Patent Application
20070193632
Not Applicable
Not Applicable
1. Field of Invention
This invention relates to novel rotary pressure porting mechanisms, more particularly to a simple, reliable, compact, anticoagulant artificial or mechanical heart valve based on the rotary pressure porting mechanisms. This valve only employs about ⅕ of the energy which conventional mechanical heart valves consume. This valve meets and exceeds most performance requirements of human heart valve including anticoagulant. Finally these rotary pressure porting mechanisms have vast applications and many advantages over conventional linear or rotary pressure porting mechanisms.
2. Description of Prior Art
The first mechanical heart valve was developed about 50 years ago, it was based on a conventional check valve mechanism or linear pressure porting mechanism which opens with forward flow and closes against reverse flow. The conventional mechanical heart valves evolved from a caged ball check valve, the title disc valve, bileaflets swing heart valve to tri-leaflet heart valve, but the basic mechanisms do not change, they are operated with linear mechanism or conventional hinge mechanism. Furthermore the conventional mechanical heart valves have inherently relatively high inertia, high energy consumption, high closing impact force and high leakage. In addition, most conventional mechanical heart valves based on the conventional hinge mechanism also have backflow (regurgitation) and do not close coordinately with heart stroke cycle, as a result the regurgitation flow takes place. The regurgitation flow or backflow not only can cause damage on the valve and blood cells, but also reduce heart pumping efficiency. Finally, the coagulation problem is still unsolved, the patients with the mechanical heart valves have to take anticoagulant drugs for life. Above all, the mechanical heart valves are never designed or considered to meet or exceed the performance requirements of the native heart valve.
In order to overcome the disadvantages of the conventional mechanical heart valve and conventional pressure porting mechanisms, many efforts have been made in the prior arts. There are many approaches to improve the conventional pressure porting mechanisms and mechanical heart valves in the prior arts, but those approaches are not systematic and sometime work against each other within a limited scope they are grouped to four approaches, especially last twenty years, most prior arts are stressed in improving bileaflets heart valve.
The first approach is to improve the hemodynamics and reduce energy loss with one leaflet or valve member heart valve. The first successful mechanical heart valve was a caged ball valve, pioneered by Starr and Edwards, based on the ball valve of U.S. Pat. No. 19,323 to Williams (1858), but the caged ball blocks the center flow stream, and damages the blood cells. Soon the hemodynamic concept of the single tilting disk valve was introduced for improvement over the caged ball valve because it reduces energy loss, and therefore largely replaced the caged ball implant. U.S. Pat. No. 3,546,711 to Bokros ( 1968) discloses a single tilting disk heart valve with journal hinges set away from the orifice wall. U.S. Pat. No. 3,835,475 to Child (1974) discloses a free-floating disk that is constrained by projections. U.S. Pat. No. 4,306,319 to Kaster ( 1981) discloses a tilting disk heart valve with an oval shaped disk and orifice. In this valve, the disk is hinged with an axis of rotation across the largest dimension of the orifice. The tilting disk heart valves have improved flow characteristics over the caged ball valves, but still partially obstruct the central flow of blood while open.
The second approach is to improve performance and reduce energy loss with bi leaflet mechanical heart valve in three following aspects (1) improvement of hinge mechanism. U.S. Pat. No. 4,276,658 to Hanson et al. (1981) shows the most popular hinge design in mechanical heart valves on the market, the combination of the hinge and stopper reduces blood stagnation, but such arrangement reduces concentricity between valve internal surface and leaflets and dynamic performance, as a result, the leakage and vibration increase, and the flat cross section of hinge pin reduces the strength of leaflet and increase stress concentration (2) reduction of leakage. Most conventional bileaflets hear valves have two seals between the valve body and the leaflets, and between the leaflets, those seals are all face to face seal which constitutes a seal only at a relative position between a valve member and a valve body, by nature, no leaflet is made perfectly, so the valve either has a good seal between the bileaflets, a bad seal between the valve body and the leaflets or vise verse. The first approach is to eliminate a seal between leaflets and is widely adopted in the industrial double disc swing checks, but it blocks the center flow stream as shown in U.S. Pat. No. 3,903,548 to Nakib ( 1975). The second approach is to improve the seal surface profile as shown in U.S. Pat. No. 5,405,382 to Kukolmikov et al ( 1995), the seal is provided between a valve and a leaflet with an spherical internal surface of the valve and a spherical surface on the leaflet edge, in fact this seal is still a conventional face to face seal with five problems, first there are two large flat areas connected with the spherical surface, if the flat area is a dominated position factor, then the spherical surface can not seal well and vise verse, second the joint area between the spherical and flat area can cause leakage and jam the leaflets, third the seal surface on the leaflet depends on the thickness of leaflet, in some cases, the thickness is too small to provide a seal, fourth the leaflets block the flow stream and create three flow streams just like conventional bileaflets valve when the valve is at open position, fifth without a pivot pin as a pivoting center, the closing force can be very high in some points around the seal surface and cause chatter and vibration. Finally there are other two approaches which are similar, one is to have a flexible valve body to compensate any geometric error of a leaflet as shown in U.S. Pat. No. 5,397,348 to Campbell et al. (1995), other is to make flexible leaflets to compensate any geometric error of a leaflet as shown in U.S. Pat. No. 6,139,575 to Shu et al Campbell et al. (2000), two approaches may work if mechanical heart valve works less frequently or in a static condition, but in a dynamic condition, opening or closing, the flexible valve body or leaflets became a spring in a valve dynamic operation system to store and release the leaflets kinetic energy rather than as a dumping device to dissipate the energy, as a result, the coefficients of restitution for the valve body and the leaflet become closed to one, those approaches can cause even more leakage, flutter and chatter (3) improvement of hemodynamic performance by changing shape of leaflets or valve internal profiles. The conventional leaflets are divided to two uneven sections by pivot axis, one larger sections is rotated clockwise and other is anticlockwise or vise verse, the difference between two sections under fluid pressure generates a torque to operate leaflets, so the hinge mechanism not only wastes flow energy and leaflet spaces but also has two opposite flow streams around the leaflet and cause backflow when the leaflet moves, the hinge problem is not consciously recognized. U.S. Pat. No. 4,274,437 to Watts. (1981) shows two conical leaflets engaged with two partial spherical surfaces on a valve body, it generates one center flow stream only when the valve is at fully open position, but the hinge mechanism still is conventional, the lager section is against to smaller section, so there are the backflow and multiple streams when the valve is approached to closed or open positions. U.S. Pat. No. 5,376,111 to Bokros et al (1994) shows the same type of leaflets with a body having a cylindrical internal surface, the blood flow is blocked by the two conical leaflets and become three flow streams through the valve when the valve is either at open position or approached to open, the backflow still exist. So in order to solve the backflow problem which is inherent with the conventional hinge mechanism, a new solution was presented by adding a backflow preventing device as shown in U.S. Pat. No. 6,638,303 to Louis A. Campbell (2003), a spring or magnetic blocks was added to increase closed speed for preventing reverse or back flow, but there are three problems, first with conventional hinge mechanism, the backflow caused by the small section on the leaflet still exist, the improvement is very limited, second, the spring or magnetic force will increase closing impact force, third the spring installed in an open manner can fall into blood flow stream if broken, it is not accepted by the medical community, on other hand the magnets block has a manufacturing problem as well as application limitation, to bond the magnetic blocks to carbon is not an easy job, moreover a patient who has a pace maker can not have a mechanical heart valve with the magnetic block, which will disturb the pace maker.
The third approach is to improve hemodynamics and reduce energy loss with tripleaflet mechanical heart valve. The tripleaflet mechanical heart valve was first developed, because it mostly resembles nature heart valve, but it never have successful clinical trials due to complexity of the structure. U.S. Pat. No. 5,843,183 to Bokros (1998) discloses an improved tripleaflet mechanical heart valve with hinge devices on the valve with stopper blocks. U.S. Pat. No. 6,896,700 to Lu et al (2005) shows an improved tripleaflet mechanical heart valve with hinge pin inserted in the valve body, although the leaflets can free move, but they are not secured and can fall out under blood flow, the profile of hinge and stopper are complicated and expensive to make, finally no clinical trials proves any tripleaflet mechanical heart valve as an alternative to bileaflets mechanical heart valve.
The four approach is to improve the pressure porting mechanisms which are basic mechanism behind all check valve and pressure control valves. The conventional pressure porting mechanisms comprises a linear and a hinge mechanisms. The linear pressure porting mechanism is shows in U.S. Pat. No. 19,323 to Williams (1858) and U.S. Pat. No. 544,376 to Porter in 1895. The hinge mechanism was invented by W. Brovo (1917) in U.S. Pat. No. 1,238,878. Since then many improvements were made, but no fundamental changes have been made in two pressure porting mechanisms, the main disadvantages of those two mechanisms still remain (1) center flow stream obstruction or flow stream obstruction (2) high impact closing force (3) size dependency. U.S. Pat. No. 6,953,026 to Yu et al. (2005) shows a pressure regulator with an improved shape of the closure member in a fuel delivery system, but the center flow stream is blocked, as a result it increases the response time and pressure loss and damages the valve. U.S. Pat. No. 5,794,652 to Mizusawa (1988) shows an improvement of check valve used in a fuel delivery system, it reduce central flow obstruction, but the valve member still block the flow. U.S. Pat. No. 3,007,488 to Wheeler ( 1961) discloses an improvement of two plates check valve, but the center flow stream is blocked, U.S. Pat. No. 5,078,177 to Tartaglia et al ( 1991) shows an improved relief valves with a cavity to provide a soft closing, but because of the nature of face to face seal with a biased spring, the soft seal is very difficult to achieve with only dumping mechanism which is a viscous friction between the gas fluid and the valve member in the cavity, thus the performance can be unpredictive. U.S. Pat. No. 6,749,592 to Lard ( 2004) and U.S. Pat. No. 6,770,062 to Phung et al (2004) shows a pressure regulator and a check valve in a chest drainage system, which are based on conventional linear porting mechanism, they block the center flow stream. The pressure regulator is not compact for mobile applications and both are complicated and expensive to produce for a disposable device, above all the closing forces still cause noise in both valves. U.S. Pat. No. 6,588,428 to Shikani et al (2003) shows a speaking valve, which is based on the conventional linear porting mechanism, it blocks the center flow stream and effect the speech quality and distort the patient true voice and is susceptible to air duct. U.S. Pat. No. 4,758,224 to Siposs (1988) and U.S. Pat. No. 6,053,896 to Wilson et al (2000) disclose a combination of check valve and relief valve in a drainage system for the heart surgery operation, but the basic disadvantages of this type of drainage system is that it can not sustain a negative pressure in the inlet of check valve due to flexible, soft leaflet of duckbill check valve, slow response to a pressure change and no pressure setting adjusting device in the relief valve, as a result, the relief valve is required to control the pressure within both the high and lower limits and a very complicated control system for the pump in the suction side. U.S. Pat. No. 6,050,081 to Jansen et al (2000) ) shows a two-way check valve, which is based on the conventional linear porting mechanism, it blocks the center flow stream and cause high pressure loss and coking.
In short, those prior arts provide no single valve meets the performances of human heart valve and or addresses the root of causes of all the disadvantages of conventional mechanical heart valve and conventional pressure porting mechanisms in a systematic manner. The high energy exchange between the valve and fluid through the valve is a root of causes of all the disadvantages and blood clot. When two solid parts have a relative motion in the valve, some energy exchange takes place as a restoring form like spring or potential energy, some energy exchange takes place as a dissipating form (creating a third part or as other form of energy, like heat) through friction, wearing like hinge and the body, when the fluid and solid part have a relative motion, some of energy exchange takes place between kinetic energy and potential energy, some energy exchange takes place through a dissipating form (creating a third part or other form of energy like heat), an erosion which is that the fluid takes away solid material, or buildup (coagulation) which is that the solid part takes away some part of the fluid, finally the heat exchange, the temperature difference between the mechanical heart valve and the surrounding tissue and blood causes energy exchange, even the chemical reaction or biologic reaction is explained by the energy exchange, without energy exchange, nothing happens. So the performance of the mechanical heart valve is depended on the level of energy exchange in three aspects (1) pressure porting mechanism which is an interaction device between the valve and fluid (2) property of the valve materials (3) property of the fluid, so the less energy exchange takes place in the valve, the less damage of blood cell, less coagulation the mechanical heart has, but what is a better mechanical heart valve or a pressure porting mechanism should be, many arguments and research, investigation were published, but they are sometime contradiction and confusion, there is no convincing theory or supporting data to explain how blood fluid mechanism through the heart valve, fortunately, we have a good example, our human heart valve, the following is our human hear valve's strengths
Those strengths and weakness are an ultimate standards to judge wither or not a mechanical heart valve qualified as a good alternative to nature heart valve or a better pressure porting mechanism.
So the medical device industry and medical community have long sought a means of improving the performance of mechanical heart valve having most of native heart valve strengths and with the few weakness, increasing reliability and anticoagulant ability and life expediency of the valve.
In conclusion, insofar as I am aware, no mechanical heart valve was formerly developed to have higher performances with a anticoagulant structure, less parts, high durability, reliability, easy manufacturing at low cost. Above all, such a valve is as good as or even better than the native heart valve in some aspects.
This invention provides a highly reliable, anticoagulant compact, efficient, mechanical heart valve. The mechanical heart valve is based on two novel rotary pressure porting mechanisms to control a flow and provide one constant central flow stream when the valve is approached to opening or closed positions. One is a hybrid functions pressure porting mechanism, it has two sections on a valve member, a spherical shell balanced section and an actuation section, only the actuation section under pressure difference generates open and closed torques. The other is an offset pressure porting mechanism which has a spherical shell valve member with an eccentric pivot axis, so the operating torque is generated by an offset and surface area of the spherical shell, so the operating torque for those two porting mechanisms can be carefully designed to balance the closing speed and impact force. This invention also provides multiple novel hinge joint mechanisms between the valve body and the valve member with less blood cell damage and less blood stagnation and in smooth concentric operation. An unique soft closing concept and mechanism is introduced in this invention, the closing mechanism comprises two stages, first stage is to impact/lock to absorb most leaflet kinetic energy to reduce coefficients of restitution to closed zero, second stage is to contact/seal, so the flutter, chatter and cavitations can be prevented or minimized even when the valve member still oscillate around the closed position. Finally the valve member acts like a cutter to remove any buildup or coagulation on the valve porting surfaces when the valve is closing or opening, while the spherical surfaces on the valve body or leaflet can be coated with anticoagulant drug and release the drug into blood fluid when the valve is closing or opening.
The valves can be constructed with one valve member, two valve members, three valve members in series or parallel or mixed manners. The two rotary pressure porting mechanisms can be applied separately or together and can be used with the conventional linear porting mechanism for other applications other than the mechanical heart valve. A spring or automatic control mechanisms may be equipped for check valve, relief valve or pressure regulator or multiple function valves or control system. Accordingly, besides objects and advantages of the present invention described in the above patent, several objects and advantages of the present invention are:
Still further objects and advantages will become apparent from study of the following description and the accompanying drawings.
Drawing Figures
a is an exploded view of a subassembly of the valve of
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The valve 100f is based on the offset pressure porting mechanism and has body 101f and leaflet 151f movably disposed in body 101f for porting flow through a port 106f, body 101f has two hinge bosses 120f with thread joints, each boss 120f is provided with a springs 145f and a nut 197f for a closing torque. Nut 197f is provided for adjusting the closing torque and securing the boss 120f. Body 101f also has two thread joints on a surface 109f to connected with body 101g or other device and on a surface 108f to connected with a drainage container with a filter or a inlet tube (not shown).
The valve 101g is based on the hydride function pressure porting mechanism and has body 101g and leaflet 151g movably disposed in body 101g for porting a flow through a port 106g, a surface 108g on port 10g has a thread joint for connecting with body 101f or others. Body 101g has a port 112g, a lower hinge hole 115g extending to a upper hinge through hole 116g and a large hinge boss 120g, leaflet 151g is movably disposed in body 101g by means of a hinge pin 168g disposed in hole 115g and hinge hole 167g to received a shaft 195g , one end of shaft 195g is disposed in hinge hole 115g to engaged with slot 167g, other end of shaft 195g is movably disposed in hole 116g . Valve 101g also has a spring 145g and a driver 196g, an operating torque is provided with one end of spring 145g biased against a slot of shaft 195g and other end of spring 145g biased against a driver 196g threaded with hole 116g. A nut 197g threaded with driver 196g is to secure a position of driver 196g. The driver 196g can be operated by manual, motor or others to control a presetting torque.
A valve 100fg is a combination of valves 100f, 100g with the thread joint between surfaces 108g and 109f to provide a drainage system. A valve 100gk is a combination of valves 100g, 100k with the thread joint in hole 112g to provide a drainage system in heart operation. Valve 100g can be used as a two-way check valve with two inlets ports defined by hole 112g and port 106g on surface 109g and one outlet port defined by port 106g on surface 108g.
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a illustrate a mechanical heart valve 200 and other alternative embodiments in accordance with the present invention. Valve 200 disposed in a native heart (not shown) by means of a groove 207 comprises a body 201 having a flow port 206 between a front surface 208 and a back surface 209 and two valve members or leaflets 251. The leaflets 251 disposed in the flow port 206 is actuated by pressure difference between upstream flow and downstream flow to regulate blood flow through port 206 between closed and open positions.
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Valve 100,200,300,400 and their alternatives can be constructed with a plurality of materials and a plurality of process for those materials The materials include metals, plastic, rubber, composite, carbon, metal coated with rubbing, plastic, carbon, ceramic and others. While the processes of those materials comprised casting, forging, molding, fabrication, stamping, bonding, machining, welding, assembly, sterilizing and others. The surfaces for contact surfaces in medical valve must be coated or treated with antifriction, rubbing material or anticoagulant drug, above all those materials for medical usage must be bio-compatible and safety. So the processes and materials should be at low cost and easy to use and flexible to be substitute.
Valve 100,200,300,400 and their alternatives are constructed with a plurality of configurations, the configurations of connecting ends include a tube adapter end, flange, wafer, lug, spited body end, welded end, inline end, threaded end, grooved end, angle body end. The configurations of the flow port comprises at least one inlet and one outlet. The configurations of functions include; check valve/check valve, check valve/pressure relief valve, check valve/pressure regulator, relief valve/relief valve, relief valve/pressure regulator and pressure regulator/pressure regulator and others. The configurations of the pressure porting mechanisms include offset/offset, offset/hybrid functions, offset/linear, hybrid functions/hybrid functions, hybrid functions/linear.
The best assembly process for valve 100 and the alternative embodiments is accomplished as followings; for valve 100 (1) hinge boss 120 of leaflet 151 is compressed to a distance which is smaller than a gap between hinge bosses 120 (2) then leaflet 151 is inserted into body 101 from surface 109 with a rotary engagement between hole 165 and pin 118. For valve 100e (1) hinge boss 170e of leaflet 151e is compressed to a distance which is smaller than a gap between slots 117e 120 (2) then leaflet 151 is inserted into body 101e from surface 109e with a rotary engagement between boss 120e and slot 117e (3) spring 145e is expended to be disposed around pin 168e (4) two ends of one end of spring 145e is respectively disposed into a slot of pin 169e and slot 117e. For valve 100fg (1) leaflet 151g is inserted into port 106f (2) hinge boss 120f with spring 145f is through hinge hole 165f of leaflet 151f and threaded through body 101f from inside of body 101f (3) nut 197f is placed into hinge boss 120f to secure hinge boss 120f from outside of body 101f 170e (4) two ends of spring 145f are respectively disposed into a slot of pin 169f and slot 117f. (5) leaflet 151g is inserted into port 106f (6) hinge bosses 168 g is inserted into slot 115g (7) hinge boss 117g is lined up with 115g (8) shaft 195g is through holes 116g, 115g engaged with 167g with spring 145g (9) driver 196g is threaded into hole 116g and over top of spring 145g (10) two ends of spring 145g are respectively disposed into a slot of pin 169f and slot 117f (11) nut 197g is threaded into drive 196g to secure 196g (12) body 101f is threaded into body 101g.
The best assembly process for valve 200 and the alternative embodiments is accomplished as followings; for valve 200, for valve 100 (1) leaflet 251 is compressed and inserted to port 206 (2) slot 267 and slot 290 are respectively lined up with hinge boss 220 and boss 241. For 200h (1) two leaflet 251h are concentrically overlapped with hinge bosses 271h, 270h within two springs 245h in L block 296h (2) setscrew 246 is threaded into hole 240h of hinge boss 220h (3) Both of hinge boss 220h are placed on both top and bottom of the two leaflets 251 h by inserting pin 218h into hole 265h and spring 245h (4) assembled leaflets 251h are inserted into body 201h by matching up between slot 240h and boss 291h (4) setscrew 246h is screwed down into groove 211h to secure 220h.
The best assembly process for valve 300 and the alternative embodiments is accomplished as followings; for valve 300; (1) leaflet 351 is compressed and inserted to port (2) Boss 320 is lined up with slot 367. For 300b (1) spring 345b is disposed into slot 317b with engagement between section 347b and surface 324b, an end of section 346b and surface 323b ( 2) leaflet 351b is inserted in body 301b by disposing boss 370b into slot 317b
The best assembly process for valve 400 and the alternative embodiments is accomplished as followings; for valve 400 (1) boss 491 on leaflet 451 is compressed to a distance which is smaller than a gap between hinge bosses 420 (2) leaflet 151 is inserted into body 401 along with boss 420 until boss 491 pass boss 420.
In the best mode of operation, valve 100 and the alternative embodiments are the followings. With valve 100 installed in a native heart, when the heart starts to pump blood fluid into leaflet 151, because the upstream pressure is larger than that of downstream, the blood pressure difference between internal spherical surface 152 in the upstream and external surface 154 in the downstream generates a balanced force on center axial 110, but there is an offset between the pivot hinge axis and spherical shell axis, an opening torque is generated to actuate the leaflet 151 to an open position until surface 174 contacts surface 109. When the heart finishes the pumping cycle, the blood flow tends to flow back, the downstream pressure is larger than that of upstream, the pressure difference between two side surfaces and internal and external surfaces 152, 154 is reverse and generates a force and cause a closing torque until surface 173 contacts surface 109.
With 100b installed in a native heart, when the heart starts to pump blood fluid into leaflet 151b, because the upstream pressure is larger than that of downstream, the blood pressure difference on spherical shell section 158b does not generates a torque due to an zero distance between centric axis and pivot axis of section 158b, while actuation section 159b has an offset between a centric axis 161b and the pivot axis of section 158b, so the blood pressure difference generates a torque to open the valve 100b until hinge pin 122b full contact one of surfaces 172b. When the heart finishes the pumping cycle, the blood flow tends to flow back, the downstream pressure is larger than that of upstream, the pressure difference is reverse and generates a closing torque on section 159b and two side surfaces of leaflet 151b until hinge pin 122b full contact other surfaces 172b.
With valve 100hk used for a drainage system in medical applications, flow fluid from a heart comes into port 106g by means of surface 108g, because of a pressure difference between upstream of 108g and downstream of 109g and the hydride function mechanism in leaflet 151g, leaflet 151g as a check valve is rotated to an open position, then the flow get into port 106f and drains out through surface 109g , while valve 100k acts as a pressure relief valve to control the pressure difference between upstream and downstream, if the difference become too high to overcome a presetting value of spring 145g , the valve 100k will open to the atmosphere and reduce the difference.
With 100gh used for a chest drainage system in medical applications, flow fluid from the chest comes into port 106f by means of surface 106f, because of a pressure difference between upstream of 108f and downstream of 112g and offset mechanism in leaflet 151f, leaflet 151f as a check valve is rotated to an open position, then the flow get into port 106f and drains into outlet 112g, while leaflet 151g as a pressure regulator control the pressure difference upstream and downstream, if the difference become too high to overcome a presetting value of spring 145g, the leaflet 151g will open to the atmosphere and reduce the difference.
With valve 100g for a two-way check system with two inlets and one outlet, flow A comes into port 106g by means of surface 108g, flow B comes into hole 112g, flow A or B flow out by means of surface 109g on port 106g. When a pressure difference between upstream of 112g and downstream of 109g increase to overcome a torque provided by spring 145g, leaflet 151g is rotated to an open position and cover hole 112g, so the flow A get into port 106f and drains out through surface 109g . When a pressure difference between upstream of 112g and downstream of 109g decreases, a torque provided by spring 145g is to move the leaflet 151g to a closed position, hole 112g is uncovered, so the flow B get into port 106f and drains out through surface 109g on port 106g.
In the best mode of operation, valve 200 and the alternative embodiments, are the followings. With valve 200 installed in a native heart, when the heart starts to pump blood fluid into internal surface of leaflet 251, because the upstream pressure is larger than that of downstream, the blood pressure difference between internal spherical surface 252 and external surface on section 258 generates a force in a centric axis of leaflet 251, but no torque is generated due to zero offset between centric axis and pivot axis, while the difference on actuation section 259 generates an force on centric axis and torque due to an offset between the centric axis and pivot axis on the actuation section 259. When the heart finishes the pumping cycle, the blood flow tend to flow back, the downstream pressure is larger than that of upstream, the pressure difference is reverse and generates a closing torque on section 259 and two side surfaces of leaflet 251 until side surfaces of leaflet 251 contact each other then slot 290 contacts lock slot 241.
With valve 200a installed in a native heart, when the heart starts to pump blood fluid into internal surface of leaflet 251a, because the upstream pressure is larger than that of downstream, the blood pressure difference between internal spherical surface 252a and external surface on section 258a generates a force in a centric axis of leaflet 251 a, but no torque is generated due to zero offset between the centric axis and the pivot axis, while the difference on cylindrical actuation section 259a generates an force on centric axis and torque due to an offset between the centric axis and pivot axis on the actuation section 259a. When the heart finishes the pumping cycle, the blood flow tend to flow back, the downstream pressure is larger than upstream, the pressure difference is reverse and generates a closing torque on section 259a and two side surfaces of leaflet 251a until side surfaces of leaflet 251b contact each other then slot 272a contacts lock boss 222a.
With valve 200h installed in a pipe line, when a pressurized fluid flows into internal surface of leaflet 251h, because the upstream pressure is larger than that of downstream, the fluid pressure difference between internal spherical surface 252h and external surface on section 258h generates a force in a centric axis of leaflet 251, but no torque is generated due to zero offset between the centric axis and the pivot axis, while the difference on the actuation section 259h generates an force on centric axis and torque due to an offset between the centric axis and pivot axis on the actuation section 259h to overcome torque on spring 245h until leaflet 251h contact surface 223h. When flow finishes the pumping cycle, the flow tend to flow back, the downstream pressure is larger than that of upstream, the pressure difference on section 259h and two side surfaces of leaflet 251h is reverse, leaflet 251h with the tied spring 245h generates a closing torque until side surfaces of leaflet 251h contact each other then slot 272h contacts lock boss 222h.
In the best mode of operation, valve 300 and the alternative embodiments are the followings. With valve 300 installed in a native heart, when the heart starts to pump blood fluid into internal surface of leaflet 351, because the upstream pressure is larger than that of downstream, the blood pressure difference between internal spherical surface 352 and external surface on section 358 generates a force in a centric axis of leaflet 351, but no torque is generated due to zero offset between centric axis and pivot axis, while the pressure difference on actuation section 359 generates an force on centric axis and torque due to an offset between the centric axis and pivot axis on the actuation section 359 until surface 374 contacts surface 324. When the heart finishes the pumping cycle, the blood flow tend to flow back, the downstream pressure is larger than that of upstream, the pressure difference is reverse and generates a closing torque on section 359 and two side surfaces of leaflet 351 until side surfaces of leaflet 251 contact each other then surface 373 contacts lock slot 323.
In the best mode of operation, valve 400 and the alternative embodiments are the followings. With valve 400 installed in a native heart, when the heart starts to pump blood fluid into internal surface of leaflet 451, because the upstream pressure is larger than that of downstream, the blood pressure difference between internal spherical surface 452 and external surface on section 458 generates a force in a centric axis of leaflet 451, but no torque is generated due to zero offset between centric axis and pivot axis, while the pressure difference on actuation section 459 generates an force on centric axis and torque due to an offset between the centric axis and pivot axis on the actuation section 459 until slot 472 contacts stopper 422. When the heart finishes the pumping cycle, the blood flow tend to flow back, the downstream pressure is larger than that of upstream, the pressure difference is reverse and generates a closing torque on section 459 and two side surfaces of leaflet 451 until lock boss 491 hits lock slot 441, then lock boss is compressed to a side due to a release slot 495, then side surfaces of leaflet 451 contact each and provides a seal.
The present invention first developed a mechanical heart valve which mostly resembles to human heart valve in the performances over all existing mechanical heart valves.
(1) One constant central flow stream.
This invention is provided with mechanical heart valves 100,200,300,400 and the alternative embodiments having a constant spherical engagement and seal between the body and the. Those heart valves have a cyclical opening for maximum of flow area and keep one constant central flow stream when the valves are approached to full closed position or open position, as a result pressure loss reduce, so does the blood cell damage.
(2) No obstructive in the center flow stream.
This invention provides mechanical heart valves 100,200,300,400 and the alternative embodiments with a constant spherical engagement and seal between the body and the leaflet, those heart valves not only provide no obstructive in the center flow stream, but also retreat the leaflet or the leaflets to the body side wall and reduce the contact area with blood flow stream, as a result pressure loss reduce, so does the blood cell damage.
(3) No closed force between valve body and valve leaflet
This invention provides mechanical heart valves 100,200,300,400 and the alternative embodiments with a constant spherical engagement and seal between the body and the leaflet, so those valves are closed with radial seals between the body and leaflet without high closed forces unlike the conventional hear valve with high impact force on the face to face seal between the valve body and leaflets. According to the medical researches, on an average, the mechanical heart valve in an adult life patient operates about 200 million times, since no material like human heart valve muscle is developed for the mechanical heart valve, every closed operation of the 200 million time does damage the blood cells and the valve one way or other. With this invention, 200 million time of the operation is eliminated while countless blood cells are saved, and the mechanical valve can be used for much longer time without damage.
(4) Soft closing between the leaflet.
This invention provides an unique solution to the problem the conventional mechanical heart valves are faced. With this two prone approaches, first is to provide proper and adequate closing torque and energy by designing a proper offset distance for eccentric actuation mechanism or proper actuation section for the hybrid function mechanism, so no excessive energy is employed to close the leaflet as indicated leaflets 151,251,351,451, second is to have a soft closing process, this process is provided with a dumping mechanism to dissipate the kinetic energy of the leaflets 151,251,351,451, with more dry dumping with valve body 101,201,301,401 and leaflets 151,251,351,451 and less viscous damping between the valve 100,200,300,400 and blood fluid. It is unlike the conventional mechanical heart valve which has most damping effect between blood and the leaflet and the valve body, such method cause more blood cell damage. The soft closing process comprise two stages; (a) impact/lock (b) contact/seal, as valve 100 shows with the eccentric cam mechanism, at the first stage that the leaflet 251 is partially engaged with body 201, the second stage is that the leaflet 251 is fully engaged with body 201, the block is provided with additional dumping effect, minimize the cavitations when fully engaged with the with body 201 as valve 100 shows with the eccentric cam mechanism, at the first stage that the leaflet 251 is partially engaged with body 201, the second stage is that the leaflet 251 is fully engaged with body 201, the block is provided with additional dumping effect, minimize the cavitations when fully engaged with the with body 201
(5) Self absorb clot material
In fact, human heart valve is a live organ, the lifeless mechanical heart valve never has such a self absorb ability, even with pyrolitic carbon material, the coagulation is inevitable for a lifeless device, however, to a certain extent, the mechanical heart valve can reach a closed result to reduce the clot accumulation, but the most important thing is to reduce the root cause of clot, blood cell damage at first place. The present invention provides a long sought, comprehensive solution to the problem. This solution include two steps, first is to reduce the damage of blood cell with each feather in this invention, second is to provide mechanical and medical cleanup methods. By design, the leaflet 151,251,351,451 along with bodies 101,201,301,401 constitute cutters, whenever the leaflets open or closes, the leaflets clean up the porting surfaces, if any clot is established, the relative movement between leaflet and the body will remove the clot, while the medical method is to coated with anti clot drug on the leaflet external surface and the body internal surfaces, so rubbing between the two surfaces will release the drug gradually. So the fundamental difference between this invention and prior arts is with this two prone approaches. so the process of rubbing between balls 146 and rotor 152 or body 153 is a process of drug releasing, such approaches are complete different from the conventional methods which are eight to prevent the coagulation which is impossible, or to ask the patients to take the anticoagulant drug for life which is troublesome, but here this mechanical heart valve is based on the assumption that the coagulation is inevitable, this mechanical heart valve is an anticoagulant drug and cleanup device for life.
(6) Leaflets internal surface contact flow stream,
As we know any contained fluid will form a boundary layer which contact solid wall, the boundary layer has zero velocity, so the velocity difference cause blood cell damage and pressure loss, more contact area between valve and blood fluid, more blood cell damage and more pressure loss. This invention mover a step further, in fact, the contact area at open position is smaller than the contact area in closed position, the leaflets 151,251,351,451 retreat the most part and cover most of internal surfaces of bodies 101,201,301,401, even better than human heart valve in terms of contact area.
(7) Valve body and leaflet as a integral part
Why we need mention this, because the nature of the human heart valve with the body and leaflet as a integral part dramatically improves the dynamitic performance of the heart valve, first there are no leakage and closing force between the valve body and leaflet, second most importantly, when the valve is closed, the impact energy among the leaflets is absorb by entire valve body or heart unlike conventional mechanical heart valve only the leaflet absorb the impact energy and it take much long time to reach stable condition. But with the impact/lock and contact/seal mechanism in this invention, mechanical heart valve can have the same performance as human heart valve, when the leaflet is approached to a close position, the lock boss and lock slot impact and lock together either with each other or with valve body, as we can find as the mass increase, the impact energy effect decrease, even the oscillation still exist for a while, because the leaflets lock with each other, there is no leakage or the cavitations.
(8) Seal only among the leaflets.
This invention provide a face to face seal for bi or triple leaflets mechanical heart valve and radial seal between the valve body and leaflets and no leaflet seal for one leaflet, all those seals has a similar sealibilty as the human heart valve does, especially the one leaflet mechanical heart valve has a better sealibilty.
(9) Shorter travel between open and closed positions
This invention provides one, two and three leaflet structures. In case of smaller size valve, the benefit with the triple leaflets structure is insignificant, in case of large size valve, this invention provide a reliable and simple triple leaflet mechanical heart valve.
(10) No hinge mechanism
The human valve has no hinge mechanism and eliminate all disadvantages of the hinge mechanism, such as fluid stagnation, hinge wearing out, blood cell damage, eccentricity which cause poor dynamic performance of the leaflet, but the hinge mechanism provide a simple rotation function. This invention provides mechanical heart valve with various improved hinge mechanisms to minimize the disadvantages of conventional hinge mechanisms. First the hinge mechanisms in valves 100,100a,100b 100d,100f,100h ,200,200a ,200c,200d ,200e,300300a, 400,400a are located on outward surfaces or as projection forms on the valve bodies to eliminate or reduce the fluid stagnation and blood cell damage. Second the full or partially cylindrical pin and hole engagements in 100, 100a,100b,100c,100d, 200,200a ,200b ,200c, 200d ,200e, 400,400a improve the concentricity and the dynamic performance of leaflet and reduce the hinge wearing. Third one hinge pivot axis feature in valves 100,100a,100b 100d,100f,100h,200d are provided with the highest dynamic performance and synchronization of the leaflet.
(11) Longevity
The invention provide the mechanical heart valve with a best fluid dynamics and optimized valve structure with less closing impact forces, so the life expediency can last about 20-40 years which is enough for most adult patients with only operation and quality life after the implanted
In terms of the weakness of human heart valve
This invention provides better structures to overcome the problem, no mechanical heart valves in this invention has this problem.
This invention provides the better fluid dynamic structure with the spherical shell leaflet having a small cross section which is normal to flow stream, it takes about ⅕ energy that human heart valve consumes.
This invention provides a better materials than human heart valve tissue in terms of resistance to diseases.
The present invention provides two novel rotary pressure porting mechanisms which are behind the mechanical heart valve in this invention. If the first successful mechanical heart valve with a caged ball valve, pioneered by Starr and Edwards was inspired by Williams's ball valve on U.S. Pat. No. 19,323 (1858), then this invention is an opposite example, the rotary pressure porting mechanisms on the mechanical heart valve are inspired by the process to mimic our human heart valve. For more then 100 years, the liner pressure porting mechanism plays a key role in our life as William did, but it's main disadvantage is obstruction of central flow stream, while the conventional rotary pressure porting mechanism with conventional hinge device came out with improvement of center flow stream, but it still blocks flow stream and is a size dependent mechanism, as size of the valves increase, so dose the torque to operate the valves, finally the actuation mechanism of the valve member is based on two opposite actuation sections, only the difference area on the two sections play a actuation role, as a result, the actuation mechanism wastes the space of the valve member and actuation energy. But those rotary pressure porting mechanisms in invention show three main advantages over prior arts beside the advantages mentioned in the mechanical heart valve as followings
(1) A design dependant mechanism. With the offset spherical mechanism, the operating torque is depend on the diameter of spherical the valve member, flow pressure and the offset between the center axis and the pivot axis, while the hybrid function mechanism is depend on the flow pressure and the area of actuation section of the valve member, so as the sizes of flow pipe or tubing increase, the size of valves based on those two pressure porting mechanisms are not necessary to increase, the offset or the selected actuation area can be decisive factors, as a result, the energy to actuate the valve members 151,251,351,451 is about ⅕ of the conventional mechanical heart valves consume (2) optimized actuation torque. The conventional pressure porting mechanisms have no way to control closing force or torque, so in most cases, the closing force either is so strong and damage the valve member or so weak and cause chatter With this invention, the closing force can be designed to close the valve member fast enough but not so strong that damage the valve member and cause chatter.(3) a quiet and soft closing. With valves 100, there is no slump closing while with 200, there is impact/lock and contact/seal mechanism, those features play a key in the fuel delivery systems, especially in liquid oxygen and hydrogen applications, any hard closing in a check valve, pressure relief valve or pressure regulator can case explosion, a real soft or no slum closing is critical requirement for such system, or medical devices used in a hospital environment, quiet closing is very important for the patient as well as doctors finally a quiet soft closing can prolong the valve life and reduce the noise and vibration. (4) Versatility. Above all those two rotary pressure porting mechanisms can be applied to a check valve or pressure relief valve or pressure regulator or the combination like valves 100f, 100g, those systems are much compact, reliable and efficient and are used in many fields like medical devices, commercial building or housing, HVAC, industrial process, food process, chemical plant oil and refinery, automotive, aerospace machine tools.
The present invention provides other long sought solution to the backflow problem on the mechanical heart valve. The native heart valve has also backflow problem, but the consequence of backflow is not as serious as in the mechanical heart valve, the difference is that a live tissue which has muscles and self repair functions while the mechanical heart valve is a lifeless device without muscles and self repair functions, so this valve is provided with backflow preventing system with three solutions, mechanical solution with watch spring 192 and magnetic for the highest reliability, the magnetic and mechanical solution with blocks 140 and 170 is the choice, for patient who has a pace maker, the mechanical solution is the choice with safety closure, so there is no possibility that the spring 192 falls into downstream.
The present invention provides various novel hinge mechanisms for different applications. The followings are the main advantages
(1) Simplicity. Most hinges mechanisms in this invention are provided with simple profiles or shape, cylindrical or flat or the combination on the hinge pins or hinge holes or the boss or slot.
(2) Less stagnation. The hinge mechanisms in valves 100,100a,100b 100d,100f,100h,200,200a,200c,200d,200e,300300a, 400,400a are located on outward surfaces or as projection forms on the valve bodies to eliminate or reduce the fluid stagnation and blood cell damage.
(3) High concentricity. The valves 100, 100a, 100b, 100c, 100d, 200,200a, 200b,200c, 200d ,200e ,400,400a are provided with the full or partially cylindrical pin and hole engagements to improve concentricity, synchronism of leaflets and the dynamic performance of leaflet and reduce the hinge wearing, vibration and noise., more importantly one hinge pivot axis features in valves 100,100a,100b 100d,100f,100h, 200d are provided with the highest dynamic performance and synchronization of the leaflets.
(4) Versatile. Most hinge mechanisms in this inventions are provided with other functions such as stopper, locking devices and backflow preventing devices, so the valve can be designed to much compact.
(5) Reliability
The reliable design features are presented through the entire invention. (a) Less moving part or any part. With one moving leaflet 151 in valve 100 and the alternative embodiments, the valves are more reliable than any mechanical heart valve with two or more part or moving parts (b)redundancy. With the dual redundant hinge mechanisms, beside hinge pin/ hinge slot, the spherical surface in the body/spherical surface in the leaflet is provided as a secondary rotation mechanism, so in case of wearing out of the hinge mechanism, the leaflet is still workable (c) inclusive designs. An inclusive designs includes a falling out proof and a loosing proof. The springs in 100h,100f,200g,200f,200h have losing proof design, while the setscrew in valve 200h and the spring in 300b have the falling proof design, in case of the screw or spring breaking down all those parts will not fall into the flow stream. The inclusive designs also can eliminate leakage path like the hinge device in valve 200h without any hinge hole through the body.
Provisional Patent Application Ser. No. 60/775,221 filed Feb. 21, 20006
| Number | Date | Country | |
|---|---|---|---|
| 60775221 | Feb 2006 | US |
