WO1999051288A1

WO1999051288A1 - Electronic regulator for fluid therapy with disposable dripping cartridge

Info

Publication number: WO1999051288A1
Application number: PCT/IT1998/000120
Authority: WO
Inventors: David Pesarin; Francesco Carugno; Anna Mainolfi
Original assignee: David Pesarin; Francesco Carugno; Anna Mainolfi
Priority date: 1998-04-07
Filing date: 1998-05-14
Publication date: 1999-10-14
Also published as: ITRM980222A1; AU7233798A; IT1299158B1; ITRM980222A0

Abstract

The present device has to be used for the intravenous administration of fluids and drugs. It is formed by two correlated parts: a dedicated and disposable cartridge, and the electronic flow regulator. The disposable dripping cartridge has a cylindrical shape and is made of plastic material. It allows the electronic device controller to read out, and check the falling drops, and to keep constant the flow rate of the administered substance. It has a built-in rubber siliconic tube that is used to regulate the fluid rate delivery through the action of a micro servomotor acting on it. The apparatus is governed by an electronic circuitry board. A microprocessor is used to analyze the input data and control the output adjusting signals. All the components are contained in a waterproof plastic body. The device once assembled is handy to use because of its compact size (cigarettes package-like) and of its light weight.

Description

DESCRIPTION

ELECTRONIC REGULATOR FOR FLUID THERAPY WITH DISPOSABLE DRIPPING CARTRIDGE

Technical Field

The new device has the ability to regulate automatically the flow rate during the administration of fluids in all those conditions where the intravenous therapy is needed. As in the management of the admitted intensive care unit patients, in the post-operative treatment, when it must be used a specific drug that requires careful dosing regimen and/or for the infusion of high calories solutions for the total parenteral nutrition.

Background art

To keep constant the dripping flow rate during intravenous fluid therapy, the actual marketed dripping infusion sets require the paramedics a continuous manually operated adjustment . This is a major wasting time procedure that significantly increases the risks in the error-administration of fluid dosage and in the intravenous delivery of those drugs with a low margin of safety. Other devices operate a forced administration delivery of fluids, using volumetric and/or peristaltic pumps that exclude the gravitational dripping. These apparatuses impose the operator complicated step by step maneuvers for their setting up. In addition

1 these delivery pumps need every-day change of the infusion tubing, because of their rapid warn out, to maintain constant the adjusted delivery rate. More over the lodgement and the inspection of these tubing sets pose further work load and complexity to the every day use of these pumps. Finally the infusion pumps are cumbersome and have a limited carrying use being heavy weighted and large volume sized. Also they need supporting poles, dedicated brackets and enough room to be positioned close to the patients.

Disclosure of invention

The present device, to be used for the administration of intravenous fluid therapy, has innovations that eliminates the aforementioned limits and drawbacks. It is composed of two parts: a dedicated dripping cartridge for the gravitational fluid infusion (see Fig.l); and of an electronic optical drop detector feed-backed with a processing data unit that regulates the flow rate. The outstanding innovation of this invention relates to the lodgement of the dedicated, disposable dripping cartridge. The new device is illustrated in the enclosed technical drawings. The Fig.l shows the longitudinal cross sectional view of the dripping cartridge. The peculiar parts of the new dripping cartridge model are numbered in the Fig.l as follows: 1) double lumen perforating needle with self-locking retracting fins. When using non collapsible fluid container, one lumen is devoted for the fluid outflow and the other for the air inflow; 2) antibacterial filter at the air inlet site of the needle with removable closing cap; 3) superior dripping cannula tip; 4)superior chamber for the detection of the dripping fluid; 5) superior diaphragm for the anchorage of the upper end of the elastomeric rubber-silicon tube;6) siliconic tube; 7) inferior diaphragm for the anchorage of the lower end of the elastomeric rubber-silicon tube; 8) inferior dripping chamber; 9) origin of the intravenous infusion tube; 10) slide seat to help in the right orientation of the cartridge inside the electronic device. Also the Fig. l shows the modules scheme of the main electronic components. In the above picture (Fig.l) the electronic circuitry modules are numbered as follows: 11) light source; 12) optical photodetector; 13) discriminator; 14) counter; 15)clock; 16) processing data unit; 17) micro servomotor.

The enclosed Fig.2 report the frontal and lateral view of the external body of the device, with the location of the control panel buttons, and the proper working position of the dripping cartridge. The same figure shows the following points: 1) four digit liquid crystal display to indicate the quantity of fluids infused per hour and the battery status charge; 2) multiple selection buttons to choose the fluid to be infused; 3) memory button to display the total amount of fluid infused from the start treatment; 4) button to activate the minimum flow rate required to keep vein open; 5) OK/START button to confirm the setted data and to activate the device; 6) ON/OFF button; 7) PAUSE button that temporarily shuts down the dripping fluid retaining the pre-setted value into memory; 8) RESET button to cancel the previous entered data and to clear from any setting error; 9) ten digit button control panel; 10) visual warning signal for the regular flow rate; 11) and 12) mechanic release latch-buttons for unlocking and ejecting the dripping cartridge; 13) skidproof grip. The dedicated and disposable dripping cartridge, made of plastic

75 material, with the help of a guiding slit, is easily inserted with a single moving action inside the electronic apparatus (see Fig.2). Once the cartridge is moved into the device through the holes located at its lower and upper end, the cartridge is automatically locked in position by a single or double locking clip (see Fig. 1 #18). So it is now

80 correctly located in its lodging place and ready to be used. Subsequently operating through the digit-key buttons of the control panel, the device is programmed choosing the kind of solution to administer (crystalloids, or colloids, or plasma, or packed red cells) and the flow rate infusion value in milliliters per hour (ml/Hr).The

85 choosing option of fluids more exactly makes it to calculate the volume of the drop exiting from the dripping cannula tip, which is another variable determining the end volume of the falling drops. Anyway the internal diameter of the dripping cannula tip is a factory fixed value and it is integrated into the memory module of the

90 processing data unit during factory programming of the microprocessor.

Next the rubber cork membrane (Fig.l #19) of the liquid container can be perforated. The lower dripping chamber (Fig.l #8) is manually squeezed for the priming of the dripping set, filling the

100 cartridge and the tube with the fluid to be administered. Finally the system can be activated.

The superior dripping chamber of the cartridge (Fig.l #4), located inside the electronic device, is positioned between the light source (Fig.l #11) and the photodetector (Fig.l #12). This positioning

105 makes it possible to detect and count the falling drops. When a drop interrupts the light beam, this is sensed by the photodetector. The captured signal is filtered and transduced by a discriminator (Fig.l #13) and sent, via the interposition of a counter (Fig.l #14) and a clock (Fig.l #15), to the processing data unit (Fig.l #16). The unit,

110 compares the data received (number of drops per unit time) with those entered by the operator (milliliters per hour). If it is needed the processing unit sends a signal to the micro servomotor (Fig.l #17) that acting on the elastomeric-siliconic tube (Fig.l #6), increase or decrease the flow rate to match it with the entered value (milliliters

115 per hour). The above mentioned action-steps of the electronic components are over and over repeated in a feedback-looped manner, to continuously adjust the flow rate to the pre-setted value.

Brief description of drawings

The numbers reported in Fig.l correspond to the following parts:

1 ) Perforating needle.

2) Closing cap for the antibacterial filter.

3 ) Superior dripping cannula tip.

4) Upper dripping chamber for the detection of the falling drops.

5) Diaphragm to secure the upper end of the siliconic tube. 6 ) Siliconic tube.

7) Diaphragm to secure the lower end of the siliconic tube.

8 ) Lower dripping chamber.

9) Origin of the intravenous infusion tubing set.

10) Sliding guide to help in the correct orientation of the cartridge inside the device.

11) Light source.

12) Photodetector.

13) Discriminator.

14) Counter.

15) Clock.

16) Processing data unit.

17) Micro servomotor.

18) Locking latch.

19) Rubber cork membrane of the fluid container.

The Fig.2 reports the following parts:

1 ) Four digit liquid crystal display.

2 ) Fluid selection buttons.

3 ) Button to display the stored memory data of total fluid quantity administered from the start treatment.

4 ) Button to select the minimum flow rate to keep vein open.

5 ) OK/START button.

6) ON/OFF button.

7 ) PAUSE button. 8) RESET button.

9 ) Ten digit control panel buttons (0 to 9).

10) Alarm signal.

11) and 12) Cartridge release latch buttons. 13) Skidproof grip.

Modes for carrying out the invention

The present device is entirely controlled by electronic components. It needs of an electronic circuitry board, the main part of which is represented by a microprocessor easily available on the market. The microprocessor must be factory programmed to be able to perform all the above mentioned feed-backed regulating functions. The only mechanical part controlled by the electronic board is the micro servomotor. This is easy to find on the market too. This micro servomotor is able to do micrometric step movements. All the electronic components and the micro servomotor, must be assembled inside a water proof plastic body. Inside the apparatus is located the receptacle site for the dripping cartridge. The device will be very compact (cigarette-package like size) and will be also light weight to stand alone hanging under the fluid containers. The disposable dripping cartridge for this new device must have a transparent dripping chamber walls for the detection of the falling drops. It is to be stressed that the elastomeric rubber tube (siliconic tube), must be integrated into the cartridge between the upper and lower dripping chambers, and once located inside the device it must be closely leveled to the micro servomotor position. Using photosensitive fluids and drugs, the dripping tubing set can be made of dark light-proof plastic. For obvious reason the dripping chamber for the detection of the drops, must have transparent walls. This part anyway is light protected from its position inside the apparatus.

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Claims

1- Electronic feed-backed flow rate regulator characterized by a disposable cartridge with an upper dripping chamber for the electronic sensed detection of the drops, a lower dripping chamber manually squeezable for the priming of the cartridge and the visual inspection of the falling drops, and by the presence between the two dripping chambers (upper and lower) of an elastomeric rubber- silicon made tube.

2- Electronic feed-backed flow rate regulator, as at claim #1, characterized by the presence on the perforator needle of the cartridge of self supporting flexible fins.

3- Electronic feed-backed flow rate regulator as to previous claims, characterized by cartridge release latch buttons to unlock and eject the cartridge. Using biologic fluids administration (plasma and other blood products), this avoids the operator any contact with the perforating needle once finished the infusion treatment .

4- Electronic feed-backed flow rate regulator as to previous claims, characterized by a compact volume (cigarettes package like) and light weight.

5- Electronic feed-backed flow rate regulator as to previous claims, characterized by easy to operate mode (self evident programming control panel and fast changing cartridge replacement). This make it simple to be activated by non-trained personnel and to be maneuvered in the domiciliary therapy. 6- Electronic feed-backed flow rate regulator as to previous claims, characterized by the stand alone suspended position under the fluid containers without using any supporting device or standing poles. 7)- Electronic feed-backed flow rate regulator as to previous claims, characterized by a built-in rechargeable battery for emergency situations and powered by alternate current with a universal voltage converter.

8)- Electronic feed-backed flow rate regulator as to previous claims, characterized by fluids selection option input, to choose among different kind of fluids to administer (crystalloids, colloids, plasma, packed red cells), each with its own specific physical characteristics (superficial tension, density, viscosity).

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