This present invention refers to a portable respiratory resuscitation device which uses a continuous-flow of oxygen whether pure or mixed with compressed air, whose pressure to be imposed to reanimated patient is controlled by two valves. It is an equipment to be used by physicians or even people having special training.

There are several equipments used for resuscitating purposes. The most commonly used are AMBUs, which consist of a part coupled to a rubber bag, the place for oxygen entrance, an outlet way for the pacient and the oxygen input. In such an equipment, the oxygen is admitted under pressure to the patient by compression of this bag; such a pressure can be watched by a pressure gage or even limited by a valve. In most of AMBUs there is neither a pressure gage nor a valve, and the pressure is controlled with base on the experience of the attending physician. In this device, the fraction of oxygen inhaled (Fi0 ₂ ) is not constant, since in most cases the mixture with the surrounding air occurs. Other point to consider is that such and equipment does not permit positive pressure at the end of expiration, in case of patient under endotracheal intubation; for newborn children, particularly premature infants, this is a relevant disadvantage. In order to improve the respiratory resuscitation, we developed a single handling device which is based on the control of a continuous-flow of oxygen or a mixture hereof with compressed air. The gas flow is admitted into a cylindrical chamber having three outled ways; one of them goes to the patient, the other contains a valve that limits the maxumum of pressure (insufflaction pressure) when the

exhalation valve (the third way of outlet) is occluded. Additionally, there is a hole which allows the coupling of a pressure age.

After defining the gas flow necessary to the patient, a Latex hose is connected from the flowmeter (existing and coupled to the source of oxygen and/or compressed air) to the admission part; the pressure gage is connected; by occluding the exhalation valve, the maximum insufflation pressure is adjusted by threading the correspondent valve. With the patient under endotracheal intubation or the proper mask coupled to the patient's outlet way, the exhalation valve is occluded,by using the operator's finger. This operation will deviate the affluent flow to the patient expanding the pulmonary alveolus, up to a level of pressure limited by the maximum insufflaction pressure limiting valve. The occlusion time of the exhalation valve - the inspiratory time - will be determined by the attending physician, and pursuant to each case. The exhalation phase will be done to the clearing of the exhalation valve. The respiratory frequency will be defined by the physician, according to the necessity of each patent.

The part has a suitable shape and size in order that an adult can handle it by using ^• only one hand. The definition of the flow will be ever determined by at least three times the value of the volume/minute; such a caution will impede the re-inhalation of the gases exhaled by the pacient.

For use in neonatology and little children, a pre-adjustment of the maximum insufflation pressure limiting valve can be done, based on a pre-defined flow (6-7 liter/minute) ; thus, with the flow stated, a scale of values is placed in the valve itself, which will correspond to pressures previously tested; this operation will dispense the use of pressure monitor, whose insertion place, in this case, will remain plugged.

The present invention can be understood even better with the

attached drawing, where Figure 1 represents and exploded view of the device.

A cylindrical chamber (8) with central outlet way (8a) ; such a way has an inner diameter of fifteen milimeters and outside diameter of twenty-two milimeters - it is the outlet way for the patient. The cylinder further has an orifice for coupling a gas pressure gage.

The part (9) is a gas admission part, which can be threaded or fastened under pressure to the part (8) . Such a part serves to admit gases within the equipment. The flow of these gases will be defined in the oxygen and/or compressed air flowmeter existing in the place of reanimation, and admitted to the equipment by means of a Latex or plastic hose. Distally to the gas admission, there are two valves : the maximum insufflation pressure valve, which is constituted by the parts (1), (2), (3), (4) and (5), which will be fastened to the main cylinder (8) by means of threading of the part (5) in the part (6) , with the aid of the part (7) . After the mouting, the assembly couples to the part (8) by threading or pressure. This valve is mounted in this following manner : the part (5) is a cylinder whose bottom has diameter smaller than the mouth. Inside this cylinder, the part (30) is inserted,the spring is placed (2) and the part is threaded (1) ; the more the part (1) is threaded over the part (5) , the more pressure of the spring over the part (3) will occur. With the increase of gas pressure inside the chamber (8) , the part (3) moves in the direction contrary to the force of the spring, thus reaching a constant pressure level; such a pressure is watched in the pressure gage. The part (4) is a threaded ring which serves to fasten the part (1) in the part (5) with the purpose of fixing the pressure defined.

The exhalation valve is composed by the parts (10) , (11) , (12) and (13) ; this valve is fixed to the main cylinder (8) by threading, sticking or casting.The exhalation valve is mounted in the following manner: the valve body (10) is an open bottom cylinder which communicates with the main chamber (8) . It

receives a spring (11) , a cursor (12) and a screw cap (13) ; The more the part is threaded (13) over the part (10) , the nearest the cursor (12) will be placed from the base hole of the part, thus difficulting the gas leakage through the part; the purpose of this operation is to retain pressure within the main chamber (8) ; It is the positive pressure in the end of the expiration that will benefit many patients in ventilating attendance. By pressing the part (12) which protrudes in the part (13) , the resistance of the spring (11) is overcome, occluding totally this outlet way. The pressure inside the main chamber will rise - due to the continous - flow of gases admitted - until the limit defined by the maximum insufflation pressure valve; By depr.βss.i'ng .the cursor (12) of the exhalation valve, the pressure drops down to the minimum limit defined in its own adjustment. The gas leakage occurs by the lateral holes existing in the cylinder (10) . The occlusion time of the exhalation valve - inspiratory time - will be determined by the attending physician and according to each case; the exhalation phase will be done to the cursor (12) decompression.

Every pressure generated within the equipment will be transmitted to the patient's aerial way under ventilating attendance, when it is coupled to said way,under endotracheal intubation or mask (8) . The flow will be defined by the attending physician; in order to avoid re-inhalation, such a flow should be at least three times the volume/minute.

We think that such a device will improve significantly the conditions of the respiratory resuscitation of patients with life risk, since:

1) it permits to supply a constant Fi0 ₂ , up to 100%;

2) it permits to limit continuously the maximum insufflation pressure;

3) it permits to reach a positive pressure in the end of the expiration;

4) it permits to maintain the patient in ventilating

attendance, even without activating the equipment (under CPAP

- continuous positive airway pressure;

5) it permits to couple a gas pressure monitor in order to monitor the pressures to which the patient will be submitted; 6) it permits to operate the respiratory ^■ resuscitation manually, with minimum effort of the operator;

7) it permits to eliminate or reduce to minimum levels the possibility of re-inhalation of gases exhaled.

The unit can be used in Intensive Care Units, nursery, transportation of patients who need ventilation support,

Emergencial Units, Anesthesiology and other situations in which the transitory ventilation support to patients is necessary.