Patent Application
20150224278
The present invention relates to medical ventilators used to assist breathing in a patient, and more particularly, this invention relates to nebulizers used with mechanical and other medical ventilators.
Medical ventilators mechanically move breathable air into and out of a patient's lungs and provide the mechanism of breathing for the patient, who typically is physically unable to breathe or is breathing insufficiently. Positive pressure ventilators are common where air or another gas mixture is forced by pressure into the trachea using an endotracheal tube that rests in the trachea and usually held in position by an inflatable balloon positioned at the end of the endotracheal tube, which allows the endotracheal tube to sit securely in the airway. The positive pressure ventilator works by increasing the patient's airway pressure through the endotracheal tube or in some examples, through a tracheostomy tube that allows the positive pressure air to flow into the airway until the cyclical ventilator pressure imparting the breath is terminated. The elastic recoil of the chest wall and lungs force the breath out using as a passive exhalation. Other mechanical ventilators include transport ventilators, intensive care ventilators, neonatal ventilators and the ubiquitous positive airway pressure ventilator (PAPA) as a form of non-invasive ventilation used at home for treatment of sleep apnea or COPD (Chronic Obstructive Pulmonary Disease).
Ventilators are often used during surgery when a patient is under anesthesia, or suffering a debilitating disease or has some other chronic condition that impairs the patient's lung function such that mechanical ventilation is required to help the patient breathe. Such debilitating problems may result from pneumonia, COPD, upper spinal chord injuries, polio, Amyotrophic Lateral Sclerosis (ALS), brain injury, stroke, drug overdose, or other diseases that affect the nerves and muscles involved in breathing.
To aid in a patient's recovery or for administering medication to a patient who may not be able to ingest or swallow such drugs, aerosol drugs are commonly administered to the patients during mechanical ventilation. The ventilator circuit may incorporate jet nebulizers or similar nebulizer devices that nebulize medication for delivery to a patient through a heated/humidified ventilator circuit. These devices are often placed in the manifold position or other locations within the ventilator circuit to provide a patient with a nebulized medication in an efficient manner. Even slight improvements in nebulizer design would be beneficial to enhance the positive effects of the ventilation.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
A nebulizer, in accordance with a non-limiting example, includes a tubular nebulizer housing having an outer surface and opposing ends defining an inlet and outlet configured to be connected in line with an inspiratory air line of a ventilator and forming an air path along a longitudinal axis through which air is delivered to a patient from a ventilator. A nebulizer nozzle is carried within the nebulizer housing and aligned with the longitudinal axis and has a gas intake end and a gas discharge end through which gas is mixed with medication and discharged into the air path. A medication receiver is carried on the outer surface of the nebulizer housing proximal to the nebulizer nozzle and formed to receive a medication container. A suction line extends from the discharge end of the nebulizer nozzle through the outer surface of the nebulizer housing into the medication receiver and draws medication upward from a medication container received within the medication receiver and mixes the medication with gas passing through the nebulizer nozzle and nebulizes the medication for discharge into the air path to a patient.
In one example, the nebulizer nozzle is formed as a venturi that is horizontally oriented when the nebulizer is connected into a ventilator inspiratory air line. A gas inlet line, in one example, is connected to the gas intake end of the nebulizer nozzle and extends through the outer surface of the nebulizer housing. In yet another example, the nebulizer housing includes first and second tubular housing members that are longitudinally aligned and connected together. One of the tubular housing members carries the nebulizer nozzle, medication receiver and suction line.
In yet another example, the medication receiver is formed as a cylindrical wall member carried on the outer surface of the tubular nebulizer housing. The suction line extends into the area defined within the cylindrical wall member. A medication container is received within the cylindrical wall member of the medication receiver and dimensioned to hold medication that is drawn upward through the suction line. A twist lock slot is formed in the cylindrical wall member and a lock protrusion is formed on the medication container that is received in the twist lock slot to lock the medication container within the medication receiver. A valve communicates with the gas intake end of the nebulizer nozzle and is configured to actuate a flow of gas through the nebulizer nozzle during each inspiratory phase of the respiratory cycle of the patient. A low pressure mixing chamber may be formed at the gas discharge end of the nebulizer nozzle. A continuous pressure is provided at the gas intake end. In an example, at standard temperature and pressure (STP), a differential pressure results in no medication being drawn upward through the suction line for nebulization until a predetermined negative inspiratory pressure is created such as occurs during the inspiratory phase of the patient's respiratory cycle.
In yet another example, a ventilator system is disclosed and includes a ventilator and an inspiratory air line connected to the ventilator through which pressurized air is provided to a patient from the ventilator. An expiratory air line is connected to the ventilator. A nebulizer as described above, for example, is connected within the inspiratory air line. A humidifier may be connected within the inspiratory air line and the nebulizer connected within the air line between the ventilator and the humidifier or connected within the expiratory air line between a patient and the humidifier.
A method aspect is also disclosed of delivering a nebulized medication to a ventilated patient by connecting the nebulizer as described above in-line with the inspiratory air line and connected to a ventilator through which pressurized air is provided to a patient. Gas is passed through the gas intake end of the nebulizer nozzle, and thus, medication is drawn upward from the medication container within the medication receiver and mixes the medication with the gas to nebulize the medication and discharge it into the air path to a patient.
Other objects, features and advantages of the present invention will become apparent from the detailed description of the invention which follows, when considered in light of the accompanying drawings in which:
Different embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown. Many different forms can be set forth and described embodiments should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art.
In this example, a nasogastric/orogastric (Ng/Og) tube 32 extends through the patient's nose and into the stomach and provides different medical functions, including feeding the patient through the tube in one example and sucking stomach contents when necessary. An example of a Ng/Og tube 32 that may be used as illustrated includes those Ng/Og tubes disclosed in commonly assigned U.S. Pat. No. 8,597,184 and U.S. Patent Publication Nos. 2011/0046653 and 2011/0040211, the disclosures which are hereby incorporated by reference in their entirety. Those particular examples include a nasogastric/orogastric (Ng/Og) airway protection device that includes an inflatable esophageal cuff that protects the patient's airway from reflux or other stomach contents that may be regurgitated. That disclosed Ng/Og tube also provides the capability to induce an involuntary reflex cough test by imparting an irritant such as tartaric acid into the airway through a nebulizer lumen. The nebulizer 40 in accordance with a non-limiting example is shown connected into the inspiratory air line 18 of the ventilator 16 and horizontally configured. It is supported on a nebulizer support frame 42 that connects onto the ventilator housing 44.
As illustrated, the nebulizer 40 is connected within the inspiratory air line 18 between the ventilator 16 and the humidifier 22 in the example shown in
Referring now to
A nebulizer nozzle 64 is carried within the nebulizer housing 44, and in the example shown in
A medication receiver 74 is formed on the outer surface 50 of the nebulizer housing 48 proximal to the nebulizer nozzle 64 and formed to receive a medication container 76 as illustrated, such that the suction line 72 extends from the gas discharge end 68 of the nebulizer nozzle 64 through the outer surface 50 of the nebulizer housing to the medication receiver 74 and draws medication upward from the medication container 76 inserted within the medication receiver and mixes the medication with gas passing through the nebulizer nozzle and nebulizes the medication for discharge into the air path 51 to a patient.
In this example, the medication receiver 74 is formed as a cylindrical wall member 78 positioned on the outer surface of the tubular nebulizer housing 48 proximal to the suction line 72 that extends through the outer surface 50 of the tubular nebulizer housing 48. The suction line 72 extends into the area (or volume) defined within the cylindrical wall member 78. The medication container 76 is received within the cylindrical wall member 78 of the medication receiver and is dimensioned to hold medication that is drawn upward through the suction line 72 that extends downward into that area or volume defined by the cylindrical wall of the medication receiver 74.
In this example, the medication container 76 is cup-shaped with cylindrical wall 80 and a curved or cup-shaped bottom 82 as best shown in
As illustrated, the nebulizer nozzle 64 is aligned with the longitudinal axis and has a gas intake end 66 and a gas discharge end 68 through which the gas is mixed with the medication drawn upward through the suction line 72 and discharged into the air path as illustrated. The nebulizer nozzle 64 is formed as a venturi 70 in the example of
In the example shown in
FIG. B is another embodiment of the nebulizer showing a different nebulizer nozzle, but still configured as a venturi, and also having a low pressure mixing chamber formed at the gas discharge end of the nebulizer nozzle. For purposes of description, similar elements in this example nebulizer of FIG. 8 are given the same reference numerals as before, except given in the 100 series.
Continuous pressure is provided at the gas intake end 166 wherein at standard temperature and pressure (STP), a differential pressure results in no medication being drawn upward through the suction line 172 for nebulization until a predetermined negative inspiratory pressure is created during the inspiratory phase of the patient's respiratory cycle. In this example, the nebulization is drawn upward through the suction line 172 into the mixing chamber 200 during that time when the ventilator is in a positive pressure cycle that is equivalent to the inspiratory phase of the patient's respiratory cycle such as when a negative inspiratory pressure is created when a patient is breathing in.
An example of a similar nebulizer structure is disclosed in commonly assigned U.S. patent application Ser. No. 13/353,611 and Ser. No. 13/799,196, the disclosures which are hereby incorporated by reference in their entirety. This embodiment includes a much longer and gradual taper to the venturi 170 as illustrated and a secondary suction line 202 that interoperates with the mixing chamber. A baffle or diffuser 204 is located proximal to the mixing chamber.
The suction line 170 acts as a primary suction line and the secondary suction line 202 aids in drawing nebulized medication that drops down before discharge through the nebulizer outlet due to the further break-up from the diffuser or baffle 204. Further details of the operation of such a nebulizer is explained in the incorporated by reference '611 and '196 applications. Although not illustrated in detail, the structure in
It is also possible to use an air flow sensor 193 to measure air flow and send a signal back to the gas valve 192 and either actuate or modify air flow through the nebulizer nozzle 164. The air flow sensor 193 could be positioned at the nebulizer outlet and sense inspiratory pressure. The droplet sizes of the nebulized medication can vary and can be small or less than 0.1 microns. The air flow can vary from 2 liters up to 15 liters air flow in one non-limiting example.
It is also possible to use the nebulizer in both a pressure limited ventilation or the volume cycled ventilation. During a pressure limited ventilation, the nebulizer is driven continuously. The nebulizer can also be operated under pulsed operation such as disclosed in U.S. patent application Ser. No. 14/166,882 filed Jan. 29, 2014, the disclosure which is hereby incorporated by reference in its entirety. This nebulizer used with a ventilator provides a horizontal venturi nozzle (HVN) and directly nebulizes in the inhalation circuit of the ventilator. There is less distance to the deposition area and little condensation with low residual volume. Small volume but high concentrated medications can be applied.
Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.
