Electronic blood pressure meter

• US 9,723,999 B2
• Filed: 10/05/2012
• Issued: 08/08/2017
• Est. Priority Date: 12/09/2011
• Status: Active Grant

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Inventors: Yamashita, Yuki, Kobayashi, Tatsuya
• Primary Examiner(s): Cheng, Jacqueline
• Assistant Examiner(s): Agahi, Puya
• Application Number:
  US14/353,328
• Publication Number:
  US 20140276146A1
• Time in Patent Office: 1,768 Days
• Field of Search: 600481, 600490-499, 338 2, 338 4, 338 36, 338 47
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02233 Occluders specially adapted therefor tourniquets A61B17/132
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/02255 the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors
• CPC Class Codes: H02H 9/001 limiting speed of change of electric quantities, e.g. soft switching on or off progressive control of electronic switches for eliminating interferences H03K17/16
• CPC Class Codes: H02H 9/002 limiting inrush current on switching on of inductive loads subjected to remanence, e.g. transformers
• CPC Class Codes: H10N 30/802 Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits

Abstract

An electronic blood pressure meter includes a cuff that is to be worn on a measurement area, a piezoelectric pump that adjusts a pressure applied to the cuff, a drive circuit that drives the piezoelectric pump, and a controller that outputs, to the drive circuit, a pulse signal defining a driving timing of the piezoelectric pump. The drive circuit includes a switching circuit for switching a connection relationship between respective voltages applied to both ends of the piezoelectric pump in response to corresponding first and second driving signals, and a signal generation circuit that outputs the first and second driving signals based on the pulse signal outputted from the controller. The signal generation circuit has a signal conditioning circuit that adjusts timings of the first and second driving signals so that the phases of the first and second driving signals do not overlap.

Claims

1. An electronic blood pressure meter capable of suppressing inrush current, the electronic blood pressure meter comprising:

a cuff that is to be worn on a measurement area;

a piezoelectric pump that adjusts a pressure applied to the cuff;

a drive circuit that drives the piezoelectric pump; and

a controller that outputs, to the drive circuit, a pulse signal defining a driving timing of the piezoelectric pump,

wherein the drive circuit comprises;

an inverting circuit that outputs a non-inverted pulse signal having a same pattern as the pulse signal and an inverted pulse signal having an inverted pattern of the pulse signal;

a first signal conditioning circuit comprising a first delay circuit and a first waveform shaping circuit for processing the non-inverted pulse signal to produce a first driving signal such that timing of a rise of a positive going pulse in the first driving signal is delayed with respect to timing of a rise of a positive going pulse in the non-inverted pulse signal;

a second signal conditioning circuit comprising a second delay circuit and a second waveform shaping circuit for processing the inverted pulse signal to produce a second driving signal such that timing of a rise of a positive going pulse in the second driving signal is delayed with respect to timing of a rise of a positive going pulse in the inverted pulse signal so that the timings of a rise and fall of the first and second driving signals do not overlap; and

a switching circuit that switches a current flow through the piezoelectric pump between a first direction and a second direction in response to the corresponding first and second driving signals.

2. The electronic blood pressure meter according to claim 1, wherein at least one of the first delay circuit and the second delay circuit comprises a variable capacitance element whose capacitance component changes in accordance with an instruction from the controller.