NONLINEAR FLOW METER

1- Technical Field

The medical & health care sector.

2- Background art:

The ventilator is a medical device that has an effective role in providing an appropriate environment for respiratory system, as it provides inhalation and exhalation artificially, allowing the doctor to control both the medical air pressure, the intensity of its flow, its propelled volume to the lung and the concentration of oxygen in it.

The ventilators vary greatly according to their purpose and required performance. This also affects the complexity of their designs and later maintenance due to the complexity of spare parts and the difficulty of finding them.

The design problem lies in the complex techniques that lead to:

1- The scarcity of the device and its lack of abundance.

2- Its high cost.

3- Difficulty in maintaining it.

4- Scarcity of spare parts needed for its maintenance.

Especially in the conditions that the world is going through from a fast-spreading violent epidemic.

3- Disclosure of Invention

The goal that we all seek in the humanitarian crisis that the world is witnessing now is to find a ventilator system:

1- performs the functions of an advanced device.

2- is easy to assemble and maintain locally.

3- Its spare parts are always available in the local markets.

To achieve these goals, two important parts were invented in this device, as expensive components were dispensed with, as follows:

• Delta Pressure Flow Tender Valve (DPFTV). • Delta Pressure Nonlinear Interpolated Flowmeter (DPNIF).

Please see Fig. 9 and Fig. 11

Detailed Description:

The device consists of two main parts

1- Electric.

2- Pneumatic mechanical.

Electrical supply (power source):

Please see Figure 1

• It is the source of power for all electrical parts of the device.

• 12vdc battery

• A circuit to regulate the operation between the electronic circuit, the power source and the battery.

Mathematical and Logical Analysis:

• It is the part responsible for analyzing all the information, whether from the sensors or from the user’s control, then deducing results and decisions on the basis of which it controls the system as a whole, which is called the processor and its peripherals.

Sensors and Monitoring:

It is the group of sensors that transmit all the physical values that the Processor is concerned with to conduct his analyzes and make his decisions.

Which are:

• Inhalation pressure gauge

• Exhalation pressure gauge

• Inhalation flow rate measure

• Exhalation flow rate

• Measurement of the minimum pressure for air

• A measure of the minimum pressure of oxygen.

• The percentage of oxygen in the mixed air Operations and making decisions:

It contains the interface to implement CPU decisions which are as follows:

• The interface circuit unit for controlling the valve is proportional to the intensity of the medical air flow

• The interface circuit unit to control the valve is proportional to the intensity of the oxygen flow.

• Interface unit for opening and closing the valve for medical air intake from the source.

• The interface unit for opening and closing the oxygen intake valve from the source.

• The interface unit of the mechanical circuit regulating the inhalation and exhalation channels.

The Alarming

The alarm unit responds to the processing unit when the following physical values are defective:

• Pressure for oxygen.

• Pressure for medical air.

• Oxygen flow rate.

• Rate of medical air flow.

• The percentage of oxygen.

• Stop alarm: This alarm is triggered when electricity is cut off during the basic breathing task. It depends on the battery’s electricity to extract its energy after the power is cut off, and this is the main role of the battery.

User interface

According to Figure 3

The screen is an easy way to communicate between the user (the doctor) and the device for the following:

First: By observing all the important variables in the operation of the device that directly affect the patient:

Pressure graph: the evolution of lung pressure over time

Volume graph: the evolution of the volume of air in the lung with time

Oxygen volume: Instantaneous oxygen volume

Oxygen flow: instantaneous amount of oxygen

Pressure: instantaneous pressure in the lung

Second: Control over these variables

O2 _v oi%: Control of oxygen content

VTmi: Control of mixture volume during the inhalation phase

TINSP: Control of the time period of inhalation

Frequency: the number of breathes per minute

Flow / MIN: control the amount of mixture during inhalation

PMAX: The maximum pressure required within the lung

PEEP: Control of the residual volume of the mixture in a lung during an exhalation process

I.E: The ratio of the time period between inhalation and exhalation

TEXP Control of the time period of exhalation

Detailed description of the mechanical part

According to Fig No. 2

Air and oxygen supply

This unit contains:

• Air and oxygen supply channels.

• High pressure air inlet valve.

• High pressure oxygen inlet valve.

Regulation and reducing Pressure

This unit contains:

• Regulating and reducing oxygen pressure.

• Medical air pressure regulator and depressor.

Control of the intensity of the flow of air and oxygen:

This unit contains:

• Proportional valve to control the intensity of the oxygen flow (it receives the control signal from the electronic part).

• Proportional valve to control the intensity of medical airflow (receives control signal from the electronic part).

Sensors and monitoring systems:

It is one of the common units between the electronic and mechanical parts.

The Department of Regulating Inhalation and Exhalation Channels:

This unit is responsible for separating the inhalation and exhalation channels to facilitate the measurement of inhalation and exhalation flow.

What was invented in detail?

Please see Fig.9 and Fig.11

• Delta Pressure Flow Tender Valve (DPFTV).

• Delta Pressure Nonlinear Interpolated Flowmeter (DPNIF). First: Delta Pressure Flow Tender Valve

According to Fig. 9

The function of this system is to precisely control the intensity of the air flow by creating a pressure difference on channels of known specification and adjusting this pressure via the electrical control signal from the control board (see Item 2 in Fig. 9) to the servo motor (see item 1 in the panel No. 9), whose rotor is fixed to the rotary manual control handle of a "non-electric" manual pressure regulator (see element 3 in Panel No. 9).

The manual pressure regulator was chosen because it is one of the most resolution, accurate and stable in its values, so it is easy to control it through a servo motor installed on the hand of the rotary manual control.

We encountered obstacles in implementing the idea:

- The relationship between rotor deflection and pressure did not make a linear curve. This obstacle was solved by using a table of convergence points and then doing an interpolation or projecting small linear curves between the converging points.

- A slight change in flow occurs when there is a change in the input pressure, and this problem was solved by placing a pressure regulator before it.

- Failure to reach the required flow value with high accuracy using the direct control method. Therefore, we have used flow metrics in the work of monitoring the flow and controlling the flow based on it with a very accurate judgment.

Second: Delta Pressure Nonlinear Interpolated Flowmeter

According to Fig. 11

We faced several obstacles in using flowmeters in the local or global market, including:

- The cost of accurate flowmeters.

- Cheap flowmeters, some that are inaccurate, and others that affect the same measured value, change them and are difficult to control.

It is a system for measuring the intensity of the flow of air or oxygen and it is based on measuring pressure difference between two points (see Element 1 in Fog. 11) on a well-defined channel, where the intensity of the flow is deduced depending on the pressure difference and the properties of the tube (see element 2 in Fig. 11). With the use of interpolation methods, performance control tables, calibration, and linearization to reach the exact physical value.

What distinguishes this device from others?

- Its accuracy as the techniques used above were used to reduce the effect of non-linearity.

- Its cheapness, as it relied on the same existing tube and on existing pressure gauges to measure pressure.

- It does not affect the measured value as it depends on the natural properties of the tube without obstructing the forced air.

Important parts to achieve safety:

Changing channel rudder:

According to Fig. No. 12 and 14

Its function when the pressure of oxygen and air disappears, as it opens the safety channel to become a source of outside air when the prepared mixed air stops.

Relief Valve: according to plate No. 10

The safety channel opens when the pressure exceeds the permissible, and this valve is present in all pressure regulators in the mechanical circuit.

Best Mode For Carrying out the Invention:

This device was invented to be present in all places that provide medical services, such as hospitals, clinics, health units, and equipped ambulances, and the respiratory service is aimed at those who need artificial respiration due to the presence of deficiencies, defects, or illnesses in their respiratory system, and is used under the supervision of a specialist doctor or trained nurse by the doctor.

Detailed explanation of the drawing boards:

According to Fig. 4 to Fig.8

Description of the circuit board of the ventilator:

Complete list of components and their functions:

Description of the drawing board for the pneumatic (air) circuit of the ventilator:

According to Fig. No. 13

- In the beginning, oxygen enters from a pressurized oxygen source with a value of 4 bar into two solenoid entry valves to control the entry on / off solenoid valve - according to Fig No. 15

- And then to a fixed manual pressure regulator to reduce the pressure to 1 bar

- And then to an on / off pressure switch to ensure that the circuit works at the minimum safe pressure) - According to Fig No. 18

- And from there to the (DPFTV) unit delta pressure flow tender valve) (where the required oxygen percentage is set) - according to Fig. No. 9

- With the entry of oxygen, the air enters from another branch to pass the same components that the oxygen passed through, so that the air is also introduced at the required pressure and the required ratio. According to Fig. No. 9

- Then the air and oxygen are mixed and passed into the assembly line and then to a variable pressure regulator to adjust the required amount of mixture - according to Fig. No. 9. - This quantity then passes to a pressure measuring device, where it sends electrical signals indicating the measured pressure value - according to Fig. No. 11

- Then the mixture passes to the tube with a larger diameter and a pressure is measured again, and other electrical signals are passed by the pressure value, and thus the amount of flow of the mixture is calculated. According to Fig. No. 11.

- Then the percentage of oxygen in the mixture is measured by an oxygen sensor.

- This is the last stage that the mixture is delivered to patient.

4- Brief description of drawing Figures:

Fig. No. 1: A block diagram of the electronic circuit.

Fig. No. 2: A block diagram of the mechanical circuit.

Fig.3: The main user interface.

Fig. No. 4: The schematic design of the microcontrollers part in electronic designs.

Fig. No. 5: The schematic design of the intermediate circuit part with the air valves in electronic designs.

Fig. No. 6: The schematic design of the part of the clamp in electronic designs.

Fig. No. 7: The schematic design of the voltage and current regulation part in electronic designs.

Fig. No. 8: The final printed circuit board.

- Fig. No. 9: the final form of the innovative design of the proportional valve (DPFTV), which consists of a wire for the electrical control signal (component 2 of Fig 9) and a servomotor (element 1 of Fig 9) mounted on a manual handle of a manual pressure regulator (element 3 of the Fig. 9).

Fig. No. 10: A detailed explanation of the Relief Valve.

- Fig. No. 11: the final illustration of the innovative design of the flow meter (DPNIF), as it consists of a tube of different diameter (element 2 of panel 11) and at the ends there are two pressure gauges (element 1 of panel 11). Fig. No. 12: The final figure of the Changing channel rudder that regulates the inhalation and exhalation channels.

- Fig. No. 13: The schematic design of the mechanical circuit, as it consists of two high pressure air inlet valves (element 1 of Panel 13), two high pressure oxygen inlet valves (element 2 of Panel 13) and two units of pressure regulator for both air and oxygen (element 3 From Panel 13) and two units of (DPFTV) (element 4 of Panel 13) to adjust the proportion of oxygen and a third unit to control the flow of mixture (element 5 of Panel 13) and two units of pressure gauge (element 6 of Panel 13) which are the mechanical part of the (DPNIF) unit.

Fig. No. 14: A sectional diagram to illustrate the performance of changing channel rudder.

Fig. No. 15: A model of an electric solenoid fluid valve.

Fig. No. 16: A model of a triple electric solenoid fluid valve.

Fig. No. 17: A model of the electric pressure switch.

Fig. No. 18: A model of a manual pressure regulator.

Fig. No. 19: Model of the oxygen sensor.