Patent Application
20220152300
The disclosure relates to device and methods for regulating and monitoring the flow rate of intravenous infusion for patients, especially neonatal patients.
A newborn is considered premature if it is born before the start of the 37th week of pregnancy. After birth the first 28 days of life are the most critical period in determining a preterm baby's survival rate. The highest cause of death for children under age five is prematurity. While there can be many complications associated with preterm births, neonatal dehydration is one of the top issues causing this high mortality rate. This medical condition is very common but can be preventable and treatable with appropriate equipment.
The issue of neonatal dehydration is more prevalent in low- and middle-income countries (LMIC) where healthcare is less accessible. High income countries have mitigated the problem for years with costly equipment, but such treatment has not been globalized for low-resource settings. The current standard of care is intravenous therapy (IV). However, there are no low-cost solutions to accurately deliver IV fluids at low infusion rates. Market available low-cost pumps do not have the precision required to modulate flow rates within acceptable parameters for a neonate. The lowest rate possible with existing low-cost pumps is 3 mL/h, while neonates require infusion rates as low as 1 mL/h. In terms of hydration treatment quality, there are other high-cost solutions available that have, for example, a desirable minimum delivery rate error, but the high cost makes these an unlikely option for low-resource settings.
Secondly, equipment with the capacity to monitor and control flow to this precision typically requires consistent high power energy sources, a luxury that most low resource hospitals do not have. The aforementioned solutions both require a dependable power source and are costly, thus fail to fulfill the situational requirements of being power-independent and low-cost.
Flow control options that do not use electronics, such as a roller clamp, do not have the option to precisely control infusion rates. Furthermore, these devices are designed towards adult patients and are not easily controlled at low flow rates needed for premature babies. In one exemplary low cost and completely mechanical solution, the flow rate can be controlled by substituting various tube sizes that are compatible with different device types. The sizes and flow rates available are limited in what is offered and is specific to the particular device. This is not ideal for low-resource settings that largely depend on donated products that may not have compatible individual pieces like varied sizes of tubing sets.
For electronic flow rate monitoring, there exist acceptable solutions in terms of strictly monitoring the flow rate. However, limitations of such solutions include that they do not have a feedback system to control the on/off state of the device. It is desirable for the monitor to shut off the IV infusion when the rate deviates from a rate preset by a clinician.
The herein disclosed technology can address the unmet need for resource-conscious IV treatment for dehydrated neonatal patients, though this technology can also be used for many other purposes and applications and is not limited to use with neonatal patients or otherwise. One implementation of the technology disclosed herein is sometimes referred to as “H2neO” because of the exemplary use with neonatal patients, but using that term does not limit the technology to use with neonatal patients. This technology can provide a low-cost, external device for regulating and/or monitoring the flow rate of a gravity-operated IV infusion device. In some embodiments, the disclosed technology can integrate at least two independent components: a mechanical regulator and a monitor. The mechanical regulator can comprise gears, a mechanically operated screw, and/or other mechanical components to pinch IV tubing at a very carefully controlled degree, controlling the flow rate through the IV tube to a precise known value. The flow rate regulator components can be purely mechanical, eliminating power usage for flow rate control, while in some embodiments the flow rate regulator can include one or more non-mechanical components. The mechanical regulator can be separated into at least two parts: an initial rate setter and a variable flow regulator mechanism. The initial rate setter can apply the initial pressure onto the tube to lower the flow rate to a manageable rate. The variable flow regulator can fine tune the flow to the required rate.
The monitoring components of the system can comprise an electrical/optical monitor or other type of monitor. In some embodiments, the monitor can comprise a 3-part, semi-open-loop system, including (1) a user interface for set flow rate input, (2) a flow rate monitor, and (3) an alarm with auto shut-off of flow, which can signal a deviation of the flow rate from the user-specified flow rate. An alarm for low battery status can also be included.
An exemplary use of there disclosed system can be as follows: The user (e.g. a clinician) can use the initial rate setter block to lower the natural flow rate first (e.g. to 25 ml/hr), then the user can then input the preset flow rate on the monitoring component to specify the reference flow rate. The user can then manually fine tune the variable flow rate regulator while cross checking with the monitor to achieve the flow rate desired. The monitor can raise a flag if, for example, the detected flow rate is deviating significantly from the desired rate, physically shutting off the IV line and stopping infusion to the patient. If this happens, the user can reset the alarm on the monitor and can manually open the line to restart the system.
The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
In some examples the flow rate regulator device can include an initial rate setter block that can significantly lower the flow rate, and a variable regulator device that compresses the tubing further in an extremely accurate manner. For example, one turn of a dial on the variable regulator device can correspond to 1 mm in vertical movement of a compressor platform to squeezes the flow tube. The two devices can work in series, with the initial rate setter first reducing the natural flow rate of the system to a predetermined rate, such as 25 mL/h, simply by constricting the tube a set amount, then the variable flow rate regulator device can provide the clinician with the precise control required to set the flow rate to the desired value and to make fine adjustments over time. The clinician can check the monitor for the current flow rate and make adjustments to achieve the desired flow rate.
As shown in
The configuration of the device 30 can utilize mechanical advantage and surface area to significantly increase the device's precision and ease of use. The train of gears with a dial handle 42 and the threaded screw shaft 40 driving fine motion of the platform 36 add more precision to the flow rate adjustment and provide fine-tunable analog adjustability via gradual rotation of the dial by the user. In some examples, the dial 42 can half as many teeth as the screw shaft 40, providing a 2:1 gear down effect, such that two rotations of the dial are required to cause one rotation of the screw shaft. The pitch of the threads of the screw shaft and platform can also be selected to control the relationship between how much the platform moves linearly for each rotation of the dial.
This design can be functional, simple, precise, and easily manufacturable. The device 30 also does not rely on electricity, being purely mechanical, and so can be trusted to function properly at any time and location, and for any duration, without needing a power supply, recharging, new batteries, etc.
At an upstream end of the flow tube 24, an initial rate setter 34 is coupled to a receiver 72 of the base 32 with the tube squeezed between a projection 68 of the rate setter 34 and the trough 62 and sidewalls of the receiver 72 (see
Different rate setters 34 with different length projections 68 can included in a set, and a user can select a desired one of the rate setters to attach to the receiver 72 to establish a desired amount of initial restriction on the tube 24, thereby setting an initial flow rate through the tube. For each rate setter in the set, the resulting gap size (e.g., distance from the end of the projection to the bottom of the trough) can be marked on the projection or elsewhere on the rate setter, for example. The set can include rate setters of sized such as 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 2.0 mm, etc. Or the set can include rate setters marked based on the resultant flow rate when using a given size tube, such a 0.5 mL/hr, 1 mL/hr, 2 ml/hr, 3 mL/hr, 5 mL/hr, 10 mL/hr, 15 mL/hr, etc.
In some embodiments, the device 30 can be fully 3D printable and easily manufacturable. The components of the device 30 can be manufactured using methods such as injection molding, 3D printing, casting, and/or other available methods. Furthermore, any materials can be used that are suitably rigid and durable, such as metals, polymers, composite materials, ceramics, and/or other materials. Similarly, the device can be simply and quickly assembled without additional fasteners or tools being required. For example, the parts can all snap together and hold each other in place. The device 30 can therefore be precise and functional for flow rate setting, low cost, easy to manufacture and assemble, reliable and functional in any environment, and have a compact configuration.
As shown in
The system 200 can also be very compact and lightweight, such as being no larger than 100 mm×76 mm×32 mm, and no heavier than 150 g. The flow rate can be primarily computed based on the drops detected within the drip chamber 8 over a time interval. The system can also include a weight-based sensor that uses change in weight (via accumulation of drops of fluid in the drip chamber) over a time interval to compute the flow rate.
The sensor(s) used to detect drops can comprise, in some examples, light emitting diodes (LED), such as with wavelength in the range of 650-1000 nm (10 m). The emitted light can be collected by a photodiode (PD) or other detectors. Using the photodiode configuration, the detection signal can comprise a negative pulse. An exemplary photodiode configuration 300 is shown in
The photodiode configuration 300 can function based on how much light the drop absorbs, refracts, and reflects. In some embodiments, the photodiode configuration can detect drops using a negative pulse from the baseline signal. The drop interrupts the beam and reduces the amount of light going to the PD. There can still be a positive signal due to light rays bouncing off the walls and refracting through the drop, but the pulse of an unknown percentage can still be detectable.
An exemplary emergency shutoff mechanism 400 is shown in
Exemplary hardware for the flow rate monitor system can include:
Flow Rate=3600000/(GTT_FACTOR*average time in ms) Equation:
For purposes of this description, certain aspects, advantages, and novel features of the embodiments of the inventive technology are described herein. The disclosed methods and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatuses, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.
Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the specification and attached figures may not show all the various ways in which the disclosed methods can be used in conjunction with other methods.
The singular terms “a”, “an”, and “the” include plural referents unless context clearly indicates otherwise. The term “comprises” means “includes without limitation.” The term “coupled” means physically linked and does not exclude intermediate elements between the coupled elements. The term “and/or” means any one or more of the elements listed. Thus, the term “A and/or B” means “A”, “B” or “A and B.”
In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosure. Rather, the scope of the disclosure is at least as broad as the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 63/115,771, filed Nov. 19, 2020, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63115771 | Nov 2020 | US |
