JP2008506423A5

JP2008506423A5 -

Info

Publication number: JP2008506423A5
Application number: JP2007518293A
Authority: JP
Filing date: 2005-06-24
Publication date: 2013-08-22
Anticipated expiration: 2025-06-24

Description

図９は、咳検出の第２の方法の詳細を例示している。一回呼吸気量の痕跡V_Tは、RC帯およびAB帯の線形的に重み付けされた和であると先に判定されているが、これがまず２個の互いに平行なFIR帯域通過フィルタを通過させられて、ピーク出力（フィルタ処理された信号の最大値によって反映されるような）が測定されて、ピーク出力が閾値Ｔを超過した場合には、起こり得る咳事象の存在を判定する。入力呼吸信号のフィルタは有限衝撃反応（FIR）設計のものであるのが好ましいが、無限衝撃反応（IIR）フィルタで、位相シフトまたは時間遅延が最小限であるものを使用してもよい。ここでは、呼吸信号位相は十分に平静で、対応する音声信号と一時的に一致したままになるようにしなければならない。
FIG. 9 illustrates details of the second method of cough detection. The tidal volume trace _VT has previously been determined to be a linearly weighted sum of the RC and AB bands, which are first passed through two parallel FIR bandpass filters. The peak output (as reflected by the maximum value of the filtered signal) is measured to determine the presence of a possible cough event if the peak output exceeds a threshold T. The input respiratory signal filter is preferably of a finite impact response (FIR) design, but an infinite impact response (IIR) filter with minimal phase shift or time delay may be used. Here, the respiratory signal phase must be sufficiently calm and remain in temporary agreement with the corresponding audio signal.

Claims

A computer system for recognizing cough events in a sensor signal,
A processor;
A readable computer memory storing a program for causing the processor to execute the following steps (1) to (5):
A computer system characterized by including:
(1) receiving sensor signal data including tidal volume (V _T ) data and audio data , wherein the V _T data includes thoracic dimension (RC) data reflecting a thoracic dimension; Waveform data combining abdominal dimension (AB) data reflecting abdominal dimensions ; step ;
(2) when the sound follicles routes received has exceeded a selected threshold, recognizes the sound event in the audio data said receiving step;
(3) A step of filtering the tidal volume (V _T ) data with a high frequency band pass filter to obtain a high frequency band pass filtered V _T data (HFB);
(4) a step of filtering the tidal volume (V _T ) data with a low frequency band pass filter to obtain a low frequency band pass filtered V _T data (LFB);
(5) Measure the duration of the sound event, select HFB if the duration is less than a predetermined time , select LFB if the duration exceeds a predetermined time, and select the selected data the amplitude of the following processes (a) and (b) performing a (a) selected V _T data is for has already exceeded the measured threshold is selected depending on the amplitude of the past V _T data when, processing of recognizing respiratory events in the selected V _T data were; sigh and (b) recognized respiratory event cough - has an intake pattern characteristics, it recognized sound event and temporarily respiratory event The process of recognizing cough events when they overlap.

The system of claim 1, wherein the selected sound envelope threshold includes a background-based noise threshold.

The exhalation-inspiration pattern characteristic has an exhalation period followed by an inspiration period, which overlaps sound events such that a minimum tidal volume (V _T ) value occurs in the central portion of the sound event. The system of claim 1, wherein the system appears in a middle symmetry.

The system of claim 1, wherein the exhalation-inspiration pattern characteristic has a peak exhalation flow that is greater than a peak exhalation flow threshold determined in dependence on an already measured peak exhalation flow.

The program causes the processor to perform a step of determining a pitch measurement of a recognized sound event by performing mel frequency wrapping, wherein the cough event comprises an inspiration-inspiration pattern characteristic. The system of claim 1, wherein a sound event that overlaps with a respiratory event is recognized only if it has a determined pitch measurement that indicates that no speech is present.

The program may cause the processor to determine that if the maximum pitch is shorter than the cough-speech threshold, if the signal output at a pitch lower than the cough-speech threshold is increasing, the average of the latest maximum pitch is less than the cough-speech threshold. 5. The system of claim 4 , wherein the step of recognizing that in one or more of the low cases, the pitch measurement indicates that the duplicate sound event does not include speech is performed.

In step (5), if the duration of the sound event is shorter than about 600 milliseconds, processing (a) and (b) is performed for HFB, and if longer than about 600 milliseconds, processing is performed for LFB (a). The system of claim 1, wherein (b) and (b) are performed.