phototransistor being disposed on opposing sides of said notch of said protruding body, such that when said LED is ON, said phototransistor is triggered by a light signal from said LED, and when said LED is OFF, said phototransistor is OFF; and

said electrical part comprising;

(a) a light beam source including an LED driver and said LED;

(b) said phototransistor for sensing the light beam during operation and generating a higher voltage pulse when the light beam reaches said phototransistor without blockage of a drip from the intravenous infusion tube and a lower voltage pulse when blocked;

(c) a peak detector coupled to receive said lower/higher pulse from said phototransistor and charged to a first voltage level during said higher pulse interval and then discharged to ground during a no-pulse interval, continuing to discharge to ground during said lower pulse interval and a following no-pulse interval;

said charging and discharging continuing alternately and generating a reference voltage between said lower pulse level and said higher pulse level;

(d) a battery test switch for testing if said battery is depleted;

(e) an amplifier for magnifying current from said phototransistor and sending out a signal K1 showing either the absence of infusion or an adequately charged battery;

(f) a power saving switch for saving power in the phototransistors by resetting the phototransistor to be OFF when the system is halted, and setting the phototransistor to be ON when the system is ON again;

(g) an input port for receiving sid K1 signal from said amplifier, said K2 signal from said select switch, or said K3 signal from said alarm reset switch;

(h) an output port for sending out a first signal (M1) to control said power saving switch, a second signal (M2) to control said battery test switch, or a third signal (M3) to control said phototransistor;

(i) a buzzer means for sending out an alarm beep, said buzzer means including a buzzer driver and a buzzer, such that said buzzer driver drives said buzzer to indicate to an operator that a malfunction occurs;

(j) a beep wave generator providing a signal (BD) to control said buzzer driver, such that a HIGH status of said signal (BD) will actuate said buzzer driver and, in turn, drive said buzzer to alarm, and when said signal (BD) is LOW, said buzzer driver is OFF and said buzzer does not alarm;

(k) an LCD display latch and driver for controlling said LCD screen;

(l) a program read-only memory (ROM) for storing a software program which runs a central processing unit (CPU) to process said signals (K1, K2, K3, M1, M2, M3, and BD).

2. The intravenous infusion counter/alarm as claimed in claim 1, wherein said peak detector includes a switch transistor connected in series with a parallel combination of a resistor and two capacitors, such that when said phototransistor outputs a higher pulse, said switch transistor will be ON and cause said capacitors to be charged to a voltage lower than said higher pulse;

when said higher pulse passes, said switch transistor will be OFF and cause said capacitors to discharge through said resistor to ground; and

when said phototransistor outputs a lower pulse, said switch transistor will be OFF and cause said capacitor to continue to discharge through said resistor to ground; and

when said lower pulse passes, said capacitors continue to discharge.