US 11,051,707 B2
Low noise subsurface spectrogram with cascaded reference circuit
Jason Felix, Vashon, WA (US); Leslie A Chertok, Vashon, WA (US); and Vandana Verma, Mountain View, CA (US)
Assigned to BIOPAUSE LLC, Vashon, WA (US)
Filed by Jason Felix, Vashon, WA (US); Leslie A Chertok, Vashon, WA (US); and Vandana Verma, Mountain View, CA (US)
Filed on Jun. 17, 2019, as Appl. No. 16/443,694.
Application 16/443,694 is a division of application No. 15/396,113, filed on Dec. 30, 2016, granted, now 10,368,756.
Prior Publication US 2020/0390343 A1, Dec. 17, 2020
Int. Cl. A61B 5/0245 (2006.01); A61B 5/0255 (2006.01); A61B 5/00 (2006.01); A61B 5/024 (2006.01); A61B 5/30 (2021.01)
CPC A61B 5/0245 (2013.01) [A61B 5/0255 (2013.01); A61B 5/02438 (2013.01); A61B 5/30 (2021.01); A61B 5/486 (2013.01); A61B 5/681 (2013.01); A61B 5/7225 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A system comprising:
a first circuit that provides a cascaded reference comprising:
a first reference generator comprising: a first pair of resistive elements configured to inject a driven first reference containing a DC voltage and power supply noise to a second reference generator or to a first amplifying and filtering circuitry; and
the second reference generator comprising: a second pair of resistive elements configured to inject a driven second reference containing a combined output of the first reference generator and an arbitrary input into a specimen or the first amplifying and filtering circuitry; and
whereby the system is configured to perform a subdermal spectrogram (SSG);
whereby the arbitrary input is driven by a signal containing multiple frequencies at the same time or a series of frequencies over time, or a combination thereof,
when the first amplifying and filtering circuitry is configured to receive the arbitrary reference signal into the specimen that has been attenuated, amplified, delayed or a combination thereof by the physical and physiological characteristics of the specimen.