公开(公告)号：US20180000424A1

公开(公告)日：2018-01-04

申请号：US15198438

申请日：2016-06-30

Applicant: ANALOG DEVICES, INC.

Inventor： SEFA DEMIRTAS ,  JASON D. KING ,  ROBERT ADAMS ,  TONY JOSEPH AKL ,  JEFFREY G. BERNSTEIN

IPC: A61B5/00 ,  A61B5/11 ,  A61B5/024

CPC classification number: A61B5/7257 ,  A61B5/02416 ,  A61B5/1118 ,  A61B5/1123 ,  A61B5/6802 ,  A61B5/681 ,  A61B5/7207 ,  A61B5/7221

Abstract: Activity monitors and smart watches utilizing optical measurements are becoming widely popular, and users expect to get an increasingly accurate estimate of their heart rate (HR) from these devices. These devices are equipped with a light source and an optical sensor which enable estimation of HR using a technique called photoplethysmography (PPG). One of the main challenges of HR estimation using PPG is the coupling of motion into the optical PPG signal when the user is moving randomly or exercising. The present disclosure describes a computationally feasible and fast HR estimation algorithm to be executed at instances of little or no motion. Resulting HR readings may be useful on their own, or be provided to systems that monitor HR continuously to prevent the problem of such systems being locked on an incorrect HR for long periods of time. Implementing techniques described herein leads to more accurate HR measurements.

公开(公告)号：US20160317096A1

公开(公告)日：2016-11-03

申请号：US14972368

申请日：2015-12-17

Applicant: ANALOG DEVICES, INC.

Inventor： ROBERT ADAMS ,  SEFA DEMIRTAS ,  JEFFREY G. BERNSTEIN

IPC: A61B5/00 ,  A61B5/024

CPC classification number: A61B5/721 ,  A61B5/02416 ,  A61B5/02438 ,  A61B5/11 ,  A61B5/725 ,  A61B5/7275 ,  A61B2562/0219 ,  A61B2562/0233 ,  G06F19/00

Abstract: Heart rate monitors are plagued by noisy photoplethysmography (PPG) data, which makes it difficult for the monitors to output a consistently accurate heart rate reading. Noise is often caused by motion. Using known methods for processing accelerometer readings that measure movement to filter out some of this noise may help, but not always. The present disclosure describes an improved front-end technique (time-domain interference removal) based on using adaptive linear prediction on accelerometer data to generate filters for filtering the PPG signal prior to tracking the frequency of the heartbeat (heart rate). The present disclosure also describes an improved back-end technique based on steering the frequency of a resonant filter in order to track the heartbeat. Implementing one or both of these techniques leads to more accurate heart rate measurements.

Abstract translation: 心率监测器受到嘈杂的光谱体积描记术（PPG）数据的困扰，使得监测仪难以输出一致的心率读数。 噪音通常由运动引起。 使用已知的处理加速度计读数的方法来测量移动以滤除某些噪声可能有助于，但不总是。 本公开描述了基于在加速度计数据上使用自适应线性预测来生成用于在跟踪心跳频率（心率）之前对PPG信号进行滤波的滤波器的改进的前端技术（时域干扰消除）。 本公开还描述了基于转向谐振滤波器的频率以便跟踪心跳的改进的后端技术。 实施这些技术中的一种或两种导致更准确的心率测量。

公开(公告)号：US20170317701A1

公开(公告)日：2017-11-02

申请号：US15271487

申请日：2016-09-21

Applicant: ANALOG DEVICES, INC.

Inventor： SEFA DEMIRTAS

IPC: H04B1/10 ,  H04L25/03

CPC classification number: H04B1/1027 ,  H04B1/1036 ,  H04B2001/1054 ,  H04L25/03853

Abstract: Embodiments of the present disclosure provide mechanisms that enable designing an FIR filter that would have a guaranteed globally optimal magnitude response in terms of the minimax optimality criterion given a desired weight on the error in the stopband versus the passband. Design of such a filter is based on a theorem (“characterization theorem”) that provides an approach for characterizing the global minimax optimality of a given FIR filter h[n], n=0, 1, . . . , N, where optimality is evaluated with respect to a magnitude response of this filter, |H(ejω)|, as compared to the desired filter response, D(ω), which is unity in the passband and zero in the stopband. The characterization theorem enables characterizing optimality for both real-valued and complex-valued filter coefficients, and does not require any symmetry in the coefficients, thus being applicable to all non-linear phase FIR filters.

公开(公告)号：US20160354038A1

公开(公告)日：2016-12-08

申请号：US15170373

申请日：2016-06-01

Applicant: ANALOG DEVICES, INC.

Inventor： SEFA DEMIRTAS ,  ROBERT ADAMS ,  JEFFREY G. BERNSTEIN ,  NOAH DANIEL STEIN ,  DAVID WINGATE

IPC: A61B5/00 ,  A61B5/0245 ,  A61B5/0255 ,  A61B5/024

CPC classification number: A61B5/721 ,  A61B5/02416 ,  A61B5/02438 ,  A61B5/725 ,  A61B2562/0219

Abstract: Heart rate monitors are plagued by noisy photoplethysmography (PPG) data, which makes it difficult for the monitors to output a consistently accurate heart rate reading. Noise is often caused by motion. Using known methods for processing accelerometer readings that measure movement to filter out some of this noise may help, but not always. The present disclosure describes an improved filtering approach, referred to herein as an iterative frequency-domain mask estimation technique, based on using frequency-domain representation (e.g. STFT) of PPG data and accelerometer data for each accelerometer channel to generate filters for filtering the PPG signal from motion-related artifacts prior to tracking frequency of the heartbeat (heart rate). Implementing this technique leads to more accurate heart rate measurements.

Abstract translation: 心率监测器受到嘈杂的光谱体积描记术（PPG）数据的困扰，使得监测仪难以输出一致的心率读数。 噪音通常由运动引起。 使用已知的处理加速度计读数的方法来测量移动以滤除某些噪声可能有助于，但不总是。 本公开描述了基于使用PPG数据的频域表示（例如STFT）和每个加速度计通道的加速度计数据来生成用于过滤PPG的滤波器的改进的滤波方法（这里称为迭代频域掩模估计技术） 在跟踪心跳频率（心率）之前的运动相关假象的信号。 实施这种技术导致更准确的心率测量。