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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/18/2025 has been entered.
Response to Arguments
Rejections under 35 USC 112
In regard to Applicant’s response filed 11/14/2025, the amended claims have overcome the rejections made to claims 1-5 and 7-14 as presented in the previous Office Action filed 08/18/2025. The previously presented rejection under 35 USC 112 is hereby withdrawn.
After further consideration of the claims, new grounds of rejection under 35 USC 112(b) for claims 11 and 12 detailed below.
Rejections under 35 USC 101
Applicant's arguments regarding the rejection of claims 1-5 and 7-14 under 35 USC 101 filed 11/14/2025 have been fully considered but they are not persuasive.
Applicant argues that the claimed invention is eligible over 101 for the following reasons:
The requirement of an implantable device to perform the claimed calculations via a processor operatively associated with a detection unit to detect signals in an electrocardiogram amounts to more than the abstract idea of a mathematical operation; and if the mathematical calculation is regarded as an abstract idea, the additional elements integrate the abstract idea into practical application; and
The determination of an ectopic signal is done using a non-routine and unconventional procedure.
Examiner respectfully disagrees and offers the following reasoning:
The requirement of the implantable device and associated additional elements is not enough to integrate the abstract idea into practical application. The implanted device and associated additional elements merely amount to linking the abstract idea to a technological environment or field of use and/or generic computer implementation of the abstract idea. They do not amount to integrating the abstract idea into a practical application.
The implementation of the abstract idea/mathematical calculation to determine an ectopic beat by calculating an average R-R interval and using a comparison threshold to identify an ectopic beat does not amount to significantly more than the mathematical concept.
With this in consideration, the rejection under 35 USC 101 is maintained.
Rejections under 35 USC 103
Applicant’s arguments, see Remarks filed 11/14/2025, with respect to the rejection(s) of claim(s) 1-5, 7, 8, and 10-12 under 35 USC 103 have been fully considered and are persuasive. Examiner agrees with Applicant’s arguments that the previously presented prior art of Olde does not teach the limitation of “wherein a number of detected ectopic signals is counted and wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals plus a number of detected noise events exceeds a threshold.” Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Sarkar et al (US 20120238891 A1), or alternatively Shaquer (US 20110152957 A1) in view of Sarkar et al (US 20120238891 A1). Additionally, new grounds of rejection are presented in view of previously presented Dyjach and Blake in view of Sarkar. New grounds of rejection detailed below.
Information Disclosure Statement
The information disclosure statement (IDS) filed on 10/25/2022 has been considered by the examiner.
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 11 and 12 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 11 has been identified as a “use” claim, because it attempts to claim a process without setting forth any steps involved in the process. The limitation of ‘applying an atrial fibrillation detection algorithm and the method for detecting an ectopic signal in an electrocardiogram’ merely recites a use and does not positively recite any active steps delimiting how this use is actually practiced. See MPEP 2173.05(q), Ex parte Erlich, 3 USPQ2d 1011.
Additionally, the limitation of “applying an atrial fibrillation detection algorithm” in claim 11 is indefinite because it is unclear what an atrial fibrillation detection algorithm is directed to. See MPEP 2172.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claims 1-5, 7 and 10-12 rejected under 35 U.S.C. 101 because the claimed invention is directed to a mental process and mathematical calculation without significantly more.
Step 1
Claims 1 and 11 directed to a method and claim 10 is directed to a machine.
Step 2A, Prong 1
Claims 1 and 10 recite the limitations of discarding ectopic signals in order to calculate an average R-R interval. These steps, given their broadest reasonable interpretation amount to an act of calculating using mathematical methods to determine a variable or number, in this case an average R-R interval.
Claim 11 recites the limitation of applying an atrial fibrillation detection algorithm and applying the method of claim 1. These steps, given their broadest reasonable interpretation, amount to an act of performing a mathematical calculation or equation to detect atrial fibrillation.
Step 2A, Prong 2
Claims 1, 10, and 11 do not include any additional elements that integrate the mental process and mathematical concept into a practical application.
Claim 1 includes the additional elements of an electrocardiogram, a processor, an implantable medical device, and a memory. The processor and memory are generically claimed such that they amount to generic computer implementation of the mental process and mathematical concept. The electrocardiogram and implantable medical device amount to generally linking the abstract idea to a particular technological environment or field of use.
Claim 10 includes the elements of claim 1 and a detection unit. The detection unit is also generically claimed such that it amounts to generic computer implementation of the mental process and mathematical concept.
Claim 11 includes the additional elements of claim 1.
Dependent claims 2-5, 7, 8, and 12 do not include any additional elements which amount to integrating the mathematical concept into a practical application. The dependent claims merely further define the steps of the mathematical concept.
None of these elements amount to integrating the mental process and mathematical concept into a practical application.
Step 2B
Claims 1, 10, and 11 do not include any additional elements that amount to significantly more than the mental process and mathematical concept.
Claim 1 includes the additional elements of an electrocardiogram, a processor, an implantable medical device, and a memory. The processor and memory are generically claimed such that they amount to generic computer implementation of the mental process and mathematical concept. The electrocardiogram and implantable medical device amount to generally linking the abstract idea to a particular technological environment or field of use.
Claim 10 includes the elements of claim 1 and a detection unit. The detection unit is also generically claimed such that it amounts to generic computer implementation of the mental process and mathematical concept.
Claim 11 includes the additional elements of claim 1.
Dependent claims 2-5, 7, 8, and 12 do not include any additional elements which amount to significantly more than the mathematical concept. The dependent claims merely further define the steps of the mathematical concept.
None of these elements amount to significantly more than the mental process and mathematical concept itself.
Moreover, the additional elements are recited at a high level of generality on page 6 of the instant application and are well understood in the cardiovascular field as indicated in Keel et al (US 20130030314 A1, [0062]). Further, simply appending well-understood, routine, conventional activities previously known to the industry, specified at a high level of generality, to the judicial exception, e.g., a claim to an abstract idea requiring no more than a generic computer to perform generic computer functions that are well-understood, routine and conventional activities previously known to the industry, as discussed in Alice Corp., 573 U.S. at 225, 110 USPQ2d at 1984 (see MPEP § 2106.05(d)). In this case, elements of general computer are being used to implement the mental process and mathematical concept of calculating an average R-R interval.
Claims 2-5, 7, 8, and 12 only further define the mental process and mathematical concept, namely the steps of the calculation for the average R-R interval.
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.
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.
Claims 1, 5, 7, 8, and 10-12 are rejected under 35 U.S.C. 103 as being unpatentable over Shaquer (US 20110152957 A1) in view of Sarkar et al (US 20120238891 A1).
Regarding claim 1, Shaquer teaches a method for detecting an ectopic signal in an electrocardiogram, the ectopic signal being caused by an ectopic cardiac beat, the method comprising the following steps that are performed by a processor (460) of an implantable medical device (410) when a computer-readable program comprised in a memory of the implantable medical device is executed on the processor (see [0100]; microcontroller 460 includes the ability to process or monitor input signals as controlled by a program code stored in a designated block of memory):
detecting, with a detection unit (212) of the implantable medical device (410), consecutive R-R intervals in an electrocardiogram (see Fig. 17, [0081]; R-wave is detected at step 302);
calculating an average R-R interval for a determinable number of latest R-R intervals (see Figs. 17-18; step 306 calculate interval average, CIA);
recognizing a signal as ectopic signal (see Figs. 17, 19; Step 312 eliminate ectopic beats) if the signal belongs to at least one of two consecutive R-R intervals, wherein
i) a first of the two consecutive R-R intervals differs from the average R-R interval more than a determined threshold (see Fig. 19, [0085]; step 334 is |RRi - CIA| > threshold1); and
ii) a second of the two consecutive R-R intervals differs from the average R-R interval more than a determined threshold, wherein the second R-R interval occurs later than the first R-R interval (see Fig. 19, [0086]; step 340 is |RRi+1 - CIA| > threshold2);
wherein the first and the second of the two consecutive R-R intervals are discarded simultaneously from calculating the average R-R interval, if the signal is recognized as ectopic signal (see Fig. 19, [0087]; step 344 if beat RRi is ectopic then RRi and RRi+1 are replaced with normal interval RRi+2).
Shaquer is silent regarding the threshold for recognizing a signal as ectopic being 5% shorter or longer than the average;
wherein a number of detected ectopic signals is counted; and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals plus a number of detected noise events exceeds a threshold.
Shaquer discloses in paragraph [0086], that ectopic beats tend to be isolated and hence affect both the immediately preceding and the immediately succeeding RR intervals, and in paragraph [0088] that the threshold to establish an ectopic beat may be expressed as a percentage of the average RR value e.g. 10% to 50%, and routine experimentation may be performed to determine optimal values. Shaquer is silent regarding the percentage of the average RR value being 5%, however, it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only skill in the art. See MPEP 2144.05(II), In re Aller, 105 USPQ 233.
Sarkar teaches a method for identifying and rejecting ectopic beats based on ventricular cycle lengths (Sarkar, Abstract) wherein RR intervals are identified as ectopic (400), wherein a number of detected ectopic signals is counted (see Sarkar Fig. 7, [0060]; ectopy counter) and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals (see Sarkar Fig. 7, [0067]; if ectopy count is greater than a count threshold, set ectopy count metric to 1) plus a number of detected noise events (see Fig. 7, [0068-0070]; the mode count is compared to a sinus rhythm threshold at step 422, if the mode count is high it may be considered positive evidence for a sinus rhythm) exceeds a threshold (see [0070]; a high ectopy count (ectopy count metric) and evidence of an underlying sinus rhythm (high mode metric) indicates a high probability that the heart rhythm is a sinus rhythm with frequent ectopic beats and a reduced likelihood of the rhythm being AF). It can be appreciated that under the broadest reasonable interpretation of the limitations of the claim, a sinus rhythm as detected by the mode count, is considered to be a noise event as it may cause irregular RR intervals that may be characterized as ectopic and therefore confound the detection of atrial fibrillation.
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Shaquer’s method for detecting an ectopic signal with the ectopic signal and noise event counters as taught by Sarkar. One of ordinary skill in the art would have been motivated to make this modification in order to more accurately determine the presence of atrial fibrillation in a signal without false positives caused by ectopic beats caused by other events such as a sinus rhythm (Sarkar [0070]).
Regarding claim 5, Shaquer and Sarkar teach the method according to claim 1. Shaquer further teaches wherein the average R-R interval is recalculated with each newly detected R-R interval (see [0081]; whenever a new R wave is detected, the average RR interval is calculated) if this newly detected R-R interval is not discarded from calculating the average R-R interval (see [0087]; if RRi and RRi+1 are identified as ectopic, they are replaced with normal interval value RRi+2).
Regarding claims 7 and 8, Shaquer and Sarkar teach the method according to claim 1. Shaquer further teaches wherein the first of the two consecutive R-R intervals is considered to be significantly shorter than the average R-R interval if the first of the two consecutive R-R intervals is at least a threshold amount shorter than the average R-R interval (see Fig. 19, step 334 is |RRi - CIA| > threshold1, [0085-0086]; if the first difference value exceeded the first threshold, RRi was either much larger or much smaller than the average RR value) and
wherein the second of the two consecutive R-R intervals is considered to be significantly longer than the average R-R interval if the second of the two consecutive R-R intervals is at least a threshold amount longer than the average R-R interval (see Fig. 19, step 340 is |RRi+1 - CIA| > threshold2, [0085-0086]; both RRi and RRi+1 should differ significantly from the average RR interval).
Shaquer is silent regarding considering an interval significantly shorter or longer than the average RR interval if the current interval is 5% longer or 5% shorter than the average. However, Shaquer discloses in paragraph [0086], that ectopic beats tend to be isolated and hence affect both the immediately preceding and the immediately succeeding RR intervals, and in paragraph [0088] that the threshold to establish an ectopic beat may be expressed as a percentage of the average RR value e.g. 10% to 50%, and routine experimentation may be performed to determine optimal values. Shaquer is silent regarding the percentage of the average RR value being 5%, however, it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only skill in the art. See MPEP 2144.05(II), In re Aller, 105 USPQ 233.
Regarding claim 10, Shaquer teaches an implantable medical device (410) for detecting an electrical signal of a human or animal heart (412), the implantable medical device comprising a processor (460),
a memory unit (see [0100]; RAM or ROM memory), and
a detection unit (212) configured to detect an electrical signal of a human or animal heart,
wherein the memory unit comprises a computer-readable program that causes the processor to perform the following steps when executed on the processor (see [0100]; microcontroller 460 includes the ability to process or monitor input signals as controlled by a program code stored in a designated block of memory):
detecting, with the detection unit (212), consecutive R-R intervals in an electrocardiogram (see Fig. 17, [0081]; R-wave is detected at step 302);
calculating an average R-R interval for a determinable number of latest R-R intervals (see Figs. 17-18; step 306 calculate interval average, CIA);
recognizing a signal as ectopic signal (see Figs. 17, 19; Step 312 eliminate ectopic beats) if the signal belongs to at least one of two consecutive R-R intervals, wherein
i) a first of the two consecutive R-R intervals differs from the average R-R interval more than a determined threshold (see Fig. 19, [0085]; step 334 is |RRi - CIA| > threshold1); and
ii) a second of the two consecutive R-R intervals differs from the average R-R interval more than a determined threshold, wherein the second R-R interval occurs later than the first R-R interval (see Fig. 19, [0086]; step 340 is |RRi+1 - CIA| > threshold2);
wherein the first and the second of the two consecutive R-R intervals are discarded simultaneously from calculating the average R-R interval, if the signal is recognized as ectopic signal (see Fig. 19, [0087]; step 344 if beat RRi is ectopic then RRi and RRi+1 are replaced with normal interval RRi+2).
Shaquer is silent regarding the threshold for recognizing a signal as ectopic being 5% shorter or longer than the average;
wherein a number of detected ectopic signals is counted; and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals plus a number of detected noise events exceeds a threshold.
Shaquer discloses in paragraph [0086], that ectopic beats tend to be isolated and hence affect both the immediately preceding and the immediately succeeding RR intervals, and in paragraph [0088] that the threshold to establish an ectopic beat may be expressed as a percentage of the average RR value e.g. 10% to 50%, and routine experimentation may be performed to determine optimal values. Shaquer is silent regarding the percentage of the average RR value being 5%, however, it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only skill in the art. See MPEP 2144.05(II), In re Aller, 105 USPQ 233.
Sarkar teaches a method for identifying and rejecting ectopic beats based on ventricular cycle lengths (Sarkar, Abstract) wherein RR intervals are identified as ectopic (400), wherein a number of detected ectopic signals is counted (see Sarkar Fig. 7, [0060]; ectopy counter) and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals (see Sarkar Fig. 7, [0067]; if ectopy count is greater than a count threshold, set ectopy count metric to 1) plus a number of detected noise events (see Fig. 7, [0068-0070]; the mode count is compared to a sinus rhythm threshold at step 422, if the mode count is high it may be considered positive evidence for a sinus rhythm) exceeds a threshold (see [0070]; a high ectopy count (ectopy count metric) and evidence of an underlying sinus rhythm (high mode metric) indicates a high probability that the heart rhythm is a sinus rhythm with frequent ectopic beats and a reduced likelihood of the rhythm being AF). It can be appreciated that under the broadest reasonable interpretation of the limitations of the claim, a sinus rhythm as detected by the mode count, is considered to be a noise event as it may cause irregular RR intervals that may be characterized as ectopic and therefore confound the detection of atrial fibrillation.
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Shaquer’s method for detecting an ectopic signal with the ectopic signal and noise event counters as taught by Sarkar. One of ordinary skill in the art would have been motivated to make this modification in order to more accurately determine the presence of atrial fibrillation in a signal without false positives caused by ectopic beats caused by other events such as a sinus rhythm (Sarkar [0070]).
Regarding claim 11, Shaquer teaches a method for detecting atrial fibrillation of a human or animal heart, the method comprising applying an atrial fibrillation detection algorithm and the method for detecting an ectopic signal in an electrocardiogram (Abstract) according to claim 1. See rejection of claim 1 made in view of Shaquer and Sarkar above.
Regarding claim 12, Shaquer and Sarkar teach the method according to claim 11, wherein the method for detecting an ectopic signal in an electrocardiogram is only carried out for a programmable time period after a beginning of the atrial fibrillation detection algorithm (see [0082-0084]; R waves are detected for analysis during the window as determined by the target count which may be in the range of 60 to 80 or alternatively the device may use a timer to track a window in which R waves are detected for analysis).
Claims 2 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Shaquer (US 20110152957 A1) in view of Sarkar et al (US 20120238891 A1), Keel et al (US 20130030314), and Gagnon-Turcotte (US 20190012515 A1).
Regarding claims 2 and 3, Shaquer and Sarkar teach the method according to claim 1. They are silent regarding the method further comprises the following steps:
calculating a first deviation, the first deviation being an average absolute deviation of the consecutive R-R intervals of the determinable number of latest consecutive R-R intervals used for calculating the average R-R interval from the average R-R interval;
multiplying the first deviation with a factor being greater than 1 to obtain an increased first deviation;
calculating a second deviation, the second deviation being an absolute deviation of a successive R-R interval from the average R-R interval;
defining the R-R interval as significantly shorter than the average R-R interval if the R-R interval is shorter than the average R-R interval and if the second deviation is greater than the increased first deviation, or
defining the R-R interval as significantly longer than the average R-R interval if the R-R interval is longer than the average R-R interval and if the second deviation is greater than the increased first deviation.
Shaquer teaches calculating an average dRR value, which corresponds to the average difference between a present RR interval and the preceding RR interval, and compares the present difference (dRR) to a threshold based on the average in order to identify any values which deviate significantly from the average (Shaquer [0012], Fig. 21). This indicates that Shaquer has identified that data points with a large deviation from the average may be problematic in analyzing the data and should be addressed. Keel teaches a method which would have been an obvious progression of the identification of deviating data points taught by Shaquer.
Keel teaches a method for performing arrhythmia discrimination by characterizing RR intervals based on their stability wherein the method of determining the stability of the RR intervals (Keel [0027-0029]) comprises:
calculating a first deviation, the first deviation being an average absolute deviation of the consecutive R-R intervals of the determinable number of latest consecutive R-R intervals (see Keel [0127]; localized R-R interval stability metric can be determined for an IEGM by determining the R-R intervals for a plurality of consecutive cardiac cycles) used for calculating the average R-R interval from the average R-R interval (see [0127]; step 604 fig 6, exemplary measures of variation, which can be determined for the R-R intervals, can include one or more of: average absolute deviation);
calculating a second deviation, the second deviation being an absolute deviation of a successive R-R interval from the average R-R interval (see Keel Fig. 6; step 604, determine corresponding localized R-R interval stability metric indicative of the R-R interval stability at corresponding ventricular region);
defining the R-R interval as significantly shorter than the average R-R interval if the R-R interval is shorter than the average R-R interval and if the second deviation is greater than the increased first deviation (see Keel [0130]; step 606, Keel Fig. 6, comparing each localized R-R interval stability metric, determined for an IEGM, to an appropriate R-R interval stability threshold), or defining the R- R interval as significantly longer than the average R-R interval if the R-R interval is longer than the average R-R interval and if the second deviation is greater than the increased first deviation (see Keel [0130]; step 606, Keel Fig. 6, if the localized R-R interval stability metric, the measure of standard deviation, exceeds the R-R interval stability threshold, the standard deviation threshold, then it can be determined that the stability criterion is not met).
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method as taught by Shaquer and Sarkar with the calculation of a first and second deviation as taught by Keel. One of ordinary skill in the art would have been motivated to make this modification in order to provide a stability metric for which subsequent signals can be compared to (Keel [0027]).
Keel does not teach multiplying the first deviation with a factor being greater than 1 to obtain an increased first deviation.
However, Gagnon-Turcotte teaches a method for identifying outlying/noisy points in a signal where the first standard deviation is multiplied by a factor greater than 1 to obtain an increased first deviation (see Gagnon-Turcotte [0081-0082]; a standard deviation can be multiplied by constant M, where M can be 2).
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method as taught by Shaquer, Sarkar, and Keel by multiplying the standard deviation with a calibration factor as taught by Gagnon-Turcotte. One of ordinary skill in the art would have been motivated to make this modification in order to account for variability in the signal and obtain the desired threshold size for excluding noise (Gagnon-Turcotte [0082]).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Shaquer (US 20110152957 A1) in view of Sarkar et al (US 20120238891 A1), Keel et al (US 20130030314), Gagnon-Turcotte (US 20190012515 A1), and Joo et al (US 20180146929).
Regarding claim 4, Shaquer, Sarkar, Keel, and Gagnon-Turcotte teach the method according to claim 2, but are silent regarding the first deviation being recalculated if the average R-R interval is updated.
However, Joo teaches recalculating the first deviation if the average R-R interval is updated (see Joo [0053]; acquisition unit 120 acquires parameter values for Mean NN, SDNN, RMSSD, and pNN50 from the RR interval data from which the ectopic beat is removed through time domain analysis and acquired parameter values for SD1, SD2, and SD1/SD2 through non-linear analysis).
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 Dyjach, Blake, Keel, and Gagnon-Turcotte by adding the active deviation recalculation of Joo. One of ordinary skill in the art would have been motivated to make this modification in order to accurately reflect the physiological system with the most up to date data after a change in average interval.
Claims 1, 5, and 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Dyjach et al (US 8280510) in view of Blake et al (US 20160367157 A1) and Sarkar et al (US 20120238891 A1).
Regarding claim 1, Dyjach teaches a method for detecting an ectopic signal in an electrocardiogram, the ectopic signal being caused by an ectopic cardiac beat (see Fig. 2; step 206a classify present RR interval as ectopic), the method comprising the following steps that are performed by a processor (see Fig. 1; microcontroller 10) of an implantable medical device (see [Col. 4, lines 57-59]; cardiac rhythm management devices are implantable devices that provide electrical stimulation), when a computer-readable program comprised in a memory of the implantable medical device is executed on the processor:
detecting, with a detection unit of the implantable medical device (see [Col. 5, lines 60-61]; controller 10 interprets electrogram signals from sensing channels), consecutive R-R intervals in an electrocardiogram (see Fig. 2; step 201 acquire next present RR interval);
calculating an average R-R interval for a determinable number of latest R-R intervals (see Fig. 2; step 204b calculate median MD of N intervals stored in buffer);
recognizing a signal as ectopic signal if the signal belongs to at least one of two consecutive R-R intervals that are outside the expected window (see [Col. 7, lines 37-38]; step 205 median – Th < RR < median Th, Fig. 2; specified threshold value Th, which may be a percentage of the computed median);
wherein the first and the second of the two consecutive R-R intervals are discarded from calculating the average R-R interval, if the signal is recognized as ectopic signal (see step 206a Classify present RR interval as ectopic_out_of_range. Do not use for HRV metric computation. Remove oldest interval from buffer, Fig. 2).
Dyjach does not teach, wherein:
i) a first of the two consecutive R-R intervals is at least 5% shorter than the average R-R interval;
and ii) a second of the two consecutive R-R intervals is at least 5% longer than the average R-R interval;
wherein the first and second of the two consecutive R-R intervals are discarded simultaneously;
wherein a number of detected ectopic signals is counted; and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals plus a number of detected noise events exceeds a threshold.
Dyjach teaches a threshold to which R-R intervals are compared and classified as ectopic if they differ more than a threshold amount, which may be a percentage of the computed median (see Dyjach Fig. 2), but does not disclose the specific percentage. However, it would have been obvious to one having ordinary skill in the art before the time of filing to use a threshold of 5% to determine significance to characterize an R-R interval as ectopic to predictably determine a discernable, statistically significant, difference between the intervals. The 5% threshold for consecutive R-R intervals is a result-effective variable, because the variable achieves a recognized result – excluding outlying (ectopic) intervals from the calculation of the average R-R interval – and a determination of an optimum or workable range for said threshold value might be characterized as routine experimentation for one of ordinary skill in the art. It can be appreciated that increasing the range to a threshold higher than 5% may result in too many outliers being included in the average calculation, while decreasing the threshold lower than 5% may result in relevant data being excluded from the average calculation. Since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See MPEP 2144.05.
Blake teaches a method for determining valid R-R intervals for heart rate variability (Blake [0098]), wherein a signal is determined to be ectopic if the signal belongs to at least one of two consecutive R-R intervals not passing a validity test (see Blake Fig. 15, [0098]; performing validity tests to determine R-R intervals of interest) wherein the first and second of the two consecutive R-R intervals are discarded at once (see Blake [0104]; once the beat is determined to be ectopic the R-R intervals with exceptional values 1601 are discarded completely). See Blake Fig. 16 below showing discarded ectopic beats.
PNG
media_image1.png
307
853
media_image1.png
Greyscale
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Dyjach’s method for detecting an ectopic signal in an electrocardiogram with the simultaneously discarded R-R intervals as taught by Blake. One of ordinary skill in the art would have been motivated to make this modification in order to ensure that the R-R intervals used for HRV calculation are valid as HRV is very sensitive to erroneous data (Blake [0098]).
Blake is silent regarding wherein a number of detected ectopic signals is counted; and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals plus a number of detected noise events exceeds a threshold.
Sarkar teaches a method for identifying and rejecting ectopic beats based on ventricular cycle lengths (Sarkar, Abstract) wherein RR intervals are identified as ectopic (400), wherein a number of detected ectopic signals is counted (see Sarkar Fig. 7, [0060]; ectopy counter) and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals (see Sarkar Fig. 7, [0067]; if ectopy count is greater than a count threshold, set ectopy count metric to 1) plus a number of detected noise events (see Fig. 7, [0068-0070]; the mode count is compared to a sinus rhythm threshold at step 422, if the mode count is high it may be considered positive evidence for a sinus rhythm) exceeds a threshold (see [0070]; a high ectopy count (ectopy count metric) and evidence of an underlying sinus rhythm (high mode metric) indicates a high probability that the heart rhythm is a sinus rhythm with frequent ectopic beats and a reduced likelihood of the rhythm being AF). It can be appreciated that under the broadest reasonable interpretation of the limitations of the claim, a sinus rhythm as detected by the mode count, is considered to be a noise event as it may cause irregular RR intervals that may be characterized as ectopic and therefore confound the detection of atrial fibrillation.
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method for detecting an ectopic signal disclosed by Dyjach and Blake with the ectopic signal and noise event counters as taught by Sarkar. One of ordinary skill in the art would have been motivated to make this modification in order to more accurately determine the presence of atrial fibrillation in a signal without false positives caused by ectopic beats caused by other events such as a sinus rhythm (Sarkar [0070]).
Regarding claim 5, Dyjach, Blake, and Sarkar teach the method according to claim 1. Dyjach further teaches wherein the average R-R interval is recalculated with each newly detected R-R interval (see Fig. 2; step 204b calculate median MD of N intervals stored in buffer), if this newly detected R-R interval is not discarded from calculating the average R-R interval (see Fig. 2; step 206a Classify present RR interval as ectopic_out_of_range. Do not use for HRV metric computation. Remove oldest interval from buffer).
Regarding claims 7 and 8, Dyjach, Blake, and Sarkar teach the method according to claim 1. They are silent regarding wherein the first of the two consecutive R-R intervals is considered to be significantly shorter than the average R-R interval if the first of the two consecutive R-R intervals is at least 5% shorter than the average R-R interval or, is at least 5% longer than the average R-R interval.
Dyjach teaches a threshold to which R-R intervals are compared and classified as ectopic if they differ more than a threshold amount, which may be a percentage of the computed median (see Dyjach Fig. 2), but does not disclose the specific percentage. However, it would have been obvious to one having ordinary skill in the art before the time of filing to use a threshold of 5% longer or shorter than the average to determine significance to characterize an R-R interval as ectopic in order to predictably determine a discernable, statistically significant, difference between the intervals. The 5% threshold for consecutive R-R intervals is a result-effective variable, because the variable achieves a recognized result – excluding outlying (ectopic) intervals from the calculation of the average R-R interval – and a determination of an optimum or workable range for said threshold value might be characterized as routine experimentation for one of ordinary skill in the art. It can be appreciated that increasing the range to a threshold higher than 5% may result in too many outliers being included in the average calculation, while decreasing the threshold lower than 5% may result in relevant data being excluded from the average calculation. Since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See MPEP 2144.05.
Regarding claim 9, Dyjach, Blake, and Sarkar teach the method according to claim 1. Dyjach further teaches wherein a number of detected ectopic signals is counted (see [Col 7, lines 5-8]; the device may also be programmed to maintain a count of ectopic events detected).
Regarding claim 10, Dyjach teaches an implantable medical device for detecting an electrical signal of a human or animal heart (see [Col. 4, lines 57-59]; cardiac rhythm management devices are implantable devices that provide electrical stimulation), the implantable medical device comprising a processor (10), a memory unit (12), and a detection unit configured to detect an electrical signal of a human or animal heart (see Fig. 1; sensing/pacing channels 11A-C and 43A-C), wherein the memory unit comprises a computer-readable program that causes the processor to perform the following steps when executed on the processor (see [Col. 5, lines 10-11]; microprocessor 10 communicating with a memory 12 via a bidirectional bus):
detecting, with the detection unit, consecutive R-R intervals in an electrocardiogram (see [Col. 5, lines 60-61]; controller 10 interprets electrogram signals from sensing channels);
calculating an average R-R interval for a determinable number of latest R-R intervals (see Fig. 2; step 204b calculate median MD of N intervals stored in buffer);
recognizing a signal as ectopic signal if the signal belongs to at least one of two consecutive R-R intervals (see [Col. 7, lines 37-38]; step 205 median – Th < RR < median Th, Fig. 2; specified threshold value Th, which may be a percentage of the computed median);
wherein the first and the second of the two consecutive R-R intervals are discarded from calculating the average R-R interval (see Fig. 2, step 204a Classify present RR interval as ectopic_insufficient_intervals. Do not use for HRV metric computation).
Dyjach does not teach, wherein:
i) a first of the two consecutive R-R intervals is at least 5% shorter than the average R-R interval;
and ii) a second of the two consecutive R-R intervals is at least 5% longer than the average R-R interval and;
wherein the first and second of the two consecutive R-R intervals are discarded simultaneously;
wherein a number of detected ectopic signals is counted; and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals plus a number of detected noise events exceeds a threshold.
Dyjach teaches a threshold to which R-R intervals are compared and classified as ectopic if they differ more than a threshold amount, which may be a percentage of the computed median (see Dyjach Fig. 2), but does not disclose the specific percentage. However, it would have been obvious to one having ordinary skill in the art before the time of filing to use a threshold of 5% to determine significance to characterize an R-R interval as ectopic in order to predictably determine a discernable, statistically significant, difference between the intervals. The 5% threshold for consecutive R-R intervals is a result-effective variable, because the variable achieves a recognized result – excluding outlying (ectopic) intervals from the calculation of the average R-R interval – and a determination of an optimum or workable range for said threshold value might be characterized as routine experimentation for one of ordinary skill in the art. It can be appreciated that increasing the range to a threshold higher than 5% may result in too many outliers being included in the average calculation, while decreasing the threshold lower than 5% may result in relevant data being excluded from the average calculation. Since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See MPEP 2144.05.
Blake teaches a system for determining valid R-R intervals for heart rate variability (Blake [0098]), wherein a signal is determined to be ectopic if the signal belongs to at least one of two consecutive R-R intervals not passing a validity test (see Blake Fig. 15, [0098]; performing validity tests to determine R-R intervals of interest) wherein the first and second of the two consecutive R-R intervals are discarded at once (see Blake [0104]; once the beat is determined to be ectopic the R-R intervals with exceptional values 1601 are discarded completely). See Blake Fig. 16 below showing discarded ectopic beats.
PNG
media_image1.png
307
853
media_image1.png
Greyscale
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Dyjach’s system for detecting an ectopic signal in an electrocardiogram with the simultaneously discarded R-R intervals as taught by Blake. One of ordinary skill in the art would have been motivated to make this modification in order to ensure that the R-R intervals used for HRV calculation are valid as HRV is very sensitive to erroneous data (Blake [0098]).
Sarkar teaches a method for identifying and rejecting ectopic beats based on ventricular cycle lengths (Sarkar, Abstract) wherein RR intervals are identified as ectopic (400), wherein a number of detected ectopic signals is counted (see Sarkar Fig. 7, [0060]; ectopy counter) and
wherein an observed cardiac rhythm is considered being a rhythm devoid of atrial fibrillation if the number of detected ectopic signals (see Sarkar Fig. 7, [0067]; if ectopy count is greater than a count threshold, set ectopy count metric to 1) plus a number of detected noise events (see Fig. 7, [0068-0070]; the mode count is compared to a sinus rhythm threshold at step 422, if the mode count is high it may be considered positive evidence for a sinus rhythm) exceeds a threshold (see [0070]; a high ectopy count (ectopy count metric) and evidence of an underlying sinus rhythm (high mode metric) indicates a high probability that the heart rhythm is a sinus rhythm with frequent ectopic beats and a reduced likelihood of the rhythm being AF). It can be appreciated that under the broadest reasonable interpretation of the limitations of the claim, a sinus rhythm as detected by the mode count, is considered to be a noise event as it may cause irregular RR intervals that may be characterized as ectopic and therefore confound the detection of atrial fibrillation.
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method for detecting an ectopic signal disclosed by Dyjach and Blake with the ectopic signal and noise event counters as taught by Sarkar. One of ordinary skill in the art would have been motivated to make this modification in order to more accurately determine the presence of atrial fibrillation in a signal without false positives caused by ectopic beats caused by other events such as a sinus rhythm (Sarkar [0070]).
Claims 2 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Dyjach in view of Blake (US 20160367157 A1), Sarkar et al (US 20120238891 A1), Keel et al (US 20130030314), and Gagnon-Turcotte (US 20190012515 A1).
Regarding claims 2 and 3, Dyjach, Blake, and Sarkar teach the method according to claim 1. They are silent regarding wherein the method further comprises the following steps: calculating a first deviation, the first deviation being an average absolute deviation of the consecutive R-R intervals of the determinable number of latest consecutive R-R intervals used for calculating the average R-R interval from the average R-R interval; multiplying the first deviation with a factor being greater than 1 to obtain an increased first deviation; calculating a second deviation, the second deviation being an absolute deviation of a successive R-R interval from the average R-R interval; defining the R-R interval as significantly shorter than the average R-R interval if the R-R interval is shorter than the average R-R interval and if the second deviation is greater than the increased first deviation, or defining the R- R interval as significantly longer than the average R-R interval if the R-R interval is longer than the average R-R interval and if the second deviation is greater than the increased first deviation.
Keel teaches calculating a first deviation, the first deviation being an average absolute deviation of the consecutive R-R intervals of the determinable number of latest consecutive R-R intervals (see Keel [0127]; localized R-R interval stability metric can be determined for an IEGM by determining the R-R intervals for a plurality of consecutive cardiac cycles) used for calculating the average R-R interval from the average R-R interval (see [0127]; step 604 fig 6, exemplary measures of variation, which can be determined for the R-R intervals, can include one or more of: average absolute deviation);
calculating a second deviation, the second deviation being an absolute deviation of a successive R-R interval from the average R-R interval (see Keel Fig. 6; step 604, determine corresponding localized R-R interval stability metric indicative of the R-R interval stability at corresponding ventricular region);
defining the R-R interval as significantly shorter than the average R-R interval if the R-R interval is shorter than the average R-R interval and if the second deviation is greater than the increased first deviation (see Keel [0130]; step 606, Keel Fig. 6, comparing each localized R-R interval stability metric, determined for an IEGM, to an appropriate R-R interval stability threshold), or defining the R- R interval as significantly longer than the average R-R interval if the R-R interval is longer than the average R-R interval and if the second deviation is greater than the increased first deviation (see Keel [0130]; step 606, Keel Fig. 6, if the localized R-R interval stability metric, the measure of standard deviation, exceeds the R-R interval stability threshold, the standard deviation threshold, then it can be determined that the stability criterion is not met).
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method as taught by Dyjach with the calculation of a first and second deviation as taught by Keel. One of ordinary skill in the art would have been motivated to make this modification in order to provide a stability metric for which subsequent signals can be compared to (Keel [0027]).
Keel does not teach multiplying the first deviation with a factor being greater than 1 to obtain an increased first deviation.
However, Gagnon-Turcotte teaches a method for identifying outlying/noisy points in a signal where the first standard deviation is multiplied by a factor greater than 1 to obtain an increased first deviation (see Gagnon-Turcotte [0081-0082]; a standard deviation can be multiplied by constant M, where M can be 2).
It would have been obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method as taught by Dyjach and Keel by multiplying the standard deviation with a calibration factor as taught by Gagnon-Turcotte. One of ordinary skill in the art would have been motivated to make this modification in order to account for variability in the signal and obtain the desired threshold size for excluding noise (Gagnon-Turcotte [0082]).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Dyjach in view of Blake, Sarkar, Keel, and Gagnon-Turcotte in further view of Joo et al (US 20180146929).
Regarding claim 4, Dyjach in view of Blake, Sarkar, Keel, and Gagnon-Turcotte teach the method according to claim 2, but are silent regarding the first deviation being recalculated if the average R-R interval is updated.
However, Joo teaches recalculating the first deviation if the average R-R interval is updated (see Joo [0053]; acquisition unit 120 acquires parameter values for Mean NN, SDNN, RMSSD, and pNN50 from the RR interval data from which the ectopic beat is removed through time domain analysis and acquired parameter values for SD1, SD2, and SD1/SD2 through non-linear analysis).
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 Dyjach, Blake, Keel, and Gagnon-Turcotte by adding the active deviation recalculation of Joo. One of ordinary skill in the art would have been motivated to make this modification in order to accurately reflect the physiological system with the most up to date data after a change in average interval.
Claims 11 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Dyjach in view of Blake, Sarkar, and Chang et al (US 10117595).
Regarding claim 11, Dyjach, Blake, and Sarkar teaches the method according to claim 1. They are silent regarding a method further comprising detecting atrial fibrillation of a human or animal heart, the method comprising applying an atrial fibrillation detection algorithm.
Chang teaches a method further comprising detecting atrial fibrillation of a human or animal heart, the method comprising applying an atrial fibrillation detection algorithm (see Chang Fig. 6: flowchart for detecting atrial fibrillation).
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 Dyjach, Blake, and Sarkar by adding the atrial fibrillation detecting method of Chang. One of ordinary skill in the art would have been motivated to make this modification in order to screen anomalous beats (PVCs and APCs) to prevent false detection of atrial fibrillation (Chang [Col. 4, lines 25-26]).
Regarding claim 12, Chang further teaches wherein the method for detecting an ectopic signal in an electrocardiogram is only carried out for a programmable time period after a beginning of the atrial fibrillation detection algorithm, or for a programmable time period after the detection of an atrial fibrillation episode (see [Chang Col. 3, lines 42-44]; only when a signal segment is identified as a cardiac arrhythmia suspect will the device record and transmit the signal).
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 Dyjach, Blake, and Sarkar by programming the method to only carry out after the beginning/detection of an atrial fibrillation event. One of ordinary skill in the art would have been motivated to make this modification in order to reduce the resource requirement on the device and prolong the operation time of the device (Chang, [Col 3, lines 44-46]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALISHA J SIRCAR whose telephone number is (571)272-0450. The examiner can normally be reached Monday - Thursday 9-6:30, Friday 9-5:30 CT.
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, Benjamin Klein can be reached on 571-270-5213. 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.
/A.J.S./Examiner, Art Unit 3792
/SHIRLEY X JIAN/Primary Examiner, Art Unit 3792