DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 2,11-13, 18, 21, 24, 26, 27 and 33-40 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 27 recites the following elements which does not appear to have support in the original disclosure:
fiber has wall thickness of about 20-40 microns
fiber has an outside diameter of 200 µm to 300 µm
an albumin sieving coefficient of less than 0.01
first selective layer along the outer surface and second selective layer along the inner surface
However, applicant’s disclosure has no data points or embodiments that support all these requirements.
The disclosure defines the OD as: “A basic dimensional parameter of interest is the outside diameter of the fiber, because a dialysis fiber should have an outside diameter of about 200 to 300 microns” in [00106.] The OD and the thickness range are described as “200 to 300 microns” and “20-40 microns,” respectively, in [0066.] None of the examples meet the wall thickness, even though F1, F2 and F16 can be considered as meeting because they are only slightly above the “about 40 micron” upper limit.
Albumin sieving coefficient is met only by F3, which does not meet the OD and wall thickness requirements. In fact, F3 is disclosed as undesirable in [00107]: “A fiber outside diameter of >350 microns is undesirable for present applications.” Only F1 and F2 have dense inner and outer layer. The fibers that meet the OD requirement are F10 to F13, which have no other data, but listed as inferior for morphology in Table 2, which also would not meet claim 33 requirements.
Therefore, it appears that applicant did not have possession of the invention claimed in claim 27 at the time of filing this application.
Applicant has not appropriately addressed this rejection in the response filed 6/12/26.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 2, 11-13, 18, 21, 24, 26, 27 and 33-40 are rejected under 35 U.S.C. 103 as being unpatentable over Ying et al (US 9,352,283) in view of Lahib et al (US 10, 369,263) and Xu et al, “Polyethersulfone (PES) hollow fiber ultrafiltration membranes prepared by PES/non-solvent/NMP solution,” Journal of Membrane Science 233 (2004) 101·· 111, and with further evidence from applicant’s own admission of prior arts.
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Independent Claim 27 recites a dialyzer cartridge having a microporous asymmetric hollow fiber membrane made of PS and PVP with skin layer on the outside to aid filtration outside-in. The claim also recites an inner selective layer, which is different in pore size/distribution or thickness compared to the outer selective layer (claim 37.) The hollow fiber is characterized by its albumin sieving coefficient, at “less than approximately 0.01,” water permeability at least approximately 6 mL/(h.mmHg.m2), and presence of elongated macrovoids. Claim 27 also recites the dimensions of the hollow fiber, and details of the cartridge.
Cartridge details are depicted in fig. 2 of Ying, which are self-explanatory. Cartridge 200 has hollow fiber 208 terminating in the end barriers 206. Housing 202, with inlet and outlet 212. Lumen inlet and outlet 210. First and second plenums 204.
Ying, Col. 9, lines 8-15 shows that the blood is circulated through the shell-side of the hollow fiber cartridge, that is blood flowing between the outside of the hollo fibers inside the housing wall.
Ying teaches such the membrane details claimed: see the figures 4A-C, abstract, and example 1A. The membrane has outside skin layer (col. 16, lines 25-30), macrovoids are clearly visible in the figures. Albumin sieving coefficient is seen in Table II, which is significantly below the range of “less than approximately 0.01,” with two data points actually <<0.01. Compare this to applicant’s Table 4, which shows a wide berth for the term “approximate”.
Regarding the inner and the outer skin layers, see figures 4A-5D of Ying.
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They show the hollow fiber as having inner and outer skin layers separated by the middle finger-link macrovoids layer. Since the outer skin layer is controlling, the inner skin layer must have larger pores as in claim 37.
Ying teaches the actual water permeability in Fig. 8. Using Fig. 8, and harvesting the data for the sample cartridge, vise, 10 fibers, 11 mm long, and 780 micron OD from the different locations in Ying, the calculated flux is >> than the 6mL/(h.mmHg.m2.). Since Ying’s is a similar membrane (hollow fiber made of PS and PVP, with similar characteristics,) inherently, the water permeability would also be in the range claimed. Evidence that such membranes would have water permeability and albumin sieving coefficient in the claimed range is readily seen in the Xu reference – see table 5. The fibers include external skinned membranes in examples 1W-6W. Applicant also admits in the specification at [0045] - [0052] that similar membranes (citing Gorsuch) have high flux.
Ying teaches thickness and diameter close to the claimed ranges: see example 1A, col. 16, lines 5-8. OD at 330 micron is close to the 200-300 micron range claimed, and thickness at 45 micron would fall withing the range ‘about 20-40 microns.’. Additionally, this reference in the same example teaches different diameters and thickness, which indicate that the thickness and diameter are not critical. Applicant also admits in the specification by citing references that the thickness and diameters are known in the art (for example, see the cited reference in [0043], Krause et al US 8,596,467, example 3.)
Applicant’s disclosure in Table 2 also has significant variation in the fiber diameter, and only one data point (F3) has BSA sieving coefficient <0.01, which does not meet the diameter and thickness, whereas only (F6) actually falls within the claimed range for thickness, showing lack of any criticality.
Dependent claims 2 and 36, macrovoids: these claims recite structure and approximate dimension ranges of the macrovoids. Finger-shaped macrovoids are commonly present in such asymmetric membranes, as taught by Ying (figures) as well as Xu. Macrovoids open into the lumen in some of the Ying membranes (see figures) while some other membranes have a lumen skin layer with specific pore sizes, like 0.5-3 microns. Macrovoids are commonly known, and known to make the membrane structurally weak, but it is difficult to find a reference that actually quantifies the dimensions of such macrovoids. The office is also not equipped to figure out the dimensions of the macrovoids from such references. The claimed dimensions are broad, and do not appear to be critical. Applicant does not show any particular reason why they are beneficial, when reference membrane structures that do not teach such voids perform equally well or better (applicant’s specification at [0045]). Therefore, they are unpatentable unless otherwise shown.
Claim 11-13 recite thickness, pore size, molecular weight cut-off and surface roughness of the selective layer. Ying teaches pore size at less than 7 nm (abstract, claims), lumen layer at 0.5-3 micron pores, molecular weight cut-off at 60 or 70KDa (col. 9 line 15: see also albumin sieving coefficient that matches this.) Ying is silent on the selective layer thickness, but the outer layer appears to be in a similar range of thickness in fig. 4B. Applicant also discloses in [0136] significant variation in this thickness with no attributable controlling variable.
Claims 18, 24, 27, 35 are directed at the composition of the polymers in the hollow fiber. All the cited references teach the same. Ying teaches the compositions in Table 1. Regarding the derivative of polysulfone in claim 25, applicant’s own admission in [0053] that it is known.
Claim 26 recites sieving coefficient of beta-2-microglobulin at least approx. 0.7: while the references do not have this data, this value would have been an inherent property of the membrane, based on other characteristics like albumin sieving coefficient, and molecular weight cut-off.
Claim 33: surface roughness is disclosed as related to the surface pore size, which is the same in Yin as that of applicants’. Yin also inherently would have the same hydrophilicity or contact angle as that of applicant’s because of PVP, which is in fact more in the Yin membrane (higher concentration in the dope). Regarding thickness of the skin layer, this also would have been inherently the same since the membrane is made similarly. See example 1A: there is no air gap and the dope is extruded directly into the coagulation bath, compared to applicant’s 6 mm air gap with “shower,” which, the examiner believes, assures a very thin external skin layer external. Compare with example 1B, the standard procedure, which produced smooth internal (lumen) skin with nm sized pores. The Xu reference also provides evidence to that fact.
Claim 34: housing structure is the same in Yin in view of Lahib.
Claims 38 and 39: Outer selective layer pore size is inherent – albumin screening coefficient depends on pore size. Inner pore size is not critical since the outer pore size controls, but also would have been inherently the same, same membrane in the reference.
Claim 40: Regarding the cross-sectional areas between the blood inlet/outlet vs. that of the mid-section (which Yin does not teach) in Fig.2, see Lahib, fig. 5B, which applicant incorporates by reference in spec. at [0029]. This design is also very common as seen from the references applicant submitted in an IDS.) Applicant thus uses an existing design, already known, and thus this element of the claims is not patentable. With respect to figure 5B, Lahib teaches that the cartridges are designed to have demonstrated … long service lives which are helpful for flow geometry (col. 12, lines 11-16,) and blood can flow at least partially traversely [sic] (col. 12 lines 35-40.) Therefore, it would have been obvious to one of ordinary skill to use the teaching of Lahib in the teaching of Yin to have the improved flow geometry.
Claims 2, 11-13, 18, 21, 24, 26, 27 and 33-40 are rejected under 35 U.S.C. 103 as being unpatentable over, Lahib et al (US 10, 369,263), with added evidence from Yin as cited in rejection 1 and applicant’s own admission of prior arts.
Lahib has a prior publication date of 2015 (PGPUB) [underlined for emphasis], and is therefore a 102(a1) reference.
As seen in this fig. 5B, teaching of the cartridge with all its details as claimed is clearly seen. This picture is the same as applicant’s fig. 2d, and this reference is incorporated by reference in spec. at [0029.] This also anticipates claim 34.
Regarding the details of the hollow fiber, materials are PES and PVP (col. 4 lines 61-67.) (This is also as in claim 16.) For dimensions, see col. 16, lines 12-15 and col. 33 lines 6-12, which meet the claimed ranges. Pore diameters of 2-7 nm and mol. Wt cut off at 50,000D, shows that the albumin sieving coefficient of less than 0.01 would be inherent (MPEP 2112). See also col. 4 lines 37-42: “retaining … especially albumin.” Water permeability – see UF coefficient of 5-100 ml.hr/m2/mmHg, which means the water permeability will be more than 6 as claimed and the exterior surface is hemocompatible – col. 14, lines 57-67. (Compare with applicant’s table 2, which has KUf at twice the permeability, whereas Lahib teaches KUf the same as permeability – compare the units.)
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Regarding the inner selective layer: since Lahib teaches the same membrane as that of applicant’s, this would have been inherent. Also see rejection 1 above regarding this limitation, which is incorporated herein. The same is true with the macrovoids in claim 36.
Claims 11 and 33: selective layer thickness and surface roughness in Lahib would be inherently the same as claimed because the same membrane is used, with the same hemocompatible (unspecified by applicant) coating. Lahib also teaches that smoothness is consistent with general filtration practice (col. 15, lines 51-55) and is a result of the choices of formulations, etc. (col. 16, lines 40-48.) See also applicant’s [0052] describing that the selective layer thickness of 0.5 micron is known in the art.
Claims 2 and 36: the membrane in Lahib appears the same as that of applicant’s. Therefore, these structural details also will be the same, and are common in asymmetric membranes. See also rejection 1 in this regard.
Claims 12 and 13: pore size and mol. Wt. cut-off already shown in claim 27 above.
Claims 18, 21, 35, 38, 39: PES/PVP ratio – while Lahib does not teach the actual ratio, it can be optimized as taught in col. 16, lines 35-47. Other details are inherent – same type of membrane. Also, this is a process limitation since most of the PVP will be eluted (not retained) from the membrane during formation.
Claim 24: added polyethylene glycol – see col. 28, lines 43-55.
Claim 26: Please also see rejection 1 which details the teaching of Yin and other secondary references, for the PES-PVP hollow fiber membrane with outside-in blood flow. The characteristics of this type of membrane are inherent, if not expressly stated in the references.
Claims 40: Lahib membrane is same as or similar to that of applicants – see the figure.
Response to Arguments
Applicant's arguments filed 6/12/26 have been fully considered but they are not persuasive. They are addressed in the rejection and in the prior actions. It is noted that applicant has not made any significant amendments to the claims. The argued improvements in flux and albumin screening coefficient is not evident in the disclosure. Arguments citing the Saito reference does not seem to have any relevance to the claims or the rejection. Claims are for a dialyzer cartridge, which is a hollow fiber membrane. “Dialyzer” signifies only an intended use. Ying teaches a hollow fiber membrane which meets the claimed invention.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KRISHNAN S MENON whose telephone number is (571)272-1143. The examiner can normally be reached Flexible, but generally Monday-Friday: 8:00AM-4:30PM.
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/KRISHNAN S MENON/ Primary Examiner, Art Unit 1777
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