Multipurpose Weighing Device

• US 20150338265A1
• Filed: 12/30/2013
• Published: 11/26/2015
• Est. Priority Date: 01/02/2013
• Status: Active Grant

• Current Assignee: Withings S.A.
• Original Assignee: Withings S.A.
• Inventors: Carreel, Eric, Buard, Nadine, Barrochin, Pierre, Faussard, Guillaume, Brac De La Perriere, Brice, Yang, Rui-Yi, Aitmbarek, Said
• Granted Patent: US 9,778,095 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: G01G 19/4144 for controlling weight of goods in commercial establishments, e.g. supermarket, P.O.S. systems
• CPC Class Codes: G01G 19/50 having additional measuring devices, e.g. for height

Abstract

Weighing device of the digital bathroom scale type, comprising four feet each having a strain gauge, four conducting portions on the top surface, and one electronic control unit, the electronic unit being configured to measure first signals indicative of periodic variations in weight and second signals indicative of periodic variations in impedance caused by the heartbeats of the user, the electronic unit being configured to determine the heart rate of the user from the first and second signals. Method for determining the heart rate of the user from the first and second signals.

Claims

1. A weighing device of the digital bathroom scale type, comprising at least one strain gauge, at least two conducting portions arranged on a top surface 6, and an electronic control unit, the method comprising at least the steps of:

the strain gauge being connected to the electronic unit and the electronic unit being configured to determine the weight of a user positioned on the weighing device, and to measure a first signal indicative of the periodic variations in weight caused by the heartbeats of the user,

the conducting portions being connected to the electronic unit and the electronic unit being configured to measure an impedance at the terminals of the user'"'"'s feet and to measure a second signal indicative of the periodic variations in impedance caused by the heartbeats of the user,

wherein the electronic unit is configured to perform a qualitative individual analysis of the first and second signals and a comparative analysis of the first and second signals so as to determine from the first and second signals the heart rate of the user, so that the measurement and display of the heart rate are made more reliable by the combined analysis of the two signals.

2. The weighing device according to claim 1 comprising four conducting portions, wherein the electronic unit is configured to inject a modulated or pulsed current between two of the conducting portions and to measure the electric potential difference between the two other conducting portions, in order to determine the variations in electric potential difference and thus determine the second

3. The weighing device according to 1, wherein the electronic unit is configured to evaluate a quality index for the first signal and a quality index for the second signal, and to determine the heart rate from the signal having the best quality index.

4. The weighing device according to 1, wherein the electronic unit is configured to perform a cross-correlation calculation on the first and second signals.

5. The weighing device according to claim 4, wherein the electronic unit is configured to measure a phase difference (dT) between the first and second signals, and to shift the second signal relative to the first signal by said phase difference so that the cross-correlation calculation eliminates noise and maximizes the useful signal portions.

6. The weighing device according to claim 3, wherein the electronic unit is configured to evaluate a quality index for the cross-correlation calculation, and to determine the heart rate from the first and second signals and from the cross-correlation calculation by choosing the one of the three having the highest quality index

7. The weighing device according claim 1, comprising four feet and four corresponding strain gauges, combined into two Wheatstone bridges, to allow the electronic unit to measure a user'"'"'s weight and weight variations

8. A method implemented in a digital bathroom scale comprising at least one strain gauge, at least two conducting portions arranged on a top surface, and an electronic control unit,

the strain gauge and the conducting portions being connected to the electronic unit to enable the electronic unit to measure the weight of a user positioned on the weighing device and an impedance at the terminals of the user'"'"'s feet,

the method comprising the steps of:

a- measuring a first signal indicative of the periodic variations in weight caused by the heartbeats of the user,

b- measuring a second signal indicative of the periodic variations in impedance caused by the heartbeats of the user,

c0- performing a qualitative individual analysis of the first and second signals and a comparative analysis of the first and second signals,

c- determining the heart rate of the user from the first and second signals, such that the measurement and display of the heart rate are made more reliable by the combined analysis of the two signals.

9. The method according to claim 8, wherein the device comprises four conducting portions, said method comprising during step b:

injecting a pulsed current between two of the conducting portions and measuring the electric potential difference between the two other conducting portions, in order to determine the variations in electric potential difference and thus determine the second signal.

10. The method according to claim 8, further comprising in step c:

performing at least one cross-correlation calculation on the first and second signals.

11. The method according to claim 10, further comprising in step c:

measuring a phase difference between the first and second signals, and shifting the second signal relative to the first signal by said phase difference, so that the cross-correlation calculation eliminates noise and maximizes the useful signal portions.