Patent Grant
8721582
1. Field of Invention
The present invention relates to dry powder delivery system, and more particular to an internal dry powder delivery system and method thereof for delivering dry powder to reach internal operation site, especially during a minimally invasive surgery or other similar internal application for beings such as humans or animals.
2. Description of Related Arts
Generally, medications are in liquid form, capsule form, pill form, and powder form. The common difficulty for physicians is how to directly apply powdered medication to the internal tissue/organ site of a human or an animal such as human gastro-intestine.
Traditionally, the only application of powdered medications is to enclose the powder in a capsule made of a material that will not immediately dissolve or to compress the powder into the pill form. When the capsule or pill is consumed into the patient's stomach and intestine, the enclosure skin of the capsule will dissolve and the powder particles will be exposed and absorbed.
Conventionally, powder form medications can be applied by topical application during open surgery. It may normally be ingested as tablets or powder capsules. Tablets and powder capsules' strengths are often diluted by gastric and intestinal juice and could not offer precise delivery and dosage control to the target wound site. In turn, physicians can not accurately control the amount of medication reaching the designated site. Therefore, it cannot be used when physicians want to directly control the dosage and dryness status of the powder to apply the target wound sites of human gastro-intestine before contact with liquid in the digestive system.
The minimal invasive procedure via endoscope has been widely used for diagnosis and surgery. When using endoscope during inspection and surgery, physicians often need to apply medications to an internal tissue site. Via endoscope, physicians can inspect the internal organ/tissue and conduct surgical procedures inside of the human body. In general, endoscopes consist of gastro-intestinal endoscope, laparoscope, thoracoscope, hysteroscope, cytoscope, laryngoscope, and nasopharyngoscope etc. Besides for medical use, endoscopes can also be used to inspect mechanical or electrical problems in the industries such as automobile maintenance, mechanical setups, petroleum engineering, electrical facilities, aviator equipments, coal-gas passages, architectures, water pipe systems etc.
For example, laparoscope and gastro-intestinal endoscopes have a standard total length about 600 mm to 1700 mm depend on the application purpose. Besides the imaging system, the internal components include a narrow working channel, similar to that of an irrigation channel or a biopsy clamp, allowing physicians to conduct minimally invasive surgeries. Currently, the most common laparoscopic and gastro-intestinal scopes used by physicians for biopsy, have a diameter of 2.8 mm and 3.2 mm respectively to enable physicians to insert catheters or devices to conduct examination, electrical incision, suture, applying medication and hemostasis, etc.
Physicians often use laparoscope and gastro-intestinal endoscope during treatment and minimally invasive surgery to examine an internal site or to inject liquid medications. The long and narrow characteristics of the working channel often cause occlusion when injection medications which could present certain limitations. In current clinical settings, endoscope's irrigation or working channel could only delivery liquid form medications (soluble/insoluble solutions and gel), restricting any powder and particle form medications that could easily lose its effectiveness when it contacts water prior to blood. In addition, through the use of endoscopes physicians could often examine gastritis lesions including tumors or ulcers and thereby provide the appropriate topical medication directly to the site. Due to the length and the narrowness of most laparoscopes and endoscopes, particles often could not overcome the resistance presented between air pressure and the inner lining of the tube which could lead to tip occlusion. Also, gastro and intestinal juice/mucus could easily enter the working channel causing obstruction. The most common problems associated with delivering dry powder medication through the working channel of an endoscopic cannula include that dry powder particles often occlude because of resistance in the long and narrow cannula through the working channel of endoscope and excess liquid and pressurized air mixed with dry particles could cause occlusion at the tip of the delivery catheter. These common problems minimize physicians' ability to deliver powered medications directly and precisely to the tissue/organ site of the human gastro-intestine via endoscope.
The current invention specifically addresses these issues and provides physicians a new alternative to delivery particles/powder medications directly to an internal site.
The present invention is advantageous in that it provides an internal dry powder delivery system which is capable of directly applying dry powder to internal tissue/organ site.
Another advantage of the present invention is to provide an internal dry powder delivery system via working channel of endoscopic cannula, which is aimed to overcome the difficulties when directly applying powdered medication to the tissue/organ site of human gastro-intestine through the narrow working channel of an endoscope.
Another advantage of the present invention is to provide a new dry powder-format drug delivery method and system thereof via working channel of endoscopic cannula, and its clinical applications, which overcome the most common problems associated with delivering dry powder medication through the working channel of an endoscopic cannula, including that dry powder particles often occlude because of resistance in the long and narrow cannula through the working channel of endoscope and excess liquid and pressurized air mixed with dry particles could cause occlusion at the tip of the delivery catheter. These common problems minimize physicians' ability to deliver powered medications directly and precisely to the tissue/organ site of the human gastro-intestine via endoscope.
Another advantage of the present invention is to offer physicians an innovative powder medication delivery system and method thereof, a new diagnosis and treatment alternatives when performing a minimally invasive procedure, such as via endoscope.
Another advantage of the present invention is to provide a new powder form medication delivery method for physicians via endoscope. This method could be used with various purposes such as hemostatic, antibiotic, tissue repair, mucosal protection, ulcer repair and antineoplastic treatment, etc.
Another advantage of the present invention is to provide an internal dry powder delivery system which enables physicians to directly apply the biocompatable polysaccharide hemostatic powder to the bleeding sites via endoscope during invasive surgery to achieve hemostasis.
In order to accomplish the above advantages, the present invention provides an internal dry powder delivery system for delivering dry powder from outside to an internal operation site, comprising:
an elongated tubular delivery channel having a feeding opening at one end thereof, an emitting opening at a distal end thereof adapted for reaching a position adjacent to the internal operation site, a diameter 3.2 mm or less, and a length long enough for enabling the emitting opening reaching the internal operation site; and
a powder supply device which is connected to the feeding opening of the delivery channel and comprises:
a gas-powder chamber a dry powder inlet for feeding in a predetermined amount of dry powder therein and a dry powder outlet communicating with the feeding opening of the delivery channel; and
a pressurized gas feeder producing pressurized gas in the gas-powder chamber mixing with the dry powder therein to form a mixture of dry powder and pressurized gas for blowing into the delivery channel through the feeding opening thereof, thereby a continuous feeding of the pressurized gas and the mixture of dry powder and pressurized gas into the delivery channel from the gas-powder chamber substantially renders the mixture of dry powder and pressurized gas to deliver to the emitting opening of the delivery channel and spray onto the designated internal operation site.
The present invention also provides a method of delivering dry powder from outside to an internal operation site, comprising the steps of:
(a) extending a distal end of an elongated tubular delivery channel to a position adjacent to an internal operation site while the other end thereof remains outside;
(b) producing pressurized gas and mixing the pressurized gas with dry powder to form a mixture of dry powder and pressurized gas in a gas-powder chamber communicating with a feeding opening provided at the other end of the delivery channel; and
(c) continuously feeding the pressurized gas and the mixture of dry powder and pressurized gas from the gas-powder chamber into the delivery channel via the feeding opening until a predetermined amount of the mixture of dry powder and pressurized gas spray out of an emitting opening provided at the distal end of the delivery channel for applying onto the internal operation site.
According to a preferred embodiment of the present invention, the delivery channel can be inserted into a human or an animal body to reach a designated internal tissue operation site via a working channel of endoscopic cannula.
Additional advantages and features of the invention will become apparent from the description which follows, and may be realized by means of the instrumentalities and combinations particular point out in the appended claims.
Referring to
According to the preferred embodiment as illustrated in
(i) Dry powder particles often occlude because of resistance in the long and narrow cannula through the working channel of endoscope.
(ii) Excess liquid and pressurized air mixed with dry particles could also cause occlusion at the tip of the delivery catheter.
These common problems minimize physicians' ability to deliver power medications directly and precisely to the tissue/organ site of, for example, the human gastro-intestine via endoscope. To effectively address the above technical difficulties, the present invention provides an internal dry powder delivery system for delivering dry powder from outside to an internal operation site, which comprises an elongated tubular delivery channel 10 and a powder supply device 20.
The elongated tubular delivery channel 10 has a feeding opening 11 at one end thereof, an emitting opening 12 at a distal end thereof adapted for reaching a position adjacent to the internal operation site, a diameter preferably 3.2 mm or less, and a length long enough for enabling the emitting opening 12 reaching the internal operation site.
The powder supply device 20 which is connected to the feeding opening 11 of the delivery channel 10 comprises a gas-powder chamber 21 and a pressurized gas feeder 22.
The gas-powder chamber 21 has dry powder inlet 211 for feeding in a predetermined amount of dry powder therein and a dry powder outlet 212 communicating with the feeding opening 11 of the delivery channel 10.
The pressurized gas feeder 22 produces pressurized gas in the gas-powder chamber 21 mixing with the dry powder therein to form a mixture of dry powder and pressurized gas for blowing into the delivery channel 10 through the feeding opening 11 thereof. Thereby, a continuous feeding of the pressurized gas and the mixture of dry powder and pressurized gas into the delivery channel 10 from the gas-powder chamber 21 substantially renders the mixture of dry powder and pressurized gas to deliver to the emitting opening 12 of the delivery channel 10 and spray onto the designated internal operation site.
By means of the above system, the procedures of delivering dry powder from outside to the internal operation site comprise the steps of:
(a) extending a distal end of the elongated tubular delivery channel 10 to a position adjacent to the internal operation site while the other end thereof remains outside;
(b) producing pressurized gas and mixing the pressurized gas with the dry powder to form a mixture of dry powder and pressurized gas in the gas-powder chamber 21 communicating with the feeding opening 11 of the delivery channel 10; and
(c) continuously feeding the pressurized gas and the mixture of dry powder and pressurized gas from the gas-powder chamber 21 into the delivery channel 10 via the feeding opening 11 until a predetermined amount of the mixture of dry powder and pressurized gas spray out of the emitting opening 12 of the delivery channel for applying onto the internal operation site.
The gas mentioned above can be any, but preferable medical use clean air, oxygen, or carbon dioxide. The pressurized gas feeder 22 can be embodied as a manual air pump as shown in
The dry powder used in the present invention refers to dry, smooth and elastic particles. To also ensure a smooth delivery, powder particles should not exceed 400 um; the preferred particle diameter should be between 1 u-250 um.
The powder medications used in present invention include but are not limited to anti-inflammatory drugs (Amoxicillin, Norfloxacin, Gentamicin etc.), anti-ulcer drugs and agents (Omeprazole, Ranitidine, Metronidazole or mucosal protective agent etc.), and anti-neoplastic drugs (Cytotoxic, hormones or biological response modifier). According to the preferred embodiment of the present invention, powder form Starch-derived Absorbable Polysaccharide Hemostat, SAPH, is used as the dry powder for hemostasis at the internal wound site.
Referring to
The powder supply device 20 is embodied to comprise a pressurized gas feeder 22 which is an elastic hollow air pump securely connected to a base 23 in a detachable manner, wherein the dry powder 30 is received inside the pressurized gas feeder 22. The dry power inlet 211 of the gas-powder chamber 21 is detachablly connected to the base 23 and communicated with the pressurized gas feeder 22.
Therefore, by compressing the pressurized gas feeder 22, the SAPH particles of dry powder 30 is pressurized to enter the gas-powder chamber 21. When the air pump 22 is compressed, air is pumped in the gas-powder chamber 21 through a gas regulator 24, which is a one-way air valve, and mixes with the dry powder 30 in the air-powder chamber 21. When the manual air pump 22 is released, additional air enters through the gas regulator 24 to prevent negative air pressure within gas-powder chamber 21 to ensure the mixture of dry powder and pressurized air pumping into the delivery channel 10 in a one-way manner without any re-sucking back into the gas-powder chamber 21.
According to the preferred embodiment as shown in
The gas valve 240 according to the preferred embodiment as shown in
Accordingly, when the pressurized gas feeder (air pump) 22 is compressed, a portion of the air pressure produced at the dry powder outlet 212 (i.e. the position between the gas valve 240 and the feeding opening 11 of the delivery channel 10) presses the valve ball 244 radically outwardly to block the inletting opening 243 so as to produce the air pressure in the gas-powder chamber 21 mixing with the dry powder 30 and blow the dry powder 30 into the delivery channel 10 for delivering the mixture of dry powder and pressurized air to the emitting opening 12 of the delivery channel 10 for spraying onto internal operation site.
Once the air pressure is reduced when the compression to the pressurized gas feeder 22 is released, the valve ball 244 drops and returns to the position stopper 245 to reopen the inletting opening 243 so that air can enter the one-way gas valve 240 and supply to the pressurized gas feeder (air pump) 22 to release the negative air pressure therein in order to prevent any re-sucking of the dry powder 30 back to the pressurized gas feeder 22.
Referring to
Accordingly, when the pressurized gas feeder (air pump) 22 is compressed, a portion of the pressurized air produced at the dry powder outlet 212 (i.e. the position between the gas regulator 24 and the feeding opening 11 of the delivery channel 10) presses the blocker 254 outwardly to block the inletting opening 252 so as to produce the air pressure in the gas-powder chamber 21 mixing with the dry powder 30 and blow the dry powder 30 into the delivery channel 10 for delivering the mixture of dry powder and pressurized air to the emitting opening 12 of the delivery channel 10 for spraying onto internal operation site.
Once the air pressure is reduced when the compression to the pressurized gas feeder 22 is released, the blocker 254 rebound by the resilient element 253 to return to its original position When the pressurized gas feeder (air pump) 22 is compressed, the air pressure produced at the dry powder outlet 212 presses the ball 263 to move from the front end piece 2611 towards the rear end piece 2612 to open the feeding valve 260 for delivering the mixture of dry powder and pressurized air to the emitting opening 12 of the delivery channel 10 for spraying onto the internal operation site.
Once the air pressure is reduced when the compression to the pressurized gas feeder 22 is released, the spring element 262 rebound the ball 263 to its original position to block the entrance of the front end piece 2611 to close the feeding valve 260.
Referring to
When the pressurized gas feeder (air pump) 22 is compressed, the air pressure produced at the dry powder outlet 212 presses the ball 263 to move from the front end piece 2611 towards the rear end piece 2612 to open the feeding valve 260 for delivering the mixture of dry powder and pressurized air to the emitting opening 12 of the delivery channel 10 for spraying onto the internal operation site.
Once the air pressure is reduced when the compression to the pressurized gas feeder 22 is released, the spring element 262 rebound the ball 263 to its original position to block the entrance of the front end piece 2611 to close the feeding valve 260.
Referring to
When the pressurized gas feeder (air pump) 22 is compressed, the air pressure produced at the dry powder outlet 212 presses the resilient blocking element 271 to block the air opening 210 and opens the feeding valve 280 for delivering the mixture of dry powder and pressurized air to the emitting opening 12 of the delivery channel 10 for spraying onto the internal operation site.
Once the air pressure is reduced when the compression to the pressurized gas feeder 22 is released, the feeding valve 280 returns to its close position and the resilient blocking element 271 rebounds to its original position to reopen the air opening 210 so that air can enter the gas valve 270 and supply to the pressurized gas feeder (air pump) 22 to release the negative air pressure therein in order to prevent any re-sucking of the dry powder 30 back to the pressurized gas feeder 22.
According to the preferred embodiment as shown in
Referring to
The gas-powder chamber 21′ has dry powder inlet 211′ for feeding in a predetermined amount of dry powder therein and a dry powder outlet 212′ communicating with the feeding opening 11 of the delivery channel 10.
The pressurized gas feeder 22′ produces pressurized gas in the gas-powder chamber 21′ mixing with the dry powder therein to form a mixture of dry powder and pressurized gas for blowing into the delivery channel 10 through the feeding opening 11 thereof. Thereby, a continuous feeding of the pressurized gas and the mixture of dry powder and pressurized gas into the delivery channel 10 from the gas-powder chamber 21′ substantially renders the mixture of dry powder and pressurized gas to deliver to the emitting opening 12 of the delivery channel 10 and spray onto the designated internal operation site.
The powder supply device 20′ further comprises a powder feeder 23′ which is seadedly connected to the dry powder inlet 211′ provided at a side of the gas-powder chamber 21′ in a detachable manner while the exit opening 231′ of the powder feeder 23′ is communicated with the dry powder inlet 211′. The dry powder 30 is received in the powder feeder 23′ and arranged to feed into the gas-powder chamber 21′ through the exit opening 231′ and the dry powder inlet 211′.
The pressurized gas feeder 22′ which is a manual bladder air pump sealedly connected to one end of the gas-powder chamber 21′ for pumping pressurized air into the gas-powder chamber 21′ manually. The gas regulator 24′ comprises a one-way gas valve 221′ provided on the pressurized gas feeder 22′ and a feeding valve 280′ affixed at the dry powder outlet 212′ of the gas-powder chamber 21′, similar to that as shown in
Accordingly, when the pressurized gas feeder 22′ is compressed, the gas valve 221′ is closed to block any outside air entering the pressurized gas feeder 22′ so as to pump in pressurized air into the gas-powder chamber 21′ mixing with the dry powder 30 therein, to open the feeding valve 280′ and to blow the dry powder 30 into the delivery channel 10′ for delivering the mixture of dry powder and pressurized air to the emitting opening 12 of the delivery channel 10 for spraying onto internal operation site.
Once the air pressure is reduced when the compression to the pressurized gas feeder 22′ is released, the feeding valve 280′ returns to its close position and the gas valve 221′ opens to enable external gas (outside air) entering the pressurized gas feeder 22′ to release the negative air pressure therein in order to prevent any re-sucking of the dry powder 30 back to the gas-powder chamber 21′ and the pressurized gas feeder 22′.
According to the preferred embodiment, the powder feeder 23′ is screwed to the dry powder inlet 211′ so that one can unscrew and detach the powder feeder 23′ to refill the empty powder feeder 23′ or filling it with different powder medication. Also, it is appreciated that more than one powder feeders can be used to selectively communicate with the dry powder inlet 211′ for different applications.
It is worth mentioning that more than one powder feeders 23′ or 23″ can be used to connect to the gas-powder chamber 21, 21′ which are selectively switched to equip with the pressurized gas feeder 22′, 22″ to feeding dry powder through the delivery channel 10. Also, a catheter can be used and functioned as the delivery channel 10.
Referring to
Alternatively, the end cap 40 can be detachably attached to the distal end of the delivery channel 10 to cover the emitting opening 12. After the delivery channel 10 is inserted into the beings until the emitting opening 12 reaches a position adjacent to the internal operation site and the mixture of dry powder and pressurized gas is deliver to the emitting opening 12, the pressure of the pressurized gas is capable of pushing the end cap 40 to detach from distal end and open the emitting opening 12.
In view of above, the pressurized gas feeder of the present invention can selectively use one of following types of air pressure source:
1. By connecting to the manual air pump 22 as shown in
2. Using the electrical pump as shown in
3. The device could be connected to medical-use oxygen, carbon dioxide, and other medical use clean-air to offer a continuously flow of gas and limit the possibility of powder and tip occlusion in the delivery channel 10. The gas supply to be used can be directly fed to the inletting opening 243 of the gas valve 240 as shown in
Besides the options for various air/gas sources, the current invention offers two types of air-powder chambers to provide a tailor-made apparatus via endoscope for any minimally invasive procedures both for diagnosis and treatments.
The first option offers the three-way air-powder chamber with an external gas source, a powder feeder, a pressurized gas feeder, and a delivery channel (catheter) attached to the gas-powder chamber. The main body of the gas-powder chamber has two incoming openings, for both gas and the dry powder, and a dry powder outlet connected to the catheter. The incoming gas flow will mix with the dry powder released from the powder feeder and then delivered through the catheter of the working channel via endoscope.
The second option provides a two-way air-powder chamber; it only has an incoming and outgoing opening. It differs with the previous device by eliminating the external powder feeder since the main mixing chamber is pre-filled with the dry powder. Once the gas is released, it mixes with the dry powder and the mixture is delivered through catheter of the working channel via endoscope. It is preferably for portable and disposable usage due to its compact size and simplified structure.
The delivery channel 10 will preferably used with medical-use materials such as PE and TEF. It is essential to select a material that has the strength and the flexibility to be inserted into the working channel of endoscope and endure any folding or twisting which could cause congestion. For gastro-intestinal endoscope, the diameter of the delivery channel 10 is preferably smaller than the regular working channel's diameter of the endoscope being used. Currently, the standard working channel diameters of gastro and intestinal endoscope are about 2.8 mm and 3.2 mm respectively. The length of the delivery channel 10 should be longer than the total length of the endoscope which it is inserted into. Normally, the average total length of gastro and intestinal endoscope are about 1600 mm and 2300 mm respectively.
Besides the incoming gas source and the outgoing channel, all connecting outlets of the system should remain completely sealed throughout use to minimize air/powder reflux and tip occlusion.
It is worth mentioning that the pressure of gas should be maintained higher enough to overcome the resistance of particles with particles, particles with the systems, plus the pressure inside of gastro-intestine where the catheter tip located.
The internal dry powder delivery system of the present invention differentiates itself from conventional medication delivery method in its specification for the delivery of dry powder particles via the working channel of an endoscope. For example, prior art patent, WO2006/049463A1, focuses on liquid and gel-form medication delivery. Liquid's fluidity causes minimal obstruction in the working channel of the endoscope, which does not contain the same strategy and technology as a dry powder delivery service via endoscope.
The current endoscope invention includes both gastro and intestinal endoscopes. It can be also adapted in laparoscope, thoracoscope, hysteroscope, cytoscope, laryngoscope, and nasopharyngoscope. The working channel diameter of laparoscope, thoracoscope, hysteroscope, cytoscope and laryngoscope are normally much bigger than gastro-intestinal endoscope. So the challenges will be less for physicians to deliver the powder format drug to the wound sites via laparscope, thoracoscope, hysteroscope, cytoscope and laryngoscope
The working channel mentioned above is the irrigation channel or a biopsy clamp channel in the endoscopic cannula.
The present invention offers a new powder format drug delivery method for physicians via endoscope. It could be used with various purposes such as hemostatic, antibiotic, tissue repair, mucosal protection, ulcer repair and antineoplastic treatment, etc.
By using the internal dry powder delivery system of the present invention, physicians can directly apply the biocompatable polysaccharide hemostatic powder to the bleeding sites via endoscope during invasive surgery to achieve hemostasis.
When all components (pressurized gas feeder, gas-powder chamber, and working delivery channel) are assembled, the present invention can provide a complete and new applicator via endoscope. The manual air pump and powder feeder allow physicians to control the flow of air and the amount of powder released through the delivery channel. The gas and feeding valves provided to the gas-powder chamber will eliminate air/powder reflux. The mechanism of this system begins with the release of gas by a manual or electrical air pump, which mixes with the dry powder presented in the air-powder chamber. By compressing the pressurized gas feeder and/or the dry powder feeder, physicians can easily control the amount of gas/power mixture released into the delivery channel. The gas flow continues to push the mixture throughout the entire delivery channel, overcoming any obstructions presented by the channel wall and/or between particles.
By using the internal dry powder delivery system of as suggested in the present invention, physicians can directly apply the powder-format biocompatible adhesives to the wound site in the gastro-intestinal wall via endoscope by minimal invasive surgery to achieve hemostasis and sealant treatment.
By using the internal dry powder delivery system as disclosed in the present invention, physicians can directly apply the antibiotic powder to the infection site in the gastro-intestinal wall via endoscope by minimal invasive surgery to achieve anti-infection treatment.
By using the internal dry powder delivery system as disclosed in the present invention, physicians can directly apply the anti-ulcer powder form medication to the ulcer site in the gastro-intestinal wall via endoscope by minimal invasive surgery to achieve anti-ulcer treatment.
By using the internal dry powder delivery system as disclosed in the present invention, physicians can directly apply the anti-cancer/tumor powder form medication to the cancer/tumor site in the gastro-intestinal wall via endoscope by minimal invasive surgery to achieve antineoplastic treatment.
By using the internal dry powder delivery system as disclosed in the present invention, physicians can directly apply the illustrating agent to the cancer/tumor site in the gastro-intestinal wall.
By using the internal dry powder delivery system and method thereof as disclosed in the present invention, physicians can apply many clinical application and treatment to patient such as hemostasis, sealing wound tissue, anti-inflamation, anti-ulcer treatment, antineoplastic treatment.
The internal dry powder delivery system and method thereof as disclosed in the present invention can be specifically designed for examination, diagnosis and treatments practices in humans and mammals. It could also be used in forensic science such as autopsy, anatomy research and scientific experiments. Besides medical and scientific uses, the internal dry powder delivery system of the present invention can be applied in engineering, military affairs, navigation, and aviation.
The internal dry powder delivery system and method thereof as disclosed in the present invention can be specifically designed for examination, diagnosis and treatments practices in humans and mammals.
One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009 1 0195842 | Sep 2009 | CN | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 471865 | Howard | Mar 1892 | A |
| 576437 | Elliott | Feb 1897 | A |
| 881238 | Hasbrouck | Mar 1908 | A |
| 1685280 | Findley | Sep 1928 | A |
| 1732566 | McKendrick | Oct 1929 | A |
| 1934793 | Crain et al. | Nov 1933 | A |
| 2122234 | Manning | Jun 1938 | A |
| 2151418 | Brown | Mar 1939 | A |
| 4184258 | Barrington et al. | Jan 1980 | A |
| 5273531 | Knoepfler | Dec 1993 | A |
| 5312331 | Knoepfler | May 1994 | A |
| 5445612 | Terakura et al. | Aug 1995 | A |
| 5951531 | Ferdman et al. | Sep 1999 | A |
| 6610005 | Tao | Aug 2003 | B1 |
| 7427607 | Suzuki | Sep 2008 | B2 |
| 7547292 | Sheldrake et al. | Jun 2009 | B2 |
| 20030181917 | Gertner | Sep 2003 | A1 |
| 20080021374 | Kawata | Jan 2008 | A1 |
| 20080214989 | Kawata | Sep 2008 | A1 |
| 20090062233 | Ji et al. | Mar 2009 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20110066132 A1 | Mar 2011 | US |
