Method for calculation the volume instilled through device for intravenous injection with dropper

The invention relates to fluid infusion in a patient's bloodstream, and more particularly, refers to a system and method for measuring the volume of fluids used in any standard apparatus for self-administered intravenous infusion.

Intravenous infusion of fluids into the patient's bloodstream is a well-known medical procedure. Liquids that are commonly used for intravenous infusion include glucose and saline solutions, medicines and blood. In general, systems for intravenous infusion consist of a reservoir, a dropper, a feeding tube and needles for intravenous infusion. In a reservoir, also called a bulb for intravenous infusion, contains the amount of fluid to be infused. With a cavity tube, the reservoir is connected to the dropper. In turn, the dropper of the feeding tube is connected to the hollow needle inserted into the patient's vein. The fluid from the reservoir through the droplet of confusion is in the bloodstream, and the rate of leakage of drops is controlled by a dropper.

Previously, to regulate the rate of intravenous fluid administration, two basic approaches were used. The first approach is to use a conventional dropper, in which the droplet flow rate through the dropper is adjusted manually, until drops fall at a given speed. This approach has the advantage of simplicity, since to maintain fluid flow through the droplet only gravity forces are required.

However, in many cases, manually-regulated droplets do not satisfy, as such dropletscan allow errors in the rate of leakage, with an increase or decrease in the prescribed speed. The reason for these errors is that the size of individual droplets that pass through the dropper, canchange from the device to the device, from the leakage velocity with which the liquid passes through the dropper, the liquid press and the vibrational effects on the dropper. In addition, despite the fact that the dripper is made carefully and with strict tolerances, the volume of the drop can vary from one dropper to another and, of course, from a device of the same type to a device of another type. This means that the leakage rate of the droplet, which is suitable for the selected fluid flow in the first drop, is not necessarily suitable for the second droplet. Besides,

In an attempt to achieve greater accuracy at infusion rates, piston infusion pumps are widely used. The advantage of such pumps is the precise regulation of infusion rates, largely irrespective of the pressure or viscosity of the liquid to be infused. However, these infusion pumps have their own disadvantages. Since they typically work with pressures up to 60 pounds per square. inch (4.2186 kg / cm²), there is always a risk of infusion due to excessive pressure. In addition, infusion pumps are relatively expensive, as well as heavy and bulky. In large measure, the weight of infusion pumps is related to the size of emergency batteries, which are necessary for feedingpump in the absence of electricity. Since the pumps are constantly driven by electric motors, the emergency batteries for infusion pumps should have a large capacity.

The most important element of regulation, above all, is the accurate measurement of the volume of liquid intended for injection.

[US Pat. No. 4,525,163, inventors of Slavik et al.] Proposes a device for controlling the flow, which includes a sensor for measuring the size of droplets. Dimensions of drops are measured bycalculating the mean values ​​after a certain amount of optically registered droplets has fallen into a burette. This can not be considered as a volume measurement, and an additional disadvantage is that the intended use for the fluid must pass through a device that is invasive.

[US Patent No. 4,504,263, inventors of Stoieer et al.] Describes an invasive flood control device in which fluid flow passes through this device. The disadvantage of invasive devices is that between use they need to be sterilized, which creates the responsibility of the hospital and, as a consequence, inconvenience for it, due to the need to have many devices with additional elements that require sterilization. In the device described by Stoieer, individual drops are measured using an infrared sensor. In addition to invasion, the disadvantage of Stoever's invention is that the author considers spherical drops, and this is not always true.

Known solutions that provide non-invasive droplet counters, for example, are described in [US Patent No. 6,083,206 by the inventor Molko]. Molko offers a device that can with great accuracy cansize droplets by registering infrared radiation that has passed through a dropper, but only makes measurements of the volume of each drop, and therefore need to rely on the size of the drop, set for a specific apparatus.

The need for accurate measurement of volume becomes critical in the case of infants who receive even less than two milliliters of liquid, designed for drop intravenous infusion, per hour.

Since infusion pumps and devices for self-administering intravenous infusion have the abovementioned advantages, it would be very beneficial to have a simple apparatus for self-administering intravenous infusion, free from the above restrictions.

BRIEF CONTENT OF INVENTORY

According to one aspect of the present invention, there is provided a device for volumetric measurements of a liquid used in a device for self-infusion, which includes a dropper. The device contains a casing, which is provided with a form that allows it to be seperated to place it around a cylindrical surface of the dropper. The casing contains a source of radiation, which is provided with a configuration that provides radiation through the drip along the trajectory, which is actually perpendicular to the axis of the cylindrical surface; and an optical receiver that is located near the part of the cylindrical surface, which is essentially in front of the source of radiation. Optical receiver adapted for quantitative determination of radiation; and the processor performs operations of calculating the volume of each drop passing through the dropper,

According to another aspect of the present invention, there is provided a method of calculating the volume administered by a device for intravenous infusion with a dropper, provided a form in which the fluid flow passes substantially along the axis of the droplet. The method consists of the steps of passing the radiation from the outer portion of the dropper through this dropper along a path substantially perpendicular to its axis to a probe located on the opposite side of the outside of the dropper; registration and quantification of the background radiation level passing through the dropper; registration and quantification of the magnitude of radiation that passes through the drop that falls through the dropper, in order to obtain data that show radiation losses due to the passing of the drop through the trajectory radiation; and calculating the volume of the drop,

According to another aspect of the present invention, there is provided a method for calculating the volume administered by a device for intravenous infusion with a dropper, provided a form in which the fluid flow passes substantially along the axis of the droplet. The method consists of the steps of passing the radiation from the outer portion of the dropper through this droplet along a path substantially perpendicular to its axis to a probe disposed of from the opposite current to the outside of the dropper; registration and quantification of the background radiation level passing through the dropper; registration and quantification of the magnitude of radiation that passes through the drop that falls through the dropper, in order to obtain data that show radiation losses due to the passing of the drop through the trajectory radiation; and conducting a measurement of '

According to the following features of the preferred embodiments of the invention and which are described below, the radiation is adapted to operate in pulsed mode.

According to the following features of the described embodiments of the invention, which is preferred, the radiation is adapted to operate in continuous mode.

In accordance with further features of the following embodiments, which is preferred, radiation is a radiation of light.

In accordance with still further features of the described embodiments of the invention, which is preferred, radiation is an infrared radiation.

In accordance with the further features of the described embodiments of the present invention, the calculated volume is used to control the flow of fluid used in the apparatus for self-infusion.

According to still further features of the described embodiments of the invention, which is given advantage, relative radiation losses are converted into volume using a compliance table. A compliance table is created by the accumulation of empirical data for droplets that pass through various infusion sets, with the determination of relative radiation losses during passage drops through radiation and then weighing drops and determining the volume of each drop in accordance with their specific gravity. The device and method are suitable for use with any device for intravenous transport and non-invasive.

The present invention successfully overcomes the disadvantages of currently known solutions and, for this purpose, offers a device and a method for measuring the volume of a drop that can be used to determine the volume of fluid used in the apparatus for self-infusion.

BRIEF DESCRIPTION OF ILLUSTRATIONS

In the present inventory, the invention is provided, only as an example, with reference to the attached illustrations. Further, the specific references to the details of the illustrations emphasize that the featured features shown are an example and serve only to explain the preferred embodiments of the present invention, and are presented to provide, as it seems, the most useful and easily understandable description of the principles and conceptual aspects of the invention. In this regard, no attempt has been made to show the structural details of the invention more detail than is necessary for a fundamental understanding of the invention. For specialists in this area, a description in conjunction with illustrations undoubtedly shows how in practice several embodiments of the invention can be implemented.

In the illustrations:

1 is a device for volumetric measurements of a liquid used in a device for self-propelled transport;

2 is an illustration of radiation pulses before and after passing through the dropper, before and during the passage of the drop through the chamber of the dropper; and

FIG. C - diagram of the sequence of operations in the method of calculating the volume of the drop.

DESCRIPTION OF THE FUNCTIONING OF AN OPPORTUNITY THAT ARE PROVIDED

The present invention relates to a method for measuring the volume of a drop that can be used to determine the volume of fluid used in the apparatus for self-infusion. Specifically, the present invention may be used to determine the volume of each drop in the apparatus for self-infusion, which facilitates the most accurate finding of the total volume of liquid intended for injection, and this can be used to regulate the flow of this fluid.

The principle of constructing and operating the device and the principle and operation of the method for measuring the volume of the drop according to the present invention can be better understood with reference to the illustration and their descriptions.

Before a detailed explanation of at least one embodiment of the invention, it should be understood that in the application of the invention, the invention is not limited to the design details and arrangement of the components that are shown in the following description or are shown in the illustrations. The invention includes other embodiments or may be implemented in practice or executed in various ways. It should also be understood that the terms used in the description of phraseology and terminology should not be regarded as restrictive.

Thus, FIG. 1 shows a device 10 for volumetric fluid measurements used in the drip device for self-administering fluids. Some of the details are shown without compliance

proportions in order to better understand the parts of the invention to which they relate and how they are combined with the device for self-infusion. Apparatus 12 for self-administered infusion typically contains a reservoir 16, a dropper 14, a feeding tube 18, and an intravenous infusion needle 20.

The device 10 comprises a casing 22 provided with a mold which allows the placement of its circular cylindrical surface 24 in a droplet 14. The casing 22 is mounted over the dropper 14 and is attached to any of the plurality of places, including the inlet in the dropper 14, or alternatively to the upper portion of the droplet 14 or to the rack holding the apparatus 12. The casing 22 contains a radiation source 26. The radiation source 26 provides a configuration that provides radiation 28 through a dropper 14 along a trajectory practically perpendicular to Si 30 cylindrical surface 24. An optical receiver 32, which is adapted to quantify the radiation, is located near the part of the cylindrical surface 24, which is substantially opposite the radiation source 26.

The radiation source 26 emits mostly infra-red light. Alternatively or additionally, other types of radiation can be used. The radiation source 26 contains a matrix infrared light-emitting diode that generates infrared light. According to the present invention, infra red radiation is generated either in continuous mode, or alternatively in pulsed mode.

Among the advantages of the pulse mode, we will note better control, taking into account the level of background radiation and energy savings. The frequency of pulse repetition is preferably a frequency of thousands of pulses, and preferably about 100,000 impulses per second. Pulse mode helps to disturb the perturbance when measuring background radiation, for example, when a drop of light from an outside source, such as sunlight, drops.

The pulsed generator of the radiation source 26 periodically excite the LEDs to form a series of excited and non-excited states.

2 shows the difference between radiation pulses that are registered and quantified by the optical receiver 32 after passing through the dropper 14 in the absence of a drop (FIG. 2a) in the path of radiation and in the presence of a drop of 42 (FIG. 2b) in the radiation path. FIG.

In Fig. 2a, the radiation pulses 40 are represented in a digital image. To convert the digitized code of radiation pulses, measured voltage or some other measurable electrical response to the analog signal, an analog-to-digital converter is used. In the absence of a drop in the path of radiation, the registration of pulses 40 passing through the drip 14 does not give significant changes in the height pulses measured by the optical receiver 32. Usually there is a difference between the radiation that enters the dropper 14 and the one recorded by the optical receiver 32 on the other sides of the dropper 14. This is a phone level or a reference level. The device 10 self-calibrates predominantly before and after, as each drop passes through the dropper 14, and this calibration takes into account any changes in the surrounding environment both inside, both in and out of the dropper. Examples of changes to be taken into account are fog-shaped droplets formed from the outside of the dropper 14, or tiny droplets sprayed on the interior surface of the dropper 14. While the device 10 is suitable for any apparatus 12 for self-injection, an intravenous infusion, there are intrinsic to them different droplets differences such as the thickness of the steel or its structure. Processor 34 controls the excitation of infrared LEDs, respectively, in the radiation emitted from the other side of the dropper 14, and adjusts the radiation level for each apparatus and repeatedly performs self-calibration before each drop. While the device 10 is suitable for any apparatus 12 for self-injection intravenous infusion, there are distinctive differences between different droplets, such as the thickness of the cell or its structure. Processor 34 controls the excitation of infrared LEDs, respectively, in the radiation emitted from the other side of the dropper 14, and adjusts the radiation level for each apparatus and repeatedly performs self-calibration before each drop. While the device 10 is suitable for any apparatus 12 for self-injection intravenous infusion, there are distinctive differences between different droplets, such as the thickness of the cell or its structure. Processor 34 controls the excitation of infrared LEDs, respectively, in the radiation emitted from the other side of the dropper 14, and adjusts the radiation level for each apparatus and repeatedly performs self-calibration before each drop.

2b shows a drop 42 passing through the dropper 14 and, as a result, a decrease in radiation emitted from the side thereof through the dropper 14. A depression 44 in the series of pulses emitted by the sensor 32 is registered, where the minimum signal 46 of the depression 44 corresponds to the diameter of the fastest segment drops 42 which passes through the drip 14. FIG. 2b shows how important it is to have tens of thousands of pulses per second, since this means that through each drop 42 passing through dropper 14 several hundred pulses will pass. With volumetric measurements of the drop accuracy the device 10 increases with the number of pulses that pass through the drop. Each pulse represents a segment of the droplet, and therefore, the greater the number of pulses that pass through the drop, gives a more accurate end result, which is the volume of the drop. The device 10 calculates the volume of the drop regardless of its shape or type of device for intravenous infusion. The droplet may be elongated or alternatively relatively wide and flat. Many factors influence the shape of the drop, including pressure, the width of the entrance to the dropper, the viscosity of the fluid, and whether the entrance to the drip is perfectly round or not.

The processor 34 carries out operations for calculating the volume of each drop of 42 passing through the dropper14 as a function of the relative radiation losses quantified by the receiver 32 during the passage of a drop 42 compared to the level of background radiation or the reference level.

In order to be able to calculate the volume of each drop, first by the accumulation of empirical data, a conformance table is formed. Empirical data are obtained when testing device 10 with manyapparatus, with each apparatus has its own type of drops. Each drop has its own pit in the irradiation that passes through the dropper. Then each drop is weighed on the analytical scales forreceiving its exact weight. Taking into account the specific weight of the liquid of each species, one can easily calculate the volume of each of them. For example, for water: 1 kilogram of water takes a volume of one liter. The values ​​of the specific gravity of differentlinks will correspond to volumes that are slightly different from the volume of water. This procedure is repeated many times, preferably thousands of times, so that the weight, and hence the volume, can be linked to the depression or integral,

Infrared light, which is in continuous mode, is a more precise method than a pulsed mode, because here there is information lost between impulses, and the lack associated with the sun's light or other light that interferes with infrared rays can be overcome by making the skin 22 opaque for outdoor light, much like a darkened drawer. Significant disadvantages are high energy requirements to ensure a continuous flow of radiation. In many cases, where the preferred source of energy for the device 10 is a rechargeable source that easily provides

maneuverability from one patient to another, continuous mode of operation of the source of radiation will rapidly drain the batteries. Alternatively, in another embodiment of the present invention, the device 10 is activated by alternating current and the battery source is preferably used for emergency power, in this case, the continuous operation mode will prevail. This is especially beneficial for a stationary device 10, or when higher precision is required.

Next, refer to FIG. 3, which is a flow chart of method 60 for calculating the volume of fluid that passes through the device for intravenous infusion with a dropper having a form in which the effervescence passes substantially along the axis of the dropper. Method 60 comprises the steps of passing the radiation 62 from the outer portion of the dropper through this droplet along a path substantially perpendicular to its axis to a probe located on the opposite side of the droplet and recording and quantifying the background radiation amounting through the droplet. If the background radiation is either too small or too large 65, then the amount of radiation that has to pass through the dropper 14 varies to a higher or lower level and the step 62 is repeated again. This stage is repeated, until the specified level of radiation is reached. This may depend on many factors, such as the type of apparatus and the formation of "frost" on the dropper. As soon as the given level of radiation is reached, it becomes possible to calculate the volume of the drop. The next stage occurs when passing droplets through a dropper 68. Radiation, preferably in the form of infrared light, passes through a droplet that falls through a dropper 70. The sensor registers and quantifies the radiation 72, on the basis of which data are obtained that show radiation losses due to dropping through the trajectory of the rays. Then the volume of the drop is calculated, as the function of the relative radiation losses recorded during the drop of the drop, in comparison with the background radiation. Designed for '

Although the invention is described in connection with specific embodiments, it is evident to the skilled person that other alternatives, improvements, and variants are possible. Accordingly, it means that all alternatives, improvements and options are within the scope of the essence and the scope of the added form of the invention.

FIG. WITH