Cardio-pulmonary activity monitor
First Claim
1. Apparatus for monitoring cardiopulmonary activity of an individual and for providing an indication of abnormal activity comprising:
- electrostatic charge collection means for positioning adjacent an individual whose cardiopulmonary activity is to be monitored said collection means having at least first and second spaced layers separated by an electrically insulative layer;
a dual integrator connected to said collection means for providing an output signal representative of changes in the electrostatic charge on said collection means occurring at a frequency between 0.1 Hz and 15 Hz;
an amplifier connected in a feedback circuit between an output terminal of said dual integrator and an input terminal thereof, said amplifier having a relatively high gain at frequencies below 0.1 Hz and a relatively low gain at frequencies above 0.1 Hz whereby the output signal of said dual integrator remains substantially at a predetermined value for input signals below 0.1 Hz in frequency; and
means connected to the output terminal of said dual integrator for providing an indication of the status of the cardiopulmonary activity.
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0 Petitions
Accused Products
Abstract
A method and apparatus for providing an indication of a cardiopulmonary activity of a person using noninvasive monitoring means and for detecting motion in the area of the apparatus includes an electrostatic charge detector for providing an output signal including signals indicative of motion and cardiopulmonary activity of the person. A detection apparatus is connected to receive the signals and to filter the extraneous noise signals from the signals of interest to provide output signals indicative only of the motion of interest or cardiopulmonary activity of the person. Breathing signals are applied to a comparator which is tripped if breathing occurs at a rate below a predetermined value. Cardiac signals are applied to a circuit which adjusts the trip level for the breathing rate if the cardiac rate declines to a level suggestive of bradycardia without breathing rate increases. The filtering circuit for the signal supplied by the charge detector incorporates a dual integrator operating as a frequency selective charged amplifier which is effective to substantially eliminate all signals outside of the range of about 0.1 to 15 Hz.
101 Citations
15 Claims
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1. Apparatus for monitoring cardiopulmonary activity of an individual and for providing an indication of abnormal activity comprising:
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electrostatic charge collection means for positioning adjacent an individual whose cardiopulmonary activity is to be monitored said collection means having at least first and second spaced layers separated by an electrically insulative layer; a dual integrator connected to said collection means for providing an output signal representative of changes in the electrostatic charge on said collection means occurring at a frequency between 0.1 Hz and 15 Hz; an amplifier connected in a feedback circuit between an output terminal of said dual integrator and an input terminal thereof, said amplifier having a relatively high gain at frequencies below 0.1 Hz and a relatively low gain at frequencies above 0.1 Hz whereby the output signal of said dual integrator remains substantially at a predetermined value for input signals below 0.1 Hz in frequency; and means connected to the output terminal of said dual integrator for providing an indication of the status of the cardiopulmonary activity. - View Dependent Claims (2, 3, 4)
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5. A motion detector of the type including an electrostatic charge collector having an electrically insulated charge collection layer, the detector comprising:
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a frequency selective charge amplifier means connected to the charge collector for providing successive signals each representative of a charge variation on the collector indicative of a motion event, said amplifier means providing said signals in response to events occurring within a predetermined range of time intervals; and a frequency selective feedback circuit connected between an output terminal and an input terminal of said amplifier means, said circuit comprising a variable gain apparatus having a relatively high gain at frequencies below a predetermined value whereby the frequency response of said amplifier amplifier falls rapidly below said predetermined value. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification