In-vivo monitoring of cellular energetics with Raman spectroscopy
Inventors
ROMFH, John P. • Vakhshoori, Daryoosh • KHEIR, John N. • Chen, Peili • Polizzotti, Brian • SALVIN, Joshua • Perry, Alison
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11717167-B2
Publication Date
2023-08-08
Expiration Date
Abstract
The inventors have developed tools for quantifying the mitochondrial redox state of in vivo, in situ tissue using resonance Raman spectroscopy. The tissue is illuminated with an excitation beam that causes the tissue to scatter Raman-shifted light, which is collected and analyzed to produce coefficients representing the relative concentrations of different chromophores in the tissue. These relative concentrations indicate the redox state of whole mitochondria, hemoglobin oxygen saturation, myoglobin oxygen saturation, and/or redox state of individual cytochrome complexes in mitochondria of the in vivo, in situ tissue. Quantifiable information about these states and/or saturations can be used to assess tissue health, including organ (dys)function before, during, and after surgery. For example, this information can be used to predict impending cardiac failure, to guide surgical interventions, to monitor organ health after transplantation, or to guide post-operative care.
Core Innovation
The invention relates to an in-vivo, in situ resonance Raman spectroscopy approach for monitoring a patient by measuring a resonance Raman spectrum of in vivo, in situ tissue. From the measured resonance Raman spectrum, the method quantifies mitochondrial redox state in the tissue based on performing regression analysis using a linear combination of reference resonance Raman spectra from whole mitochondria in reduced and oxidized states, where the reference spectra represent weighted average redox states of cytochromes and effects of the cytochromes on each other in a mitochondrial membrane.
The regression analysis outputs a determined redox state of whole mitochondria in the in vivo, in situ tissue. In addition to mitochondrial redox state, the approach can quantify at least one of hemoglobin oxygen saturation, myoglobin oxygen saturation, and/or redox state of individual cytochrome complexes in mitochondria. A further described concept is determining relative concentrations of a plurality of chromophores based on Raman-shifted light and a Raman library from whole mitochondria in reduced and oxidized states.
The quantified mitochondrial redox state and related metrics are used for determining and/or predicting dysfunction and for assessing tissue health around clinical events. The document describes use cases including assessing adequacy of tissue protection and predicting and monitoring organ dysfunction after surgery and reperfusion, including impending cardiac failure and monitoring cardiac function. Additional described monitoring includes transplant monitoring and outpatient monitoring, including tongue measurements.
Claims Coverage
The independent claims cover a patient monitoring method, a monitoring system, and a method variant using chromophore concentration determination from Raman-shifted light. Across the independent claims, there are core inventive features centered on in-vivo resonance Raman measurement of tissue and regression or library-based determination using reference spectra from whole mitochondria in reduced and oxidized states, leading to whole-mitochondria redox state and related oxygenation/redox readouts and dysfunction assessment.
Monitoring using in vivo resonance Raman quantification by regression to whole-mitochondria reduced/oxidized references
Measuring a resonance Raman spectrum of in vivo, in situ tissue with a Raman spectroscopy system; quantifying a mitochondrial redox state of the in vivo, in situ tissue based on the resonance Raman spectrum, where quantifying comprises performing a regression analysis using a linear combination of reference resonance Raman spectra from whole mitochondria in reduced and oxidized states, the reference spectra representing weighted average redox states of cytochromes and effects of the cytochromes on each other in a mitochondrial membrane, and determining a redox state of whole mitochondria based on the regression analysis.
System for resonance Raman spectrum to mitochondrial redox state quantification using whole-mitochondria reference regression
Providing a laser to generate an excitation beam; a probe to illuminate in vivo, in situ tissue and collect a Raman signal; a spectrometer to generate a resonance Raman spectrum; and a processor to quantify a mitochondrial redox state based on the resonance Raman spectrum, wherein the processor quantifies by performing regression analysis of the resonance Raman spectrum using a linear combination of reference resonance Raman spectra from whole mitochondria in reduced and oxidized states representing weighted average redox states of cytochromes and effects of the cytochromes on each other in a mitochondrial membrane, and determining a redox state of whole mitochondria based on the regression analysis.
Monitoring by Raman-shifted light chromophore concentration determination using a whole-mitochondria reduced/oxidized library
Illuminating in vivo, in situ tissue with an excitation beam at 441 nanometers; collecting Raman-shifted light scattered from the in vivo, in situ tissue in response to the excitation beam; determining a spectrum of the Raman-shifted light; determining relative concentrations of each of plurality of chromophores based on the spectrum and a library of Raman spectra from whole mitochondria in reduced and oxidized states representing weighted average redox states of cytochromes and effects of the cytochromes on each other in a mitochondrial membrane; determining based on the relative concentrations at least one of a redox state of whole mitochondria, hemoglobin oxygen saturation, myoglobin oxygen saturation, or redox state of individual cytochrome complexes in mitochondria; and determining and/or predicting a dysfunction of the in vivo, in situ tissue based on the redox state/oxygenation/redox readout.
Across the independent claims, the coverage centers on obtaining an in-vivo resonance Raman spectrum, or Raman-shifted spectrum, from patient tissue and using regression analysis or chromophore concentration determination against a Raman library derived from whole mitochondria in reduced and oxidized states to determine redox state of whole mitochondria, optionally including hemoglobin and myoglobin oxygen saturation and/or cytochrome-complex redox states, and using these outputs for determining and/or predicting dysfunction.
Stated Advantages
Enables quantifying a mitochondrial redox state of in vivo, in situ tissue based on an in-vivo resonance Raman spectrum using regression against reference resonance Raman spectra from whole mitochondria in reduced and oxidized states.
Provides additional quantified readouts including hemoglobin oxygen saturation, myoglobin oxygen saturation, and/or redox state of individual cytochrome complexes in mitochondria.
Supports determining and/or predicting dysfunction of the in vivo, in situ tissue based on the determined redox, oxygenation, and redox readouts.
Supports monitoring a patient with an implemented system including a laser, probe, spectrometer, and processor configured to quantify mitochondrial redox state using the regression analysis approach.
Documented Applications
Assessing adequacy of tissue protection during surgery and predicting and monitoring tissue function after reperfusion using mitochondrial redox state and related oxygenation and redox metrics.
Monitoring organ dysfunction around surgery, including impending cardiac failure and post-reperfusion function.
Transplant monitoring.
Outpatient monitoring including tongue measurements.
Interested in licensing this patent?