A method of vascularizing cardiac tissue using an instrument through the vascular system to an entry situs located at or adjacent the cardiac tissue is provided including providing a flowable agent comprising microspheres or microparticles having a particulate size range of 1 micron to 1 mm, introducing the agent through the instrument, imparting a particle moving force through the instrument that is generated externally to cause the microspheres or microparticles to pass directly through contiguous tissue to target cardiac tissue, the particle-moving force imparting a high pressure on the agent of several thousand psi, the microspheres or microparticles passing through the contiguous tissue without any mechanical means, whereupon the microspheres or microparticles directly enter the target cardiac tissue, forming channels in the wall of the myocardium at spaced locations and in communication with the interior of the heart, and introducing the flowable agent in the channels.

This invention relates generally to medical systems and procedures and more particularly to systems and procedures for delivering a flowable treatment agent into targeted tissues, e.g., cardiac tissue, of a living being.
Cardiovascular disease is the leading cause of death in the industrial world today. During the disease process, atherosclerotic plaques develop at various locations within the arterial system of those affected. These plaques restrict the flow of blood through the affected vessels. Of particular concern is when these plaques develop within the blood vessels that feed the muscles and other tissues of the heart. In healthy hearts, cardiac blood perfusion results from the two coronary arterial vessels, the left and right coronary arteries that perfuse the myocardium from the epicardial surface inward towards the endocardium. The blood flows through the capillary system into the coronary veins and into the right atrium via the coronary sinus. When atherosclerosis occurs within the arteries of the heart it leads to myocardial infarctions, or heart attacks, and ischemia due to reduced blood flow to the heart tissues. Over the past few years numerous devices and methods have been evaluated for treating cardiovascular disease, and for treating the resulting detrimental effects that the disease has upon the myocardium and the other heart tissues. They are: traditional surgical methods (e.g. open heart surgery), minimally invasive surgery, traditional interventional cardiology (e.g. angioplasty, atherectomy, stents), and advanced interventional cardiology (e.g. catheter based drug delivery). Other recent advances in cardiovascular disease treatment involve transmyocardial revascularization (TMR), and growth factor and gene delivery.
Traditional methods for treating cardiovascular disease utilize open surgical procedures to access the heart and bypass blockages in the coronary blood vessels. These procedures require an incision in the skin extending from the supra-sternal notch to the zyphoid process, the sawing of the sternum longitudinally in half, and the spreading of the rib-cage to surgically expose the patient's heart. Based upon the degree of coronary artery disease, a single, double, triple, or even greater number of vessels are bypassed. Each bypass is typically performed by creating a separate conduit from the aorta to a stenosed coronary artery at a location distal to the occluded site. In general, the conduits are either synthetic or natural bypass grafts. Grafting with the internal thoracic (internal mammary) artery directly to the blocked coronary site has been particularly successful with superior long-term patency results. During conventional cardiac surgery, the heart is stopped using cardioplegia solutions and the patient is put on cardiopulmonary bypass. The bypass procedure uses a heart-lung machine to maintain circulation throughout the body during the surgical procedure. A state of hypothermia may be induced in the heart tissue during the bypass procedure to preserve the tissue from necrosis. Once the procedure is complete, the heart is resuscitated and the patient is removed from bypass.
There are great risks associated with these traditional surgical procedures such as significant pain, extended rehabilitation time and high risk of mortality for the patient. The procedure is time-consuming and costly to perform. Traditional cardiac surgery also requires that the patient have both adequate lung and kidney function in order to tolerate the circulatory bypass associated with the procedure and a number of patients which are medically unstable are thus not a candidate for bypass surgery. As a result, over the past few years, minimally invasive techniques for performing bypass surgery have been developed and in some instances the need for cardiopulmonary bypass and extended recovery times are avoided. A number of companies, e.g., Heartport, Inc. of Redwood City, Calif. and Cardiothoracic Systems, Inc. of Cupertino, Calif., have developed devices that allow for cardiac surgical procedures that do not require a grossly invasive median sternotomy or traditional cardiopulmonary bypass equipment. The procedures result in a significant reduction in pain and rehabilitation time.
In addition, as an alternative to surgical methods, traditional interventional cardiology methods (e.g. angioplasty, atherectomy, and stents) non-surgical procedures, such as percutaneous transluminal coronary angioplasty (PTCA), rotational atherectomy, and stenting have been successfully used to treat this disease in a less invasive non-surgical fashion. In balloon angioplasty a long, thin catheter having a tiny inflatable balloon at its distal end is threaded through the cardiovascular system until the balloon is located at the location of the narrowed blood vessel. The balloon is then inflated to separate and expand the obstructing plaque and expand the arterial wall, thereby restoring or improving the flow of blood to the local and distal tissues. Rotational atherectomy utilizes a similarly long and thin catheter, but with a rotational cutting tip at its distal end for cutting through the occluding material. Stenting utilizes a balloon tipped catheter to expand a small coil-spring-like scaffold at the site of the blockage to hold the blood vessel open.
While many patients are successfully relieved of their symptoms and pain with traditional interventional procedures, in a significant number of patients the blood vessels eventually restenose or reocclude within a relatively short period of time. As such, researchers have explored advanced interventional cardiology methods (e.g., catheter based drug delivery, radiation therapy, etc.) to delay or prohibit the process of restenosis. As summarized by Raoul Bonan, MD ("Local Drug Delivery for the Treatment of Thrombus and Restenosis, IAGS Proceedings, The Journal of Invasive Cardiology, 8:399-408, October 1996), the cardiology community has recently begun to augment standard catheter-based treatment techniques with devices that provide local delivery of medications to the treated site. This localized administration of drugs has shown promise for counteracting clotting, reducing inflammatory responses, and blocking proliferative responses.
Several devices are reported to be under evaluation for site specific drug delivery, such as the so-called "Channel Balloon" catheter of Boston Scientific (Natick, Mass.), the "Infiltrator" device of InterVentional Technologies (San Diego, Calif.), the "InfusaSleeve" device of LocalMed Inc. (Sunnyvale, Calif.), the "Dispatch" catheter of SciMed/Boston Scientific (Natick, Mass.), and an ultrasound enhanced catheter of EKOS (Bothell Wash.). The "Channel Balloon" catheter is an over-the-wire catheter with separated ports for balloon inflation and drug infusion. The "Infiltrator" device utilizes nipples in a balloon to force a drug into vessel wall.
U.S. Pat. No. 5,279,565 (Klein et al.) discloses a device for infusing a treatment site with a medicinal agent. The device has a flexible body and deflectable support frames that are deployed radially against the intended treatment site. The InfusaSleeve device of LocalMed, Inc. slides over existing balloons to position drug delivery ports against the artery wall. The Dispatch is an over the wire catheter with separate ports for drug infusion and balloon inflation.
U.S. Pat. No. 5,527,292 (Adams et al.) describes an intravascular device having an elongated flexible tube sized for insertion into a coronary vessel beyond a distal end of a guide catheter. In certain applications, the intravascular device is used as a drug (or other fluid) delivery device or as an aspiration device. In other applications, the intravascular device is used as a guiding means for placement of an angioplasty device, such as a guide wire or a balloon catheter. EKOS (Bothell, Wash.) has developed a site-specific catheter that uses ultrasound energy to enhance the performance of a thrombolytic drug. The ultrasound energy transports the drug molecules into the strands of fibrin bundles to dissolve clots more effectively than drugs alone. Several other drug delivery catheters have been described.
Balloon-tipped catheters, appropriate for drug delivery procedures, are also described in U.S. Pat. No. 5,087,244 (Wolinsky et al.). In particular, this patent describes a catheter having a balloon near its distal end is expanded with a medication that then flows through minute holes in the balloon surface at a low flow rate. The catheter pressurizes the medication so that it can be perfused at a controlled low flow rate to penetrate into the wall of the localized tissue.
U.S. Pat. No. 5,021,044 (Sharkawy) describes an intravascular treatment apparatus having a plurality of holes on the outer surface of the catheter body through which a drug may be delivered to a site within a vessel.
U.S. Pat. No. 5,112,305 (Barath et al.) describes a catheter for delivery of therapeutic chemical agents to an interior wall of a vessel, the catheter having a balloon near its distal end with tubular extensions projecting from its outer surface. The catheter is pressurized with a drug, which causes the balloon to expand. The drug then flows throughout the tubular extension into the vessel wall.
U.S. Pat. No. 4,406,656 (Hattler et al.) describes a collapsible multi-lumen venous catheter that can be used for drug injection.
U.S. Pat. No. 5,498,238 (Shapland et al.) discloses a method of simultaneous angioplasty and drug delivery to a localized portion of coronary or peripheral arteries or any other type of body passage that has a stricture. The drug delivery device is first positioned in a body passageway. The device is expanded in order to dilate the passage while simultaneously causing a selected drug to be transported across a drug transport wall of the device for direct contact with the passageway wall.
U.S. Pat. No. 5,415,637 (Khosravi) describes an intravascular catheter that is capable of delivering a drug, that is in the form of an already mixed solution or in the form of pellets, both intraluminally and endoluminally to an artery.
U.S. Pat. No. (Spears) describes a method for treating a lesion in an artery by bonding a bioprotective material to the arterial wall with thermal energy to provide localized drug delivery. The device can use drugs that are trapped within microspheres that can be thermally bonded to tissues.
U.S. Pat. No. 4,994,033 (Shockey et al.) describes an intravascular treatment apparatus having a pair of expansion members concentrically arranged near its distal end wherein a drug is delivered to the outer expansion member. The expansion member expands against the vessel wall forcing the drug through minute holes in the outer member to bathe the vessel wall.
U.S. Pat. No. 5,456,667 (Ham et al.) describes an intravascular catheter with an expandable region formed of a tubular material at the distal end of the catheter body in a one-piece configuration and is radially expanded and contracted by means of a control wire. The interior of the expandable region is in fluid communication with a lumen in the catheter body to allow the delivery of a fluid to the artery via openings in the surface of the expandable region. The catheter is particularly adapted to hold open an artery after a vascular procedure such as a balloon angioplasty, and if desired to introduce a therapeutic drug or other fluid to the site of the vascular procedure.
The assignee of this present invention is also the assignee of previously described catheter-based devices for the local delivery of drugs into the arterial system. See for example, U.S. Pat. No. 4,589,412 (Kensey) and U.S. Pat. No. 4,631,052 (Kensey) disclose atherectomy catheters that utilize a cutting tip that is driven by the application of fluid pressure. As described, the catheters can be used to deliver drugs, oxygen, nitrates, calcium channel blockers or contrast media through the catheter tip into the arterial lumen.
U.S. Pat. No. 4,747,406 (Nash) and U.S. Pat. No. 4,686,982 (Nash), which are assigned to the same assignee as this invention, describe recanalization catheters with a high speed working end that is driven by a flexible drive shaft mounted within a bearing. The specification describes the use of fluid to cool and lubricate the catheter, as well as reduce the incidence of snagging as a result of the positive pressure applied to the artery wall. The fluid can include nitrates, drugs, or contrast media.
U.S. Pat. No. 4,664,112 (Kensey), U.S. Pat. No. 4,679,558 (Kensey et al.), and U.S. Pat. No. 4,700,705 (Kensey), assigned to the same assignee as this invention, describe small diameter catheter devices with a high-speed working head used for dilating lumens and stopping arterial or other lumen spasm. The specifications describe the use of fluids to cool and lubricate the catheter. The fluid can carry contrast media or drugs. The catheters may be useful for opening restrictions in lumens by bombarding the restriction with propelled fluids at high pressure which may force the liquid into the lumen walls by increasing the local dynamic or hydrostatic pressure induced by the injected liquid or the moving working head.
U.S. Pat. No. 4,790,813 (Kensey), also assigned to the same assignee as this invention, describes an atherectomy catheter that utilizes a cutting tip that is driven by the application of fluid pressure. As described, that catheter has the potential for the delivery of drugs, oxygen, nitrates, calcium channel blockers or contrast media through the catheter tip into the arterial lumen.
U.S. Pat. No. 4,795,438 (Kensey et al.), also assigned to the same assignee as this invention, describes a flexible small diameter catheter for effecting the formation of a restriction in a vessel. The patent teaches of a rotary catheter that is used to deliver fluid, particles, sclerosing liquid, micron-sized particles, and adhesive agents. In one aspect of the invention, the particles are embedded into the tissue contiguous with the working head of the catheter. The embedded particles cause the tissue to change, e.g. form scar tissue, whereupon a restriction is formed. Another aspect of the invention describes the use of abrasive particles to sclerose or abrade tissue.
U.S. Pat. No. 4,749,376 (Kensey et al.), U.S. Pat. No. 5,042,984 (Kensey et al.), and U.S. Pat. No. 4,747,821 (Kensey et al.), all assigned to the same assignee of this invention, describe drive-wire driven rotary catheters for opening an arterial restriction. The devices utilize the rotation of a working head to cause fluid to be thrown radially outward from the working head to impact the artery wall.
In general, these previous devices are suited to deliver drugs and other therapeutic agents locally to the immediate lumen (e.g., artery) wall to address restenosis. However, they do not address the problem of treating other heart tissues (e.g., myocardium) located beyond the arterial wall.
It has been shown that some patients can receive significant benefits from recently developed medical treatments. Some of these treatments are applied to other tissues of the heart (e.g. the myocardium). In addition, although the non-surgical interventional cardiology procedures are much less costly and less traumatic to the patient than traditional coronary bypass surgery, there are a number of patients for which these procedures are not suitable. For certain types of patients the presence of extremely diffuse stenotic lesions and total occlusion in tortuous vessels prohibits them from being candidates for traditional cardiac surgery. For these patients, direct myocardial revascularization has been performed by inducing the creation of new channels, other than the coronary arteries themselves, which are designed to supply oxygenated blood and remove waste products from the heart tissue (e.g. myocardium). Myocardial revascularization is a technique that was conceived to supplement the blood supply delivered to the heart by providing the ischemic inner surface of the heart, known as the endocardium, with direct access to the blood within the ventricular chamber. Typically the endocardium receives its nutrient blood supply entirely from the coronary arteries that branch through the heart wall from the outer surface known as the epicardium.
Needle acupuncture approaches to direct myocardial revascularization have been made and were based upon the premise that the heart of reptiles achieve myocardial perfusion via small channels between the left ventricle and the coronary arterial tree as described by Sen et al. in their article entitled "Transmyocardial Acupuncture: A New Approach To Myocardial Revascularization" in the Journal of Thoracic and Cardiovascular Surgery, 50:181-187, August, 1965. In that article it was reported that researchers attempted to duplicate the reptilian anatomy to provide for better perfusion in human myocardium by perforating portions of the ventricular myocardium with 1.2 mm diameter needles in 20 locations per square centimeter. It has been shown that the perfusion channels formed by mechanical methods such as acupuncture generally close within two or three months due to fibrosis and scaring. Pifarre et al. evaluated the feasibility of direct myocardial revascularization from the left ventricle through artificially created channels. Their results are described in an article entitled "Myocardial Revascularization by Transmyocardial Acupuncture, A Physiologic Impossibility" in the Journal of Thoracic and Cardiovascular Surgery, 58:424-431, September, 1969. Pifarre et al. concluded that results were not encouraging. As a result, these types of mechanical approaches were abandoned in favor of other methods to effect the transmyocardial revascularization (TMR).
Similar revascularization techniques have involved the use of polyethylene tubes, endocardial incisions, and the creation of perforated or bored channels with various types of needles, and needle acupuncture. For example, T-shaped tubes have been implanted in the muscle, with the leg of the T-tube extending into the ventricular cavity as reported by Massimo et al. in an article entitled "Myocardial Revascularization by A New Method of Carrying Blood Directly From the Left Ventricular Cavity into the Coronary Circulation" appearing in J. Thorac. Surg., 34:257-264, August, 1957. In an article entitled "Experimental Method For Producing A Collateral Circulation To The Heart Directly From The Left Ventricle" by Goldman et al. in the Journal of Thoracic and Cardiovascular Surgery, 31:364-374, March 1965, several experimental methods for myocardial revascularization are described. One method involved the implantation of excised perforated carotid arteries into the left ventricular wall. Goldman et al. also examined the use of implanted perforated polyethylene tubing in a similar fashion.
U.S. Pat. No. 5,591,159 (Taheri) describes a device for effecting myocardial perfusion that utilizes slit needles to perforate the myocardium. The device uses a trans-femoral approach to position the device into the left ventricle of the patient. A plunger is activated to cause the needles to enter the myocardium several times. Perforation of the myocardium may be effected by means of a laser beam transmitted through the lumen of the needle or high velocity drill.
U.S. Pat. No. 5,655,548 (Nelson et al.) describes a method for perfusing the myocardium using a conduit disposed between the left ventricle and the coronary sinus. In one method, an opening is formed between the left ventricle and the coronary sinus, and the coronary ostium is partially occluded using a stent that prevents the pressure in the coronary sinus from exceeding a predetermined value. Blood ejected from the left ventricle enters the coronary sinus during cardiac systole. The apparatus limits the peak pressure in the coronary sinus to minimize edema of the venous system. The system utilizes retroperfusion via the coronary sinus of the venous system.
U.S. Pat. No. 5,755,682 (Knudson et al.) describes a device that establishes a channel leading directly from a chamber of a heart to a coronary artery. In one described method, a channel is created that extends through the deep coronary arterial wall through underlying cardiac musculature into the underlying chamber of the heart by using a scalpel, electro-surgical cutting blade, laser, or by radio-frequency ablation. A device is placed inside the channel to conduct blood from the heart chamber into the coronary artery.
Previous researchers had explored long term retroperfusion via the coronary sinus but found that its leads to edema of the cardiac veins which are incapable of sustaining long-term pressures above about 60 mm Hg. The procedure basically places a stent-like plug in the left ventricle so that blood flows into the coronary sinus and then into the myocardium via the venous system using retroperfusion, not into the myocardium directly. In the aforementioned Nelson et al. patent there is disclosed the use of a cutting instrument, such as a cannulated needle, a rotating blade, or medical laser to provide the required opening for the conduit. It is believed that when implanted in the heart, the plug and stent will result in long-term retrograde perfusion of the myocardium using the cardiac venous system and will cause a redistribution of the flow within the venous system so that a greater fraction of the deoxygenated blood will exit through the lymphatic stem and the Thebesian veins (any of the minute veins of the heart wall that drain directly into the cavity of the heart). The inventors also describe the use of a conduit that takes the place of the coronary sinus.
Researchers have also evaluated the used of lasers to create channels in the myocardium. U.S. Pat. No. 4,658,817 (Hardy) describes a surgical carbon dioxide laser with a hollow needle mounted on the forward end of the hand-piece. The needle is used to perforate a portion of the tissue, for instance the epicardium, to provide the laser beam direct access to distal tissue of the endocardium for lasering and vaporization. The device does not vaporize the tissue of the outer wall instead it separates the tissue which recoils to its native position after the needle's removal. This technique eliminates surface bleeding and the need for suturing the epicardium as is done with other techniques. The device includes a port that allows the needle to be cleaned via an injection of saline.
In U.S. Pat. No. 5,607,421 (Jeevanandam) discloses that laser channels remain open because carbonization associated with the laser energy inhibits lymphocyte, macrophage, and fibroblast migration. Thus, in contrast to channels created by needle acupuncture, laser channels heal more slowly and with less scar formation, which allows endothelialization and long term patency.
An article entitled "New Concepts in Revascularization of Myocardium" (by Mirhoseini et al. in Ann. Thor. Surg., 45:415-420, April 1988) discusses the work of investigators exploring several different approaches for direct revascularization of ischemic myocardium. One revascularization technique utilizes "myoepexy", which consists of roughening of the myocardial surface to enhance capillarization. Another technique, known as "omentopexy" (the operation of suturing the omentum to another organ), consists of sewing the omentum over the heart to provide a new blood supply. Another approach involves implanting the left internal mammary artery directly into heart muscle so that blood flowing through the side branches of the artery will perfuse the muscle.
It has been reported by Moosdorf et al. in their article entitled "Transmyocardial Laser Revascularization—Morphologic Pathophysiologic And Historical Principles Of Indirect Revascularization Of The Heart Muscle" in Z Kardiol, 86(3): 147-164, March, 1997 that the transmyocardial laser revascularization results in a relevant reduction of clinical symptoms such as angina and an increase of exercise capacity in approximately two thirds of the patients treated. Objective data of enhanced myocardial perfusion as assessed by positron emission tomography, thallium scans, and stress echocardiography has also been presented in other studies. Some researchers have found that TMR channels created by CO2 lasers are surrounded by a zone of necrosis with an extent of about 500 microns. In heart patients who died in the early postoperative period (1 to 7 days) almost all channels were closed by fibrin clots, erythrocytes, and macrophages. At 150 days post procedure, they observed a string of cicatricial tissue (scar tissue resulting from the formation and contraction of fibrous tissue in a flesh wound) admixed with a polymorphous blood-filled capillary network and small veins, which very rarely had continuous links to the left ventricular cavity. At the 2-week post procedure point a granular tissue with high macrophage and monocyte activity was observable. See for example, the article by Krabatsch et al. entitled "Histological Findings After Transmyocardial Laser Revascularization" appearing in J. Card. Surg. 11:326-331, 1996, and the article by Gassler et al. entitled "Transmyocardial Laser Revascularization. Historical Features In Human Nonresponder Myocardium" appearing in Circulation, 95(2): 371-375, Jan. 21, 1997.
PLC MEDICAL's (Franklin, Mass.) Heart Laser and Eclipse's (Sunnyvale, Calif.) TMR 2000 laser revascularization system's have recently been clinically tested and neither device has shown significant survival benefit between laser-based transmyocardial revascularization and medical management. However, in general the use of the devices did result in a two-class reduction in angina symptoms in the months following the procedure. Recent data was reported with respect to functional improvement, long-term survival, and angina relief after three years in 70 patients suffering from refractory angina yet not amenable to conventional revascularization. The patients were treated with PLC's CO2 Heart Laser. After the revascularization procedure with the Heart Laser, the angina class reduction seen at the first year persisted for at least three years with an accompanying increase in exercise tolerance. A significant increase in long-term mortality was not observed, however.
To date, studies have shown that no matter which laser, CO2 or Holmium are used, the clinical results following a laser-based transmyocardial revascularization procedure were almost identical: patients had an increase in exercise tolerance, a two-class reduction in angina symptoms, and no significant alteration in left ventricular ejection. BAXTER, J&J, CARDIODYNE and BARD/CORMEDICA are other companies that are also exploring laser-based TMR systems.
In co-pending U.S. patent application Ser. No. 08/958,788, filed on Oct. 29, 1999, entitled Transmyocardial Revascularization System, which is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein, there is disclosed a system making use of mechanically created punctures to provide the same benefits as laser-created channels by initiating a healing response and effecting denervation in the myocardium. In particular, that system makes use of implants within the myocardial tissue to perpetuate a foreign body or healing response. That application additionally discloses the use of pharmaceuticals, growth factors and genetic material to provide the heart with an initial and perpetuating stimulus for healing itself.
More recently, other researchers have had related ideas Pelletier et al. examined myocardial channels created by lasers and the resulting injury that leads to an angiogenic response mediated by a number of growth factors. This work is described by Pelletier in "Angiogenesis and Growth Factor Expression in a Model of Transmyocardial Revascularization" (Annals of Thoracic Surgery, 66:12-18, 1998). With similar thoughts in mind, other companies are also investigating non-laser alternatives for myocardial revascularization. ANGIOTRAX (Sunnyvale, Calif.) is investigating a percutaneous device and flexible tip surgical handpiece for mechanically creating channels. BOSTON SCIENTIFIC (Natick, Mass.) is working with ARTHROCARE on the development of a radio-frequency (RF) system for percutaneous TMR. The device creates holes in the myocardium with needle electrodes that deliver RF energy at 450 kHz. The device utilizes a catheter that has been designed by SciMed. RADIUS MEDICAL (Maynard, Mass.) is exploring a percutaneous RF devices that utilizes a hollow guidewire, 0.021 or 0.035 inches in diameter that utilizes 13 kHz, that is passed through a 6 French diagnostic catheter. Contrast media is injected through the hollow wire to help position the device tip against the endocardial tissue. RADIUS believes that the hollow wire can be used to infuse proteins or genetic material into the myocardium. U.S. Pat. No. 5,810,836 (Hussein et al.) describes a stent for insertion into a heart wall for transmyocardial revascularization. The device generates needle-made, or drilled, channels in the heart wall. A stent is implanted in each channel to maintain the patency of the channel. In European Patent Application No. 97107784.7, assigned to United States Surgical of Norwalk, Conn., a coring device is described for removing tissue during a biopsy or transmyocardial procedures. The coring member is rotatable and linearly advanceable at coordinated predetermined rates to core body tissue. The tissue can be cauterized during the coring procedure. European Patent Application number 98201480.5 and PCT International application number PCT/US98/08819 of C. R. BARD in Murray Hill, N.J. describes a "TMR stent and delivery system." That system includes a device which pierces the myocardial tissue and a stent which is implanted to permit the flow of blood from the left ventricle directly into the tissue for direct revascularization. Patent Cooperation Treaty (PTC) international application number PCT/US97/03523 of Energy Life Systems of Costa Mesa, Calif. describes a similar system. German patent number DE 296 19 029 U1 (Kletke) describes a needle for myocardial penetration. A needle is used to create a series of puncture canals. The canals are protected by the placement of continuous length of a resorbable suture, which is looped into each puncture.
In addition, researchers are exploring the percutaneous and direct surgical injection of growth factors and genetic material. Mack et al. describes experiments to improve myocardial perfusion in an article entitled "Biologic Bypass with the Use of Adenovirus-Medicated Gene Transfer of the Complementary Deoxyribonucleic Acid for Vascular Endothelial Growth Factor 121 Improves Myocardial Perfusion and Function in the Ischemic Porcine Heart" in The Journal of Thoracic and Cardiovascular Surgery 115:168-177, January 1998. Sanborn et al. described the potential injection of angiogenic proteins and genes directly into the heart via the endocardium with a percutaneous fluoroscopically guided system in an abstract entitled "Percutaneous Endocardial Gene Therapy: In Vivo Gene Transfer and Expression" in the Journal of the American College of Cardiology 33:262A, February 1999. Uchida et al. described growth factor injections in "Angiogenic Therapy of Acute Myocardial Infarction by Intrapericardial Injection of Basic Fibroblast Growth Factor and Heparin Sulfate: An Experimental Study" American Heart Journal 130:1182-1188, December 1995. Uchida utilized a catheter system for percutaneous transluminal administration of drugs through the right atrium into the pericardial cavity with a 23 gauge 4 mm long needle. U.S. Pat. No. 5,244,460 (Unger et al.) describes a method for inserting a catheter into a coronary artery and for infusing multiple coronary drug injections, containing blood vessel growth promoting peptides (i.e. fibroblast growth factor), through an infusion port into the catheter over a period of time.
In summary, there are a number of potential mechanisms which individually or in combination may be responsible for the improvements seen in patients subjected to the previously described myocardial revascularization techniques including: (1) new blood flow through the created channels, (2) angiogenesis (stimulation of the creation of new blood vessels), (3) cardiac denervation, (4) the placebo effect, (5) ablation of ischemic myocardium, and (6) formation of collateral circulation.
Currently it is believed that cardiac denervation and angiogenesis are the primary causes for post procedure angina relief and improved perfusion respectively. The inj ury damages nerves thereby minimizing the pain sensation and stimulates angiogenesis. While the aforementioned techniques and methods for revascularizing the myocardium offer some promise they never the less suffer from one disadvantage or another. As a first example, the lasers are very expensive to purchase. The aforementioned U.S. patent application Ser. No. 08/958,788, filed on Oct. 29, 1997 is directed to the same or similar medical benefits achieved by use of non-laser devices, such as those disclosed and claimed therein. As a second example, the design of the interventional cardiology catheter-based drug delivery systems appear unable to delivery drugs to tissues located beyond the arterial walls. Significant benefit could be gained by the delivery of agents (e.g. foreign body particles, drugs, growth factors, genetic material, etc.) into heart tissues beyond the arterial wall. Those devices that have considered direct injection of drugs or genetic material into the myocardium simply deposit the material within a channel that is typically created by a needle. As the myocardium dynamically contracts, deposits of materials in these channels will likely migrate unless stabilized with a mechanical or chemical anchor of some sort. It is the intent of this invention to overcome these and other shortcomings of the prior art.

This patent is subject to a terminal disclaimer.

Systems and methods for delivering agents into targeted tissue of a living being


An apparatus for determining a resonant frequency of a wind turbine tower is provided. The apparatus includes a processing unit configured to receive an acceleration measurement value, the acceleration measurement value representative of the acceleration of the wind turbine tower in the direction parallel to a rotor rotational axis of the wind turbine and/or in the direction perpendicular to both the rotor rotational axis and the tower axis of the wind turbine. The apparatus includes a memory configured to store a series of acceleration measurement values, and the processing unit includes a Fourier transform module configured to calculate a spectral vector based on calculating a convolution-based fast Fourier transform of the series of acceleration measurement values, and includes a resonant frequency calculation module configured to calculate the tower resonant frequency based on the calculated spectral vector.

In wind turbine systems known in the art, sudden changes in the velocity of the wind that acts on the rotor of the wind turbine causes its tower to sway back and forth and sideways. Such, oftentimes circle-like, oscillation of the wind turbine tower is known to significantly shorten the technical life period of the tower, and also to produce significant mechanical load in the yaw system and gearing.
Such oscillations can be still dramatically increased in cases of variable speed turbines, in which certain rotational speeds can cause oscillations that match the tower resonant frequency.

Apparatus and method for determining a resonant frequency of a wind turbine tower


In the inventive plunger pump, a plunger is pressed on a shaft by a spring via a thrust bearing having rolling elements clamped by a pair of bearing washers. By such a configuration, the motion of the shaft is immediately transmitted to the plunger, irrespective of whether the radius of the profile of a cam for driving the shaft back and forth is in the increment phase or decrement phase, so that the suction and discharge of liquid is performed without delay, since no play (or gap) exists in the transmission mechanism between the cam and the plunger. Thus, the fluctuation in the pressure is minimized during the operation of the pump and, when a low pressure gradient elusion is carried out, the solvents are supplied at the desired flow rates accurately.

FIG. 2 shows a conventional plunger pump 10 including a pump head 11 and a pump body 12 which are connected to each other via a connector part 13. In the pump head 11, a cylindrical passage is formed, which is referred to as a cylinder 15, wherein a plunger 16 is inserted. Further, a suction passage 17 and a discharge passage 18, both connected to the cylinder 15, are provided in the pump head 11, and a suction check valve 19 and a discharge check valve 20 are disposed in the above passages, respectively.
The plunger 16 extends through the connector part 13 into the pump body 12, where the rear end of the plunger 16 is fixed to a plunger holder 21 having a diameter larger than that of the plunger 16. The plunger holder 21 is accommodated in a cavity formed at the front end of a shaft 22 which can move back and forth in the pump body 12, where the plunger holder 21 is held at its front and rear ends. The front and rear ends of the plunger holder 21 are spherical, whereas the inner face of the cavity for retaining the rear end of the plunger holder 21 is flat. Thus, even when the plunger 16 is held in the cavity, it still has a degree of freedom, Ftr, to move transversely, i.e. in the direction vertical to the central axis, and another degree of freedom, Fro, to rotate, or swivel.
The shaft 22 is driven back and forth by a cam 25 and a spring 26, where the shaft 22 is regulated by a cam follower 27 provided at the rear end of the shaft 22 and a bearing 28 provided in the pump body 12 so that it can move only in the direction of its axis.
The space between the front part of the plunger 16 and the pump head 11 and the space between the rear part of the plunger 16 and the connector part 13 are sealed by seals 30 and 31, respectively. Leakage of a liquid from the cylinder 15 is prevented by the seal 30, and leakage of the a plunger-washing liquid, which is supplied through a plunger-washing passage 32 when necessary, is prevented by the seals 30 and 31.
Since the plunger 16 is held by the two seals 30, and 31 at its front and rear parts, respectively, the plunger 16 is bound to move on the straight line passing through both the centers of the seals 30 and 31. On the other hand, the shaft 22 is bound to move in the direction of the axis determined by the bearing 28 as described above. In assembling the plunger pump 10, the axis of the plunger 16 and the axis of the shaft 22 may be displaced transversely from each other and/or inclined to each other. In these cases, not only the plunger 16 moves incorrectly, but also such an excessive force may be transmitted to the seals 30 and 31 that results in damage to the seals. In view of this, the contacting part of the plunger 16 (i.e. its rear end) is shaped spherical while the contacting part of the shaft 22 (i.e. the inner face of the cavity of the shaft 22) is flat, so that the degrees of freedom for the plunger 16 to move in the traversal direction and to rotate, Ftr and Fro, are provided as described above.
When the plunger holder 21 is set in the cavity of the shaft 22, a small gap of about several tens of .mu.m is left at the front and/or rear ends of the plunger holder 21, so that the plunger 16 has the degrees of freedom in motion and rotation as described above. Due to the gap, however, a time lag occurs between the motion of the plunger 16 and the actual suction and discharge of liquid by the pump 10, which causes various problems such that the pumping pressure fluctuates during the pumping operation, for example. Particularly, when a low pressure gradient elusion is carried out, the flow rates of solvents pumped out by different pumps, respectively, cannot be regulated correctly, so that the actual concentration of the mixture of the solvents at a time point cannot be equal to an objective concentration predetermined corresponding to the time point.
When the pump 10 is assembled, a small displacement or inclination is allowed between the axis of the plunger 16 and the axis of the shaft 22, as described above. Here, however, the inclination between the two axes prevents the shaft 22 and the plunger 16 from moving smoothly during the operation of the pump 10. The reason is explained as follows. Referring to FIG. 3, when the shaft 22 thrusts the plunger holder 21 with its axis 52 being inclined to the axis 53 of the plunger 16, the contacting point where the flat end of the shaft 22 contacts with the spherical end of the plunger holder 21, moves from the point P0 to the point P1. When the contacting point moves, an excessive, force is worked on the seals 30 and 31 by the plunger 16 due to the friction between the shaft 22 and the plunger holder 21, which may cause damage to the seals 30 and 31 and/or leakage of the liquid.


A row of the data block which is a set of the data sector is distributed to constitute two blocks. In this case, as a distribution condition, an even-number row block of the even-number sector and the odd-number row block of the even-number sector, the odd-number row block of the even-number sector and an even-number row block of the even-number sector are obtained. Then, the block is aggregated in the transmission order, and an outer parity is scattered to each sector to form an interleaved form.

1. Field of the Invention
The present invention relates to data processing method and apparatus, and recording medium for an error-correcting product code favorable for use in the recording and transmission of digital data.
More particularly, the present invention relates to a data processing system using an error-correcting product code which comprises a data section, an error-correcting outer parity and an error-correcting inner parity which are effective in the case where information data is recorded on a plurality of kinds of recording media particularly having a largely different recording density.
Here, particularly, in a method for forming the outer parity, a PO series created by n sets of data items aggregated by n rows is used. Consequently, even when the error-correcting product code block is recorded on a recording medium in an order of data transmission without carrying out data interleave process; the capability of coping with the defect is largely improved.
2. Description of the Related Art
In a system in which digital data is recorded on an optical disk in bytes (one byte is equal to eight bits) or digital data is transmitted to a transmission channel, a Reed-Solomon error-correcting product code block is conducted to process data. That is, (M×N) bytes of data is arranged in a matrix containing an M rows×N columns. Then, PO bytes error-correcting word is added to each column of M bytes information portion. Then, (M+Po) rows×(N+Pi) columns Reed-Solomon error-correcting product code block is conducted. Then, the Reed-Solomon error-correcting product code block having (M+N) rows×(N+Pi) columns is constructed.
Then, the Reed-Solomon error-correcting product code block is either recorded on a recording medium or transmitted to a transmission channel. The error correction processing portion and on the reproduction side of the recording media or on the receiving side of the transmission channel are capable of correcting random errors and burst errors on the information reproduction portion by using the error-correcting words PO and PI.
Such Reed-Solomon error-correcting product code block has a higher data processing efficiency with a decrease in a ratio of a redundant portion (Pi×M+Po×N+Po×Pi) of the error-correcting word with respect to the whole word referred to as a redundancy ratio, namely (M+Po)×(N+Pi). On the other hand, the error-correcting capability is also heightened with respect to the random error and the burst error with an increase in the Pi and Po.
Here, it is known that the Reed-Solomon error-correcting code block having small M and N, namely small Pi and Po has a lower correcting capability because of relatively higher probability of error in error correction in the case where the Reed-Solomon error-correcting product code blocks having the same redundancy ratio are compared with each other.
On the contrary, it is known that since Pi and Po can be increased at the same redundancy ratio with an increase in M and N, a high error-correcting capability can be obtained. However, such capability cannot be realized unless the constraint conditions described below are satisfied.
A first constraint condition is that M+Po and N+Pi must be equal to or less than 255 bytes as a code length for constructing the Reed-Solomon error-correcting product code block (in the case where the length of the code is eight bits). Incidentally, the Pi described above refers to the PI series error-correcting code length while Po refers to the PO series error-correcting code length.
A second constraint condition is a cost constraint resulting from the scale of the hardware.
By the way, when considered on the basis of the above conditions, optical disk standards such as a DVD-ROM, a DVD-RAM, a DVD-R or the like which are the information recording media in recent years are made public as a standard in which the improved Reed-Solomon error-correcting product code block is adopted. Out of these standards, the DVD-ROM and the DVD-RAM are established as DIS16448 (DVD-ROM having a diameter of 80 mm) and DIS16449 (DVD-ROM having a diameter of 120 mm) and DIS16825 (DVD-RAM).
In this DVD standard, the above idea is adopted with respect to the error-correcting word processing method so that the error-correcting capability is remarkably improved with error-correcting word having a small redundancy ratio as compared with the method used in the conventional optical disks.
The concept on the error-correcting method of the DVD is basically described above, the fundamental problem is to what level the target of the random error-correcting capability and the burst error-correcting capability is to be set. In order to set such level, the recording method of the recording medium and the generation of defects resulting from the handling thereof must be considered.
The recording/reproducing method is determined from the recording/reproducing beam spot size resulting from the recording wavelength and the optical system characteristic in the optical disk system. Here, the recording density constitutes a large factor in the determination of the error-correcting method. In the determination of the burst error correction capability, the defect length such as scratches or the like generated in the handling of the discs can be determined from experience. With respect to the error-correcting capability, the multiplication of line recording density by the physical defect length constitutes a burst error length of information data with the result that the error correcting capability is required to be raised in the improvement of the recording density.
The recording density can be described as follows with particular reference to the reproduction system.
When, a light source wavelength is denoted by λ, and a numeric aperture of an object lens is denoted by NA, the recording density stands proportional to (NA/λ)2. The wavelength adopted in the DVD is 650 nm while NA is 0.6.
In the error-correcting method, a row side inner parity of RS (182, 172, 11) and a column side outer parity of RS (208, 192, and 17) are adopted by means of PI (inner parity)=10 bytes and PO (outer parity)=16 respectively with respect to the (M×N)=(192×172) bytes information data block in terms of the Reed-Solomon error-correcting product code (RS is referred to as Reed-Solomon). The block used in this error-correcting method is referred to as the error-correcting product code block.
Here, with respect to the error-correcting product code block, the error is corrected in the PI series a first, and an error mark is attached to a row whose error cannot be corrected. Thereafter, at the time of the error correction on the PO series, the error mark is treated as an error position. When the so-called "erasure correction" method for calculating and extracting only error patterns is used, a maximum of 16 rows of burst errors can be corrected. In the DVD, since the recording density is data bit length=0.267 μm, 0.000267×8×182×16=6.2 mm is given. It is possible to say that about 6 mm burst error-correcting capability is given.
However, as a next generation DVD an examination is started on an optical disk having a large capacity resulting from further increase in the density. For the further increase in capacity exceeding the DVD, the recording density must be increased. Recently, in order to meet such request, a blue laser diode having a wavelength of 450 nm is made public. When such laser diode is used, it is expected that the recording density can be improved by about 2.6 times in the optical system similar to the DVD or the like. With the improvement in the optical system, four to five times higher density can be realized so that a fine image such as a high definition image such as a Hi-Vision or the like can be recorded for two or more hours on one disc.
In such increase in the density (for example, the line density is about twice as compared with the conventional one), only about 3 mm error-correcting capability can be provided with respect to the burst error when the conventional error-correcting method is introduced.
Furthermore, as described above, the error-correcting word length is 255 bytes at most as long as 1 word=8 bit system processing system is used. Since the PO series is 208 bytes in the DVD standard, the burst error correcting capability is close to the limit in the above error-correcting method so that only little improvement can be expected.
In order to expand the error-correcting word length, the word length may only be lengthened. With respect to the word length, a multiple of eight can be easily used. As a consequence, 1 word=16 bits can be considered. The scale of the error-correcting circuit as hardware is extremely large as compared with the conventional one so that there arises many problems.
In such a case, there is generally available a technique in which the burst error-correcting capability is improved while maintaining the error-correcting code length by adopting a data interleave to scatter the burst error.
However, the data interleave is not adopted even in the DVD standard. The reason goes as follows: in the case where an error is created which exceeds the error-correcting capability in the reproduction processing in the case of an image signal in which information data is compressed, the error data is scattered with the result that a disadvantage of the reproduced image is generated at many positions. In the reproduction processing of the image signal, it is thought that processing of concentrating and reproducing disadvantageous images as much as possible is favorable as a processing of generated disadvantage. This is because the processing can be completed with the reproduction of an instant disadvantageous image.
Besides, a structure close to the current DVD system is favorable for the upper compatibility with respect to the next generation system.
Points Noted by the Inventors of the Present Invention
Generally, in the error-correcting processing method such as a package medium or the like, the Reed-Solomon product code block method is introduced in many cases. This is because high performance and high efficiency can be expected in the case where an error in the defect error data can be detected and corrected such as a defect generated in the package media in the manufacture and distribution thereof.
With respect to the unit of the processed data, 1 word=1 byte (8 bits) is favorable. When the application development of the system is considered, it is required to suppress a processing circuit to an appropriate hardware scale. Besides, this fact is also required for facilitating a connection to the recording medium and transmission channel because a front and rear processing circuit is provided in the recording on the recording medium and data transmission to the transmission channel in addition to the error-correcting processing.
Under the circumstances, use of the Reed-Solomon error-correcting product code block used in the current DVD is optimal as an error-correcting method which can correspond to a large improvement in the recording density of the recording medium.
row side inner parity RS (182, 172, 11)
column side outer parity RS (208, 192, 17)
However, the problem is that it is required to settle the improvement of the burst error correction capability.

Data processing method and apparatus, recording medium, reproducing method and apparatus


A method is described for the preparation of electrostatographic toner particles which involves the surface treatment of a pigment by depositing thereon a coating of a low melting point wax. The method involves preparing a mixture of a wax solution and a pigment dispersion which is heated to a temperature sufficient to assure dissolution of wax and permitting the mixture to cool slowly to room temperature at which point a coating of wax is deposited upon the surface of the pigment. The wax coated pigment particles are then used as a component of the organic phase in a limited coalescence process.

Electrostatic toner polymer particles are commonly prepared by a process commonly referred to as "limited coalescence." In this process, polymer particles having a narrow size distribution are obtained by forming a solution of a polymer in a solvent that is immiscible with water, dispersing the polymer/solvent solution in an aqueous medium containing a solid colloidal stabilizer, and removing the solvent. The resultant particles are then isolated, washed, and dried.
In the practice of this technique, toner particles are prepared from any type of polymer that is soluble in a solvent that is immiscible with water. Thus, the size and size distribution of the resulting particles can be predetermined and controlled by the relative quantities of the particular polymer employed, the solvent, the quantity and size of the water insoluble solid particulate suspension stabilizer and the size to which the solvent-polymer droplets are reduced by the agitation employed.
Limited coalescence techniques of this type have been described in numerous patents pertaining to the preparation of electrostatic toner particles because such techniques typically result in the formation of toner particles having a substantially uniform size and uniform size distribution. Representative limited coalescence processes employed in toner preparation are described in U.S. Pat. Nos. 4,833,060 and 4,965,131.
In the conventional limited coalescence techniques described heretofore, the judicious selection of toner additives such as charge control agents and pigments permits control of the surface roughness of toner particles by taking advantage of the aqueous organic interphase present. However if any toner additive employed for this purpose is highly surface active or hydrophilic in nature, it tends to be present at the surface of the toner particles. Unfortunately, this leads to numerous potential problems such as lower charge/mass, rougher particles, poor thermal transfer, poor electrostatic transfer, reduced pigment coverage, interference with the limited coalescence process, sensitivity to environment, and the like.
Accordingly, workers in the art have recognized that toner additives must either be avoided or kept away from the particle surface. One method for obviating this limitation is to select an additive which is neither surface active or hydrophilic in nature. However, it is often not feasible to find an alternative additive evidencing the properties sought. Thus, it then becomes necessary to modify the surface of the additive.
Efforts to achieve this end have generally focused upon the use of suitable dispersion aids as, for example, polymers with acid or other polar functionality as described in copending application Ser. No. 501,819, filed by M. Nair. Z. Pierce and D. Tyagi. These polymeric stabilizers are used to treat carbon pigment to prevent the hydrophilic carbon from migrating to the surface. Toners prepared in this manner evidence enhanced electrostatic transfer, reduced electrical conductivity, and low D-min or fog.
A similar treatment employed in conjunction with toners of smaller particle size has frequently been found unsuccessful due to an increase in solution viscosity of the organic phase at the concentration of dispersant and pigment level employed. Limited coalescence toners prepared with an organic phase of this type tend to yield particles of broad size distribution and tend to interfere with the limited coalescence process. Furthermore, use of this technique requires the presence of reactive sites on the additive surface of the toner particles to which a dispersant may associate.
Recently, a technique was described in copending application Ser. No. 890,057, filed May 28, 1992, entitled, "Electrostatographic Toner and Method for the Preparation Thereof", for obviating the foregoing limitations wherein a highly surface active pigment was coated with a hydrophobic wax which is insoluble in the solvents commonly employed in toner preparation. Studies revealed that the wax coating prevents the pigment from migrating to the surface of the toner and provides a spherical surface thereto. This results in a narrow distribution of charge from particle to particle and permits image transfer without the occurrence of fog in the background. The wax coating also reduces the likelihood of surface contamination by the pigment due to the fact that it is kept away from the surface. Particulate material prepared in accordance with this technique evidences charging characteristics that render the particles suitable for use as electrostatographic toner particles. Unfortunately, this technique cannot be used when fine dispersion is desired since the melt dispersion process is not efficient. For that purpose, a dispersion made by media milling is appropriate.

Electrostatographic toner including a wax coated pigment and method for the preparation thereof


A racetrack memory cell device include a dielectric, an electrode disposed in the dielectric, a metal strap disposed in the dielectric, a nanowire disposed in the dielectric between the electrode and the metal strap and a magnetic tunnel junction disposed in the dielectric on the metal strap, and axially with the nanowire.

The present invention relates to racetrack memory devices, and more specifically, to racetrack memory cells having vertical nanowire storage elements.
Racetrack memory is a type of non-volatile magnetic memory that utilizes current-controlled motion of magnetic domain walls in a magnetic nanowire to encode information. Multiple magnetic domain walls can be moved along the nanowire "racetrack." In typical configurations, a magnetic tunnel junction (MTJ) is located at a distinct location along the track; the MTJ is used to read out the device by sensing the magnetization of the nanowire as domain walls shift through the nanowire.
Typical configurations implement in-plane nanowires, horizontally positioned with respect to the wafer plane. It had been theorized that to achieve very high bit density, the ideal racetrack memory cell would have the racetrack nanowire oriented perpendicular to the wafer plane. Devices with such vertically oriented racetracks are extremely challenging to build, and there have been proposals for vertical racetrack cells but few structures proposed that have any specific details about the structure or fabrication methods, and no practical method proposed to integrate an MTJ for readout. Furthermore, integration of an MTJ in direct contact with the nanowire is challenging even in planar-nanowire configurations, because it often introduces process defects that lead to pinning of the domain walls at the site of the MTJ. To date there is no known fabrication method for vertical nanowires.

Racetrack memory cells with a vertical nanowire storage element


An indication of the formability of metallic sheet is determined using a correlation between nondestructively measurable ultrasonic properties and a formability index. A calibration relation is initially established by measuring ultrasonic velocities at various angles to the rolling direction of sheet specimens with noncontacting electromagnetic acoustic transducers, calculating an ultrasonic correlation parameter from the measurements, destroying the specimens in tensile tests to measure a formability index, and then correlating the ultrasonic correlation parameter with the formability index. Once this relationship is established, the formability index of a working sample, which is not to be destroyed, is found by making the same types of ultrasonic property measurements on the working sample, calculating the ultrasonic correlation parameter for the working sample, and then employing the previously established correlation to ascertain the formability index for the working sample.

This invention relates to the nondestructive evaluation of the formability of metallic sheet materials such as steel, and, more particularly, to an ultrasonic technique for making such evaluations.
One of the largest tonnage uses of steel throughout the world is found in the preparing of thin flat sheets by rolling, and then forming the sheets into useful products. Most of the exterior of an automobile is made of formed steel sheets, for example. Steel sheet material is also used in siding, appliances, office equipment, containers, and a myriad of other products.
One common forming procedure is die forming, wherein the steel sheet is placed between a male die and a female die in a press. As the press closes, the sheet of steel is deformed into the shape dictated by the closed dies. Other sheet forming techniques such as bending, drawing, and ironing are also used for particular products.
Most of the steel used in sheet forming is a low carbon steel of 0.05-0.20 weight percent carbon in iron, with minor amounts of other elements present. Studies over the years have shown that such steels, as well as many other sheet materials, do not deform uniformly in sheet forming operations, due to textures created as the sheet is rolled from thicker stock. The textures result from crystallographic preferred orientations in the rolled sheet.
The nonuniform deformation of the steel sheet leads to various types of problems with the formed sheet products. In the extreme case, the steel may fail in the forming operation, such as by tearing, so that a part cannot successfully be formed. In less severe situations, there may be nonuniform thinning of the formed sheet product so that there are local thin regions or there may be nonuniform strains around the edges of the sheet known as "ears", for example.
The occurrence of these problems depends upon many factors, including the nature of the forming operation, the type of metal, melting practice for the metal, composition variations in the metal, the heat treatment of the metal, and the sequence of rolling steps used to prepare the flat sheet. While it would be desirable to determine the optimum set of conditions for these parameters and then hold them constant, such precise control is simply not possible for the very large quantities of metal used and the present state of manufacturing technology.
Consequently, various types of tests have been developed to evaluate the formability of sheet material before an attempt is made to form it. These tests generally utilize destructive measurements of mechanical properties of sheet material to determine a formability index. If the formability index is within certain allowed values, then the sheet material is judged to be acceptable for the particular forming operation and is shipped to the user for forming. On the other hand, if the formability index does not meet the required limitations, the sheet must be diverted for other, less demanding uses, or scrapped.
While the basic viability and utility of the formability index approach as a cost-saving procedure has been established, it suffers from some important shortcomings in a typical industrial setting. Presently operable techniques for measuring the formability index require that the sample being evaluated be either destroyed by mechanical testing, or at the least excised from the larger sheet in which it is embedded. This requirement is not fatal to the use of the test, but it does mean that there is a delay in obtaining test results, that it is impossible to perform "on line" measurements on the sheet as it is being rolled, and that at the least there is wasted material when samples are cut from the sheet.
There has been proposed the possibility of measuring a formability index by propagating ultrasonic waves of different types (i.e., shear waves of differing polarizations) in the plane of the sheet, but no technique has been demonstrated. It has also been proposed to propagate waves through the thickness of a sheet to determine a modulus value which is said to be related to a formability index, but again no operable method has been demonstrated.
It would be particularly desirable to have the capability to perform on line tests as the sheet is being rolled, to permit problems to be discovered without delay. Conceivably, the results of such a test could be used to actively control the rolling operation to reduce the incidence of problems caused by rolling speed, roll bites, and other controllable factors.
One possible approach to development of a nondestructive formability evaluation that could be used on line has been the discovery of crystallographically based orientation distribution coefficients, or ODCs. The ODCs can be correlated to the irregular crystallographies that cause formability problems, and can be measured nondestructively and on line with X-ray machines. The ODC approach has the shortcomings that it is heavily based in theory and therefore can be subject to the effects of erroneous assumptions of the theory, and does not take into account many of the variables known to affect sheet formability, such as composition of the sheet material. Moreover, a reflection-mode X-ray measurement samples only textures near the surface, which may not accurately reflect the character of the interior of the sheet. To sample the interior of the sheet, a transmission-mode X-ray measurement must be made, which requires a high-power X-ray source and special detectors, and can be hazardous if there is leakage of the X-rays. Although the ODC approach has some promise, as a result of these problems it has not achieved a wide degree of acceptance in the industrial community.
There remains a need for an improved approach to measuring the formability of sheet materials, preferably by a nondestructive technique that would permit on line measurement and control. The present invention fulfills this need, and further provides related advantages.

Nondestructive ultrasonic evaluation of formability of metallic sheets


A process aid for improving the processability of non-fluorinated melt processible polymers contains a fluoroelastomer having a Mooney viscosity (ML (1+10) at 121° C.) between 30 and 100 and at least two interfacial agents, one a polycaprolactone having a Mn between 2000 and 8000 and the other a polyalkylene oxide having a Mn between 3000 and 5000.

The melt extrusion of non-fluorinated melt processible polymers into shaped structures such as tubing, pipe, wire coating or film is accomplished by well-known procedures wherein a rotating screw pushes a viscous polymer melt through an extruder barrel into a die in which the polymer is shaped to the desired form and is then subsequently cooled and solidified into a product having the general shape of the die.
In order to achieve low production costs, it is desirable to extrude the polymer at rapid rates. Higher extrusion rates may be readily obtained by increasing the rate of revolution of the extruder screw. However, this technique is subject to limitations imposed by the viscoelastic properties of the polymer substrate. Thus, at very high extrusion rates an unacceptable amount of thermal decomposition of the polymer can result. Further, extrudates having a rough surface are often obtained which can lead to formation of an undesirable pattern on the surface of the extrudate.
In Blatz, U.S. Pat. No. 3,125,547, it is disclosed that the use of 0.01-2.0 wt. % of a fluorocarbon polymer that is in a fluid state at the process temperature, such as a fluoroelastomer, will reduce die pressure in extrusions of non-fluorinated polymers such as high and low density polyethylenes and other polyolefins. Further, use of this additive allows significant increase in extrusion rates without melt fracture.
More recently, improved fluoropolymer process aid compositions have been disclosed in, for example, U.S. Pat. Nos. 4,855,360; 6,642,310 B2 and U.S. 2006/0025523 A1. These compositions contain both a fluoropolymer and an interfacial agent such as a polyalkylene oxide or a polycaprolactone. The number average molecular weight (Mn) of these interfacial agents may be anything between about 400 to over 200,000. Low Mn (<5000) polyethylene glycol (PEG) works especially well in some process aids to reduce the time required to eliminate melt fracture of extrudable compositions. However, the low Mn PEG is moderately soluble in water which can cause massing problems in humid environments. Low Mn PEG is also susceptible to production of very low molecular weight fragments through thermally induced oxidative decomposition, making it potentially unstable during processing of the non-fluorinated melt processible polymer. These very low molecular weight PEG fragments can impart undesirable odor or taste characteristics in the extrudate, or cause unreliable printing or sealing of extruded films as the fragments bloom out of the polyethylene host polymer.
Thus there is a need for a process aid composition which reduces melt fracture in non-fluorinated melt processible polymers without massing or decomposing.

Fluoroelastomer process aid contains polyalkylene oxide and polycaprolactone


A photomask and a method for forming a photomask are disclosed in which die regions that define features for a process step of a semiconductor fabrication process are formed on a photomask and a test pattern for a different process step is formed in a blading area of the photomask. Also, a method for forming test structures is disclosed in which the photomask is exposed to transfer the test pattern to a semiconductor substrate. The process step that is associated with the test pattern is then performed, forming a test structure on the semiconductor substrate. By utilizing blading areas of photomasks and including test patterns for different process steps on the same photomask, more test structures can be obtained, without the need to generate additional photomasks for testing purposes.

In conventional integrated circuit fabrication processes an integrated circuit layout design is generated that includes multiple layers of design data. The integrated circuit layout design is then sent to a photomask vendor who generates photomasks that are to be used in the subsequent fabrication process. More particularly, each layer of design data is converted into a single photomask that includes multiple die regions that include the design features indicated by the layout design. Portions of the photomask that are outside of the die regions, typically referred to as "blading areas," extend on all four sides of each photomask. These blading areas are typically left blank and are covered during the exposure process by blades.
During the integrated circuit manufacturing process semiconductor wafers are subjected to numerous process steps, with each process step performed sequentially on a particular semiconductor wafer. Conventionally, for each process step that requires patterning, a single photomask is used to transfer the pattern to individual semiconductor wafers.
With technologies moving to ever smaller feature sizes, integrated circuit designs and manufacturing processes have become increasingly complex. As a result there has been a growing need to test integrated circuit designs and manufacturing processes. Conventionally, test patterns are taped out to scribe lines located between die regions. However, scribe lines are long and thin, limiting the number of test patterns that can be formed on each photomask. Moreover, it is impractical to purchase additional photomasks for testing because of the high cost of photomasks. Accordingly, there is a need for a method for forming test structures on semiconductor substrates that does not require taping out test structures to scribe lines. Moreover, there is a need for a method for forming test structures on semiconductor substrates that does not increase the number of photomasks. The present invention meets the above needs.

Method for forming photomask having test patterns in blading areas


A liquid jet printing apparatus is provided having a nozzle for emitting a stream of liquid droplets toward a substrate, a charging section for providing an electrical charge to liquid droplets and a pair of electrically conductive deflection plates for creating an electrical field capable of deflecting the liquid droplets to a desired location on the substrate, wherein a resistor is provided between a power source and the electrical field to limit current from the power source during electrical arcing between the deflection plates, thereby minimizing disruption to the electrical field and minimizing electromagnetic pulses.

U.S. Pat. No. 7,438,396 B2 discloses a continuous ink jet printer having an array of nozzles for simultaneously printing across the width of a substrate, such as a textile fabric. For each nozzle there is (i) a droplet formation section, such as a piezoelectric transducer, (ii) a droplet charging section, such as parallel metal plates, and (iii) a droplet deflection section, for directing the path of the droplet to the desired location on a substrate to be printed. The range of deflection of the droplets is such that adjacent nozzles can overlap, to print a seamless pattern on the substrate. The deflection plates are spaced apart and oppositely charged, for example at 1 to 5 kV, to produce an electrical field. The charge on the droplets and/or the strength of the electrical field created by the deflection plates can be varied, to create more or less deflection of the droplet. In one example, uncharged droplets are not deflected and collect in the gutter.
During operation of the printer, liquid can collect on the surface of the deflection plates, leading to arcing between the plates and a subsequent disruption of the electrical field and printer electronics.

Resistor protected deflection plates for liquid jet printer


A spatial graphical user interface for interfacing with a plurality of data sources to create a layered image includes a content acquisition module configured to acquire a first primary image from any one of the data sources where the primary image has at least an image of one object thereon. A transparent layer generating module generates a transparent layer to be overlaid over the primary image which spatially corresponds to the primary image. A link generating module generates an icon on the transparent layer over the at least one object such that the icon represents a link to data contained in the data sources related to the object on the primary image. The layered image is the combined view of the primary image, the transparent layer and icons on the transparent layer.

In the field of data management, particularly in larger corporations, it is not uncommon for number of legacy data bases and document repositories to be maintained, each of which operates using different architectures. Furthermore, in the case of engineering drawings, maps or other similar drawings used by utility companies, the basic image files are often non-intelligent raster format drawings or are otherwise not in a format suitable for easy modification.
However, there is need to integrate disparate files such as (maps, drawings, image files, text files, sensor information, GPS data, etc. . . . ) into a single file so that once a first file is retrieved, other files corresponding to objects on that first file can also be easily retrieved. For example, in the case of an engineering drawing, there can be hundreds if not thousands of objects on a single image, each of which has corresponding data on file in the system, such as additional sub-images, text files etc. . . . . However, in many cases, the first image file can not be modified to add links to these related data files.
Traditional data integration solutions require that the current software applications be replaced with already integrated alternatives as in the case of Enterprise Resource Planning (ERP) solutions, or very costly, time consuming integration code must be written to get separate application software and associated data to work together.
Additionally, standard Computer Aided Design (CAD) and Geographic Information Systems (GIS) typically require a vector rather than a raster format for drawings and maps to be used. Also, prior art systems require the user to work in the native file format of the image document that is being overlain.

Spatial graphical user interface and method for using the same


A sensor having a housing; two highly conductive elements fixed in-part within the housing and in-part exposed external of the housing; the conductive elements separated from one another within the housing in a normally open arrangement. A resilient dome-cap is positioned within the housing, and in some embodiments is conductive and in constant contact with one of the conductive elements, and in other embodiments the dome-cap need not be conductive. A depressible actuator is movably retained by the housing with a portion thereof external of the housing to be accessible for depressive force to be applied thereto by a mechanical device or human finger/thumb. The actuator also includes a portion positioned to allow depressive force applied thereto to be applied to the dome-cap. Pressure-sensitive variable-conductance material is contained within the housing and electrically positioned as a variably conductive element in a current flow path between the two conductive elements. Depression of the actuator causes the dome-cap to bow downward, causing a user discernable tactile sensation indicating actuation of the sensor, and transferring force through the dome-cap into the pressure-sensitive variable-conductance material for providing variable electrical flow between the two conductive elements dependant upon the applied pressure. The resilient dome-cap returns to a raised position and the flow path is again rendered open when the actuator is no longer depressed. Methods of manufacturing the variable electrical output tactile-feedback sensor are also disclosed.

1. Field of the Invention
The present invention relates to electrical sensors of the type useful for controlling electrical flow through a circuit. The present invention specifically involves the use of a tactile feedback dome-cap in conjunction with pressure-sensitive variable-conductance material to provide momentary-On pressure dependent variable electrical output. The tactile feedback is user discernable for indicating actuation and de-actuation of the sensor. Novel structural embodiments and methods of manufacturing are disclosed.
2. Description of the Related Prior Art
There are many prior art types of switches (sensors) and switch packages. While used widely in many fields, switches and switch packages are used in game controllers for use in controlling imagery, and in computer keyboards, other computer peripherals, and in many other host devices not related to computers.
A very common prior art switch is comprised of: a housing typically of non-conductive plastics; a first and a second conductive element fixed to the housing and in-part within the housing and in-part exposed external of the housing; a conductive dome-cap typically made of metal having a degree of resiliency and positioned within a recess of the housing and between a depressible actuator and the two conductive elements. The actuator is retained to the housing via a flange of the actuator positioned beneath a housing plate with a portion of the actuator extending through a hole in the housing plate to be exposed external of the housing and thus accessible for depression by a mechanical member or a human finger or thumb. Typically, at the four corners of the housing are plastic studs formed of continuations of the housing material. The distal ends of the studs pass through aligned holes in the housing plate, and when the housing plate is properly located, the distal ends of the studs are flattened and enlarged commonly using heating and mechanical pressure so as to retain the housing plate to the housing. The conductive elements are typically highly conductive and serve as electrical conductors but also sometimes additionally serve as mechanical members or legs for structural attachment to circuit boards, although they are often connected directly to wires. The two conductive elements are separated from one another within the housing in a normally open arrangement or fashion. An end portion of the first conductive element within the housing is positioned to be in constant contact with an edge of the dome-cap. Sufficient depression of the actuator causes the actuator to apply force to the dome-cap, causing the dome-cap to bow (snap-through) downward, causing a center portion of the dome-cap to contact a more centrally positioned end of the second conductive element and resulting in a conductive bridging or closing between the first and second conductive elements with the current flow path being through the conductive dome-cap. The dome-cap when pressed against sufficiently to bow toward the second conductive element has resistance to moving which begins low and increases toward a snap-through threshold wherein at the threshold the dome-cap snaps creating a snap or click which is user discernable in the form of a tactile sensation. The dome-cap then moves further toward the second conductive element. The dome-cap being of resilient design, returns to a raised position off of the second conductive element when the actuator is no longer depressed, and thus the switch or sensor is a momentary-On type. A tactile sensation is also produced by the dome-cap upon returning to the normally raised position and in doing so moving back through the snap-through threshold. As those skilled in the art recognize, the portion of the actuator which is external of the housing can be of numerous sizes and shapes, for example to accommodate attachment of extending and/or enclosing members such as buttons and the like, etc.
Such prior art switches are either On or Off and provide corresponding all or nothing outputs. These simple On/Off switches are not structured to provide the user proportional or analog control which is highly desirable and would be very beneficial in many applications.
Another type of prior art sensor is described in U.S. Pat. No. 3,806,471 issued Apr. 23, 1974 to R. J. Mitchell for "PRESSURE RESPONSIVE RESISTIVE MATERIAL". Mitchell describes sensors which utilize pressure-sensitive variable-conductance material to produce analog outputs. However, Mitchell fails to recognize any need for tactile feedback to the user upon actuation and de-actuation of the sensor. Thus, Mitchell fails to anticipate any structuring useful for providing a tactile feedback discernable to a human user of his sensors.
There have been hundreds of millions of momentary-On snap switches made and sold in the last 25 years. Pressure-sensitive variable-conductance sensors have also been known for decades, and yet the prior art does not teach a pressure-sensitive variable-conductance sensor which includes tactile feedback to the user upon actuation and de-actuation of the sensor. Clearly a pressure-sensitive variable-conductance sensor which included tactile feedback to the user would be of significant usefulness and benefit, particularly if provided in a structural arrangement which was inexpensive to manufacture. Such a sensor would be useful in a wide variety of applications wherein human input is required. Such applications would include home electronics, computers and generally devices operated by the human hand/finger inputs.


Bipolar forceps for grasping and coagulating tissue, are constructed so as not to damage the mesosalpinx fused with a fallopian tube, when carrying out uterine tube sterilisation by coagulation. To this end the forceps are provided with a first and a second jaw for gripping and holding the tissue to be coagulated, the first jaw having a recess at its distal end and a mandrel being provided on the second jaw, which mandrel protrudes into the recess in the first jaw with clearance, when the jaws are in a closed position. A region between the jaws, which accommodates the tissue to be coagulated is limited distally by the mandrel and proximally by a limb of a bar on the first jaw for engaging in the second jaw when the jaws are in their closed position.

Coagulation forceps type are, for example, disclosed in German Utility Model No. 75 18 245. These forceps are especially intended for uterine tube sterilisation by coagulation of the fallopian tube and are provided to this end with jaws which are adapted to the fallopian tube to be coagulated. The distal part of one of the jaws is accordingly bent in the form of a hook so that the fallopian tube and the mesosalpinx can be pulled into the abdominal cavity for the appropriate treatment. Such displacement of the fallopian tube and the mesosalpinx has the advantage that coagulation can take place at a safe distance from the surrounding tissue of the body, so that damage to that tissue is avoided. The embodiment described ensures that the mesosalpinx is securely held not only above the fallopian tube, but also directly by means of the bent part of said one jaw.
Forceps for the electro-coagulation of anatomical structures by means of high-frequency current are also described in German Patent Application No. 2 325 626. These forceps have two pairs of mutually electrically insulated clamping jaws, having free end portions formed as hooks and which can be moved with respect to one another.
When carrying out uterine tube sterilisation by means of coagulation, it is important to avoid, inter alia, damaging the mesosalpinx during coagulation, thereby to avoid or exclude complaints and risks associated with the bleeding and/or scarring of the mesosalpinx.


A calibration assisting device includes a reference load data storage means 30d for storing, as a reference load data, the reference load data produced from load sensor 10 when a desired reduced quantity is generated in a vehicle weight measuring device 40, a load data fetching means 30a1 for fetching the load data produced from the load sensor 10, a tire load data fetching means 30a2 for fetching a tire load data produced from the vehicle weight measuring device 40, a reduced quantity detecting means 30a3 for detecting a reduced quantity on the basis of the tire load data thus fetched, a calibration information creating means 30a4 for creating calibration information on the basis of the load data fetched by the load data fetching means 30a1 corresponding to the tire load data and the reference load data stored in the reference load data storage means 30d when the reduced quantity is detected, and a calibration information outputting means 30a5 for outputting the calibration information produced from the calibration information creating means 30a4. In such a configuration, the calibration assisting device can assist the calibration of the weight meter.

1. Field of the Invention
This invention relates to a calibration assisting method, device and system, and more particularly to a calibration assisting method, device and system for assisting the calibration of a weight meter for measuring the loaded weight of a vehicle produced from a load sensor. The load data varies according to a distortion of an axle, which is generated when the load applied to the vehicle is conducted to the axle.
2. Description of the Related Art
The measurement of the weight loaded on a vehicle is carried out, for a large vehicle such as a truck, in order to prevent a traffic accident such as turnover on the side of the vehicle due to overloading and promotion of vehicle deterioration. Conventionally, measurement of loaded weight of the vehicle was carried out in such a manner that the vehicle is placed on a platform scale. This manner requires large-scale facilities and a large installing space. Therefore, the number of the platform scales, which can be set, is limited and hence the measurement cannot be carried out for a large number of vehicles. In addition, the production cost is also increased.
In order to obviate these inconveniences, in recent years, a weight meter has been proposed in which it is mounted on the vehicle itself to measure the loaded weight. In a conventional weight sensor mounted on the vehicle, sensors for weight measurement, e.g. strain gage sensors are attached to both left and right ends of each of both front and rear axles. The loaded weight is measured on the basis of the sum of the outputs of the respective sensors, which are proportional to the loads applied to the front/rear and left/right tires.
In the weight meter, in order to maintain the measurement accuracy, the relationship between the outputs from the sensors and an actual weight of the matter to be measured is investigated, and on the basis of the investigation result, a sensor signal is calibrated. There is the following known calibrating method.
For example, with a weight loaded on a stand installed on the upper portion of a container, calibration is carried out. In this case, a specific structure is required to fix the stand to the container. In addition, since excessive load is applied from the upper portion of the container, the container may break. The labor of placing a large number of weight members placed at a height of 2 meter or higher is enormous and entails danger.
The method for calibrating the weight meter safely and easily is disclosed in JP-A-2001-228015. In accordance with this method, the weight meter can be calibrated safely and easily in such a manner that a plurality of spring members are hung from the container for accommodating a matter to be conveyed, a weight member having a prescribed weight is placed on a stand supported by the spring member and the relationship between the output of the load cell sandwiched between the container and the body frame of the vehicle and the weight of the weight member is examined.
However, since the above calibration method is carried out using the weight member, time and labor are required to load/unload the weight member so that the weight meter cannot be calibrated for a short time. A structure must be provided for supporting the above stand with respect to the container, vehicle, etc.

Calibration assisting method, device and system


A guidewire assembly having selectively adjustable stiffness and tip curvature includes a hollow guidewire having a distal portion terminating at a distal tip, a curvature-modifying element anchored to the distal tip, and a stiffness-modifying element displaceable within the hollow guidewire towards and away from the distal tip so as to vary a stiffness of the distal portion. The stiffness-modifying element and the curvature-modifying element are frictionally linked such that movement of the stiffness-modifying element from a current position over a first range of motion causes corresponding displacement of the curvature-modifying element, thereby modifying a state of curvature of at least part of the distal portion of the guidewire. Movement of the stiffness-modifying element beyond the first range of motion displaces the stiffness-modifying element relative to the curvature-modifying element.

The present invention relates to medical devices for interventional cardiology and radiology.
Various procedures, such as percutaneous coronary intervention (PCI) procedures, involve navigating a guidewire along a convoluted intravascular access path and, in some cases, crossing a lesion or other obstacle with the guidewire. The different stages of guidewire deployment in such cases have differing requirements for guidewire tip curvature and guidewire stiffness.
Certain guidewires have capabilities for adjusting tip curvature. Others have capabilities for varying tip stiffness. However, existing adjustable guidewires typically only have the ability to vary one of these two parameters, or have a fixed correlation between them.
It would be advantageous to provide a guidewire in which the stiffness and tip curvature can be modified in an independent, or near-independent manner.

Guidewire having selectively adjustable stiffness and tip curvature


A chair occupancy monitoring device having pressure sensitive switch housed within a flexible cover. A cushion formed by a pair of foam pads positioned between the cover and the switch protects the switch and increases patient comfort. The switch includes first and second oppositely disposed base members. First and second electrical conductors are mounted to an interior portion of the first and second base members, respectively, on the surface facing the opposing base member. A gap is created between the electrical conductors by a pair of separator members which are disposed intermediate the oppositely disposed surfaces of the first and second base members and are mounted to a side portion of at least one of the base members. At least one electrically non-conductive contact limiter member is disposed intermediate the electrical conductors, covering a portion of the second electrical conductor. The separator members and contact limiter each have a compressibility defining a spring constant where the spring constant of the contact limiter is greater than the spring constant of the separator members. When the patients weight is applied to the device the separator member and the contact limiter member are compressed allowing the first electrical conductor to contact an uncovered portion of the second electrical conductor. When the patient's weight is removed the contact limiter and separator expand to break the contact and reopen the gap.

The present invention relates to a pressure-sensitive switch apparatus and, more particularly, to such an apparatus for use in monitoring the presence of a patient in a wheel chair or other type of normal household seating.
A problem of considerable concern to health care providers is that of patients leaving a wheel chair when the patient is not safely ambulatory. The use of restraints to ensure the safety and well-being of such patients is becoming impracticable in many instances, not only because of legal issues relating to patient's rights, but also because of a change to a more considered approach by medical and nursing staff toward patients. Concerns regarding the use of restraints are even more acute in the case of home care where patients are typically cared for by family members.
There is a need, therefore, for a less invasive approach to monitor patients restricted to a wheel chair or other type of seating and to alert health care providers when patients attempts movement on their own.