Patent Application
20130064687
This document relates to a compressor apparatus for providing compressed gas, and in particular to a shuttling by-pass compressor apparatus used with a ventilator system to achieve steady flow rates using less power.
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing of a patient using a machine called a ventilator. The ventilator may include a prior art compressor apparatus that draws in gas and delivers compressed gas to the patient in a controlled manner to meet patient specifications. As shown in
In one embodiment, a compressor apparatus may include a first compressor head for generating a first gas flow, a second compressor head in fluid flow communication with the first compressor head for generating a second gas flow, and an output connector in fluid flow communication with the first compressor head and the second compressor head for permitting a continuous alternating output of gas flow by the first compressor head and the second compressor head. The compressor apparatus may also include a shuttling by-pass component in fluid flow communication with the first compressor head and the second compressor head for permitting alternating gas flow between the first compressor head and the second compressor head such that a portion of the first gas flow is diverted from the first compressor head to the second compressor head and a portion of the second gas flow is diverted from the second compressor head to the first compressor head in an alternating sequence.
In another embodiment, a method for using a compressor apparatus may include:
In yet another embodiment, a method of manufacturing a compressor apparatus may include:
Additional objectives, advantages and novel features will be set forth in the description which follows or will become apparent to those skilled in the art upon examination of the drawings and detailed description which follows.
Corresponding reference characters indicate corresponding elements among the view of the drawings. The headings used in the figures should not be interpreted to limit the scope of the claims.
As described herein, various embodiments of a compressor apparatus having a shuttling by-pass component is configured such that a portion of each gas flow generated by one compressor head is diverted to the other compressor head, and vice versa, through a shuttle component to achieve an efficient steady output of gas at extremely low flow rates. The result is a minimum to maximum flow ratio that is much greater than standard compressor apparatuses.
Referring to the drawings, various embodiments of the compressor apparatus are illustrated and generally indicated as 100 in
Referring to
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As shown, the first compressor head 102 includes a pump casing 124A defining a chamber 134A having an arrangement of a connecting rod 128A engaged to an eccentric mass 130A and counterweight 132A disposed therein. The bottom portion of the connecting rod 128A is engaged to the eccentric mass 130A and counterweight 132A, while the top portion of the connecting rod 128A is engaged to a flexible diaphragm 126A through a set screw 162A. Moreover, the bottom portion of the connecting rod 128A is engaged to the rotatable shaft 144 of the motor 116 for moving the connecting rod 128A in an eccentric motion. In operation, the eccentric movement of the connecting rod 128A by the motor 116 moves the diaphragm 126A in a reciprocating motion. An adaptor plate 136A may engage one end of the motor 116 to the pump casing 124A.
In one embodiment, the top portion of the pump casing 124 is engaged to the bottom portion of a compressor head housing 118A, while the top head of the compressor head housing 118A is engaged to a cover head 138A. The compressor head housing 118A includes an inlet 140A that communicates with the intake chamber 110A for permitting the gas flow A to enter therein. The intake chamber 110A is in fluid flow communication with the cavity 112A through a plurality of one-way intake valves 120A that permit the inflow of gas into the cavity 112A from the intake chamber 110A, but prevents retrograde gas flow back into the intake chamber 110A. In addition, the cavity 112A is in fluid flow communication with the exhaust chamber 122A through a plurality of one-way exhaust valves 122A that permit the inflow of gas into the exhaust chamber 114A from the cavity 112A, but prevents retrograde gas flow back into the cavity 112A. The cavity 112A is configured to act in concert with the reciprocating diaphragm 126A such that movement of the diaphragm 126A from the cavity 112A during one-half cycle causes gas flow into the cavity 112A from the intake chamber 110A, while movement of the diaphragm 126A toward the cavity 112A during the other half-cycle causes the gas to become compressed and flow from the cavity 112A and into the exhaust chamber 114A such that the compressed gas exits the outlet connector 107 through the outlet 142A of the compressor head housing 118A.
Similar to the first compressor head 102, the second compressor head 104 includes a pump casing 124B defining a chamber 134B having an arrangement of a connecting rod 128B engaged to an eccentric mass 130B and counterweight 132B disposed therein. The bottom portion of the connecting rod 128B is engaged to the eccentric mass 130B and counterweight 132B, while the top portion of the connecting rod 128B is engaged to a flexible diaphragm 126B through a set screw 162B. Moreover, the bottom portion of the connecting rod 128B is engaged to the rotatable shaft 144 of the motor 116 for moving the connecting rod 128B in an eccentric motion. In operation, the eccentric movement of the connecting rod 128B by the motor 116 moves the diaphragm 126B in a reciprocating motion. An adaptor plate 136B may engage one end of the motor 116 to the pump casing 124B.
In one embodiment, the top portion of the pump casing 124 is engaged to the bottom portion of a compressor head housing 118B, while the top head of the compressor head housing 118B is engaged to a cover head 138A. The compressor head housing 118B includes an inlet 140B that communicates with the intake chamber 110B for permitting the gas flow B to enter therein. The intake chamber 110B is in fluid flow communication with the cavity 112B through a plurality of one-way intake valves 120B that permit the inflow of gas into the cavity 112B from the intake chamber 110B, but prevents retrograde gas flow back into the intake chamber 110B. In addition, the cavity 112B is in fluid flow communication with the exhaust chamber 122B through a plurality of one-way exhaust valves 122B that permit the inflow of gas into the exhaust chamber 114B from the cavity 112B, but prevents retrograde gas flow back into the cavity 112B. The cavity 112B is configured to act in concert with the reciprocating diaphragm 126B such that movement of the diaphragm 126B from the cavity 112B during first half cycle causes gas flow into the cavity 112B from the intake chamber 110B, while movement of the diaphragm 126B toward the cavity 112B during the second half cycle causes the gas to become compressed and flow from the cavity 112B and into the exhaust chamber 114B such that the compressed gas exits the outlet connector 107 through the outlet 142B of the compressor head housing 118B.
As further shown, the shuttling by-pass component 108 may be an elongated hollow shaft that permits two-way gas flow between the first compressor head 102 and the second compressor head 104 when diverted gas flow A2 and diverted gas flow B2 alternately flow between the compressor heads 102 and 104. The shuttling by-pass component 108 defines one end that engages a by-pass fitting 148A for coupling the shuttling by-pass component 108 to the cover head 138A of the first compressor head 102 and an opposite end that engages another by-pass fitting 148B for coupling the shuttling by-pass component 108 to the second compressor head 104. Sealing elements 158A, such as O-rings, provide a fluid-tight seal between the cover head 138A and the by-pass fitting 148A, while sealing elements 158B provide a fluid-tight seal between the cover head 138B and the by-pass fitting 148B. In one embodiment, the by-pass fitting 148B is operatively engaged to a solenoid 150 through a by-pass seat 152 having a spring 154. The spring 154 applies a bias for permitting or preventing fluid flow communication through an orifice 149 formed by the cover head 138B, which is configured to engage the by-pass seat 152 by action of the solenoid 150 which opens and closes the orifice 149 to diverted gas flow A2 or B2. As such, the presence of the shuttling by-pass component 108 allows for the compressor apparatus 100 to achieve extremely lower and steadier flow rates in comparison to the flow rates achievable by the conventional compressor apparatus 10 without the by-pass component 108.
In operation, the solenoid 150 opens the by-pass seat 152 during the exhaust stroke of the first compressor head 102 to permit diverted gas flow A2 to flow from the first compressor head 102 to the second compressor head 104 during first half of cycle of operation. Similarly, the solenoid 150 opens the by-pass seat 152 during the exhaust stroke of the second compressor head 104 to permit diverted gas flow B2 to flow from the second compressor head 104 to the first compressor head 102 during the second half cycle of operation in order to complete a full cycle of operation by the compressor apparatus 100. In some components, the orifice size of the shuttling by-pass component 108 may be tailored to achieve a particular flow rate by the compressor apparatus 100 by diverting a specific amount of diverted gas flow from each of the first and second compressor heads 102 and 104. In other embodiments, the shuttling by-pass component 108 may include a variable orifice (not shown) that provides a variable-sized opening for varying the degree of diverted gas flow A2 or B2 permitted to flow through the shuttling by-pass component 108 to the other compressor head 102 or 104 in order to provide flow adjustment capability. In this manner, the amount of diverted gas flow A2 and B2 may be adjusted for achieving different degrees of low flow rates by the compressor apparatus 100.
In some embodiments, the shuttling by-pass component 108 may be a screw drive or rotary actuator that may be used to open the orifice 149 as a substitute for the solenoid 150.
The advantages of incorporating the shuttling by-pass component 108 into the compressor apparatus 100 is that it lowers the potential steady flow rate attainable by the compressor apparatus 100 by diverting a portion of the gas flow from one compressor head during its exhaust cycle to the other compressor head during its intake cycle, and vice versa, as one full cycle of operation of the compressor apparatus 100 is completed. For example, the compressor apparatus 100 with the shuttling by-pass component 108 can achieve an extremely low flow rate, such as 0.1 liters per minute, when about 97% (based on an 80+ liters per minute of compressor apparatus 100 capacity) of the exhausted gas flow is diverted to the other compressor head and vice versa. This results in a maximum to minimum flow ratio of 800 to 1. The same bypass function may be applied to other compressors with varying capacity to achieve either higher or lower bypass flow rates.
In some embodiments, the shuttling by-pass component 108 may be incorporated into the compressor apparatus 100 having a motor with a fixed power source as an after market modification, which may be used as a means of achieving flow adjustment for the compressor apparatus by varying the amount of gas flow that may be diverted through the shuttling by-pass component 108.
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The compressor apparatus 100 with the shuttling by-pass component 108 may have applications outside the medical field described herein. For example, the compressor apparatus 100 may be used in heating and air conditioning applications as well as refrigeration industries where multi-speed compressors are commonly used.
Two different tests were conducted to demonstrate the superior performance of the compressor apparatus 100 with the shuttling by-pass component 108 in comparison with the prior art standard compressor apparatuses 10 without the shuttling by-pass component 108. The first test was directed to comparing minimum/maximum flow rate ratios exhibited by the standard compressor apparatuses 10 relative to the compressor apparatus 100 and the second test was directed to comparing the variance in flow rate between a standard compressor apparatus 10 and the compressor apparatus 100 with the shuttling by-pass component 108. With respect to the first test, tables 1-5 below provide test results that compare the maximum/minimum flow rate ratio achieved by the compressor apparatus 100 with the shuttling by-pass component 108 (Table 5) with the maximum/minimum flow rate ratios achieved by four prior art standard compressor apparatuses 10 without the shuttling by-pass component 108 (Tables 1-4). As shown, table 1 represents a standard compressor apparatus 10 without the shuttling by-pass component 108 manufactured under the product name GAST 15D, which exhibits a minimum flow rate of 0.2 liters per minute at a voltage setting of 2 volts and a maximum flow rate of 17.1 liters per minute at a voltage setting of 12 volts.
Table 2 represents another standard compressor apparatus 10 without the shuttling by-pass component 108 manufactured under the product name T-Squared, which exhibits a minimum flow rate of 5.1 liters per minute at a voltage setting of 1 volt and a maximum flow rate of 82.3 liters per minute at a voltage setting of 12 volts. Table 3 represents another standard compressor apparatus 10 without the shuttling by-pass component 108 manufactured under the product name KNF, which exhibits a minimum flow rate of 31.1 liters per minute at a voltage setting of 1 volt and a maximum flow rate of 73.8 liters per minute at a voltage setting of 8 volts. Table 4 represents yet another standard compressor apparatus 10 without the shuttling by-pass component 108 manufactured under the product name Powerex, which exhibits a minimum flow rate of 1.3 liters per minute at a voltage setting of 1.7 volts. Finally, table 5 represents a compressor apparatus 100 with the shuttling by-pass component 108 manufactured by the Applicants, which exhibits a minimum flow rate of 0.1 liters per minute at a voltage setting of 1 volt and a maximum flow rate of 48.1 liters per minute at a voltage setting of 12 volts when the shuttling by-pass component 108 is made operational, while the compressor apparatus 100 exhibits a minimum flow rate of 3.1 liters per minute at a voltage setting of 1 volt and a maximum flow rate of 83.5 liters per minute when the shuttling by-pass component 108 is made non-operational. As noted above, the compressor apparatus 100 with the shuttling by-pass component 108 can operate to make the shuttling by-pass component 108 operational at times to achieve any extremely low flow rate, while making the shuttling by-pass component 108 non-operational at times to achieve an extremely high flow rate. Table 6 shows the minimum flow rate, maximum flow rate, and the output flow ratios (maximum flow rate/minimum flow rate) for each of the aforementioned compressor apparatuses 10 without the shuttling by-pass component 108 in comparison with the compressor apparatus 100 having the shuttling by-pass component 108.
As shown in table 6, the flow rate ratio of the compressor apparatus 100 with the shuttling by-pass component 108 is almost ten times the flow rate ratio of the closest standard compressor apparatus 10 without the shuttling by-pass component 108. For example, the flow rate ratio of the GAST 15D compressor apparatus 10 without the shuttling by-pass component 108 of table 1 is 85.5 to 1, the flow rate ratio of the T-Squared compressor apparatus 10 without the shuttling by-pass component 108 of table 2 is 16.1 to 1, the flow rate ratio of the KNF compressor apparatus 10 without the shuttling by-pass component 108 of table 3 is 2.4 to 1, and the flow rate ratio of the Powerex compressor apparatus 10 without the shuttling by-pass component 108 of table 4 is 61.0 to 1. In contrast, the flow rate ratio of the compressor apparatus 100 when the shuttling by-pass component 108 is made operational is 481 to 1, while an even higher flow rate ratio of 836 to 1 can be achieved when the compressor apparatus 100 switches the shuttling by-pass component 108 between operational mode to achieve a low flow rate of 0.1 liters per minute and the non-operational mode to achieve a high flow rate of 83.5 liters per minute as illustrated in
Table 7 shows the results of the second test for comparing the variance in flow rate, referred to as pulsations, for a standard compressor apparatus 10 as compared with the compressor apparatus 100 having the shuttling by-pass component 108 at the same flow rate of 10 liters per minute. Minimizing the flow rate pulsations or the variance in flow rate by the compressor apparatus when maintaining a particular flow rate is important since a large variance in flow rate can be felt by a patient connected to a ventilator when the compressor apparatus exhibits a high variance in flow rate when maintaining a particular flow rate. The graph illustrated in
It should be understood from the foregoing that, while particular embodiments have been illustrated and described, various modifications can be made thereto without departing from the spirit and scope of the invention as will be apparent to those skilled in the art. Such changes and modifications are within the scope and teachings of this invention as defined in the claims appended hereto.
