Program: Invention Factory

Year: Summer 2018

Goal: Invent a tangible product that meets a significant need, in six weeks. During the program, must present weekly to guest evaluators, file a provisional patent application, and compete for the best invention.


  • Provisional Patent: US 62/722,356

  • easy to wear, discreet watch-like wearable with LCD screen and variable strap length

  • connected to a phone app for user personalization and customization, as well as visual tracking

  • tracks menstruation and ovulation in a on-intrusive way, using four physiological markers

  • device measures heart rate, basal body temperature, and estimates blood pressure and stress levels

  • unique algorithm to track, estimate, and notify the user of her menstruation cycle and ovulation

  • all electronics encased inside the acrylic box, for safety and stability

  • rechargeable battery


Technical Details

Intended to allow women to achieve greater control of becoming pregnant of avoiding pregnancy by accurately tracking their ovulation and menstruation cycle, Yours Truly is able to provide menstruation information without the traditional obtrusive, complicated, and expensive lab/hospital methods. Yours Truly uses the correlations between the different parts of a menstruation cycle and one's hormone levels, and corresponding changes in physiological markers.

The device measures and estimates basal body temperature, resting heart rate, blood pressure levels, and stress levels with sensors. An accelerometer is used to ensure that only the basal body temperature and resting heart rate are tracked, as both occur when the user is not moving, or resting. A temperature sensor, a galvanic sensor for skin conductivity and estimated stress levels, and a pair of pulseoximeters are used for heart rate and estimate blood pressure. For the estimation of blood pressure, the time difference, or the pulse transit time, between the two pulseoximeters is used. With the data from the galvanic sensor and changes in skin conductance, the blood pressure estimations are also taken into consideration when determining the stress levels of the user.

Yours Truly also adapts to the user based on previous cycles of data, able to provide a more personalized means of tracking for the woman. A series of unique algorithms were created to ensure that Yours Truly can accurately estimate the different parts of the menstruation cycle, and improve as each cycle passes. Data acquired from the sensors will be analyzed and trended, and predictions for ovulation and the different parts of the menstruation cycle will be improved.

The device displays ovulation and menstruation states subtly on its screen with the watch face, and also transmits the data to a cellphone application. The cellphone application allows the user to visually see the different trends in her physiological markers, the length of different parts of the menstruation cycle, and more. The user can also add notes, or notifications, for days that she chooses. This could aid in the estimation and prediction for the menstruation cycle, as physiological markers can also be affected by food, exercise, and more. The application can also send a notification to a partner, to notify them of specific days and phases, such as ovulation.

The current prototype can be improved (smaller size, faster computing power, longer battery life, more customization, etc) once it goes into manufacturing. Custom made sensors, chips, and other electronics, as well as the body of the watch, can be improved with increase in available funds, time, and development.

© 2021 by Olivia Heui Young Park

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