NORRED EXHIBIT 2140 - Page 1
`Medtronic, Inc., Medtronic Vascular, Inc.,
`& Medtronic Corevalve, LLC
`v. Troy R. Norred, M.D.
`Case IPR2014-00111
`
`

`

`the forces which are exerted from the ventricular 111yoc11rdium (Cardiovascular
`Research22 7 1988)(Jour11al of Biomcchanics33(6):653—658 2()0()June)
`111 11 similar fashionas the aortic /
`root this structure allow the valvular apparatur to open with the least amount of sti.ain
`
`The cmonary arteries arise within 01 above theQnus ofv}11salva. The blood flow ofthe heart
`occurs mostly when the ventricle relaxes At this 111116116 cusps of the aortic valve are closed and as
`mentioned the diastolic forces of the blood against the valve are dispersed along the valve 11nd adjacent
`sinus. The opening or ostia of the coronary arteries when located near the apex 11nd middle of the sinuses
`allows for the most laminar flow characteristics. This111 turn promotes the greates>amount of flow with the
`least amount of 1esistance ln disease statcsjwhere these relationships are lost it 1111s been proposed that
`this could lead to increase sticss at the corona1y ostia (The A01tic Valve CRC press).
`These integral relationshipinot only pertain to the gross anatomy of the valvular apparatus but
`alsothe microanatomvshewfihefiegmhmtumfflesemuettwes.JThe amount of elastinIS in a higher
`concentration as shown by staining methods (American Journal of Pathology 445 (7): 193.1). This allows a
`greater amount of dilatation of the structures in this area. Further, scanning electron micrographs have
`shown the unique arrangement of collagen in the valves which permit the unique reversal of curvature
`which is vital in the function of the valve (figure 6)( Anatomic Embryology 172(61): 1985). The fibers are
`unusually small and arranged in sheets with unique distances between each strand. In theory,this would
`give 11 greater amount of tensile strength while allowing continued flexibility. As always, nature 1111s
`selected the most efficient machinery, and we have only to discover the reasons why.
`
`11.
`
`Aortic Valve Dynamics and Physics
`
`The aortic valve is better understood in a dynamic state given it is not a static structure. To fully
`understand this structure it is integral to understand the opening and closing of the valve. the motion of the
`various parts? the design of the valve in vitro 11nd the hydrodynamics of the valve. The valve’s ultimate
`function is to allow fluid transfer from the ventricle to the systemic circulation.
`[11 order to do this
`effic1ently it minimi7cs shear stless resistance to flow and tensile for.ces
`The opening and closing of the aortic valve depends upon differential p1essures flow velocity
`characteristicsand as mentioned earlier Jthe unique anatomic relationship between the valves and the 1112»«1:31J11, 11
`@iirusesof»%1
`v11 One of the most compiehensivc studyeeneompassed a model developed by Bellhouse J
`et al.
`In this model,
`the flow of fluid through the aortic valve was studied by injecting dye within the flow
`of fluid.
`Some of the pertinent observations found within this model were as follows: 1) The valve opens
`rapidly, and as the leaflets move into the sinuses, vortices form between the leaflet and the sinus walls; 2)
`The flow enters the sinus at the sinus ridge, curls back along the sinus wall and leaflet and then back into
`the main stream; .3) During the end of systole the vorticcal motion created during contraction forces the
`valves back toward a closed position. These observations are 1111p01tant to show that absolute p1essure
`differences created between the aorta and ventricle are not the source of initial closure of the aortic valves.
`In fact,
`it would be detriminal to valve stress if these f01ces dictated closure of the aortic valve.
`F01
`example, if two objects are 11 greater distance apart and a set amount of force is applied to each, the greater
`distance would produce greater velocity and the momentum at impact would be greater. Therefore, if the
`leaflets are closed or near closure as contraction is coming to 1111 end then the force used for coaptation
`would be less. Less force per cycle equates to greater longevity of the valve.
`In conclusion, the cusps 11nd
`the relationship of closure for prosthetic valves must incorporate passive closure during systole which
`would logically lengthen the lifespan of any such device.
`To expand these concepts. the theory of laminar flow and 110w the native aortic valve
`accomplishes this must be developed. A laminar flow is predicted by 11 Reynolds number which
`incorporates the laws as described by Pouiselle and Bernoulli.
`111 generaL the lower the
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`NORRED EXHIBIT 2140 - Page 2
`NORRED EXHIBIT 2140 - Page 2
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