# Patent

## Title
Nitrous oxide anesthetic administration system

## Abstract

The present invention is a method and system for administering nitrous oxide. The system includes a fluid control system for controlling the flow of nitrous oxide and oxygen to the patient. A nitrous oxide and oxygen supply, vacuum source, a breather bag, and a nasal delivery interface system are fluidly connected to the fluid control system and a patient. The fluid control system also includes a safety scavenge system including a mass airflow sensor, master controller, nitrous oxide valve, and alarm. The mass airflow sensor reads the scavenging vacuum pressure which it communicates to the master controller. Depending upon the scavenging vacuum pressure, the master controller can activate an alarm or shut off the flow of nitrous oxide. In operation, the present invention provides a system for administering anesthesia/analgesia gas which prevents excessively high volumes of exhaled nitrous oxide in the operatory environment through monitoring of the scavenge vacuum pressure.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This continuation application is related to and claims priority from earlier filed continuation-in-part application Ser. No. 12/890,176 filed Sep. 24, 2010, non-provisional patent application Ser. No. 12/567,729 filed Sep. 25, 2009, and provisional patent application Ser. No. 61/100,149, filed Sep. 25, 2008, all of which are incorporated herein by reference.


BACKGROUND OF THE INVENTION
The present invention relates to a system for administering gas. More particularly, the present invention relates to a system for administering anesthesia/analgesia gas which provides convenient, direct access by a medical practitioner, a clear line of vision for the medical practitioner, and flexibility to accommodate the patient and medical professional's needs.
N2O analgesia has been used for over a century to successfully relax and sedate dental patients. Originally and until recently the application of these gages was virtually unrestricted and thus the supply system required was relatively unencumbered. With the advent of mandatory scavenge systems for nitrous delivery, these units became much more bulky and difficult to use in day to day practice and this utilized rate declined.
Typically, the compressed medical gages are delivered to the practitioner's facility in gas cylinders. These cylinders either connect to a central distribution system, serving multiple operating rooms, or they are portable and are mounted on rolling carts which serve one operating room and patient. These cylinders are connected via hoses or piping to a regulating system which controls delivery pressure, flow rate and blended ratio. There are monitors, gages and other devices to provide information to the practitioner regarding the delivery parameters. From the control device, gas flows via flexible hoses to a nasal delivery interface device. As shown in FIG. 1, vacuum scavenging of expelled gases flows from the nasal delivery interface device, via flexible tubing, into the centralized building vacuum utility system.
These essential components are incorporated into support systems. Systems commonly found in the art fall into three general categories: a) cart mounted tanks and controls, b) cart mounted controls and c) wall or stationary cabinet mounted controls.
Cart mounted tanks and control systems utilize an open or closed, wheeled cart. (FIGS. 4, 9). Portable O2 and N2O tanks are mounted on the cart. The control system and breather bag are usually mounted on a center pole attached to an open cart or supported by the shell of an enclosed cart. The patient supply tubing connects the cart outlet to the nasal delivery interface device. Referring to FIG. 2, the scavenging tubing connects the nasal delivery interface device via flexible tubing into the centralized building vacuum utility system.
As illustrated in FIGS. 1-2, current systems running from the control devices to the nasal delivery interface device use multi lumen hose systems which are long, heavy, complex and somewhat stiff. They pull on the patient's head and limit practitioner accessibility to the patient's mouth area. As a result they also limit the ability of the practitioner to reposition the patient's head.
Cart mounted control systems are similar to those above, except that the O2 and N2O are supplied from a central source via floor or wall gas outlets rather than from in situ tanks. Flexible hoses route the gases from the outlet to the control system. The control system and breather bag are mounted on a center pole attached to an open, wheeled cart. The patient supply tubing connects the cart outlet to the nasal delivery interface device. The scavenging tubing connects the nasal delivery interface device via flexible tubing into the centralized building vacuum utility system.
As illustrated in FIG. 3, wall and cabinet mounted systems have the O2 and N2O gas supplied via flexible or rigid tubing from a central source. This tubing is enclosed in the walls of the operatory with other centralized utilities. The control system and breather bag are mounted to the wall or cabinet unit. The mounting may be a flush mount, surface or articulated arm mount design. Long patient supply tubing connects the control systems to the nasal delivery interface device on the patient. Long scavenging system tubing connects the nasal delivery interface device into the centralized building vacuum utility system.
Also, wall mounted systems are typically separated from the patient chair by a work surface or passageway. Wall mount systems have long hose lengths between the control devices and the nasal delivery interface device. The longer the hose length, the longer the latency period between changing a control setting and the patient actually receiving that changed gaseous output. In addition, the hose position and length interferes with operator positioning. Tubing runs from the wall mounted, control system outlet to the nasal delivery interface device. This tubing crosses a passageway or work surface and blocks or encumbers which ever of these it traverses.
As illustrated in FIGS. 4-8, cart mounted systems can be located behind one of the practitioners or tucked under the back of the patient chair. In either case, visual monitoring of critical information in impeded. This is a dangerous situation because unknown changes occurring in the gaseous anesthetic system can be detrimental to the patient. Additionally, excess gas expelled into the operatory is harmful to the practitioners.
Also, carts located in the passageways, or workplace around the patient chair, cause inference as the practitioners move around the patient. Staff can trip over the carts and be injured and the flow of other technology and emergency access is impeded. As well as the cost of damaging an anesthetic system, rupturing any high pressure, 2000 psi, system can be very dangerous to all occupants of the operatory.
There are two main drawbacks of the systems describe above. First, current systems usually put the system controls out of direct reach of the medical professional when he/she is seated in normal treatment positions. This limitation is especially burdensome with wall mounted systems. This makes it difficult for the medical professional to accomplish anesthetic system adjustments without walking around or reaching around the patient. This awkward arrangement slows access and response to emergency situations. Second, current systems often put monitoring device displays and gauges out of direct view of the doctor and assistant.
Therefore, it would be particularly desirable to provide a system or method for anesthesia/analgesia gas delivery provides a nitrous oxide anesthetic administration system which provides convenient, direct access by a medical practitioner, a clear line of vision for the medical practitioner, and flexible to accommodate the patient and professional's needs. Currently, there is no known nitrous oxide anesthetic administration system in the prior art which provides these benefits.
BRIEF SUMMARY OF THE INVENTION
An embodiment of the present invention preserves the advantages of prior art nitrous oxide anesthetic administration systems or methods. In addition, it provides new advantages not found in currently available nitrous oxide anesthetic administration systems or methods and overcomes many disadvantages of such currently available nitrous oxide anesthetic administration systems or methods.
The present invention is a system for administering nitrous oxide which is preferably attached to a patient chair. The system generally includes: a mounting surface structure, a fluid control system attached to the mounting surface structure, a nasal delivery interface system connected to a patient and fluid control system, a nitrous oxide and oxygen supply connected to the fluid control system, a vacuum source for scavenging, a breather bag connected to the fluid control system, a mounting plate assembly to interface with patient or dental chairs, an adjustable post mechanism attached to the mounting plate assembly and the mounting surface structure, supply gas connectors and mixed gas output connectors attached to the fluid control system, and other hardware and tubing that is necessary to administer nitrous oxide in a health care environment, preferably a dentist's office.
The system includes an adjustable post mechanism attached to a patient or dental chair. The adjustable post mechanism is attached to a mounting plate assembly which is attached to a lower portion of a patient chair. The adjustable post mechanism is configured for height adjustment and pivotal adjustment to provide convenience of use to a practitioner.
The mounting surface structure includes a top surface and a bottom surface. The bottom surface of the mounting surface structure is attached to a top end of the adjustable post mechanism. The mounting surface structure positioned along a horizontal axis or approximately 180 degrees. The mounting surface structure attached to a breather bag a proximal end and a fluid control system at a distal end closest to a practitioner.
A fluid control system for controlling the flow of nitrous oxide and oxygen is attached to the mounting surface structure. The fluid control system including a fluid flow meter mounted on a top surface of the fluid control system. A display of the fluid flow meter positioned along a vertical axis at less than 90 degrees relative to the mounting surface structure to provide a better view to the practitioner. A nitrous oxide and oxygen supply fluidly connected to the fluid control system using fluid connectors fixedly attached to the bottom surface of said mounting surface structure.
A nasal delivery interface system fluidly connected to the fluid control system. The nasal delivery interface system including a single scavenging tube and a single nitrous oxide and oxygen tube fluidly connected to a single nasal delivery mask. The fluid control system including a mixed gas output connector fluidly connected to the single nitrous oxide and oxygen tube. A vacuum source fluidly connected to the single scavenging tube for scavenging excess gases and the fluid control system.
A breather bag is vertically mounted to a top surface of the mounting surface structure. The breather bag positioned along a vertical axis or about 90 degrees depending upwardly from the mounting surface structure. The breather bag mounted rearward or behind of the fluid control system to allow full view of fluid flow meter display. The breather bag fluidly connected to the control system by way of an elongated tubular structure attached to a front surface of the fluid flow meter.
The fluid control system also includes a safety scavenge system including a mass airflow sensor, master controller, nitrous oxide valve, and alarm. The mass airflow sensor reads the scavenging vacuum pressure which it communicates to the master controller. Depending upon the scavenging vacuum pressure, the master controller can activate an alarm or shut off the flow of nitrous oxide. In operation, the present invention provides a system for administering anesthesia/analgesia gas which prevents excessively high volumes of exhaled nitrous oxide in the operatory environment through monitoring of the scavenge vacuum pressure.
The safety scavenge system more specifically includes the following components. The mass airflow sensor for reading scavenging vacuum pressure is fluidly connected to the scavenging tube before the vacuum source. The master controller in electrical communication with the mass airflow sensor for receiving the scavenging vacuum pressure reading from the mass airflow sensor which is compared to a predetermined range. A visual alarm is in electrical communication with the master controller which instructs the visual alarm to activate if the scavenging vacuum pressure is less than a first predetermined range. An audio alarm is in electrical communication with the master controller which instructs the audio alarm to activate of the scavenging vacuum pressure is less than a second predetermined range. A nitrous oxide valve is fluidly connected to the nitrous oxide supply and in electrical communication with the master controller which shuts off the nitrous oxide shut-off valve when the scavenging vacuum pressure is less than a third predetermined range.
In operation, the present invention provides a system for administering anesthesia/analgesia gas which provides convenient and direct access to a medical practitioner. The practitioner connects the nasal delivery interface system to the patient and to the fluid control system. After the nasal mask is attached to the patient, the nitrous oxide/oxygen gas is turned on and the gas enters a single tube fluidly connected with a nasal delivery mask. Throughout the administration of the gas, the system allows the practitioner a direct view and a close proximity to the upright breathing bag, fluid control system including display, patient, and all other parts of the nitrous oxide administration system which makes the administration of the gas much more efficient, safe, and less time consuming. Also, the mounting of the nitrous oxide anesthetic administration system to a patient's chair provides greater stability and convenience to a practitioner.
When the vacuum source is operational, any excess gases are scavenged from the patient through the nasal delivery mask, along a single scavenging tube, and returns back through the fluid control system. By only having two tubes, the patient and practitioner are given additional space and movement and reduce the possibility of entanglement.
In addition, the present invention includes the following method for administering nitrous oxide to a patient. First, a fluid generated by a vacuum source is provided. Second, nitrous oxide fluid from a nitrous oxide source is provided. Third, a means for scavenging excess nitrous oxide is in fluid connection with the nitrous oxide source and the vacuum source. Fourth, a safety scavenge system is connected to the fluid connection between the nitrous oxide source and the vacuum source. The safety scavenge system includes a mass airflow sensor, master controller, alarm, and nitrous oxide valve. Fifth, the means for scavenging excess nitrous oxide is connected to the vacuum source and the nitrous oxide source onto a patient. Sixth, a flow rate flow rate of the vacuum source is increased to provide fluid into the safety scavenge system. Seventh, nitrous oxide is released through the safety scavenge system upon the vacuum source reaching a predetermined range. Eighth, excess nitrous oxide is retrieved from the means for scavenging excess nitrous oxide using the vacuum source. Ninth, the vacuum source is decreased below the third predetermined range which prevents the safety control valve from releasing nitrous oxide. The safety scavenge system actuated by flow fluids to control the release of nitrous oxide therethrough.
It is therefore an object of the present invention to provide a method or system for a nitrous oxide anesthetic administration system which provides convenient access to nitrous oxide for a practitioner and patient.
It is a further object of the present invention to have direct access to the fluid control system and patient during administration of the nitrous oxide.
It is also an object of the present invention to provide a clear line of vision for the medical practitioner and flexibility to accommodate the patient and practitioner's needs.
Another object of the present invention is to eliminate the problems associated with current nitrous oxide delivery and scavenging systems.
Furthermore, another object of the present is to provide greater safety to patients and medical or dental persons during release of nitrous oxide in a medical or dental office.
A further object of the present invention is to provide a system for administering anesthesia/analgesia gas which prevents excessively high volumes of exhaled nitrous oxide in the operatory environment through monitoring of the scavenge vacuum pressure
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
The novel features which are characteristic of the nitrous oxide anesthetic administration systems and methods are set forth in the appended claims. However, the nitrous oxide anesthetic administration systems and methods, together with further embodiments and attendant advantages, will be best understood by reference to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a prior art nitrous oxide anesthetic administration system;
FIG. 2 is prior art nasal delivery interface device;
FIG. 3 is a prior art wall mounted nitrous oxide anesthetic administration system;
FIG. 4 is a prior art cart mounted nitrous oxide anesthetic administration system;
FIG. 5 is a prior art cart mounted nitrous oxide anesthetic administration system;
FIG. 6 is a prior art cart mounted nitrous oxide anesthetic administration system of FIG. 5;
FIG. 7 is a prior art cart mounted nitrous oxide anesthetic administration system of FIG. 5;
FIG. 8 is a prior art cart mounted nitrous oxide anesthetic administration system of FIG. 5;
FIG. 9 is a prior art nitrous oxide anesthetic administration system;
FIG. 10 is a left side view of the nitrous oxide anesthetic administration system of the present invention;
FIG. 11 is a right side view of the invention of FIG. 10;
FIG. 12 is front perspective view of the invention of FIG. 10;
FIG. 13 is a partial left side view of the invention of FIG. 10;
FIG. 14 is a left side view of the invention of FIG. 10;
FIG. 15 is a rear perspective view of the invention of FIG. 10;
FIG. 16 is a sample of prior art dental chairs which can be utilized with the present invention;
FIG. 17 is a close-up view of a bottom portion of the present invention;
FIG. 18 is close-up view of gas connectors used with the present invention;
FIG. 19 is a front perspective view of the present invention; and
FIG. 20 is a schematic illustration of another embodiment of the present invention which includes a safety scavenging system.



DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 10-19, a nitrous oxide anesthetic administration system 10 of the present invention is shown. The present invention is a nitrous oxide administration system 10 which provides convenient, direct access by a medical practitioner, a clear line of vision for the medical practitioner, and flexibility to accommodate the patient and medical professional's needs.
It should be understood that this invention is well suited and preferably used in a dental office environment; however, it may be used in any environment where delivery of objects to a work area is desired. The invention will be disclosed herein in connection with a dental office environment; however, the present invention is not intended to be limited to that particular use and may be used in any health care setting or any setting where a nitrous oxide is required. The configuration of the system components may vary depending on variations in the patient chair, physical site constraints and on the needs of a particular dental practice
Most importantly, the nitrous oxide administration system 10 includes a mounting surface structure 20 and adjustable post mechanism 30 which is mounted directly to a patient chair 500 using a mounting plate assembly 40. A system for delivering nitrous oxide is attached to the mounting surface structure 20 or adjustable post mechanism 30 to provide convenient and direct access to the practitioner for delivering the nitrous oxide to the patient, which will be further explained herein.
The nitrous oxide anesthetic administration system may include some elements of prior art nitrous oxide delivery systems. For example, it may include a low-vacuum fluid generated by a vacuum source, a nitrous oxide fluid provided by a nitrous oxide source, and a scavenging mask. In addition, the nitrous oxide safety system may also include an oxygen source, mixing valve, flow meter, breathing bag, and tubing or lines. Note, the nitrous oxide anesthetic administration system of the present invention may also include elements of the system disclosed in “Nitrous Oxide Safety System” (Non-Provisional patent application Ser. No. 12/398,783 filed Mar. 5, 2009).
Referring to FIG. 1, the present invention is a system for administering nitrous oxide 10 which is preferably attached to a patient chair 500. The system generally includes: a mounting surface structure 20, a fluid control system 50 attached to the mounting surface structure 20, a nasal delivery interface system 60 connected to a patient and fluid control system 50, a nitrous oxide and oxygen supply (not shown) fluidly connected to the fluid control system 50, a vacuum source (not shown) for scavenging excess gases, a breather bag 70 fluidly connected to the fluid control system 50 and mounted to the mounting surface structure 20 in a vertical orientation, a mounting plate assembly 40 (FIG. 17) to interface with patient or dental chairs from multiple manufacturers, an adjustable post mechanism 30 attached to the mounting plate assembly 40 and the mounting surface structure 20, supply gas connectors 80A, 80B (FIG. 18) and mixed gas output connector 90 attached to the fluid control system 50, and other hardware, software, lines, and tubing that are necessary to administer nitrous oxide in a health care environment, preferably a dentist's office.
The system includes an adjustable post mechanism 30 attached to a patient or dental chair 500. The adjustable post mechanism 30 may include a cylindrical post 30A that is both pivotally and height adjustable within a corresponding sleeve 30B. The post 30A may slidably engage within the sleeve 30B and may be positioned in a fixed or temporary position when necessary. The post 30A may be secured into a position by use of methods known in the art including ratcheting mechanisms or a tightening collar. The adjustable post mechanism 30 is configured and arranged for height adjustment and pivotal adjustment to provide convenience of use to a practitioner.
The adjustable post mechanism 30 is attached to a mounting plate assembly 40 which is attached to a lower portion of a patient chair 500. Referring to FIG. 17, the mounting plate assembly 40 may include a chair attachment structure 42, a base plate 44, and a vertical extension structure 46 connecting the chair attachment structure 42 and the base plate 44. The base plate 44 defines an aperture for receipt of a bottom end of the adjustable post mechanism 30. The base plate 44 is attached to the adjustable post mechanism 30 with sufficient strength and can accommodate a wide range of adjustable post mechanisms 30. The base plate 44 lies along a horizontal axis. The chair attachment structure 42 is connected or attached to a bottom or lower portion of a patient chair 500 at a proximal end. The chair attachment structure 42, at the distal end, attaches to an extension structure 46 using methods known in the art. The extension structure 46 attaches to the chair attachment structure 42 and the base plate 44. In one embodiment, the extension structure 46 extends downwardly from the chair attachment structure 42 and is secured, at a top end, to the chair attachment structure 42 using a bolt or other fastener. The base plate 44 then attaches to a bottom end of the extension structure 46. Once the chair attachment structure 42, extension structure 46, and base plate 44 are secured to one another, they form a mounting plate assembly 40 for possible adaptation to other chairs made by various manufacturers. It should be noted that the mounting plate assembly 40 may interface with a variety of patient chairs 500A-E from multiple manufacturers as illustrated in FIG. 16.
The mounting surface structure 20 includes a top surface and a bottom surface. The bottom surface of the mounting surface structure 20 is attached to a top end of the adjustable post mechanism 30. The mounting surface structure 20 is positioned along a horizontal axis or approximately 180 degrees. The mounting surface structure 20 is attached to the breather bag 70 at a proximal end and a fluid control system 50 at a distal end closest to a practitioner.
Referring to FIGS. 14 and 19, a fluid control system 50 for controlling the flow of nitrous oxide and oxygen is attached to the mounting surface structure 20. The fluid control system 50 includes a fluid flow meter 52 mounted on a top surface of the fluid control system 50. A display of the fluid flow meter 52 is positioned along a vertical axis at less than 90 degrees, preferably between 30 degrees to 45 degrees, relative to the mounting surface structure 20 to provide a better view to the practitioner. Referring to FIG. 18, the nitrous oxide and oxygen supply (not shown) is fluidly connected to the fluid control system 20 using fluid connectors 80A, 80B fixedly attached to the bottom surface of said mounting surface structure 20. The fluid control system 50 also includes an emergency air intake port.
Referring to FIGS. 12-13, a nasal delivery interface system 60 is fluidly connected to the fluid control system 50. The nasal delivery interface system 60 includes a single scavenging tube 60B and a single nitrous oxide and oxygen tube 60A fluidly connected to a single nasal delivery mask 62. The fluid control system 500 including a mixed gas output connector 90 fluidly connected to the single nitrous oxide and oxygen tube 60A. A vacuum source (not shown) is fluidly connected to the single scavenging tube 60B for scavenging excess gases and the fluid control system 50. Note, the vacuum source may be provided by a variety of methods known in the art.
Referring to FIG. 15, the breather bag 70 is vertically mounted to a top surface of the mounting surface structure 20. The breather bag 70 is positioned along a vertical axis or about 90 degrees depending upwardly from the mounting surface structure 20. The breather bag 70 is mounted rearward or behind the fluid control system 50 to allow full view of fluid flow meter display 52. The breather bag 70 is fluidly connected to the control system 50 by way of an elongated tubular structure 72 attached to a front surface of the fluid flow meter 52.
In operation, the present invention provides a system for administering anesthesia/analgesia gas 10 or any type of gases which provides convenient and direct access to a medical practitioner. The practitioner connects the nasal delivery interface system 60 to the patient and to the fluid control system 50. After the nasal mask 62 is attached to the patient, the nitrous oxide/oxygen gas, or anesthetic, is turned on and the gas enters a single tube 60A fluidly connected with the nasal delivery mask 62. Throughout the administration of the gas, the system 10 allows the practitioner a direct view and a close proximity to the upright breathing bag 70, fluid control system 50 including display 52, patient, and all other parts of the nitrous oxide administration system 10 which makes the administration of the gas much more efficient, safe, and less time consuming. Also, the mounting of the nitrous oxide anesthetic administration system 10 to a patient's chair provides greater stability and convenience to a practitioner.
In summary, the present invention provides a system for administering anesthesia/analgesia gas 10 which provides convenient, direct access by a medical practitioner, a clear line of vision for the medical practitioner, and flexibility to accommodate the patient and medical professional's needs. The present invention is a novel configuration which mounts the control system, monitoring devices, safety devices and breather bag which mounts directly or indirectly to the patient chair.
Some of the benefits of the proposed novel invention are as follows. The present invention shortens hoses from the fluid control system to the patient to reduce cost, complexity and weight. The present invention minimizes control input to nasal delivery interface device output (latency) by at least 50% by shortening hose length. The present invention minimizes patient head access limitation and movement restriction by minimizing hose lengths, stiffness and multiples. The present invention eliminates dual hoses for each of: O2/N2O and scavenge. The present invention puts controls within direct, forward reach of doctor (from normal treatment position) throughout procedure. The preset invention puts displays and gauges in direct view of doctor and assistant throughout procedure to enhance practitioner and patient safety. The present invention provides open passage around patient and patient support chair by eliminating support cart. The present invention provides open passage around patient and patient support chair by eliminating tubing crossing passageways. The present invention eliminates potential of toppling cart and damaging systems by eliminating tubing crossing passageways. The present invention eliminates the potential danger caused by damaging a high pressure gas system. The present invention maximizes visibility of breather bag by doctor and assistant throughout procedure by orienting breather bag, or bellows, superior to inlet rather than current designs which hang breather bags inferior to their inlet. The present invention reduces patient anxiety prior to their procedure by reducing the visual impact of the anesthetic apparatus. The present invention minimizes system size, complexity and cost. The present invention has system configuration adaptable to all operatory configurations. The present invention has a system capable of mounting to most commercially available patient chairs via model specific interface plates. Most importantly, the present invention mounts directly to the patient chair to accomplish all of the above.
Now referring to another embodiment of the present invention as schematically illustrated in FIG. 20 which includes a fluid control system 50 having a safety scavenge system 200. The safety scavenge system 200 includes a mass airflow sensor 210, master controller 220 which includes a CPU or processor, nitrous oxide valve 250, and various alarms 230, 240. The mass airflow sensor 210 reads the scavenging vacuum pressure which it communicates to the master controller 220. Depending upon the scavenging vacuum pressure and a set of predetermined ranges, the master controller 220 can activate an audio alarm 240, visual alarm 230, or shut off the nitrous oxide valve 250. In operation, the present invention provides a system for administering anesthesia/analgesia gas which prevents excessively high volumes of exhaled nitrous oxide in the operatory environment through monitoring of the scavenge vacuum pressure.
The safety scavenge system 200 more specifically includes the following components. It should be noted that the safety scavenge system 200 may be available within the fluid control system 50 as an internal component or as a standalone unit attached between the flow meter nitrous oxide inlet and nitrous oxide gas source or supply. The mass airflow sensor 210 for reading scavenging vacuum pressure is fluidly connected to the scavenging tube 60B before the vacuum source 100. The master controller 220, including a CPU or processor, in electrical communication with the mass airflow sensor 210 for receiving the scavenging vacuum pressure reading from the mass airflow sensor 210 which is compared to a predetermined range.
In one embodiment, the predetermined range is related to the American Dental Association's recommended 45 LPM (liters per minute) scavenge vacuum when nitrous oxide is in use. Typically, if scavenge pressure falls below the 45 LPM, it will trigger a light or visual alarm (less than 45 LPM), audio or audio/visual alarm (less than 25 LPM), or the nitrous oxide flow will be stopped (less than 15 LPM). Of course, these predetermined ranges as a triggering point may be adjusted according to the user's preferences including activating or deactivating certain responses.
A visual alarm 230 is in electrical communication with the master controller 220 which instructs the visual alarm 230 to activate if the scavenging vacuum pressure is less than a first predetermined range. An audio alarm 240 or audio/visual alarm is in electrical communication with the master controller 220 which instructs the audio alarm 240 to activate if the scavenging vacuum pressure is less than a second predetermined range. A nitrous oxide valve 250 is fluidly connected to the nitrous oxide supply and in electrical communication with the master controller 220 which shuts off the nitrous oxide shut-off valve 250 when the scavenging vacuum pressure is less than a third predetermined range.
One example of a configuration of the safety scavenge system 200 is illustrated in FIG. 20. The scavenge hose 60B is connected between the nasal mask or hood and the inlet port 90B of the fluid control system 50. A dental vacuum is plugged into the outlet port 80B. A portion of the flow is diverted through a mass airflow sensor valve 210. The electrical output of the mass airflow sensor 210 is sent to a processor or master controller 220 where it is calibrated at LPM flow. In operation, the processor output will turn on a warning light 230 when the flow falls below 45 LPM. An alarm 240 sounds when flow falls below 25 LPM. The nitrous oxide valve is shut off when the flow falls below 15 LPM.
In addition, the present invention includes the following method for administering nitrous oxide to a patient. First, a fluid generated by a vacuum source is provided. Second, nitrous oxide fluid from a nitrous oxide source is provided. Third, a means for scavenging excess nitrous oxide is in fluid connection with the nitrous oxide source and the vacuum source. Fourth, a safety scavenge system is connected to the fluid connection between the nitrous oxide source and the vacuum source. The safety scavenge system includes a mass airflow sensor, master controller, alarm, and nitrous oxide valve. Fifth, the means for scavenging excess nitrous oxide is connected to the vacuum source and the nitrous oxide source onto a patient. Sixth, a flow rate flow rate of the vacuum source is increased to provide fluid into the safety scavenge system. Seventh, nitrous oxide is released through the safety scavenge system upon the vacuum source reaching a predetermined range. Eighth, excess nitrous oxide is retrieved from the means for scavenging excess nitrous oxide using the vacuum source. Ninth, the vacuum source is decreased below the third predetermined range which prevents the safety control valve from releasing nitrous oxide. The safety scavenge system actuated by flow fluids to control the release of nitrous oxide therethrough.
Therefore, while there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.

## Claims

1. A system for administering nitrous oxide to a patient, comprising:
a fluid control system for controlling the flow of nitrous oxide and oxygen;
a nasal delivery interface system fluidly connected to the fluid control system;
a nitrous oxide and oxygen supply fluidly connected to the control system;
a vacuum source fluidly connected to a scavenging tube for scavenging excess gases;
the fluid control system includes a safety scavenge system, the safety scavenge system comprising:
a mass airflow sensor for reading scavenging vacuum pressure fluidly connected to the scavenging tube before the vacuum source;
a master controller in electrical communication with the mass airflow sensor for receiving the scavenging vacuum pressure reading from the mass airflow sensor which is compared to one or more predetermined ranges; and
a nitrous oxide valve fluidly connected to the nitrous oxide supply and in electrical communication with the master controller which shuts off the nitrous oxide shut-off valve when the scavenging vacuum pressure is less than the one or more predetermined ranges.

2. The system of claim 1, further comprising:
a visual alarm in electrical communication with the master controller which instructs the visual alarm to activate if the scavenging vacuum pressure is less than the one or more predetermined ranges.

3. The system of claim 1, further comprising:
an audio alarm in electrical communication with the master controller which instructs the audio alarm to activate of the scavenging vacuum pressure is less than the one or more predetermined ranges.

4. The system of claim 1, wherein the fluid control system including a mixed gas output connector fluidly connected to said single nitrous oxide and oxygen tube.

5. The system of claim 1, further comprising:
a means for mounting a fluid control system and a breather bag to a medical chair which provides convenient and direct access to a medical practitioner, the fluid control system attached to the means for mounting the fluid control system.

6. The system of claim 1, wherein said nasal delivery interface system comprises a nitrous oxide and oxygen tube fluidly connected to a nasal delivery mask.

7. A method for administering nitrous oxide to a patient, comprising the following steps:
providing a fluid generated by a vacuum source;
providing nitrous oxide fluid from a nitrous oxide source;
providing a means for scavenging excess nitrous oxide in fluid connection with said nitrous oxide source and said vacuum source;
connecting a safety scavenge system to the fluid connection between the nitrous oxide source and said vacuum source, the safety scavenge system including:
a mass airflow sensor for reading scavenging vacuum pressure fluidly connected to the means for scavenging excess nitrous oxide;
a master controller in electrical communication with the mass airflow sensor for receiving the scavenging vacuum pressure reading from the mass airflow sensor which is compared to one or more predetermined ranges; and
a nitrous oxide valve fluidly connected to the nitrous oxide source and in electrical communication with the master controller which shuts off the nitrous oxide valve when the scavenging vacuum pressure is less than the one or more predetermined ranges;

positioning the means for scavenging excess nitrous oxide connected to said vacuum source and said nitrous oxide source;
increasing flow rate of the vacuum source to provide fluid into the safety scavenge system;
releasing nitrous oxide through said safety scavenge system upon the vacuum source reaching or exceeding the one or more predetermined ranges; and
whereby the safety scavenge system is actuated by fluids to control the release of nitrous oxide therethrough.

8. The method of claim 7, further comprising:
a visual alarm in electrical communication with the master controller which instructs the visual alarm to activate if the scavenging vacuum pressure is less than the one or more predetermined ranges.

9. The method of claim 7, further comprising:
an audio alarm in electrical communication with the master controller which instructs the audio alarm to activate of the scavenging vacuum pressure is less than the one or more predetermined ranges.

10. The method of claim 7, further comprising:
retrieving excess nitrous oxide from the means for scavenging excess nitrous oxide using the vacuum source.

11. The method of claim 10, further comprising:
decreasing the vacuum source below the one or more predetermined ranges which prevents the safety control valve from releasing nitrous oxide.