Prosecution Insights
Last updated: July 17, 2026
Application No. 18/234,026

ULTRASONIC BARRIER CHAMBER FOR FLUID SYSTEMS

Non-Final OA §103
Filed
Aug 15, 2023
Examiner
LE, QUYNH DAO
Art Unit
3781
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Fresenius SE & Co. KGaA
OA Round
2 (Non-Final)
34%
Grant Probability
At Risk
2-3
OA Rounds
6m
Est. Remaining
40%
With Interview

Examiner Intelligence

Grants only 34% of cases
34%
Career Allowance Rate
15 granted / 44 resolved
-35.9% vs TC avg
Moderate +5% lift
Without
With
+5.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
27 currently pending
Career history
83
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
96.2%
+56.2% vs TC avg
§102
1.7%
-38.3% vs TC avg
§112
1.3%
-38.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 44 resolved cases

Office Action

§103
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 The information disclosure statement (IDS) submitted on 08/23/2023 and 12/06/2024 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Response to Arguments Applicant’s arguments filed 12/16/2025, with respect to the rejection(s) of claim(s) 1 and claim 20 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made. See rejection of claims below. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-4, 6, 7, 9-15, and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Boag et al. US 3,964,479 A (hereinafter Boag) in view of Yuds et al. US 2019/0358388 A1 (hereinafter Yuds). Regarding claim 1, Boag discloses a device 8 (Fig. 1 – device 8) for monitoring an extracorporeal circuit (Fig. 1 demonstrates an extracorporeal blood circulation) in which a blood pump 6 (Fig. 1 – pumping means 6) is disposed to convey blood (Col. 2, line 41-42 – “6 represents pumping means in the system for pumping the patient's blood therethrough”), the device 8 (Fig. 1) comprising: vent 22 (Fig. 1 – air passage tube 22) of a drip chamber 12 (Fig. 3 – drip chamber 12) of the extracorporeal circuit (Fig. 1). However, Boag does not disclose one or more ultrasonic transducer positioned in a predetermined vicinity of a vent; a controller coupled to the one or more ultrasonic transducers, the controller configured to cause the one or more ultrasonic transducers to emit ultrasonic signals that displace particles in contents of the drip chamber away from the vent. Yuds, in the same field of endeavor of dialysis treatment (Abstract), teaches one ultrasonic transducer 702 (Fig. 7 – transducer/ultrasonic head 702). Yuds, in another embodiment, teaches a controller 12 (Fig. 1 – hemodialysis system 12) coupled to the one ultrasonic transducer (Par. 48 – “the hemodialysis machine 12 may control an ultrasonic head”), the controller 12 (Fig. 1) configured to cause the one ultrasonic transducer to emit ultrasonic signals (Par. 48 – “the hemodialysis machine 12 may control an ultrasonic head, generating sounds waves…”) that displace particles in contents of the chamber (Par. 48 – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”, and Par. 50 – “Breaking up clots using the ultrasonic head”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of Boag to further incorporate an ultrasonic transducer coupled to a controller as taught by Yuds, in order to break up clots in blood flowing through the chamber (Par. 41 of Yuds), in this instant case, through the drip chamber of Boag. Since the ultrasonic transducer of Yuds can be arranged below the drip chamber (Par. 30 and Par. 27 of Yuds), the incorporated ultrasonic transducer 702 of Boag in view of Yuds will also be below the drip chamber 12 of Boag, thus the transducer 702 will indeed be “positioned in a predetermined vicinity of the vent of drip chamber”. Furthermore, one of ordinary skill in the art would have had the technological capability to recognize that the broken-up blood clots within the drip chamber of Boag in view of Yuds should return to the patient as it is well-known in the field that extracorporeal blood treatment withdraws and return treated blood. Therefore, the “displaced particles” after the actuation of ultrasonic signals in the drip chamber 12 of Boag will be away from the vent 22 of Boag. Thus, the limitation of “away from the vent” is met. Regarding claim 2, Boag in view of Yuds discloses the invention of claim 1. Boag in view of Yuds further discloses wherein the controller 12 (Fig. 1 of Yuds) causes the one ultrasonic transducer 702 (Fig. 7 of Yuds) to emit the ultrasonic signals of a predetermined frequency (Par. 48 of Yuds – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”), the predetermine frequency configured to displace the particles (Par. 48 of Yuds – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”, and Par. 50 – “Breaking up clots using the ultrasonic head”). However, Boag in view of Yuds does not currently disclose particles larger than a predetermined size. Examiner notes that in Par. 39, Yuds discusses that an ultrasonic head is provided in some embodiments for breaking up clots or blasticing clotting masses before they reach a critical size; thus indicating that there are some level of monitoring the size of the clumps within a chamber. Par. 29 of Yuds also discusses that clotting causes the blood cells 304 (Fig. 3) to vibrate more slowly and will therefore have a higher amplitude of reflected light compared to blood cells 304 that are not clotting. For example, section 316 when illuminated by the light source 312 will have a lower amplitude of reflected light compared to section 318. On this basis, the clotting of section 318 will be blasted with ultrasonic energy, while the non-clotting section 316 will not because section 316 is monitored to not be at a predetermined size for ultrasonic treatment. Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have had the technological capability to recognize that that the ultrasonic transducer of Boag in view of Yuds will only perform ultrasonic treatment to particles larger than a predetermined size, also as taught by Yuds. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP 2143.A.). Regarding claim 3, Boag in view of Yuds discloses the invention of claim 2. Boag in view of Yuds further discloses wherein the particles that are larger than the predetermined size (Par. 50 of Yuds – clots versus red blood cells) cause condensation (Par. 50 of Yuds - clots) on the vent 22 (Fig. 1 of Boag). Examiner notes that once the modification is made as discussed in claim 1 and 2, the particles that are blood clots of Yuds will be displaced away from vent 22 of Boag since the blood clots will cause blockage on the vent 22 of Boag. Thus, the limitation is met. Regarding claim 4, Boag in view of Yuds discloses the invention of claim 2. Boag in view of Yuds further discloses wherein the particles (Par. 50 of Yuds – clots) that are displaced by the ultrasonic transducer 702 (Fig. 7 of Yuds) comprise red blood cells (Par. 50 of Yuds – “…red blood cells such that they cannot form clots…”; thus clots are formed of red blood cells). Regarding claim 6, Boag in view of Yuds discloses the invention of claim 1. Boag in view of Yuds further discloses further comprising a pore size (Fig. 1 of Boag depicts a filter 60, wherein Col. 4, line 47-56 of Boag discusses a pore size of said filter – “a hydrophobic filter 60 is included... Hydrophobic filter materials are well known and easily available in the market, an example being that currently being marketed under the trademark "Acropor" by the Gelman Instrument Company of Ann Arbor, Michigan, Acropor being a microporous hydrophobic organic polymer membrane filter of about 0.45 microns pore size”; Examiner does note that that this pore size is not positively claimed within claim 6 and is currently interpreted to be a functional language limitation) of the drip chamber 12 (Fig. 1 of Boag). However, Boag in view of Yuds currently does not disclose further comprising one or more sensors to monitor a pore size of the drip chamber. Yuds, in the same field of endeavor of dialysis treatment (Abstract) and in another embodiment, teaches one sensor 602 (Fig. 6 – optical sensor assembly 602) to monitor clots or masses of red blood cells of a certain size (Par. 40 – “the ultrasonic head can be used to locally detect clots or masses of red blood cells between 20 μm and 100 μm at a lower frequency, e.g., at 50 MHz,”, wherein an ultrasonic head is a part of the optical sensor assembly 602 as discussed in Par. 38). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of Boag in view of Yuds to further include a sensor, also as taught by Yuds, in order to monitor the particles size (Par. 40 of Yuds). Examiner contends that since said sensor of Yuds is capable of monitoring particle sizes of the drip chamber shown in Fig. 6 of Yuds (consistent system layout of Applicant’s Fig. 2), the sensor 602 of Yuds is highly capable of monitoring the pore size of Boag’s drip chamber 12. Thus, the limitation is met. Regarding claim 7, Boag in view of Yuds discloses the invention of claim 6. Boag in view of Yuds further discloses wherein the one sensor 602 (Fig. 6 of Yuds) comprise a second set of ultrasonic transducers (Par. 38 of Yuds – “an optical sensor assembly 602 with a fiber-optic sensor and an ultrasonic or piezoelectric head… Ultrasonic heads that can be used include high frequency transducers”), the second set of ultrasonic transducers (Par. 38 of Yuds) to emit ultrasonic signals of a second predetermined frequency (Par. 40 of Yuds – “the ultrasonic head can be used to locally detect clots or masses of red blood cells between 20 μm and 100 μm at a lower frequency, e.g., at 50 MHz”). Examiner notes that once the modification is made as discussed in claim 6, the optical sensor assembly of Yuds will be incorporated into the device of Boag in view of Yuds, including the second operating frequency. Thus, the limitation is met. However, Boag in view of Yuds does not currently disclose wherein the controller is coupled with the second set of ultrasonic transducers, the controller configured to cause the second set of ultrasonic transducers to emit ultrasonic signals. Since it has been established in the modification of claim 1 that the controller 12 of Yuds will be coupled to the ultrasonic transducer, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of Boag in view of Yuds to further have the second set of ultrasonic transducer coupled to the controller of Boag in view of Yuds, as Yuds already demonstrates that the controller 12 provides signals to instruct ultrasonic transducer to emit signals. Thus, the limitation is met. Regarding claim 9, Boag in view of Yuds discloses the invention of claim 2. Boag in view of Yuds further discloses wherein the one ultrasonic transducer 702 (Fig. 7 of Yuds) is a first set of ultrasonic transducers 702 (Fig. 7 of Yuds), the predetermined frequency (Par. 48 of Yuds – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”) is a first predetermined frequency (Par. 40 of Yuds and Par. 38 of Yuds discuss breaking up clots, wherein “the ultrasonic head can produce sound waves at 65 MHz to break up clots”). However, Boag in view of Yuds currently does not disclose the device comprises a second set of ultrasonic transducers that are coupled with the controller, which causes the second set of ultrasonic transducers to emit ultrasonic signals of a second predetermined frequency, different from the first predetermined frequency, the ultrasonic signals of the second predetermined frequency prevent blood clots in the contents of the drip chamber. Yuds, in another embodiment, teaches a second predetermined frequency (Par. 50 – “20 Hz”), the ultrasonic signals of the second predetermined frequency prevent blood clots in the contents of the drip chamber (Par. 50 – “the ultrasonic head can emit a constant low frequency in the range of 20 Hz that “stirs” red blood cells such that they cannot form clots”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller of Boag in view of Yuds and duplicate the ultrasonic transducer to include another set of ultrasonic transducer, since it has been held that mere duplication of the essential working parts of a device involves only routine skill in the art. Furthermore, the court held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced. In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960). See MPEP 2144. Furthermore, Yuds discusses that the ultrasonic head/transducer can also emit at another range such as 20 Hz to constantly stir red blood cells, as opposed to 65 MHz to break up blood clots as established above; therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second set of ultrasonic transducer to emit at a different frequency, as Yuds teaches both embodiments. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP 2143.A.). Regarding claim 10, Boag in view of Yuds discloses the invention of claim 9. Boag in view of Yuds further discloses wherein the second set of ultrasonic transducers emits ultrasonic signals continuously that prevents red blood cells from clotting (Par. 50 of Yuds – “the ultrasonic head can emit a constant low frequency in the range of 20 Hz that “stirs” red blood cells such that they cannot form clots”). Examiner notes that once the combination is made as discussed in claim 9, the emitted frequency by the second set of ultrasonic transducers will continuously prevents clotting as taught by Yuds. Thus, the limitation is met. Regarding claim 11, Boag in view of Yuds discloses the invention of claim 9. However, Boag in view of Yuds does not currently disclose wherein the second set of ultrasonic transducers emits ultrasonic signals of a third predetermined frequency, different from the first and second predetermined frequencies, the ultrasonic signals of the third predetermined frequency sever chains of red blood cells. Yuds, in another embodiment, teaches wherein the set of ultrasonic transducers emits ultrasonic signals of a third predetermined frequency (Par. 50 – “50 MHz”), the ultrasonic signals of the third predetermined frequency sever chains of red blood cells (Par. 50 – “the ultrasonic head can emit a series of brief bursts at 50 MHz to sever long chains of red blood cells”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second set of ultrasonic transducer of Boag in view of Yuds to further emit a third frequency, also as taught by Yuds, in order to sever long chains of red blood cells (Par. 50 of Yuds) and because as Yuds teaches both embodiments. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP 2143.A.). Examiner notes that once the modification is made as discussed, the third frequency at 50 MHz is indeed different from the first frequency of 65 MHz and the second frequency 20 Hz (see claims 9 -10 above). Thus, the limitation of “different from the first and second predetermined frequencies” is met. Regarding claim 12, Boag discloses a dialysis system (Fig. 1 depicts an extracorporeal blood circulation system with an artificial kidney 4), comprising: a venous drip chamber 12 (Fig. 3 – drip chamber 12; Examiner notes that drip chamber 12 is located on the return line of the system, which is consistent with Applicant’s venous drip chamber 132; thus, the limitation is met) comprising a vent 22 (Fig. 1 – air passage tube 22); However, Boag does not disclose one or more ultrasonic transducers positioned in a predetermined vicinity of the vent; a controller coupled with the one or more ultrasonic transducers, the controller configured to cause the one or more ultrasonic transducers to emit ultrasonic signals that displace particles in contents of the venous drip chamber away from the vent. Yuds, in the same field of endeavor of dialysis treatment (Abstract), teaches one ultrasonic transducer 702 (Fig. 7 – transducer/ultrasonic head 702). Yuds, in another embodiment, teaches a controller 12 (Fig. 1 – hemodialysis system 12) coupled with the one ultrasonic transducer (Par. 48 – “the hemodialysis machine 12 may control an ultrasonic head”), the controller 12 (Fig. 1) configured to cause the one ultrasonic transducer to emit ultrasonic signals (Par. 48 – “the hemodialysis machine 12 may control an ultrasonic head, generating sounds waves…”) that displace particles in contents of the venous drip chamber (Par. 48 – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”, and Par. 50 – “Breaking up clots using the ultrasonic head”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the transducer of Boag to be ultrasonic and coupled to a controller as taught by Yud, in order to break up clots in blood flowing through the chamber (Par. 41 of Yud), in this instant case, through the drip chamber of Boag. Since the ultrasonic transducer of Yuds can be arranged below the drip chamber (Par. 30 of Yuds), the incorporated ultrasonic transducer 702 of Boag in view of Yuds will also be below the drip chamber 12 of Boag, thus the transducer 702 will indeed be “positioned in a predetermined vicinity of the vent”. Furthermore, one of ordinary skill in the art would have had the technological capability to recognize that the broken-up blood clots within the drip chamber of Boag in view of Yud should return to the patient as it is well-known in the field that extracorporeal blood treatment withdraws and return treated blood. Therefore, the “displaced particles” after the actuation of ultrasonic signals in the drip chamber 12 of Boag will be away from the vent 22 of Boag. Thus, the limitation of “away from the vent” is met. Regarding claim 13, Boag in view of Yuds discloses the invention of claim 12. Boag in view of Yuds further discloses wherein the venous drip chamber 12 (Fig. 3 of Boag) is top-vented (Fig. 3 of Boag – air passage tube 22 is disposed on the top of chamber 12). Regarding claim 14, Boag in view of Yuds discloses the invention of claim 12. Boag in view of Yuds further discloses wherein the controller 12 (Fig. 1 of Yuds) causes the one ultrasonic transducer 702 (Fig. 7 of Yuds) to emit the ultrasonic signals of a predetermined frequency (Par. 48 of Yuds – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”), the predetermined frequency selected to displace the particles (Par. 48 of Yuds – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”, and Par. 50 – “Breaking up clots using the ultrasonic head”) However, Boag in view of Yuds does not currently disclose particles larger than a predetermined size. Examiner notes that in Par. 39, Yuds discusses that an ultrasonic head is provided in some embodiments for breaking up clots or blasticing clotting masses before they reach a critical size; thus indicating that there are some level of monitoring the size of the clumps within a chamber. Par. 29 of Yuds also discusses that clotting causes the blood cells 304 (Fig. 3) to vibrate more slowly and will therefore have a higher amplitude of reflected light compared to blood cells 304 that are not clotting. For example, section 316 when illuminated by the light source 312 will have a lower amplitude of reflected light compared to section 318. On this basis, the clotting of section 318 will be blasted with ultrasonic energy, while the non-clotting section 316 will not because section 316 is monitored to not be at a predetermined size for ultrasonic treatment. Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have had the technological capability to recognize that that the ultrasonic transducer of Boag in view of Yuds will only perform ultrasonic treatment to particles larger than a predetermined size, also as taught by Yuds. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP 2143.A.). Regarding claim 15, Boag in view of Yuds discloses the invention of claim 14. Boag in view of Yuds further discloses further comprising a pore size (Fig. 1 of Boag depicts a filter 60, wherein Col. 4, line 47-56 of Boag discusses a pore size of said filter – “a hydrophobic filter 60 is included... Hydrophobic filter materials are well known and easily available in the market, an example being that currently being marketed under the trademark "Acropor" by the Gelman Instrument Company of Ann Arbor, Michigan, Acropor being a microporous hydrophobic organic polymer membrane filter of about 0.45 microns pore size”; Examiner does note that that this pore size is not positively claimed within claim 6 and is currently interpreted to be a functional language limitation) of the drip chamber 12 (Fig. 1 of Boag). However, Boag in view of Yuds currently does not disclose further comprising one or more sensors to monitor a pore size of the drip chamber. Yuds, in the same field of endeavor of dialysis treatment (Abstract) and in another embodiment, teaches one sensor 602 (Fig. 6 – optical sensor assembly 602) to monitor clots or masses of red blood cells of a certain size (Par. 40 – “the ultrasonic head can be used to locally detect clots or masses of red blood cells between 20 μm and 100 μm at a lower frequency, e.g., at 50 MHz,”, wherein an ultrasonic head is a part of the optical sensor assembly 602 as discussed in Par. 38). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of Boag in view of Yuds to further include a sensor, also as taught by Yuds, in order to monitor the particles size (Par. 40 of Yuds). Examiner contends that since said sensor of Yuds is capable of monitoring particle sizes of the drip chamber shown in Fig. 6 of Yuds (consistent system layout of Applicant’s Fig. 2), the sensor 602 of Yuds is highly capable of monitoring the pore size of Boag’s drip chamber 12. Thus, the limitation is met. Regarding claim 18, Boag in view of Yuds discloses the invention of claim 14. Boag in view of Yuds further discloses wherein the one ultrasonic transducer 702 (Fig. 7 of Yuds) is a first set of ultrasonic transducers 702 (Fig. 7 of Yuds), the predetermined frequency (Par. 48 of Yuds – “The hemodialysis machine 12 can provide signals to instruct the ultrasonic head to emit a series of brief ultrasonic bursts at an empirically determined frequency…”) is a first predetermined frequency (Par. 40 of Yuds and Par. 38 of Yuds discuss breaking up clots, wherein “the ultrasonic head can produce sound waves at 65 MHz to break up clots”). However, Boag in view of Yuds currently does not disclose the dialysis system comprises a second set of ultrasonic transducers that are coupled with the controller, which causes the second set of ultrasonic transducers to emit ultrasonic signals of a second predetermined frequency, different from the first predetermined frequency, the ultrasonic signals of the second predetermined frequency prevent blood clots in the contents of the venous drip chamber. Yuds, in another embodiment, teaches a second predetermined frequency (Par. 50 – “20 Hz”), the ultrasonic signals of the second predetermined frequency prevent blood clots in the contents of the drip chamber (Par. 50 – “the ultrasonic head can emit a constant low frequency in the range of 20 Hz that “stirs” red blood cells such that they cannot form clots”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller of Boag in view of Yuds and duplicate the ultrasonic transducer to include another set of ultrasonic transducer, since it has been held that mere duplication of the essential working parts of a device involves only routine skill in the art. Furthermore, the court held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced. In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960). See MPEP 2144. Furthermore, Yuds discusses that the ultrasonic head/transducer can also emit at another range such as 20 Hz to constantly stir red blood cells, as opposed to 65 MHz to break up blood clots as established above; therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second set of ultrasonic transducer to emit at a different frequency, as Yuds teaches both embodiments. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP 2143.A.). Regarding claim 19, Boag in view of Yuds discloses the invention of claim 18. Boag in view of Yuds further discloses wherein the controller 12 (Fig. 1 of Yuds) causes the second set of ultrasonic transducers to perform: emit ultrasonic signals continuously to prevent red blood cells from clotting (Par. 50 of Yuds – “the ultrasonic head can emit a constant low frequency in the range of 20 Hz that “stirs” red blood cells such that they cannot form clots”). Examiner notes that once the combination is made as discussed in claim 18, the emitted frequency by the second set of ultrasonic transducers will continuously prevents clotting as taught by Yuds. Thus, the limitation is met. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Boag in view of Yuds as applied to claim 2 above, and further in view of Van Driel et al. US 5,811,658 A (hereinafter Van Driel). Regarding claim 5, Boag in view of Yuds discloses the invention of claim 2. However, Boag in view of Yuds discloses wherein the ultrasonic signals of the predetermined frequency allow the particles that are smaller than the predetermined size to pass through the vent. Van Driel, in the same field of endeavor of ultrasonic diversion of microair in blood (Title), teaches wherein the ultrasonic signals 24 (Fig. 2 – acoustic radiation 24) of the predetermined frequency (Claim 6 – “said frequency is substantially 1 MHz”) allow the particles 26 (Fig. 2 – small bubbles 26) that are smaller than the predetermined size (Col. 3, line 12-15 – “the system 10 can measure bubble sizes and counts more accurately because small bubbles will not be masked by large ones, and the detectors 30 and 46 can each be more finely tuned within a smaller range of bubble sizes”) to pass through the vent 33 (Fig. 2 – vent 33). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of Boag in view of Yuds to further have the ultrasonic signals allow smaller particles to pass through the vent as taught by Van Driel, in order to combat the problem of air emboli (Col. 1, line 28 of Van Driel) as microair bubbles have been suspected to cause memory loss, strokes, and other undesirable effects in the patient (Col. 1, line 16-18 of Van Driel). Claims 8, 16, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Boag in view of Yuds as applied to claim 6 and claim 15 above, and further in view of Ahmadi et al. US 2022/0126010 A1 (hereinafter Ahmadi), evidenced by Thayumanavan et al. US 2009/0184047 A1 (hereinafter Thayumanavan) Regarding claim 8, Boag in view of Yuds discloses the invention of claim 6. However, Boag in view of Yuds does not disclose wherein, in response to the pore size being detected to be less than a predetermined threshold, the controller performs at least one from a group of operations, the group of operations comprises, stopping the blood pump, closing a venous clamp, and alerting a user. Ahmadi, in the same field of endeavor of dialysis system preventing air bubbles (Par. 3), teaches wherein, in response to the measured pressure being detected to be more than a predetermined threshold (Par. 62 – “An increase in the value of subsequent pressure measurements at pressure transducer 13 may indicate clotting of the gas removal filter 2,”), the controller 112 (Fig. 3 – application 112) performs at least one from a group of operations, the group of operations comprises alerting a user (Par. 62 – “If clotting of air removal filter 2 or excess unremoved air is detected, application 112 may include an operation to signal an alarm 16”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller of Boag in view of Yuds to alert a user upon detection of the sensor as taught by Ahmaid, in order to notify of clotting in the filter (Par. 62 of Ahmadi), and as it is well-known in the field of extracorporeal blood treatment to provide cautionary message to the operators and inform them of improper air venting. Examiner further notes that the clogging detection method of Ahmadi is operated based on pressure measurement (Par. 62 of Ahmadi – “An increase in the value of subsequent pressure measurements at pressure transducer 13 may indicate clotting of the gas removal filter 2, or excess unremoved air in gas removal filter 2 and/or vent tubing 10”). According to evidentiary reference Thayumanavan, it is known in the art that “the movement of water from one side to the other side of the membrane causes change in pressure, compared to the atmospheric pressure, inversely proportional to membrane dimension. As pore size decreases, increased pressure change can be observed” as discussed in Par. 61; therefore, one of ordinary skill in the art would have had the technological capability to reasonably deduce a membrane dimension and pore size from the measured increase pressure at the membrane/filter, and compare said value to a new predetermined threshold due to the established inverse relationship. Thus, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller of the combination to utilize the pore size parameter derived from the monitored pressure change for detecting air/clogging, as Thayumanavan evidently discusses the inverse relationship between increased pressure and pore size. Regarding claim 16, Boag in view of Yuds discloses the invention of claim 15. However, Boag in view of Yuds does not disclose wherein, in response to the pore size being detected to be less than a predetermined threshold, the controller performs at least one from a group of operations, the group of operations comprises, stopping a blood pump, closing a venous clamp, and alerting a user. Ahmadi, in the same field of endeavor of dialysis system preventing air bubbles (Par. 3), teaches wherein, in response to the measured pressure being detected to be more than a predetermined threshold (Par. 62 – “An increase in the value of subsequent pressure measurements at pressure transducer 13 may indicate clotting of the gas removal filter 2,”), the controller 112 (Fig. 3 – application 112) performs at least one from a group of operations, the group of operations comprises alerting a user (Par. 62 – “If clotting of air removal filter 2 or excess unremoved air is detected, application 112 may include an operation to signal an alarm 16”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller of Boag in view of Yuds to alert a user upon detection of the sensor as taught by Ahmaid, in order to notify of clotting in the filter (Par. 62 of Ahmadi), and as it is well-known in the field of extracorporeal blood treatment to provide cautionary message to the operators and inform them of improper air venting. Examiner further notes that the clogging detection method of Ahmadi is operated based on pressure measurement (Par. 62 of Ahmadi – “An increase in the value of subsequent pressure measurements at pressure transducer 13 may indicate clotting of the gas removal filter 2, or excess unremoved air in gas removal filter 2 and/or vent tubing 10”). According to evidentiary reference Thayumanavan, it is known in the art that “the movement of water from one side to the other side of the membrane causes change in pressure, compared to the atmospheric pressure, inversely proportional to membrane dimension. As pore size decreases, increased pressure change can be observed” as discussed in Par. 61; therefore, one of ordinary skill in the art would have had the technological capability to reasonably deduce a membrane dimension and pore size from the measured increase pressure at the membrane/filter, and compare said value to a new predetermined threshold due to the established inverse relationship. Thus, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller of the combination to utilize the pore size parameter derived from the monitored pressure change for detecting air/clogging, as Thayumanavan evidently discusses the inverse relationship between increased pressure and pore size. Regarding claim 17, Boag in view of Yuds in view of Ahmadi discloses the invention of claim 16. The combination further discloses wherein the one sensor 602 (Fig. 6 of Yuds) comprise a second set of ultrasonic transducers (Par. 38 of Yuds – “an optical sensor assembly 602 with a fiber-optic sensor and an ultrasonic or piezoelectric head… Ultrasonic heads that can be used include high frequency transducers”), the second set of ultrasonic transducers (Par. 38 of Yuds) to emit ultrasonic signals of a second predetermined frequency (Par. 40 of Yuds – “the ultrasonic head can be used to locally detect clots or masses of red blood cells between 20 μm and 100 μm at a lower frequency, e.g., at 50 MHz”). Examiner notes that once the modification is made as discussed in claim 15, the optical sensor assembly of Yuds will be incorporated into the device of Boag in view of Yuds, including the second operating frequency. Thus, the limitation is met. However, the combination does not currently disclose wherein the controller is coupled with the second set of ultrasonic transducers, the controller configured to cause the second set of ultrasonic transducers to emit ultrasonic signals. Since it has been established in the modification of claim 12 that the controller 12 of Yuds will be coupled to the ultrasonic transducer, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of the combination to further have the second set of ultrasonic transducer coupled to the controller of Boag in view of Yuds, as Yuds already demonstrates that the controller 12 provides signals to instruct ultrasonic transducer to emit signals. Thus, the limitation is met. Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Ahmadi in view of Treu et al. US 2023/0211059 A1 (hereinafter Treu), evidenced by Thayumanavan et al. US 2009/0184047 A1 (hereinafter Thayumanavan). Regarding claim 20, Ahmadi discloses a computer-implemented method (Par. 2 – “methods for detecting air in a fluid return line and automatically purging the air therefrom”, Fig. 4 depicts a controller 8), comprising: using one or more sensors 6, 13 (Fig. 4 – gas detector 6 and pressure transducer 13), a pore size of a drip chamber 19 (Fig. 5 – drip chamber 19 and an opening such as vent port 4) However, Ahmadi does not currently disclose detecting a pore size of a drip chamber coupled to a pump that causes a fluid to flow through the drip chamber; and in response to the pore size of the drip chamber being below a predetermined size, causing the pump to stop the flow of fluid. Ahmadi, in another embodiment, teaches detecting clotting of a chamber 2 (Fig. 1 – gas removal filter 2, and Par. 62 – “If clotting of air removal filter 2… is detected”, this detection is done via transducer 13 and indicate “clotting of the gas removal filter 2… in gas removal filter 2 and/or vent tubing 10”) coupled to a pump (Par. 62 – blood pump) that causes a fluid to flow through the chamber 2 (Fig. 1, and Par. 62 – “ (i.e. blood) flow rate through inlet 1 and outlet 5”, which indicates that the blood pump has to be coupled to the chamber 2 to deliver blood to and from said chamber). Treu, in the same field of endeavor of detecting possible clotting in filters (Par. 74 and Par. 361), teaches in response to the outlet pressure exceeds a predetermined threshold (Fig. 48A, and Par. 362 – “The blood pump outlet pressure sensor 564 can be continuously monitored… If the blood pump outlet pressure sensor 564 exceeds a predetermined threshold value”), causing the pump to stop the flow of fluid (Par. 364 – “the system stops all pumps S4807 for a period of time”). It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Ahmadi to further include detection of filter clogging via sensors, also as taught by Ahmadi, since as Ahmadi teaches both embodiments. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (MPEP 2143.A.). Examiner further notes that the clogging detection method of Ahmadi is operated based on pressure measurement (Par. 62 of Ahmadi – “An increase in the value of subsequent pressure measurements at pressure transducer 13 may indicate clotting of the gas removal filter 2, or excess unremoved air in gas removal filter 2 and/or vent tubing 10”). According to evidentiary reference Thayumanavan, it is known in the art that “the movement of water from one side to the other side of the membrane causes change in pressure, compared to the atmospheric pressure, inversely proportional to membrane dimension. As pore size decreases, increased pressure change can be observed” as discussed in Par. 61; therefore, one of ordinary skill in the art would have had the technological capability to reasonably deduce a membrane dimension and pore size from the measured increase pressure at the membrane/filter. Thus, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Ahmadi to utilize the pore size parameter derived from the monitored pressure change for detecting air/clogging, as Thayumanavan evidently discusses the inverse relationship between increased pressure and pore size. Furthermore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Ahamdi to further stop the pump in response to an exceeding of a threshold value as taught by Treu, in order to detect possible clotting in filters (Par. 361 of Treu). Treu discusses that “clotting building up in a filter (e.g., a blood filter) will obstruct blood flow, and thus increase resistance of flow thorough the filter, which will be observable as an increase in the pressure…” and “It is expected that if the filter(s) are not clogged, the pressure reading will be at a normal level”. Therefore, one of ordinary skill in the art would have had the technological capability to recognize the relationship between the increased pressure and pore/opening size of the combined drip chamber, such that increased pressure inversely correlates to pore size as clots causes pressure build up as evidenced by Thayumanavan above, and apply said known technique to a similar method (Both Ahamdi and Treu’s method teaches detecting and purging air). Thus, the limitation “in response to the pore size of the drip chamber being below a predetermined size” is met. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Milo US 2003/0221561 A1 Spickermann et al. US 2012/0091048 A1 Blanton US 7,699,799 B2 Folden et al. US 7,938,967 B2 Hohlfeld et al. US 5,022,899 A Any inquiry concerning this communication or earlier communications from the examiner should be directed to QUYNH DAO LE whose telephone number is (571)272-7198. The examiner can normally be reached Monday - Friday 8:30 am - 5:30 pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sarah Al-Hashimi can be reached at (571) 272-7159. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /QUYNH DAO LE/Examiner, Art Unit 3781 /JESSICA ARBLE/Primary Examiner, Art Unit 3781
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Prosecution Timeline

Aug 15, 2023
Application Filed
Sep 18, 2025
Non-Final Rejection mailed — §103
Dec 16, 2025
Response Filed
Apr 20, 2026
Non-Final Rejection mailed — §103 (current)

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Prosecution Projections

2-3
Expected OA Rounds
34%
Grant Probability
40%
With Interview (+5.4%)
3y 5m (~6m remaining)
Median Time to Grant
Moderate
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