Whether a woman wants to use the Fertility Awareness Method (FAM) to help her get pregnant or to avoid getting pregnant, here is the thing about the menstrual cycle-underlying mechanism called folliculogenesis:

Folliculogenesis (click for a primer) is not merely a process involving hormonal signals – it’s a process of integration of all hormonal and neurological inputs, which the cervix monitors. And our Ovulona biosensor monitors the cervix.

Ovulona profile with fertile days and BBT - e2 detect progress

Click on the image of a baseline cycle for a slide in PDF about folliculogenesis and the wealth of information inherent in the electronic signature of the menstrual cycle profile

The ovulographic monitoring of folliculogenesis in vivo is understood to capture the fine-tuning effects on folliculogenesis of the direct neural control via ovarian and uterine innervation and the acute effects of local (autocrine and paracrine) modulatory actions. Those effects cannot be detected by the systemic peripheral variables such as the BBT or the urinary levels of hormones monitored by the commercially available home-use technologies.

Here is to illustrate the variability of the ovulation day as captured by  Ovulona prototypes when tested by Natural Family Planning Clinic at Marquette University. Differences in ovulation days from -5 to +3 days between the two consecutive cycles are shown in this small sample of 10 NFP clinic patients.

Ref.: ACCURACY OF THE OVULON FERTILITY MONITOR with a note  https://biozhena.files.wordpress.com/2018/12/fehring-schlaff-ovulon-publication-with-note.pdf


Summary of 10 NFP clinic patients, 2 consecutive cycles each

Patient number

Ovulation days in two consecutive cycles

Difference between those two cycles


Has given birth before or not

1 16, 17 +1 35 mother
2 14, 17 +3 33 mother
3 17, NA NA 42 mother
4 15, 14 -1 33 mother
5 20, NA NA 30 mother
6 19, 18 -1 38 mother
7 16, 13 -3 29 no children
8 21, 24 +3 19 no children
9 18, 13 -5 41 no children
10 10, 12 +2 22 no children


Our ovulographic monitoring of folliculogenesis in vivo (via the cervix) can determine the 3 days of the so-called fertile window even when the timing is affected –as often happens– by stress, discussed in  https://biozhena.wordpress.com/stress-and-fertility-fertile-window-ovulation/ .

Non-baseline cycle w delayed ovulation- algor applied AND next cycle, no ovu delay - e1

The image illustrates (click it to enlarge) the Ovulona menstrual cyclic profile algorithm’s ability to address the effects of stress on the fertile window and ovulation timing. Refer for more to the page linked above the image.

In summary: The slow rate of descent of the Ovulona signal from the short-term predictive peak to the ovulation marker nadir (or minimum) in cycle 4 indicates an extended period of time (here 2 additional days)  required for the circhoral and the circamensual pacemakers (of the brain and of the ovary, respectively) to synchronize as the absolute precondition of ovulation.






Two ways to synchronize

It is speculated that an alternative synchronization activity is reflected on the descending branch of the long-term predictive peak in the cyclic record of cycle 5, which was recorded by the same woman in her menstrual cycle following after the cycle with the delayed ovulation (cycle 4).

The star-marks in the star-embellished image below here highlight how the Ovulona captured the two alternative mechanisms of brain-ovary synchronization -the precondition of ovulation- in two consecutive cycles recorded by the same woman.

The information-rich and interpretable features of the menstrual cyclic profile make this detection possible. See this in the interpretable features link to four PDF slides; the first slide-suggested navigation (with the curved arrows) is best but this applies to Firefox browser, and the sticky notes can be scrolled also apparently only in Firefox.

The Smart Ovulonawill perform the data interpretation electronically (the algorithm is proprietary as are the method and apparatus).

A reminder: Ovulation is detected as the lowest minimum (a nadir of repeatable narrow range of amplitudes) in the graph of the daily menstrual cycle readings, after the long-term and short-term predictive peaks. That’s due to a switch at ovulation from estrogen dominance to progesterone dominance (as found in 3 mammalian species: estrogen drove the signal up  versus progesterone drove it down – which is indicated in slide 2 in the above-linked interpretable features set of 4 PDF slides).

This switch is quite dramatic, and even the peripheral hormone measurements in women reflect that. For example, salivary steroid concentrations on ovulation day are: estradiol 8 pmol/l and progesterone 110 pmol/l; the steroid data are cited from  www.paleoanthro.org/static/journal/content/PA20080172.pdf.

Non-baseline cycle w delayed ovulation- algor applied AND next cycle, no ovu delay - e2 (arrests), starsClick image to enlarge in a new tab 
Same for next two images (when finished, close the tab)


Folliculogenesis and why we track it

Let’s reiterate that folliculogenesis is a process of integration of all neuroendocrinological inputs (i.e. ovary – brain feedback interactions, hormonal and neurological), which the cervix monitors, and the Ovulona sensor monitors the cervix.

HPG loop w. any stress affects timing text - edited


So, there you have it:


Why We Track Folliculogenesis (from Transforming, white) ed.2 

 For the linked FDA clearance letter summary click

For a blog article about the effects of stress on fertility click 


Now we highlight the significance of this for an important aspect of women’s health, of women’s life:

The Ovulona tracking menstrual cycles will be key to managing fertility/reproductive issues of women with depression and perceived stress. These are associated with irregular cycles and not associated with psychmeds (ref.: https://ncbi.nlm.nih.gov/pmc/articles/PMC6118267/ ). Logically, the Ovulona Folliculogenesis-In-Vivo technology should be used to examine menstrual cycle details (example) in relation to symptoms and treatment.


Folliculogenesis In Vivo™ cervix monitoring technology provides longitudinal signature records of the menstrual cycle vital sign.

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