INTRACRANIAL PRESSURE ESTIMATING METHOD AND INTRACRANIAL PRESSURE ESTIMATING DEVICE

• US 20190328248A1
• Filed: 06/12/2017
• Published: 10/31/2019
• Est. Priority Date: 06/17/2016
• Status: Active Grant

• Current Assignee: Ichikawa Electric Co., Ltd., Shinshu University National University Corporation
• Original Assignee: Ichikawa Electric Co., Ltd.
• Inventors: KOIKE, Norio, YASUMOTO, Satoshi, NAKANO, Jun, SAI, Yukio, FURIHATA, Kenji, GOTO, Tetsuya, HONGO, Kazuhiro
• Granted Patent: US 11,278,212 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61B 5/036 by means introduced into body tracts A61B5/032 and A61B5/035 take precedence
• CPC Class Codes: A61B 5/6817 Ear canal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

An intracranial pressure estimating method includes: an acquisition step (S10) of acquiring time-series data on external ear canal pressure pulse waves of a subject; an analysis step (S12) of analyzing external ear canal pressure pulse wave data obtained by digitalizing the time-series data on the external ear canal pressure pulse waves, to calculate a first formant frequency of the external ear canal pressure pulse wave data; a correction step (S13) of correcting the calculated first formant frequency based on personal information on the subject to calculate a corrected value; and an estimation step (S14) of calculating an estimated value of an intracranial pressure based on the calculated corrected value.

Claims

1. An intracranial pressure estimating method for estimating an intracranial pressure from time-series data on external ear canal pressure pulse waves, the method comprising:

an acquisition step of acquiring time-series data on external ear canal pressure pulse waves of a subject;

an analysis step of analyzing external ear canal pressure pulse wave data obtained by digitalizing the time-series data on the external ear canal pressure pulse waves to calculate a first formant frequency of the external ear canal pressure pulse wave data;

a correction step of correcting the first formant frequency based on personal information on the subject to calculate a corrected value; and

an estimation step of calculating an estimated value of an intracranial pressure based on the corrected value.

2. The intracranial pressure estimating method according to claim 1,

wherein the analysis step includes analyzing data obtained by subjecting the external ear canal pressure pulse wave data to high-pass filter processing to calculate the first formant frequency.

3. The intracranial pressure estimating method according to claim 1, wherein the estimation step includes calculating an estimated value PICP of the intracranial pressure based on the following equation:

PICP=A·

ln(Xf1)+B

where A and B are constants, and Xf1 is the corrected value.

4. The intracranial pressure estimating method according to claim 3, wherein the correction step includes calculating the corrected value Xf1 based on the following equation:

Xf1=f1+β

1·

ln(K/Age)+β

2·

FM

where f1 is the first formant frequency, β

1, K, and β

2 are constants, Age is the age of the subject, and FM is the sex of the subject (0 for male and 1 for female).

5. An intracranial pressure estimating device comprising:

an external ear canal pressure pulse wave sensor that detects external ear canal pressure pulse waves of a subject; and

an arithmetic unit that estimates an intracranial pressure from time-series data on the external ear canal pressure pulse waves,

wherein the arithmetic unit analyzes external ear canal pressure pulse wave data obtained by digitalizing the time-series data on the external ear canal pressure pulse waves, calculates a first formant frequency of the external ear canal pressure pulse wave data, corrects the first formant frequency based on personal information on the subject to calculate a corrected value, and calculates an estimated value of the intracranial pressure based on the corrected value.