Method and apparatus for wide-band phase gradient signal acquisition

Abstract

The present disclosure facilitates capture (e.g., bipolar capture) of differentially-acquired wide-band phase gradient signals (e.g., wide-band cardiac phase gradient signals, wide-band cerebral phase gradient signals) that are simultaneously sampled. Notably, the exemplified system minimizes non-linear distortions (e.g., those that can be introduced via certain filters such as phase distortions) in the acquired wide-band phase gradient signals so as to not affect the information therein that can non-deterministically affect analysis of the wide-band phase gradient signal in the phase space domain. Further, a shield drive circuit and shield-drive voltage plane may be used to facilitate low noise and low interference operation of the acquisition system.

1 .- 24 . (canceled) 
     
     
         25 . A signal acquisition board comprising:
 a multi-layer printed circuit board comprising:
 a first layer that serves as a reference ground plane; 
 a second layer co-planar to the first layer that serves as a cable-shield drive voltage plane; and 
 one or more signal layers having a pair of conductive traces running substantially therethrough and across one or more regions coincident and coplanar to the second ground layer, wherein the pair of conductive traces electrically couple, across a connector directly or indirectly affixed to the multi-layer printed circuit, ends of at least two signal-carrying conductors to differential input pins of an analog-to-digital conversion and amplifier stage mounted on a surface of the multi-layer printed circuit, wherein a first signal-carrying conductor of the at least two signal-carrying conductors is associated with a first cable and a second signal-carrying conductor of the at least two signal-carrying conductors is associated with a second cable; 
 wherein the second ground layer electrically couples, over the at least one connector, i) a first outer conductor that serves as an outer shield of the first cable and ii) a second outer conductor that serves as an outer shield of the second cable, to drive potentials of the first outer conductor and the second outer conductor to that of the cable-drive voltage plane. 
   
     
     
         26 . The signal acquisition board of  claim 25 , wherein the first cable and the second cable terminate at a single cable-pin connector, the single cable-pin connector having a coupling element configured to releasably mate to the connector of the signal acquisition board. 
     
     
         27 . The signal acquisition board of  claim 25 , wherein the pair of conductive traces are arranged, on a same set of signal layers of the one or more signal layers, and in close proximity to one another such that substantial lengths of each conductive trace of the pair of conductive traces are substantially parallel to one another. 
     
     
         28 . The signal acquisition board of  claim 27 , wherein each conductive trace of the pair of conductive traces has a length and have a same number of via so as to have a substantially similar impedance characteristics as one another. 
     
     
         29 . The signal acquisition board of  claim 28 , wherein each conductive trace of the pair of conductive traces includes an impedance element arranged between a respective pin of the connector and a respective differential input pins of the analog-to-digital conversion circuit, and wherein the pair of conductive traces has a capacitance element coupled therebetween to form, with the impedance elements, an antialiasing filter. 
     
     
         30 . The signal acquisition board of  claim 25 ,
 wherein the multi-layer printed circuit board further comprises a conductive housing that serves as a grounded shield cage, wherein the conductive housing spans a portion of the second ground layer to encapsulate a substantial portion of the pair of conductive traces, and wherein the conductive housing is affixed to the surface of the multi-layer printed circuit and is electrically coupled to the reference ground plane.   
     
     
         31 . The signal acquisition board of  claim 25 , wherein the analog-to-digital conversion and amplifier stage forms a single integrated circuit having one or more analog-to-digital converters (ADCs) with built-in programmable gain amplifiers (PGAs). 
     
     
         32 . The signal acquisition board of  claim 25 , wherein the multi-layer printed circuit board further comprises:
 one or more processors and one or more memory components coupled to the one or more processors, wherein the one or more processors and the one or more memory components are arranged on a portion of the surface of the multi-layer printed circuit that do not coincide or overlap with the cable-drive voltage plane of the second layer.   
     
     
         33 . The signal acquisition board of  claim 25 , wherein the pair of conductive traces forms a part of a first differential input channel of the signal acquisition board. 
     
     
         34 . The signal acquisition board of  claim 33 , further comprising a second differential input channel and a third differential input channel, wherein each of the second differential input channel and the third differential input channel comprises a pair of conductive traces running substantially through the one or more signal layers across the one or more regions coincident and coplanar to the cable-drive voltage plane of the second ground layer, wherein each of the second differential input channel and the third differential input channel connects to a pair of cables having at least one signal-carrying conductor and an outer conductor that serves as an outer shield of the signal-carrying conductor, and wherein the cable-drive voltage plane electrically couples, over the at least one connector, to the outer conductors of the pair of cables so as to drive potentials of the outer conductors to that of the cable-drive voltage plane. 
     
     
         35 . The signal acquisition board of  claim 25 , wherein the analog-to-digital conversion and amplifier stage are configured to amplify signals of the differential input pins without filtering that causes distortion above 1 kHz. 
     
     
         36 . The signal acquisition board of  claim 35 , wherein the amplified signals are analyzed, in a phase-associated analysis, along with a data set associated with oxygen saturation readings concurrently acquired with the amplified signals to generate an output data set in a report and/or a display, and wherein the output data set is used in a diagnosis of cardiac disease.