Patent Application
20200164234
This invention relates to apparatus and methods for monitoring the serviceability of breathing apparatus.
Emergency breathing devices are used in mining, tunneling, the armed forces, chemical plants, pulp/paper plants, water treatment plants, and confined space entry industries where immediate reliable access to breathable oxygen may be required. Such breathing devices used in the mining market require daily inspection to assure that the device is in working order and has not exceeded the usable service life based on the date of manufacture. Currently this includes a daily visual inspection of temperature and humidity indicators mounted in the case of the breathing device, verification of the manufacture date printed on the case, visual inspection for external damage to the case, and a quarterly inspection of the chemical bed using a hand held sound monitor.
An aspect of the present invention is to provide a breathing apparatus comprising: a case containing at least a chemical for generating oxygen; and a monitoring circuit within the case, the monitoring circuit including a plurality of sensors configured to sense parameters within the case relevant to an operational status of the breathing apparatus, and a controller configured to receive signals from the sensors and to produce an output signal indicating the operational status of the breathing apparatus.
Another aspect of the present invention is to provide a method for monitoring a breathing apparatus, the method comprising: using a plurality of sensors within a case of a breathing apparatus to sense parameters relevant to an operational status of the breathing apparatus; and processing signals from the sensors to produce an output signal representative of the operational status of the breathing apparatus.
The present invention provides a breathing apparatus including a compliance system capable of monitoring relevant environmental conditions that can degrade the function of the breathing apparatus. In various embodiments, the compliance system may include several hardware components. These components can include circuitry configured to monitor one or more parameters that may be relevant to the operational status of the breathing apparatus. The monitored parameters can be used to produce data that can be output, for example, through a data interface or wireless transmitter. The data can then be received at a receiving device, such as a hand held reader or a fixed reader. In some embodiments, the monitored parameters can be used to produce a visible indication of the operational status of the breathing device.
In some embodiments, the self-rescuer utilizes a bi-directional chemical canister system, where the exhaled air moves through a carbon dioxide absorption/oxygen generation canister twice, before the oxygen returns to the user. In view of the possible life-saving nature of the self-rescuer, it is necessary to verify the serviceability of the self-rescuer. For example, excessive humidity or temperature within the case could adversely affect the ability of the chemical to produce oxygen.
In the embodiment shown, the circuit board 22 is located inside and near the top of the self-rescuer emergency breathing apparatus 10. A single circuit board may thus contain all of the sensors. The status LED should be visible to the user, but could be separated from the main circuit board 22 in certain embodiments. If the self-rescuer emergency breathing apparatus 10 has more than one sealed chamber, a humidity sensor and a pressure sensor may be provided in each sealed chamber.
The monitoring circuitry 32 of
The controller output signal includes information relevant to the serviceability of a breathing apparatus. In some embodiments, the output can be a binary pass/fail signal. In other embodiments, the output signal can include detailed information about the parameters measured by the sensors.
The signal at the output of the controller can be sent to a radio transceiver 40 that transmits the information contained in the output signal using antenna 42. Alternatively, or in addition, the output signal on line 36 can be sent to a data interface 44. A receiver 46 is configured to receive the data on antenna 48 and/or by a connection to the data interface.
The controller can also be configured to drive a status indicator, such as a light emitting diode 49. The status indicator can then alert the user in the event that one or more of the monitored parameters exceed predetermined levels during use or storage. The status indicator can be visible through the window of the case.
An external reader may be configured to receive data from the monitor monitoring circuit, for example from the data interface, or over the air using an antenna. The reader can be a mobile and/or stationary unit, and can be battery operated or hardwired. The reader may be configured to query the monitoring circuitry for the status of the breathing apparatus, for example using a cable connected to the data interface or via the near field radio transceiver. This data collected by the reader can include the unique identification of the breathing apparatus, the breathing apparatus status, recorded sensor data and operating life of the unit. The unique identification may comprise a serial number assigned during manufacture and programmed into the monitoring circuit. The data can be retrieved from the reader using a plug-in external memory or the reader can be connected to a computer for data transfer. When the reader is stationary or fixed, it can be mounted in any desired location, such as a doorway, wall, or adjacent to a storage unit for the monitors. In one embodiment, battery life of the monitoring circuit may be increased by placing a fixed reader in or near a storage unit for the monitors, in which case the reader may “ping” the nearby monitoring circuits in order to activate their radio transceivers, rather than having the monitoring circuits periodically send transmissions.
The data interface can be a stand alone component that allows the hand held or fixed reader to communicate with network protocols that are not native to the compliance system. These can include but are not limited to Ethernet, Wireless networks and cell networks.
Data collected from the monitor can be stored or printed for compliance verification. Collection may include transfer over a wireless network connection or wired link. The data can also be maintained in a central database and monitored for the customer as a service. Status alerts can be sent via email, text message or other messaging methods to one or more recipients. Messages can include information such as current breathing apparatus status, remaining service life or retrieved sensor readings.
An on-board, real-time clock may also be provided in the monitoring circuit. In one example, the clock can be initiated when the unit is made, and set to expire after a predetermined amount of time, e.g., an “end-of-service-life” signal may then be generated, displayed and transmitted as described above. The clock function can be performed within the microcontroller, or by a separate component.
Examples of suitable humidity sensors 24 for use in the present breathing apparatus include conventional capacitive, resistive, or thermal conductivity type sensors. The humidity sensor may trip at any desired humidity level, e.g., at least 70%, 80% or 90% relative humidity.
Examples of suitable pressure sensors 28 for use in the present breathing apparatus include conventional piezoelectric, capacitive, inductive, resistive, or strain gauge sensors. Pressure switches may also be used to detect pressure changes within the case. The pressure sensor 28 determines if the high pressure oxygen cylinder inside the sealed case 12 develops a leak, which would cause the internal pressure in the case 12 to rise.
Examples of suitable temperature sensors 30 for use in the present breathing apparatus include conventional thermocouples, resistive temperature devices such as thermistors, infrared radiators, bimetallic devices, liquid expansion devices, molecular change-of-state, silicon diodes and the like. A threshold temperature may be mandated by, e.g., NIOSH requirements. A primary purpose of the temperature sensor is to assure that the internal plastic, rubber, and urethane components are not damaged by excessive temperature exposure. It is noted that once a unit is sealed during manufacture it may not be opened until use, and there may be no way to inspect the internal components for temperature damage.
The impact sensor 26 may be of any suitable conventional design. In certain embodiments, the impact sensor 26 may comprise an impact sensor design 50 as shown in
Wrapping of the wire 58 in the cut-outs 55 of the support board 52 as shown in
In certain embodiments, cumulative impact forces will cause the bead 56 to move, e.g., vibrate, and stretch the wire 58 from which the bead is suspended until the wire 58 eventually breaks, causing an open circuit. The sensor 50 may work in all directions, but one axis may be more sensitive than others. Multiple sensors may be used to respond to impacts from different directions, but a single sensor is adequate for many applications.
The impact sensor wire 58 can be connected to an electrical ground. In one embodiment, the microprocessor includes an internal pull-up resistor that can be selected as general purpose input to which the impact sensor 50 is connected. When the impact sensor 50 is in its normal state, a general purpose input pin may be shorted to ground by the sensor. When the impact sensor 50 is subjected to one or more impacts, the wire 58 can stretch and eventually break. If the wire 58 breaks and the impact sensor 50 becomes an open circuit, then the voltage on the general purpose input may switch to a high level, e.g., goes to a logic level voltage of about 5 volts. This change in voltage can then be detected by the microprocessor and used to produce a signal indicating that the sensor 50, and thus the device having the sensor, has been subjected to excessive impact forces. Once the circuit is open, there is no way to reset the device.
The impact sensor 50 may be used to detect single impact events. However, the sensor can also are used to detect cumulative impacts, e.g., an article including the sensor is dropped 20 times from a height of 5 feet. In certain embodiments, the impact sensor 50 may be constructed or tuned in order to sense various types of impact forces such as vibrational amplitudes and/or frequencies of cumulative impacts. The components of the impact sensor 50 may be adjusted in order to change the force(s) required to break the wire(s) and open the circuit. For example, the mass of the bead 56 may be adjusted and/or the tension or cross-sectional area of the wire 58 may be changed.
The status of each breathing apparatus can be stored along with a unique identifier for reporting and regulatory compliance using a wireless reader. The status may be a pass/fail indication, historical data, or both. This information may be stored in a memory in the breathing apparatus and/or at some other location.
The disclosed embodiment can monitor the temperature, humidity, impact exposure, oxygen cylinder integrity, and service life of a breathing apparatus. However, other types or numbers of parameters may be monitored in accordance with other embodiments of the invention.
While the present invention has been described in terms of several embodiments, it will be apparent to those skilled in the art that various changes can be made to the disclosed embodiments without departing from the scope of the invention, as set forth in the following claims.
The present application claims priority and the benefit of the filing date under 35 U.S.C. § 120 of U.S. application Ser. No. 14/869,447 filed on Sep. 29, 2015, which claims the benefit under 35 U.S.C. § 119 of U.S. Provisional Ser. No. 62/056,927 filed Sep. 29, 2014 and U.S. Provisional Ser. No. 62/067,310 filed Oct. 22, 2014, all of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62056927 | Sep 2014 | US | |
| 62067310 | Oct 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14869447 | Sep 2015 | US |
| Child | 16773260 | US |
