Analog platform for intravascular image acquisition
A circuit and design for an analog front end is provided. The AFE includes a number of sub-stages each with multiple optional or alternative pathways to complete the circuit. These pathways can be dynamically set during runtime based on the type of imaging catheter used with the AFE or can be set at manufacturing.
1 . An analog front end (AFE) for an intracorporeal image acquisition device, comprising:
a high-pass filter stage, the high-pass filter stage comprising a plurality of high-pass filters and at least one switch selectable to electrically couple one of the plurality of high-pass filters to an input;
a gain stage comprising:
a plurality of voltage attenuators,
a plurality of amplifiers circuits, and
a plurality of jumper locations, wherein one or more jumpers are installed in at least one but not all of the plurality of jumper locations to electrically couple one of the plurality of voltage attenuators to an output from the high-pass filter stage and to electrically couple an output from the one of the plurality of voltage attenuators to a one of the plurality of amplifier circuits; and
a low-pass filter stage comprising a plurality of low-pass filters and at least one switch selectable to electrically couple one of the plurality of low-pass filters to an output from the gain stage.
2 . The AFE of claim 1 , wherein the plurality of high-pass filters comprise a first high-pass filter and a second high-pass filter, wherein the first high-pass filter is between a 0 and 12 megahertz high-pass filter, and wherein the second high-pass filter is between a 15 and 30 megahertz high-pass filter.
3 . The AFE of claim 2 , wherein at least one switch of the high-pass filter stage comprises a first switch and a second switch and wherein the first switch and the second switch are configured to be dynamically controlled by a controller circuit and arranged to electrically couple the input to the analog front end to a selected one of either the first high-pass filter or the second high-pass filter and to electrically couple the output from the selected one of either the first high-pass filter or the second high-pass filter to the output of the high-pass filter stage.
4 . The AFE of claim 3 , wherein the first high-pass filter and the second high-pass filter are T high-pass filters comprising a pair of capacitors in arranged in series and an inductor electrically coupled between ground and the center of the pair of capacitors.
5 . The AFE of claim 1 , wherein the plurality of voltage attenuators of the gain stage comprise a first voltage attenuator and a second voltage attenuator, wherein the first voltage attenuator is a 12 decibel voltage attenuator, and wherein the second voltage attenuator is a 28 decibel voltage attenuator.
6 . The AFE of claim 5 , wherein the gain stage further comprises a digital to analog converter and at least one transimpedance amplifier, wherein the transimpedance amplifier is electrically coupled to a control input of either the first voltage attenuator or the second voltage attenuator based on the one or more jumpers.
7 . The AFE of claim 5 , wherein the plurality of amplifier circuits comprises a first amplifier circuit and a second amplifier circuit, wherein the first amplifier circuit comprises an inductor, an operation amplifier (op-amp), and a plurality of resistors arranged to form an amplifier circuit, and wherein the second amplifier circuit comprises an op-amp and a plurality of resistors arranged to form an amplifier circuit.
8 . The AFE of claim 1 , wherein the plurality of voltage attenuators comprise a first pair of voltage attenuators and a second pair of voltage attenuators and wherein one of the amplifier circuits is electrically coupled between the first one of the first pair of voltage attenuators and a first one of the second pair of voltage attenuators based on the one or more jumpers.
9 . The AFE of claim 1 , wherein the gain stage comprises a first gain stage and a second gain stage, wherein the second gain stage comprises a clipping operational amplifier (op-amp).
10 . The AFE of claim 9 , wherein the second gain stage further comprises a first amplifier circuit, a second amplifier circuit, and a plurality of pairs of jumper locations, wherein a pair of jumpers are installed in one of the plurality of pairs of jumper locations to electrically couple an input to the second gain stage to either a selected one of the first amplifier or the second amplifier and to electrically couple the output of the selected one of the first amplifier or the second amplifier to the clipping op-amp.
11 . The AFE of claim 1 , wherein the plurality of low-pass filters comprise a first low-pass filter and a second low-pass filter, wherein the first low-pass filter is less than or equal to a 60 megahertz low-pass filter, and wherein the second low-pass filter is greater than a 60 megahertz low-pass filter.
12 . The AFE of claim 1 , comprising at least one analog to digital converter (ADC) drivers.
13 . An intracorporeal image acquisition device comprising:
image acquisition circuitry comprising an analog front end (AFE) and a digital processing circuit coupled to the AFE, the digital processing circuit arranged to receive a digitized signal from the AFE, the AFE comprising:
a high-pass filter stage, the high-pass filter stage comprising a plurality of high-pass filters and at least one switch selectable to electrically couple one of the plurality of high-pass filters to an input;
a gain stage comprising:
a plurality of voltage attenuators,
a plurality of amplifiers circuits, and
a plurality of jumper locations, wherein one or more jumpers are installed in at least one but not all of the plurality of jumper locations to electrically couple one of the plurality of voltage attenuators to an output from the high-pass filter stage and to electrically couple an output from the one of the plurality of voltage attenuators to a one of the plurality of amplifier circuits; and
a low-pass filter stage comprising a plurality of low-pass filters and at least one switch selectable to electrically couple one of the plurality of low-pass filters to an output from the gain stage.
14 . The intracorporeal image acquisition device of claim 13 , wherein the plurality of high-pass filters comprise a first high-pass filter and a second high-pass filter, wherein the first high-pass filter is between a 0 and 12 megahertz high-pass filter, and wherein the second high-pass filter is between a 15 and 30 megahertz high-pass filter.
15 . The intracorporeal image acquisition device of claim 14 , wherein at least one switch of the high-pass filter stage comprises a first switch and a second switch and wherein the first switch and the second switch are configured to be dynamically controlled by a controller circuit and arranged to electrically couple the input to the analog front end to a selected one of either the first high-pass filter or the second high-pass filter and to electrically couple the output from the selected one of either the first high-pass filter or the second high-pass filter to the output of the high-pass filter stage.
16 . The intracorporeal image acquisition device of claim 15 , wherein the first high-pass filter and the second high-pass filter are T high-pass filters comprising a pair of capacitors in arranged in series and an inductor electrically coupled between ground and the center of the pair of capacitors.
17 . The intracorporeal image acquisition device of claim 13 , wherein the plurality of voltage attenuators of the gain stage comprise a first voltage attenuator and a second voltage attenuator, wherein the first voltage attenuator is a 12 decibel voltage attenuator, and wherein the second voltage attenuator is a 28 decibel voltage attenuator.