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 .
Information Disclosure Statement
An Information Disclosure Statement has not been filed as of the writing of this office action.
Specification
The disclosure is objected to because of the following informalities:
Pg. 2 ln 1-2 “Such that it can accelerate the process of bone reconstruction and reduce the time of post-injury reconstruction for patients” is an incomplete sentence. It appears that it is a fragment cut off from the preceding sentence (Pg. 1 ln 14-15)
In Pg. 10 ln 4, “…meaning there is no any hole in the specimen” should read “…there are no holes in the specimen”.
Appropriate correction is required.
35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, requires the specification to be written in “full, clear, concise, and exact terms.” The specification is replete with terms which are not clear, concise and exact. The specification should be revised carefully in order to comply with 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112. Examples of some unclear, inexact or verbose terms used in the specification are:
Pg. 4 ln 1 “100 to 200 degree”
Pg. 4 ln 11-12 “absolute temperature of 433 degree”
There are multiple instances in the specification beyond the ones cited above where a temperature value is stated without a corresponding temperature scale (OC, OF, K).
Claim Status
The status of claims 1-11 are pending examination.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1, ln. 9 recites the limitation “the plurality”. There is insufficient antecedent basis for this limitation in the claim. For the purpose of examination, claim 1, ln. 9 will be interpreted as adding more Mg-Zn-Zr alloy powder on the previously sintered layer.
Claims 2-11 are also rejected by virtue of their dependency on claim 1.
Claim 7, ln. 13 “at 100 to 200 degree” renders the claim indefinite. It is unclear as to what temperature units are used to define the range (OC or OF). Additionally, the limitation can be read as setting a relative angle of the substrate rather than the substrate temperature. For the purpose of examination, claim 7 will be interpreted as setting the substrate to a temperature between 100OC and 200OC.
Regarding claims 8-10, it is unclear as to how the steps in the outlined heat treatment procedure relate to one another. For example, claim 8 is quoted below:
The method of producing medical implants adopting additive manufacturing of claim 1, wherein the method further comprises:
putting the medical implant in a furnace for 1.5 hours;
heating the medical implant to an absolute temperature of 583 degrees, and
maintaining it for 2 hours;
quenching the medical implant to room temperature
The heat treatment procedure, as claimed, is unclear on how the initial 1.5 hours the medical implant is in the furnace relates to heating the implant to the claimed temperature. To elaborate, it is unclear whether the initial claimed time is concurrent to the heating step or independent of the heating step. It is also unclear whether the two hours includes the previously claimed 1.5 hours or is occurring after the implant has reached the claimed temperature. Is the furnace at room temperature during these 1.5 hours or at a different temperature? In total, claim 8 is indefinite due to the wording of the outlined procedure.
Claims 9 and 10 are also indefinite for the same issues discussed in claim 8. For the purpose of examination, the claims will be interpreted as if the initial claimed times in the furnace are used to heat the implant to the claimed temperature. They will also be interpreted as if the second maintaining time occurs after the implant reaches the claimed temperature.
Additionally, claim 8, ln. 1, “an absolute temperature of 583 degrees” renders the claim indefinite. It is unclear what temperature scale should be used. The term “absolute” implies that the claimed temperature scale should be interpreted as K, while the presence of the word “degree” after the claimed value implies that the temperature scale should be interpreted as either OC or OF. Therefore, the metes and bounds of claim 8 are not properly defined.
Since claims 9 and 10 also use the same wording to define claimed temperatures (Claim 9, ln. 7; Claim 10, ln. 13; Claim 10, ln. 1), they are also rendered indefinite. For the purpose of examination, the temperatures outlined in claims 8-10 will be interpreted as 583K and 433K, or equivalently, 210OC and 160OC.
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 1 -7 are rejected under 35 U.S.C. 103 as being unpatentable over Sutcliffe (US 2015/0135897 A1) in view of Läheenkorva (EP 4 023 263 A1).
Regarding Claim 1, Sutcliffe teaches
a method of manufacturing products utilizing additive manufacturing, specifically via selective laser melting (SLM) or selective laser sintering (SLS) ( [0092] & Clm. 2), where it teaches powder layer deposition on a substrate [0056].
A laser is used to selectively melt or sinter the powder (Clm. 2)
within a specified power range (Clm. 15).
The process is taught as a layer-by-layer basis, where subsequent powder layers are distributed and sintered on a previously sintered layer [0003], [0056]
until an article is manufactured.
Sutcliffe fails to teach that the powder used for the method comprises a Mg-Zn-Zr alloy. However, Sutcliffe discloses that the outlined method can be used to manufacture components for use in the medical industry [0092].
Läheenkorva teaches a medical implant made of an Mg-Zn-Zr alloy (Läheenkorva claims 1 and 2). Additionally, they disclose that the implant can be made with additive manufacturing, particularly using SLS [0017], [0074].
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Sutcliffe’s method with the Mg-Zn-Zr alloy powder of Läheenkorva because the alloy powder is a beneficial biodegradable alloy powder for medical implants that exhibits high mechanical strength and low corrosion [0007]. Furthermore, the combination teaches one of ordinary skill how to make Läheenkorva’s biocompatible medical implant via the SLS process of Sutcliffe [0007]-[0017].
Regarding Claim 2, Sutcliffe teaches an average particle size of up to 100 μm (Sutcliffe claim 19), which reads on the claimed powder diameter of 50 – 100 μm. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Regarding Claim 3, Sutcliffe teaches laser beam moving speeds up to 400mm/s and between 400 mm/s to 600 mm/s ([0016], Figs. 3 & 4), which reads on the claimed beam speed of 200 – 800 mm/s. Sutcliffe also teaches laser powers up to 200 W (Clm. 15), which reads on the claimed beam power of 90 - 130 W. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Regarding Claim 4, Sutcliffe discloses a beam spot diameter of up to 100 μm [0033], which reads on the claimed diameter of 50 – 100 μm. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Regarding Claim 5, it is claimed that the composition of the Mg-Zn-Zr alloy powder does not exceed 5 wt% Zn, and does not exceed 0.5 wt% Zr.
As previously discussed, Sutcliffe fails to teach that the powder used in his claimed method comprises a Mg-Zn-Zr alloy.
However, Läheenkorva teaches an implant comprising a biodegradable magnesium alloy with an overlapping composition comprising of (Clm. 1):
Zn in the range of 0.5-6 wt%,
Zr in the range of 100-900 ppm,
and a balance in Mg.
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Regarding Claim 6, Sutcliffe teaches a thickness up to 100 μm (Clm. 18), which reads on the claimed powder layer thickness of 50 – 100 μm. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Regarding Claim 7, Sutcliffe teaches that the substrate of the specimens was heated to 180OC during laser processing [0062], which reads on the claimed substrate temperature of 100 - 200OC. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Claims 8-10 are rejected under 35 U.S.C. 103 as being unpatentable over Sutcliffe (US 2015/0135897 A1) in view of Läheenkorva (EP 4 023 263 A1) as applied to claim 1 above, and in further view of Wu (CN 110681869 A, using US 2024/0123499 A1 for citation).
When examining the claims, it is noted that a person having ordinary skill in the art knows that:
The heat treatment step in claim 8 is analogous to a T4 temper, where the alloy is heated above the solvus temperature to dissolve MgZn precipitates within the αMg-phase, and then quenched.
The heat treatment step in claim 9 is analogous to a T5 temper, where the alloy is artificially aged at a temperature below the solvus temperature of MgZn precipitates in the αMg-phase, and then quenched or air-cooled.
The heat treatment step in claim 10 is analogous to a T6 temper, which is composed of the T4 temper and T6 temper in sequence.
This interpretation is further reinforced in the specification of the instant invention, where the treatments outlined in claims 8, 9, and 10 are labeled as T4, T5, and T6, respectively (pg. 11-13 and Tables 1-2).
Regarding Claim 8, where the claimed method further comprises putting the medical implant in a furnace for 1.5 hours, heating it to a temperature of 583K (310OC), maintaining the temperature for 2 hours, and quenching it to room temperature; neither Sutcliffe nor Läheenkorva teach a heat treatment step.
Wu teaches a method for producing an alloy with a Mg-Zn-Zr composition using additive manufacturing (specifically selective laser melting). Wu also teaches a heat treatment step after the manufacture of the alloy with the purpose of enhancing mechanical properties. The taught heat treatment either comprises an artificial aging step (a T5 temper) or a combination of a solution treatment step (a T4 temper) and an artificial aging step to constitute a T6 temper (Clm. 1 and [0014], [0045-0046]).
Wu teaches a method for manufacturing a Mg-Zn-Zr alloy with the further limitation that the solution treatment is done for 0.25-2 hours at a temperature between 450OC and 520OC. (Clm. 9). Wu also teaches quenching the alloy afterwards in cold water to 20OC in the description [0045]. While Wu’s claimed times overlaps with the instant claim, the temperature ranges do not.
It is noted that Wu is silent on the time needed to raise an alloy to temperature for the above heat treatments. However, a person having ordinary skill in the art knows that the mechanism of the discussed temper occurs during the time at the peak temperature, and that the time to reach temperature has no further impact on the tempering.
It is well known in the art to look at the Mg-Zn phase diagram when evaluating the temperatures for a T4 temper for the taught alloy compositions. For the taught compositions, both the instantly claimed temperature and the temperature range claimed by Wu bring the implant/alloy above the solvus temperature. That is, both temperature ranges dissolve the MgZn precipitates as required for a T4 temper. It would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to substitute the higher temperature ranges of Wu with the claimed 310OC temperature for the same taught times and reasonably expect the same outcome of an T4 tempered alloy/implant. Claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result, which is different in kind and not merely in degree from the results of the prior art. See MPEP 2144.05.
Therefore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to combine the method of Sutcliffe and the alloy composition of Läheenkorva with the heat treatment step of Wu to produce a Mg-Zn-Zr medical implant with enhanced mechanical properties like high strength and high toughness (Abstract). Furthermore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to make the substitutions discussed above and reasonably expect the same outcome of an T4 tempered alloy/implant.
Regarding Claim 9, where the claimed method further comprises putting the medical implant in a furnace for 1 hour, heating it to a temperature of 433K (160OC), maintaining the temperature for 24 hours, and air cooling to room temperature; neither Sutcliffe nor Läheenkorva teach a heat treatment step.
Wu claims a method for manufacturing a Mg-Zn-Zr alloy as discussed in claim 8, with the further limitation that the artificial aging treatment (a T5 temper) is done for 0-512 hours at a temperature between 175OC and 225OC. (Clm. 10). Wu also teaches quenching the alloy afterwards in cold water to 20OC in the description (Wu paragraph 46).
It is noted that Wu is silent on the time needed to raise an alloy to temperature for the above heat treatments. However, a person having ordinary skill in the art knows that the mechanism of the discussed temper occurs during the time at the peak temperature, and that the time to reach temperature has no further impact on the tempering.
While Wu teaches quenching the alloy rather than air-cooling, a person having ordinary skill in the art knows that quenching post treatment is an obvious variation of the T5 temper. Therefore, it would be obvious to one of ordinary skill to substitute quenching with air cooling reasonably expect the same outcome of an alloy/implant with enhanced mechanical properties.
The temperature range taught in Wu is close enough to the limitations set forth in the instant claim that that one of ordinary skill in the art would recognize that, upon looking at the Mg-Zn phase diagram for the taught concentrations, a person having ordinary skill in the art can reasonably expect the two temperatures to have the same outcome of improved mechanical properties in a T5 tempered alloy/implant. Therefore, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. See MPEP 2144.05.
Therefore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to combine the method of Sutcliffe and the alloy composition of Läheenkorva with the heat treatment step of Wu to produce a Mg-Zn-Zr medical implant with enhanced mechanical properties like high strength and high toughness (Abstract). Furthermore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to make the substitutions discussed above and reasonably expect the same outcome of an T5 tempered alloy/implant.
Regarding Claim 10, where the claimed method further comprises putting the medical implant in a furnace for 1.5 hours, heating it to a temperature of 583K (310OC), maintaining the temperature for 2 hours, quenching it to room temperature, putting it back in a furnace for 1 hour, heating it to a temperature of 433K (160OC), maintaining the temperature for 24 hours, and air cooling to room temperature; neither Sutcliffe nor Läheenkorva teach a heat treatment step.
Wu claims a method for manufacturing a Mg-Zn-Zr alloy as discussed in claim 8, with the further limitation that the solution treatment (a T4 temper) is done for 0.25-2 hours at a temperature between 450OC and 520OC. Wu then claims a method for manufacturing a Mg-Zn-Zr alloy as discussed in claim 8, with the further limitation that the artificial aging treatment (a T5 temper) is done for 0-512 hours at a temperature between 175OC and 225OC. (Clm. 10). Wu also teaches quenching the alloy in cold water after the T5 and T6 steps [0045],[0046].
For the T4 temper step, claim 10 has the same issues as claim 8. For the T5 temper step, claim 10 has the same issues as claim 9. Together, a prima facie case of obviousness exists. Claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result, which is different in kind and not merely in degree from the results of the prior art. See MPEP 2144.05.
Therefore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to combine the method of Sutcliffe and the alloy composition of Läheenkorva with the heat treatment step of Wu to produce a Mg-Zn-Zr medical implant with enhanced mechanical properties like high strength and high toughness (Abstract). Furthermore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to make the substitutions discussed in claims 8 and 9 and reasonably expect the same outcome of an T6 tempered alloy/implant.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Sutcliffe (US 2015/0135897 A1) in view of Läheenkorva (EP 4 023 263 A1) as applied to claim 1 above, and in further view of Zhai (“Fluoride Coatings on Magnesium Alloy Implants”).
Neither Sutcliffe or Läheenkorva teach HF immersion of the produced medical implant. However, Läheenkorva teaches the Mg-Zn-Zr implant may comprise a coating that lowers the corrosion rate of biodegradable Mg alloys [0104]. It also teaches that the coating can be produced via conversion coating ([0104] ln 44-48). In this case, conversion coating is interpreted as any method that creates a coating on the surface of the object via a chemical reaction.
Zhai teaches that Immersion fluorination is a popular technique for producing corrosion-resistant coatings comprising MgF2 in Mg-alloy medical implants, and is traditionally done by simply immersing the implants in certain concentrations of HF solution for certain times (pg. 3, §3.2 “Immersion Fluorination”).
Zhai also includes a table of coating thicknesses produced on Mg alloys via HF immersion (Zhai Table 1), along with associated immersion times and HF concentrations. While the table does not list any alloys that correspond to a Mg-Zn-Zr composition, a person having ordinary skill in the art would know that the primary chemical reactions responsible for creating the coating (reactions (1)-(10)) are the same for both the listed alloys and Mg-Zn-Zr alloys.
In addition, entries within the table are near the instantly claimed HF solution concentrations, immersion times, and layer thicknesses. Zhai further discloses an approximately linear relationship between the coating layer thicknesses and fluorination times corresponding to the instantly claimed immersion times and for different HF concentrations (Fig. 2). Zhai also elaborates on the exact relationship between the coating layer thickness and HF concentration (pgs. 4-5, §3.2 “Immersion Fluorination”). In all, the tabulated concentrations, times, and coating thicknesses in Zhai are close enough to the limitations set forth in the instant claim that it would be obvious to one of ordinary skill in the art that, based on the underlying scientific theory, immersing a Mg-Zn-Zr implant in 42% HF for 24 hours will yield a coating with a thickness near range of values taught by Zhai. Therefore, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. See MPEP 2144.05.
Therefore, it would be obvious for a person having ordinary skill in the art before the effectively filed date of the claimed invention to combine the teachings of Sutcliffe and Läheenkorva with the HF treatment taught by Zhai to create a coating on the surface of the medical implant and improve the corrosion resistance of the magnesium alloy.
Related Art
Papenberg (“Mg-Alloys for Forging Applications – A Review”)
Papenberg discloses a Mg-Mn phase diagram for alloys with a composition between 0-10 wt% Zn (Papenberg Fig. 21).
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Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAVIER FLORES whose telephone number is (571)272-9130. The examiner can normally be reached Mon-Fri 9:30AM-6:00PM.
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/J.F./Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735