WO2022086350A1

WO2022086350A1 - Volumetric manual ventilator

Info

Publication number: WO2022086350A1
Application number: PCT/PE2021/050014
Authority: WO
Inventors: Claudio Bruno CASTILLÓN LEVANO
Original assignee: Pontificia Universidad Católica Del Perú
Priority date: 2020-10-23
Filing date: 2021-07-05
Publication date: 2022-04-28
Also published as: PE20220845A1

Abstract

The present invention relates to a volumetric manual ventilator (VMV) having a pneumatic configuration that allows a controlled series of volumes of air and/or oxygen to be supplied to a patient's lungs according to his or her pulmonary compliance and individual need for ventilation, using a volume-regulating module with bellows pneumatically actuated by a resuscitation bag. The invention is based on control of the interaction of three fluids that are not mix together, such as: control fluid, composed solely of air; inhaled fluid, composed of air and/or oxygen; and exhaled fluid, composed of air with carbon dioxide.

Description

MANUAL VOLUMETRIC FAN

FIELD OF THE INVENTION

The present invention has been developed in the technological field of manual pulmonary ventilation devices, the same ones that allow to cyclically supply a series of volumes of air and/or oxygen to the lungs of a patient.

STATE OF THE ART

In the state of the art there is patent document W02017200399A1, published on November 23, 2017 and entitled "Manual resuscitator with adjustable volume"; This document describes an electro-pneumatic manual lung ventilator that controls and monitors the volume and pressure it delivers to a patient's lungs. The device comprises a flow sensor, a pressure sensor, a digital processing module and a graphical interface; however, this device is difficult to use, since it requires two sterilization methods; one for the electronic system and one for the pneumatic system; It should be considered that adequate sterilization is a fundamental requirement for all manual ventilators, in order to avoid the spread of diseases between patients.

Another patent document that can be considered as background is US2007267019A1, published on November 22, 2007, with the title "Manually operated apparatus, and balloon and valve housing unit for a manually operated breathing apparatus", which discloses a manual bag-type ventilator that connects with an elastic bellows inside a chamber, which has the sole function of acting as a valve. The chamber includes a predetermined pressure valve of overpressure protection; it is adjustable by a threaded ring between 20 to 60 cm of water column. However, this precedent does not include a volume regulation module, where a bellows and a numerical scale allow to measure and control the volume of air and/or oxygen that is supplied to the lungs of a patient.

Another background document is US5628305A, published on May 13, 1997, entitled "Universal Ventilation Device"; This background describes a ventilator that separates gas from the victim from the rescuer and delivers a known adjustable volume of gas at a known adjustable rate. However, this device does not control the pressure of the air and/or oxygen that it supplies to the patients, therefore, its use can cause lung injuries to them, due to the excess pressure of said gaseous mixture that depends on the skill of the operator. health personnel and the type of patient treated (pulmonary compliance of the patient, type of disease, age, need for ventilation, etc.).

Another patent document considered as background is US2003062047A1, published on April 03, 2003, entitled "Sealed pressure breathing device", this background describes a manual breathing device that comprises an opening that serves as an inlet port to inhale air by the patient, the second port to exhale carbon dioxide and an adjustable pressure screw cap can be attached to a manual air bag. However, this background does not mention whether it allows the pressure from the bag to be preset and does not allow the volume of air and/or oxygen delivered to a patient's lungs to be measured or controlled.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a volumetric manual ventilator (hereinafter, VMV) whose pneumatic configuration allows supplying a controlled series of volumes of air and/or oxygen to the lungs of a patient, depending on their lung compliance and their particular need for ventilation. ventilation, by means of a bellows located in a transparent rigid chamber and which, in addition, is actuated pneumatically by a resuscitation bag. This invention is based on the control of the interaction of three fluids that do not mix with each other, such as: a control fluid, composed only of air; an inspiration fluid, composed of air and/or oxygen; and an expiration fluid, composed of air with carbon dioxide (see figures 7 and 8).

This invention mainly includes a control flow supply module, a pressure regulation module, and a volume regulation module, where the volume regulation module includes a transparent rigid chamber with at least three cavities, a bellows, a air-oxygen retention valve and a double function valve, one of the cavities being hermetically sealed by the bellows, which in turn is coupled with the resuscitation bag through its base, arranged in such a way that its elongation it develops towards the interior of the transparent rigid chamber, the other two cavities are hermetically sealed with the air-oxygen retention valve and with the double function valve, likewise, this transparent rigid chamber presents a numerical volume scale.

The configuration of this device offers the following technical effects:

• Simplifies accurate monitoring and control of the volume and pressure of air and/or oxygen delivered to patients' lungs.

• Facilitates the determination of the patient's lung compliance.

• Allows patients to provide ventilatory therapy with less risk of hypoxemia, hypercapnia, volutrauma, barotrauma, etc., since pulmonary ventilation is performed according to each patient's pulmonary compliance.

It facilitates its sterilization since it only has mechanical elements, which can be sterilized by conventional means such as steam autoclaves. • Its configuration based solely on mechanical elements makes it independent of energy supplies, such as batteries.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1: Manual volumetric ventilator with its components.

Figure 2: Schematic of the resting state of the VMV.

Figure 3: VMV during inspiration.

Figure 4: Diagram of the inspiration phase.

Figure 5: VMV during volume control.

Figure 6: Schematic of the volume control status.

Figure 7: VMV during expiration.

Figure 8: Diagram of the expiration phase.

Figure 9: Graphs of pressure, flow and volume during pulmonary ventilation.

DETAILED DESCRIPTION OF THE INVENTION

The volumetric manual ventilator has the following main parts:

- A control flow supply module.

- A pressure regulation module.

- A volume regulation module.

- Ventilation ducts. Control Flow Supply Module'. Made up of a resuscitation bag (1), a chamber (2) and an air retention valve (3). The resuscitation bag (1) and the chamber (2) are joined in a single hollow body, forming a cavity for air supply, instead the air retention valve (3) is located on one side of the chamber (two).

Service regulation module/?: Made up of an adjustable relief valve

(4) located in the chamber (2), adjustment means (5) of the adjustable relief valve (4), a regulation knob (6) connected with the adjustment means

(5) to allow handling and a numerical pressure scale (7) on the adjustment means (5).

Volume regulation module: Made up of a transparent rigid chamber (8) with at least three cavities, one of the cavities is hermetically sealed by a bellows (9), which in turn is coupled with the resuscitation bag (1 ) by its base and is arranged in such a way that its elongation develops towards the interior of the transparent rigid chamber (8), the other two cavities are hermetically sealed with an air-oxygen retention valve (10) and a double valve function (11 ). In addition, the transparent rigid chamber (8) has a numerical volume scale (14) on its surface. It should be noted that in a particular embodiment of this transparent rigid chamber (8), it is also translucent.

Ventilation ducts: Made up of a proximal duct (12) and an expiration duct (13), both are connected to the transparent rigid chamber (8) by means of the double function valve (11).

Regarding the control fluid (16), it is basically a gaseous mixture made up of air extracted from the environment, which allows the bellows (9) to elongate, while the inspiration fluid (17) is a gaseous mixture made up of air , air and oxygen or only oxygen and that enters the patient's lungs (15), finally, the expiratory fluid (21), is the gaseous mixture that the patient exhales after inspiration. In a particular embodiment of the invention, the numerical pressure scale (7) is in a range from 0 to 60 cmH ₂ 0 and the numerical volume scale (14) is in a range from 0 to 1000 cm ³ .

It should be noted that the elongation of the bellows (9) is directly proportional to the pressure of the air contained in the bellows, therefore, the greater the pressure of the control fluid, the greater the elongation of the bellows (9).

The maximum pressure level of the air contained in the bellows (9) is preset with the pressure adjustment knob (6) and the numerical pressure scale (7).

The numerical pressure scale (7) of the pressure regulation module is corrected to directly measure the pressure of the inspiratory fluid (17). The correction consists of subtracting from the value of the numerical pressure scale (7) the elastic opposition force of the bellows (9) and the contraction force of the resuscitation bag (1); caused by the types of materials with which they are built and their structural configurations.

The functional description of the invention is presented below:

Initially, the VMV is in a state of rest, that is, there is no movement of fluids through it (Figures 1 and 2) or movement of fluids from the VMV to the patient's lungs.

Preliminary phase

• Calculation of the inspiratory volume of the patient: Normally a patient requires 6 cm ³ of inspiratory fluid for each kilogram of weight; For example, if the patient weighs 80 kg, then he needs 480 cm ³ of air-oxygen in each inspiration of each respiratory cycle.

• Determination of the patient's lung compliance: it is known that the compliance equation is C=AV/AP; Likewise, by theory it is accepted that the pulmonary compliance of an 80 kg patient is 0.06 — - — which

which is equivalent to 60 cm ³ for every 1 cmH ₂ 0 of pressure.

• Determination of the pre-setting level of the relief valve: the preliminary pre-setting level of the relief valve (4) to ventilate the 80 Kg patient is determined by applying the compliance formula P=V/C=480/60 =8 cmH ₂ 0.

Test lung ventilation

Taking the 80 kg patient as an example, the same one that requires 480 cm3 of inspiratory fluid, a test ventilatory cycle is performed as follows:

• The maximum pressure level (23) is preset at 8 cmH ₂ 0, with the adjustment knob (6), since this pressure value is adequate to achieve ventilation with 60 compliance, which is recommended for patients with 80kg

• A first test delivery is made to the patient, according to the phases of normal pulmonary ventilation (see below).

• The volume supplied to the patient is quantified with the elongation of the bellows (9).

• If the supplied volume is 480 cm ³ constants; a normal inspiratory phase is passed (see below) and the ventilatory process is continued.

• If the supplied volume is greater than the desired volume of 480 cm ³ , its level is reduced by loosening the knob (6) of the pressure regulation module. Another test lung is then performed on the patient with the MVV and the delivered volume is measured; and if at this time the value of the desired volume is approached (480 cm ³ ), the normal inspiratory phase is passed and the process of pulmonary ventilation continues.

• If the supplied volume is less than the desired volume (480 cm ³ ), the pressure level of the control fluid is increased by adjusting the knob (6). of the pressure regulation module, but only up to a limit allowed by the doctor so as not to cause barotrauma to the patient. Then, if with this increase in the pressure level the desired volume (480 cm ³ ) is supplied, the normal inspiratory phase is passed and the process of pulmonary ventilation continues.

• Then, if despite this adjustment of the knob (6) the desired volume (480 cm ³ ) has not been delivered, the frequency of manual ventilation is proportionally increased, tightening and releasing the resuscitation bag (1 ). , to compensate for the deficiency in the volume supply of the inspiratory fluid (17), and continues to ventilate cyclically at said respiratory rate.

Normal pulmonary ventilation

• Normal inspiratory phase: With the preset level on the numerical pressure scale (7) of the relief valve (4) in the preliminary phase, the user presses the resuscitation bag (1), then part of the air contained in it moves into the bellows (9), said gaseous fluid or control fluid (16) lengthens the bellows (9), according to its geometry, inside the transparent rigid chamber (8), until the pressure of the control fluid (16) contained inside the resuscitation bag (1) and chamber (2) is equal to the opposing force of the relief valve (4). In turn, the lengthening of the bellows (9) causes the displacement of the inspiration fluid (17), from inside the transparent rigid chamber (8) towards the patient's lungs (15), since the dual function valve (11 ) opens into your airway. Therefore, in this process, the manual force (18), which exerts pressure on the resuscitation bag (1), is greater than the force of the patient's pulmonary compliance (19), so that the latter does not offer opposition. to the inspiration fluid (17) that is pushed by the control fluid (16) (see figures 3 and 4). This can be seen in the trajectory of the line represented between points "a" and "b" of the pressure graph "A"; in the path of the line plotted between points "e", "f", "g" and "h" of flow graph "B"; and, in the path of the graphed line between points "k" and "I" of the volume graph "C", as shown in figure 9.

• Volume control phase: After the inspiratory phase, when the internal pressure of the control fluid (16) contained in the resuscitation bag (1) and the chamber (2), has reached the maximum pressure level

(23) preset by the user with the numerical pressure scale (7) of the pressure regulation module, the following phenomena occur: a) the control fluid is lost to the environment (16) that overcomes or exceeds the preset pressure in the relief valve (4), b) stops the increase in pressure of the control flow (16) contained in the resuscitation bag (1) and the chamber (2), c) stops the growth of the bellows (9 ), d) the inspiratory fluid (17) is stopped. The period described between the inspiratory phase and the expiratory phase is called the volume control phase, because in this period the volume remains constant at a maximum volume level.

(24), because there is no flow of inspiration or expiration despite the user continuing to press on the resuscitation bag (1). This volume can be measured directly by observing the extended end of the bellows and the numerical volume scale (14) of the transparent rigid chamber (8). Therefore, in this process, the manual force (18) is equal to the force of the pulmonary compliance (19), which stops the inspiratory fluid (17) (figures 5 and 6). This can be observed in detail in the trajectories of the lines represented between points "b" and "c" of the pressure graph "A", "h" and "i" of the flow graph "B"; and "I" and "m" of the volume graph "C" of Figure 9.

• Expiratory phase: When the resuscitation bag (1) stops being pressed by the user, said bag tends to recover its resting state, absorbing a second control fluid through the air retention valve (3); Simultaneously, the bellows (9) also returns to its rest state, absorbing a second inspiration fluid into the transparent rigid chamber (8), through the air-oxygen retention valve (10). Another simultaneous effect is that the double valve function (1 1) opens towards the expiration duct (13) so that the expiration fluid (21) goes out into the environment. Therefore, in this process, the manual force (18) is minimal or tends to zero, so the force of the pulmonary compliance (19) is the one that acts to generate the expiratory fluid (21) (see figures 7 and 8). This process can be observed in the trajectories of the lines plotted between points "c" and "d" of the pressure graph "A", "i" and "j" of the flow graph "B"; and “m” and “n” of the volume graph “C” in figure 9. This process is repeated in each respiratory cycle of the patient, as can be seen in figure 9, where graph “A” shows the level of the preset pressure, graph B shows the displacement of inspiratory fluid and expiratory fluid from the patient and graph "C" shows the controlled volumes of air and/or oxygen that are cyclically delivered to the patient.

Claims

CLAIMS A volumetric manual ventilator that cyclically supplies a series of controlled and quantified volumes of air and/or oxygen to a patient, considering their ventilation and pulmonary compliance requirements, which has a control flow supply module, a pressure regulation and ventilation ducts, which also comprise: the control flow supply module includes a resuscitation bag (1), a chamber (2) and an air retention valve (3), so that the resuscitation bag (1) and the chamber (2) are joined to form a cavity for air supply and the air retention valve (3) is located on one side of the chamber (2); the pressure regulation module includes an adjustable relief valve (4) located in the chamber (2), adjustment means (5) of the adjustable relief valve (4), a regulation knob (6) connected with the means adjustment (5) and a numerical pressure scale (7);

CHARACTERIZED BECAUSE it has a volume regulation module that includes a transparent rigid chamber (8) with at least three cavities, a bellows (9), an air-oxygen retention valve (10) and a double function valve (11), being that one of the cavities is hermetically sealed by the bellows (9), which in turn is coupled with the resuscitation bag (1) through its base, arranged in such a way that its elongation develops towards the interior of the transparent rigid chamber (8), the other cavities are hermetically sealed with the air-oxygen retention valve (10) and with the double function valve (1 1), likewise, this transparent rigid chamber (8) has a numerical scale of volume (14). The volumetric manual ventilator that supplies a series of controlled and quantified volumes of air and/or oxygen in relation to the requirements of a patient, according to claim 1, CHARACTERIZED IN THAT the numerical volume scale (14) is a set of graduations printed on the surface of the transparent rigid chamber (8). The volumetric manual ventilator that supplies a series of controlled and quantified volumes of air and/or oxygen in relation to the requirements of a patient, according to claim 1, CHARACTERIZED IN THAT the numerical pressure scale (7) is a set of graduations printed on the adjustment means (5) of the pressure regulation module. The volumetric manual ventilator that supplies a series of controlled and quantified volumes of air and/or oxygen in relation to the requirements of a patient, according to claim 1, CHARACTERIZED IN THAT the ventilation ducts include: a proximal duct (12) and a breathing tube (13), both are connected to the transparent rigid chamber (8) by means of the double function valve (1 1).