Sphygmogram measure method and device for two closed measured points
First Claim
1. A sphygmogram measure method for measuring pulse pressure at two adjacent measure points, comprising the steps of:
- Step 1;
positioning an upstream pressure sensor and a downstream pressure sensor at a certain distance L in accordance with the bloodstream direction;
Step 2;
acquiring the signals from the upstream and the downstream pressure sensors and passing the signals through preamplifier and filter circuits and offset adjust circuits to acquire an analog form of upstream pressure P0(t) and downstream pressure PL(t);
Step 3;
converting the analogy analog form of upstream pressure P0(t) into a digital upstream pressure P0(n) using an A/D converter at a sampling frequency of 200 to 400 Hz and then storing the digital upstream pressure into a digital signal process unit;
Step 4;
filtering the analog form of upstream pressure P0(t) and downstream pressure PL(t) by two low-pass filters to obtain their fundamental waves;
Step 5;
detecting the zero-cross signal of the fundamental wave of the upstream and downstream pressure signals to trigger and stop the counting of a counter, and obtaining the time lag τ
between the two pressure signals by output of the counter;
Step 6;
storing the digitized upstream pressure signal P0(t) and time lag τ
in the digital signal process unit; and
Step 7;
calculating the digital downstream pressure PL(n) in the digital signal process unit by using the digital upstream pressure P0(n) and time lag τ
, where PL(n) P0(n+τ
).
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Accused Products
Abstract
A sphygmogram measure method and device includes an upstream and a downstream pressure sensor arranged in accordance with the bloodstream direction to measure the pulse pressure of two adjacent points on radial artery in the wrist. The pulse pressures are processed and converted to analog signals by an amplitude filter circuit and an adjusting circuit. The analog signal of upstream pulse pressure is converted to a digital signal, which is stored in a digital signal process unit. The signals of upstream pulse pressure and downstream pulse pressure are also transmitted as a start signal and a stop signal respectively to a counter which measures the time lag of a pulse wave passing through the two pressure sensors. The digital signal process unit uses the digital signals of upstream pulse pressure and time lag to calculate the digital signal of downstream pulse pressure.
8 Citations
6 Claims
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1. A sphygmogram measure method for measuring pulse pressure at two adjacent measure points, comprising the steps of:
-
Step 1;
positioning an upstream pressure sensor and a downstream pressure sensor at a certain distance L in accordance with the bloodstream direction;
Step 2;
acquiring the signals from the upstream and the downstream pressure sensors and passing the signals through preamplifier and filter circuits and offset adjust circuits to acquire an analog form of upstream pressure P0(t) and downstream pressure PL(t);
Step 3;
converting the analogy analog form of upstream pressure P0(t) into a digital upstream pressure P0(n) using an A/D converter at a sampling frequency of 200 to 400 Hz and then storing the digital upstream pressure into a digital signal process unit;
Step 4;
filtering the analog form of upstream pressure P0(t) and downstream pressure PL(t) by two low-pass filters to obtain their fundamental waves;
Step 5;
detecting the zero-cross signal of the fundamental wave of the upstream and downstream pressure signals to trigger and stop the counting of a counter, and obtaining the time lag τ
between the two pressure signals by output of the counter;
Step 6;
storing the digitized upstream pressure signal P0(t) and time lag τ
in the digital signal process unit; and
Step 7;
calculating the digital downstream pressure PL(n) in the digital signal process unit by using the digital upstream pressure P0(n) and time lag τ
, where PL(n) P0(n+τ
). - View Dependent Claims (2)
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3. A sphygmogram measure device for measuring pulse pressure at two adjacent measure points, comprising:
-
a wrist holder that stabilizes a wrist but does not press a vessel therein;
a set of pressure sensing devices mounted in the wrist holder and comprising a seat, an upstream pressure sensor mounted in the seat, a downstream pressure sensor mounted in the seat and a drive device disposing the seat downwards, the upstream pressure sensor including a first casing mounted in the seat, an upstream chip mounted in the first casing and a first resilient cover covering the upstream chip, the downstream pressure sensor including a second casing mounted in the seat, a downstream chip mounted in the second casing and a second resilient cover covering the downstream chip, a first chamber defined between the upstream chip and the first resilient cover and a second chamber defined between the downstream chip and the second resilient cover, the first and the second chambers filled with fluid, the central tip of the first resilient cover being a first column head which extends out of the bottom edge of first casing and the central tip of second resilient cover being a second column head extending out of the bottom edge of second casing ; and
a detecting circuit connected to the upstream pressure sensor and the downstream pressure sensor. - View Dependent Claims (4, 5, 6)
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Specification