DESC:TECHNICAL FIELD

[001] The present subject matter described herein, in general, relates toa fluid level detectors and more particularly to afluid level detector to indicate when the container is empty of fluid. The present invention is useful in thehealth carefield in case of an intravenous therapy for detecting the completion of fluid infusion by monitoring the fluid level of a drip chamber.

BACKGROUND

[002] In a medical care field, Intravenous therapy (IV) is used to correct electrolyte imbalances, to deliver medications, for blood transfusion or as fluid replacement to correct. Intravenous therapy is used widely as the intravenous route is the fastest way to deliver fluids and medications throughout the body. 90-95% of patients in the hospital receive some type of intravenous therapy.

[003] When intravenous therapy is given to the patient, nurses usually start the intravenous therapy and goes to attend other patients in the hospital and/or nursing home. In between nurses have to visit the patient monitor the IV fluid level. In most of the cased a patient is given fluids intravenously and the liquid to be injected is often stored in bags hung above the patient. The substance gravity feeds from the bag through plastic tubing to the needle. The flow of IV fluid is usually adjusted by clips that can be connected to the tube that runs to the needle end.

[004] Air embolism is one complication that can occur during an intravenous injection. This happens when a large quantity of air enters the blood stream. However IV bags are not rigid - they collapse as they empty. A properly primed line connected to a patient is a closed system - there is no air that can get into the line as the bag empties. If we look at the tube, we will see that a small amount of fluid remains in the tubing, thus, no air gets into the patient. Also the back pressure of blood in a patient's vein will reach an equal pressure with the air and blood usually backs up into the IV tubing.

[005] The purpose of the drip chamber is to prevent air from getting in the IV intravenous tubing. If the IV bag accidentally goes empty and air does start to proceed down into the tubing and after a certain point at which the pressure of the IV fluid equalizes with the pressure exerted by the blood pressure in the vein such that the IV devices is in the chance of air actually entering a peripheral vein through an iv cannula is very unlikely. At this point of pressure equalization, blood starts backing up into the tubing because it is exerting a greater pressure on the IV line than the IV fluid and eventually it will no more push fluid in the vein. Further flowing of fluid from IV stops and if left unnoticed, the blood in the IV line and IV cannula coagulate. Also, if the IV is in a central line, there is a problem if a bag runs dry then more than a couple of cc's of air run into the vein. Any IV on a central line should be on an IV pump to begin with. An IV pump has an air detector in it, so that air never gets into the patient's central circulation because of the negative pressure pull due to the termination of the central line in the vena cava of the heart, air and fluid will be sucked into a central line that is accidentally left open to the atmosphere. This is why changing IV tubing on a central line needs to be done with care and the patient has to breath and hold it for a couple of seconds or perform a valsalva maneuver while you do the actual change over. The danger of air being sucked into a central line is air embolism. It takes well over a couple of cc's of air pulled into the central circulation for an air embolism to occur.

[006] The prior art document, CA1329896 C discloses an empty container detector to detect air in a fluid line between a medication infusion reservoir such as an IV bottle or bag and an IV injection set or a medication infusion pump utilizing a detector apparatus which clamps onto a segment of tubing.

[007] The prior art document, EP0239253 A2 discloses an empty container with drop sensor detector which includes a photoelectric transducer associated with a transparent fluid container below the fluid level in the container to generate a variable control signal. As envisioned by the present invention, the control signal is variable between a first state wherein fluid is detected and a second state wherein an absence of fluid is indicated.

[008] The prior art document, US 4277226 A discloses IV Pump with empty supply reservoir and occlusion detector which includes a detector which provides an alarm when the supply bag or reservoir becomes empty or an occlusion occurs between the supply bag and the pump.

[009] The prior art document, US 4884065 A discloses a device for use to detect air in a fluid line between a medication infusion reservoir such as an IV bottle or bag and an IV injection set or a medication infusion pump is disclosed which utilizes a detector apparatus which clamps onto a segment of tubing.

[0010] The prior art document, US 5139482 A an apparatus for signalling an accidental loss of blood from a patient's fluid infusion line.

[0011] The prior art document, US 5102392 A discloses an air detector that utilizes a unitary type sensor for detecting air bubbles or columns in an infusion solution flowing through a tube.

[0012] Thus, in view the hitherto attempts to proposean empty container detector devices so to prevent air to enter the IV line between the fluid source and the patient, there is a continuing need for a low cost, yet effective empty container detector system which is simple to use and thereby reduces efforts to continuously monitor a patient undergoing IV fluid therapy.

SUMMARY OF THE INVENTION

[0013] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

[0014] An object of the present invention is to provide a low cost infusion therapy device to deliver efficient medication in case of blood/fluid transfusion.

[0015] Another object of the present invention is to provide a portable device to be associated with the fluid source of various medical devices regardless of the particular type or construction of the medical device.

[0016] Accordingly, the present invention provides a mechanism to determine the level of fluid source and a subsequently indication to a user of depletion of fluid so that intravenous therapy (IV) is stopped before air is brought into the operating system of the medical device and into the IV infusion tube.

[0017] In one implementation, the present invention provides a system for detection of fluid level and indication,the system comprises a liquid sensor for detecting liquid present in tubes, a transmitter module, for transmitting signals corresponding to fluid levels in a tube, and a receiver module, for receiving the signals transmitted using said transmitter, indicator to indicate a user of fluid empty event.

[0018] In one implementation, the present invention provides a method for detection of fluid container emptiness and a subsequent indication, the method comprises, detection, using a liquid sensor, liquid present in a tube and transmitting a signal; processing, using a transmitter module, said signal processed and transmitting a signal;receiving, using a receiver module, said signal processed and indicating a useran event of no liquid state.

[0019] In one implementation, an IV emptiness indicator system is disclosed. The IV emptiness indicator system comprises at least one transmitter device communicably coupled with at least one flow sensor and configured to transmit at least one output signal, wherein said flow sensor is coupled to at least one IV tube; andat least one receiver device configured to receive the output signal and thereby by generating at least one indicia for at least one user.

[0020] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:

[0021] Figure 1 illustratesa Transmitter module and a receiver module used in the present invention, in accordance with an embodiment of the present subject matter.

[0022] Figure 2 illustrates a perspective view of a present invention, in accordance with an embodiment of the present subject matter.

[0023] Figure 3 illustrates an OPB350 series liquid sensors, in accordance with an embodiment of the present subject matter.

[0024] Figure 4 illustrates a detection of the change in transmissivitydetected to trip a transistor switch output, in accordance with an embodiment of the present subject matter.

[0025] Figure 5 illustrates the physical look of the device OPB350.

[0026] Figure 6 illustrates the electrical construction of the device OPB350.

[0027] Figure 7 illustrates the pin details of the device OPB350.

[0028] Figure 8 illustrates the typical application circuit.

[0029] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0030] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

[0031] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0032] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

[0033] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0034] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0035] Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

[0036] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0037] Referring now to figure 1, in one implementation, the transmitter module may be a radio frequency transmitter and the receiver module may be a radio frequency receiver. The transmitter module comprises a flow sensors or tube liquid sensors for detecting the liquid present in the tube.The sensors may identify if liquid is present in clear tubes that have an outside diameter of 1/16” [1.6mm], 1/8" [3.2mm], 3/16" [4.8 mm] or 1/4" [6.3 mm]. The current variation may beavailable at the output of the sensors. The output signal may be fed to the monitoring device or a transmitter module mounted on the IV stand which may process the signal for IV tube emptiness through radio frequency transmitter. Radio frequency receiver on device mounted on receiver module may process the signal and may indicate the user by alarm beep.

[0038] In one implementation, processing the output signals means, the state of liquid indication will be passed by the transmitter device to receiver device over wireless media. This output signal is nothing but indication of liquid presence in the IV tube. When receiver device receives this data, the microcontroller on the receiver device will process this data value to provide indication to the user who is wearing receiver device on his hand by means of LED indication or Buzzer output.

[0039] Referring now to figure 2, in one implementation, the liquid sensor for detecting a liquid in a tube may be positioned on an IV tube. The transmitter module may be positioned on an IV tube stand. The receiver module may be placed in positioned on a wrist of a user.

[0040] Referring now to figure 3, in one implementation, the OPB350 series liquid sensor may be designed to work with 1.6mm, 3.2mm, 4.8 mm and 6.3 mm outside diameter clear tubes. When output reference circuitry is added, multiple output states such as “fluid present,” “no fluid present” and “no tube present” may be recognized. Figure 2 shows OPB350 series liquid sensors.Clear liquid present causes the phototransistor to sink the maximum current, while dark liquid present causes it to sink the minimum current. As bubbles pass through the tube, the signal will vary between the “liquid present” and “no liquid” states. If no tube is present, the phototransistor sinks current between the dark fluid and clear Fluid states. Identification of the typical current values for each situation will be required. The ratio between the different states allows acknowledgement of different conditions.

[0041] It is well known that, the TT Electronics OPB350 is a slot-type photo sensor with a 1/8-in. sensing gap. A built-in 50-mA emitter aims at the 30-V 50-mA-capable photo transistor to create a photo-interrupter-style detector.

[0042] In one implementation, the TT Electronics OPB350 may work as follows:
By searching for contrast variations, the optical sensor can detect the presence of the meniscus as it passes by the optical receiver as shown in figure 4. These transitions are “latching” so to say as the level fills or drains because there is a different transmissivity between an empty and a filled tube.

[0043] For example, if the tube is empty, the light passes through rather easily and trips the photo transistor in the receiver section. This causes the output to go to a logic 0 level (in a typical NPN open-collector output), and provides a sink path for the current.

[0044] When the liquid fills the tube, the transmissivity is reduced and the photo transistor no longer gets enough light to switch. In this case, it floats and is pulled up externally by a pull-up resistor to present a logic 1 to the control circuitry.

[0045] Figure 5 illustrates the physical look of the device OPB350.

[0046] Figure 6 illustrates the electrical construction of the device OPB350.

[0047] Figure 7 illustrates the pin details of the device OPB350.

[0048] Figure 8 illustrates the typical application circuit.

[0049] In one implementation, a basic comparator circuit may be used for converting analog signals to a digital output. The output is HIGH when the voltage on the non-inverting (+IN) input is greater than the inverting (-IN) input. The output is LOW when thevoltage on the non-inverting (+IN) input is less than the inverting (-IN) input. The inverting input (-IN) is also commonly referred to as the "Threshold" or "Vth" input. From calculation threshold or reference voltage (Vth) will be 4.1V. This voltage will be given to inverting (-IN) input of LM339.

[0050] When the IV tube is filled with IV liquid, the transmissivity is reduced and the photo transistor no longer gets enough light to switch. Due to which, photo transistor does not conduct and therefore voltage on the non-inverting (+IN) input becomes zero. Therefore, output of the comparator will be LOW (Logic 0). This state can be considered as “liquid present”state.

[0051] When the IV tube becomes empty, the light passes through rather easily and trips the photo transistor in the receiver section. Due to which, photo transistor conducts and therefore voltage on the non-inverting (+IN) input becomes 4.3V (Vcc – Forward bias voltage of transistor = 5 - 0.7 = 4.3V). Therefore, output of the comparator will be HIGH (Logic 1). This state can be considered as “no liquid”state.

[0052] Some of the important features of the present invention, considered to be noteworthy are mentioned below:
1. Low cost device
2. Easy to use.
3. Easy to install
,CLAIMS:1. An IV emptiness indicator system comprising:
at least one transmitter device communicably coupled with at least one flow sensor and configured to transmit at least one output signal, wherein said flow sensor is coupled to at least one IV tube;
at least one receiver device configured to receive the output signal and thereby by generating at least one indicia for at least one user.

2. The IV emptiness indicator system as claimed in claim 1, wherein the receiver device is remotely located and communicably coupled to the transmitter device.

3. The IV emptiness indicator system as claimed in claim 1, wherein the transmitter device is mounted on a IV tube stand and the receiver device is a wearable device for an attending person.

4. The IV emptiness indicator system as claimed in claim 1, wherein the flow sensor is configured to detect a liquid present in the tube.

5. The IV emptiness indicator system as claimed in claim 1, wherein the flow sensor is configured to output a current variation as the output signal.

6. The IV emptiness indicator system as claimed in claim 5, wherein the output signal is fed to the transmitter device to process the output signal for IV tube emptiness.

7. The IV emptiness indicator system as claimed in claim 1, wherein the flow sensor is preferably an OPB350series liquid sensor.

8. The IV emptiness indicator system as claimed in claim 1, wherein the flow sensor is preferably an OPB350series liquid sensor, configured to work with 1.6 mm, 3.2 mm, 4.8 mm and 6.3 mm outside diameter tubes.

9. The IV emptiness indicator system as claimed in claim 1, wherein the transmitted comprises an output reference circuitry configured to generate the indicia indicating “fluid present,” “no fluid present” and “no tube present” and thereby transmitting the indicia to the receiver module for displaying the indicia.

10. The IV emptiness indicator system as claimed in claim 1, wherein:
if a liquid is not present in the tube, causes a phototransistor signal of the flow sensor to sink the maximum current; and/or
if a liquid is present in the tube, causes a phototransistor signal of the flow sensor to sink the maximum current.

11. The IV emptiness indicator system as claimed in claim 10, wherein if a bubble passes through the tube, the phototransistor signal will vary between the “present” and “not present” states.

12. The IV emptiness indicator system as claimed in any of the preceding claims, wherein a ratio between the “present” and “not present” states allows acknowledgement of different conditions.
13. The IV emptiness indicator system as claimed in claim 1, wherein the indicia is at least one of a blinking of at least one LED, audio indicator, video indicator, vibration, or any combination thereof.