US 5,197,489 A · Activity monitoring apparatus with configurable filters

Abstract

An activity monitor adapted to be worn on the non-dominant wrist of a subject includes a bimorphous beam motion sensor. The output signal of the sensor is amplified in an amplifier circuit having a selectable amplification factor, and filtered by highpass and lowpass filter circuits having individually selectable cut-off frequencies to obtain an analog signal for processing having a bandpass and amplitude characteristic corresponding to a particular body activity under observation. A control and processing circuit within the monitor includes a microprocessor which responds to either resident internal operating instructions or to externally supplied operating instructions, or to designated data signal parameters, to provide configuration control signals to the amplifier and filter circuits, and processing of the collected data, appropriate to the particular activity being monitored. The processed data is digitally stored in an internal memory for subsequent transfer through a data port to an associated computer for display or further processing.

Claims33

Dependent claims

An activity monitor responsive to body motion for detecting and recording the occurrence of predetermined body movements in a human subject wherein each said predetermined body movement has a characteristic frequency spectrum, said activity monitor comprising:

a motion detector for producing a detector output signal in response to body movements of the subject;
highpass filter means for attenuating the spectrum of said detector output signal below a predetermined lower threshold frequency;
lowpass filter means for attenuating the spectrum of said detector output signal above a predetermined upper threshold frequency;
said detector output signal being filtered by said highpass and lowpass filter means whereby the spectrum of said signal corresponds to the characteristic frequency spectrum of the predetermined body movement;
memory means of finite capacity;
conversion means for sampling said detector output signal and storing the resulting sample signals in said memory means;
said upper threshold frequency and said lower threshold frequency each being configurable in response to an applied configuration control signal;
and said activity monitor further including a processor circuit having a plurality of selectable operating modes, each mode corresponding to at least one said predetermined body movement, said processor circuit applying configuraton control signals to each said filter means to obtain a frequency spectrum in said detector output signal corresponding to the characteristic frequency spectrum of the predetermined body movement selected by selection of a said operating mode.

5 more elements

A programmable patient monitoring system for detecting and recording an occurrence or absence of at least one patient body movement in a human or animal patient over time, said patient monitoring system comprising:

an activity monitor securable to a desired location on a patient whose body movements are being monitored, said activity monitor including means for sensing movement of the patient's body and means for simultaneously generating an analog electrical signal having waveform configuration, frequency and amplitude characteristics reflective of the effect said at least one body movement has on said sensing means, said activity monitor further including a configurable amplifier means for selectively adjustably amplifying said analog electrical signal to a desired amplification level, configurable highpass filter means for attenuating a component portion of said analog signal having a frequency below a selectively adjustable lower threshold frequency;
configurable lowpass filter means for attenuating a component portion of said analog signal having a frequency above a selectively adjustable upper threshold frequency;
said activity monitor further including memory means of finite capacity, conversion means for sampling said selectively amplified and filtered analog signal, for converting said signal to a plurality of signal resultants and for storing the signal resultants in said memory means, said amplifier means, said highpass filter means and said lowpass filter means each being configurable in response to applied configuration control signals, said activity monitor further including a processor circuit having a plurality of programmably selectable operating modes corresponding to a plurality of configuration settings, each setting being specifically appropriate for monitoring a predetermined body movement, said processor circuit applying said configuration control signals to said lowpass filter, said highpass filter and said amplifier, whereby said patient monitoring system is programmed by said processor circuit to specifically detect and record movement data relating to said at least one predetermined human body movement.

Dependencies are inferred from the claim text.

Activity monitoring apparatus with configurable filters

Life of this patent

Activity monitoring apparatus with configurable filters

Life of this patent

Abstract

Claims33