Integrated circuit for physiological signal measurement
First Claim
1. An integrated circuit comprising:
- a plurality of analog signal amplifiers, each said analog signal amplifier having an amplifier input connected to an external input voltage and a signal amplifier output; and
wherein each said signal amplifier output is resistively connected to an input of an analog to digital converter means for receiving said signal amplifier output and for converting said signal amplifier output to a digital output; and
an averaging amplifier means for receiving a plurality of analog averaging inputs, for generating a sum of said plurality of analog averaging inputs, and for generating an external analog averaging output by amplifying said sum; and
wherein there is a one-to-one correspondence between said analog averaging inputs and said signal amplifier outputs; and
wherein each analog averaging input is switchably connected to one corresponding signal amplifier output; and
averaging switching means for receiving digital averaging selection bits and for selecting which of said analog averaging inputs is switched to a corresponding signal amplifier output, in response to said digital averaging selection bits; and
digital control means for generating said averaging selection bits in response to an external digital command input.
4 Assignments
0 Petitions
Accused Products
Abstract
A mixed analog and digital integrated circuit with features which are especially useful for application as a front end for physiological signal instrumentation such as electrocardiographs, electromyographs, and electroencephalographs. The integrated circuit has 5 signal channels, each with analog amplification and analog to digital conversion. The channels can be configured for various combinations of input signal amplification, input signal summation, analog output driving, and AC impedance measurement. The integrated circuit has 2 digital serial input lines and 2 digital serial output lines, all designed for direct connection to optical couplers. Channel configuration, gain, and other parameters are externally controllable by a serial digital input signal. Up to 6 compatible devices can be serially connected in a chain.
-
Citations
19 Claims
-
1. An integrated circuit comprising:
-
a plurality of analog signal amplifiers, each said analog signal amplifier having an amplifier input connected to an external input voltage and a signal amplifier output; and wherein each said signal amplifier output is resistively connected to an input of an analog to digital converter means for receiving said signal amplifier output and for converting said signal amplifier output to a digital output; and an averaging amplifier means for receiving a plurality of analog averaging inputs, for generating a sum of said plurality of analog averaging inputs, and for generating an external analog averaging output by amplifying said sum; and wherein there is a one-to-one correspondence between said analog averaging inputs and said signal amplifier outputs; and
wherein each analog averaging input is switchably connected to one corresponding signal amplifier output; andaveraging switching means for receiving digital averaging selection bits and for selecting which of said analog averaging inputs is switched to a corresponding signal amplifier output, in response to said digital averaging selection bits; and
digital control means for generating said averaging selection bits in response to an external digital command input. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. An integrated circuit comprising:
-
a plurality of analog signal amplifiers, each said analog signal amplifier having an amplifier input connected to an external input voltage and a signal amplifier output; and wherein each said signal amplifier output is switchably and resistively connected to an input of an analog to digital converter means for receiving said signal amplifier output and for converting said signal amplifier output to a digital output; and an averaging amplifier means for receiving a plurality of analog averaging inputs, for generating a sum of said plurality of analog averaging inputs, and for generating an external analog averaging output by amplifying said sum; and wherein there is a one-to-one correspondence between said analog averaging inputs and said signal amplifier outputs; and
wherein each analog averaging input is switchably connected to one corresponding signal amplifier output; anda plurality of impedance measurement means for generating a digital impedance signal, each said impedance measurement means comprising; impedance signal generating means for generating an alternating output current through an external impedance, thereby generating an alternating voltage across said external impedance; and rectification means for receiving and rectifying said alternating voltage, thereby generating a DC analog impedance voltage; and analog to digital conversion means for receiving said DC analog impedance voltage and for converting said DC analog impedance voltage to said digital impedance signal. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. An integrated circuit comprising:
-
a plurality of analog signal amplifiers, each said analog signal amplifier having an amplifier input connected to an external input voltage and a signal amplifier output; and a first plurality of analog to digital converter means for receiving and converting an analog A/D input to a digital output signal, wherein there is a one-to-one correspondence between said first plurality of analog to digital converter means and said plurality of analog signal amplifiers; and a second plurality of analog to digital converter means, comprising a subset of said first plurality of analog to digital converter means, wherein analog to digital converter means in said second plurality of analog to digital converter means have switchable inputs; and a plurality of impedance measurement means for generating a digital impedance signal, each said impedance measurement means comprising; impedance signal generating means for generating an alternating output current through an external impedance, thereby generating an alternating voltage across said external impedance; and rectification means for rectifying said alternating voltage, thereby generating a DC impedance voltage; and wherein there is a one-to-one correspondence between said second plurality of analog to digital conversion means and said plurality of impedance measurement means; and
wherein, for analog to digital converter means which are in said first plurality of analog to digital converter means but which are not in said second plurality of analog to digital converter means, each analog A/D input is resistively connected to a corresponding signal amplifier output; andwherein analog to digital converter means in said second plurality of analog to digital converter means further comprise; A/D input switching means for receiving digital A/D switch selection bits and for selecting whether said analog A/D input is resistively connected to a corresponding signal amplifier output or is connected to a corresponding DC impedance voltage, in response to said digital A/D switch selection bits; and digital control means for receiving an external digital command input and for generating said A/D switch selection bits in response to said external digital command input. - View Dependent Claims (14, 15, 16, 17, 18, 19)
-
Specification