79 results about "Tissue oxygenation" patented technology

An apparatus and method for determining tissue oxygenation such as arterial and venous oxygenation and cerebral oxygenation. In one embodiment the optical properties of tissue are determined using measured light attenuations at a set of wavelengths. By choosing distinct wavelengths and using light attenuation information, the influence of variables such as light scattering, absorption and other optical tissue properties can be minimized.

Methods and apparatus for measuring cerebral O2 saturation and detecting cerebral hypoxia-ischemia using multi-wavelength near infrared spectroscopy (NIRS). Near-infrared light produced by an emitter is directed through brain tissue. The intensity of the light that passes through the brain tissue is measured using photodiode detectors positioned at distinct distances from the emitter. This process is conducted for at least three wavelengths of near-infrared light. One of the wavelengths used is substantially at an isobestic point for oxy-hemoglobin and deoxy-hemoglobin, but the other two may be any wavelengths within the near-infrared spectrum (700 nm to 900 nm), so long as one of the additional wavelengths is greater than the isobestic point and the other is less than the isobestic point. Tissue oxygenation is calculated using an algorithm derived from the Beer-Lambert law. Cerebral hypoxia-ischemia may be diagnosed using the calculated tissue oxygenation value.

A surgical instrument may be configured to sense a light re-emitting probe to resolve tissue oxygenation, the surgical instrument including: an optical emitter configured to excite the light re-emitting probe within an absorption band of the light re-emitting probe; an optical detector configured to receive the re-emitted light from the probe; and a signal processor configured to resolve the tissue oxygenation based on the received light. The surgical instrument can be a surgical stapler anvil or a flexible substrate having a tissue interfacing surface. Further, a monitoring device may be configured to map oxygenation of a tissue containing a light re-emitting probe, the monitoring device including: an optical emitter configured to excite the light re-emitting probe; at least one optical detector configured to receive the re-emitted light from the probe; and a signal processor that is configured to resolve the tissue oxygenation at multiple points to generate an oxygen map.

A method of analyzing a patient's tissue oxygenation capabilities includes measuring a tissue chromophore whose light absorption properties depend on the oxygenation state of the tissue and generating data representative of tissue oxygenation before, during and after a controlled ischemia event. From this data characterizing data, including ischemia onset slope, ischemia onset response time, ischemia recovery slope, ischemia recovery response time or hyperemia is automatically determined. This characterizing data is related to corresponding characterizing data determined from a control population. The relationship may be displayed on a graphical display.

Provided are substituted benzaldehydes and derivatives thereof that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions comprising the modulators, and methods for their use in treating disorders mediate by hemoglobin and disorders that would benefit from increased tissue oxygenation.

Provided are substituted heteroaryl aldehydes and derivatives thereof that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions comprising the modulators, and methods for their use in treating disorders mediate by hemoglobin and disorders that would benefit from increased tissue oxygenation.

An apparatus and method for determining tissue oxygenation such as arterial and venous oxygenation and cerebral oxygenation. In one embodiment, the optical properties of tissue are determined using measured light attenuations at a set of wavelengths. By choosing distinct wavelengths and using light attenuation information, the influence of variables such as light scattering, absorption and other optical tissue properties can be minimized.

Appropriate assessment of wound oxygenation is critical to establish a diagnosis, to monitor the effect of the treatment, to guide the therapeutic process, to identify the presence of infection, and to predict the treatment outcome. Embodied systems and methods represent an enabling technology for noninvasive and objective assessment of wound tissue oxygenation. In addition to wound healing, disclosed embodiments offer low cost and portable avenues for noninvasive assessment of multiple clinical parameters for the detection and intervention of various malignancies in multiple soft tissue systems.

Provided are substituted benzaldehydes and derivatives thereof that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions comprising the modulators, and methods for their use in treating disorders mediate by hemoglobin and disorders that would benefit from increased tissue oxygenation.

A method is provided of measuring in vivo of an endogenous fluorophore in a tissue site. A known excitation wavelength of the endogenous flurophore is selected within a range of wavelengths at which the endogenous flurophore undergoes fluorescence. The tissue site is irradiated with irradiated light having at least the selected excitation wavelength within the range of wavelengths. A fluorescence emission of the tissue site resulting from the irradiation thereof is detected. A relative or absolute concentration of the endogenous fluorophore is determined by multiplying it by a calibration factor that depends one at least one of, a known excitation and emission property of the endogenous fluorophore, an intensity of the irradiated light, optical properties of an excitation probe, and specific properties of the tissue. The relative or absolute concentration of the endogenous fluorphore is used to estimate at least one of a, in vivo cellular energy production status or state of end-organ tissue oxygenation.

A high temperature-stable and highly purified cross-linked (optionally ≧70% β-β linked) tetrameric hemoglobin with high efficiency of oxygen delivery suitable for use in mammals without causing renal injury and vasoconstriction is provided. The dimeric form of hemoglobin is degenerated and purification processes are performed on red blood cells from whole blood. Controlled hypotonic lysis in an instant cytolysis apparatus prevents lysis of white blood cells. Nucleic acids from white blood cells and phospholipids impurities are not detected. Blocking of reactive sulfhydryl groups by a sulfhydryl reagent is performed in an oxygenated environment. Flowthrough column chromatography removes different plasma protein impurities. N-acetyl cysteine is added to the cross-linked tetrameric hemoglobin to maintain a low level of met-hemoglobin. The stabilized hemoglobin is preserved in an infusion bag with aluminum overwrap to prevent formation of inactive met-hemoglobin from oxygen intrusion. The product finds use in tissue oxygenation and cancer treatment.

The present invention uses vertical-cavity surface-emitting lasers (VCSELs) as illumination source for simultaneous imaging of blood flow and tissue oxygenation dynamics in vivo, or a means to monitor neural activity in brain slices ex vivo. The speckle pattern on the brain tissue due to a VCSEL's coherence properties is the main challenge to producing low-noise high-brightness illumination, required for evaluating tissue oxygenation. Moreover, using oxide-confined VCSELs we show a fast switching from a single-mode operation scheme to a special multi-modal, multi-wavelength rapid sweep scheme. The multi-modal, multi-wavelength rapid sweep scheme reduces noise values to within a factor of 40% compared to non-coherent LED illumination, enabling high-brightness VCSELs to act as efficient miniature light sources for various brain imaging modalities and other imaging applications. These VCSELs are promising for long-term portable continuous monitoring of brain dynamics in freely moving animals.

Prolonged and severe tissue hypoxia results in tissue necrosis in pedicled flaps. We demonstrate the potential of near-infrared spectroscopy for predicting viability of compromised tissue portions. This approach clearly identifies tissue regions with low oxygen supply, and also the severity of this challenge, in a rapid and non-invasive manner, with a high degree of reproducibility. Early, nonsubjective detection of poor tissue oxygenation following surgery increases the likelihood that intervention aimed at saving the tissue will be successful.

A new class of micro- and nano-particulate paramagnetic spin probes useful for magnetic resonance imaging techniques, including electron paramagnetic resonance (EPR) and magnetic resonance imaging (MRI). The probes are lithium phthalocyanine derivative compounds. Also provided are suspensions and emulsions comprising lithium phthalocyanine derivative probes. Also provided are noninvasive methods for measuring noninvasive methods of measuring oxygen concentration, oxygen partial pressure, oxygen metabolism, and nitric oxide concentration in a specific tissue, organ, or cell in vivo or in vitro.

Acoustical-based methods that increase tissue oxygenation, and equipment for carrying out the methods, are provided. The methods involve exposing tissue to low frequency sound in order to increase blood flow in the tissue, and hence oxygenation of the tissue. The methods may be used to treat or prevent disorders related to ischemia and low blood flow, such as shock, stroke and congestive heart failure.

Provided are cycloalkyl- and cycloalkenyl-substituted benzaldehydes and heteroaldehydes of formula (I) that act as allosteric modulators of hemoglobin, methods and intermediates for their preparation, pharmaceutical compositions containing the modulators, and methods for their use in treating disorders mediated by hemoglobin and disorders that would benefit from increased tissue oxygenation.

A portable multi-spectral imaging system and device is disclosed. The system includes at least one image acquisition device for acquiring an image from a subject, a filtering device to filter the light received by the image acquisition device, a processor for processing the image acquired by the image acquisition device, and a display. There is software running on the processor that determines oxygenation values of the subject based on the processed image.

Methods for preparation of a heat stable hemoglobin based oxygen-carrier-containing pharmaceutical composition such that beta-beta cross-linking is favored are provided. Using the methods of the present invention, the oxygen affinity of the resultant molecule can be controlled so that hemoglobin based oxygen carriers tailored for specific applications can be produced. Lower oxygen affinity crosslinked hemoglobin is useful for applications requiring rapid tissue oxygenation (e.g. hemorrhagic shock) while higher oxygen affinity cross-linked hemoglobin is useful for applications requiring a slower rate of oxygenation (e.g. cancer adjunct therapy). A highly purified and heat stable crosslinked non-polymeric tetrameric hemoglobin having beta-beta cross-linking of greater than 40-60% and suitable for use in mammals without causing renal injury and vasoconstriction is produced. A high temperature and short time (HTST) heat processing step is performed to effectively remove any undesired dimeric hemoglobin, non-crosslinked tetrameric hemoglobin, and plasma protein impurities.

A new class of micro- and nano-particulate paramagnetic spin probes especially useful for magnetic resonance imaging techniques, including electron paramagnetic resonance (EPR) and magnetic resonance imaging (MRI). The probes are lithium phthalocyanine derivative compounds. Also provided are suspensions and emulsions comprising lithium phthalocyanine derivative probes. Also provided are noninvasive methods for measuring noninvasive methods of measuring oxygen concentration, oxygen partial pressure, oxygen metabolism, and nitric oxide concentration in a specific tissue, organ, or cell in vivo or in vitro.

Based on diffusion principles and Fick's Law of difflision, Applicant has developed a method and two apparatuses to increase tissue oxygenation through a patient's damaged tissue to heal wounds quickly. Applicant's method is to create an enclosed environment, immediately outside a patient's damaged tissue, in which the oxygen concentration is reduced to prompt an outward supply of oxygen flows from blood capillaries to the damaged tissue and eventually out of the skin. Applicants' disclosed apparatuses use two different ways to reduce the oxygen: oxygen scavengers (e.g., oxygen-absorbing packets); and burning off the oxygen.

Prolonged and severe tissue hypoxia results in tissue necrosis in pedicled flaps. We demonstrate the potential of near-infrared spectroscopy for predicting viability of compromised tissue portions. This approach clearly identifies tissue regions with low oxygen supply, and also the severity of this challenge, in a rapid and non-invasive manner, with a high degree of reproducibility. Tissues remaining below a certain hemoglobin oxygen saturation threshold (oxygen saturation index <1) for prolonged periods (>6 h) became increasingly dehydrated, eventually becoming visibly necrotic. Tissues above this threshold (oxygen saturation index >1), despite being significantly hypoxic relative to the pre-elevation saturation values, remained viable over the 72 h post-elevation monitoring period. The magnitude of the drop in tissue oxygen saturation, as observed immediately following surgery, correlated with the final clinical outcome of the flap tissue. These results indicate the potential of near infrared spectroscopy and imaging to monitor tissue oxygenation status and assess tissue viability following reconstructive surgery. Early, nonsubjective detection of poor tissue oxygenation following surgery increases the likelihood that intervention aimed at saving the tissue will be successful.

A method of analyzing a patient's tissue oxygenation capabilities includes measuring a tissue chromophore whose light absorption properties depend on the oxygenation state of the tissue and generating data representative of tissue oxygenation before, during and after a controlled ischemia event. From this data characterizing data, including ischemia onset slope, ischemia onset response time, ischemia recovery slope, ischemia recovery response time or hyperemia is automatically determined. This characterizing data is related to corresponding characterizing data determined from a control population. The relationship may be displayed on a graphical display.

An assembly used to promote wound healing through the creation of an oxygen gradient, whereby the oxygen gradient hastens the diffusion of oxygen from underlying capillaries and subcutaneous tissue up through and over an overlying target site of skin tissue. In an exemplary embodiment, the assembly provides a flush cycle and / or a negative pressure cycle to enhance the flow of oxygen from the subcutaneous tissue and the capillaries to the target site. In an exemplary embodiment, the assembly further comprises a means for maintaining a constant relative humidity over the wound site.

A high temperature-stable and highly purified α-α cross-linked tetrameric hemoglobin suitable for use in mammals without causing renal injury and vasoconstriction is provided. The dimeric form of hemoglobin is degenerated and purification processes are performed on red blood cells obtained from whole blood. Controlled hypotonic lysis in an instant cytolysis apparatus prevents the lysis of white blood cells. Nucleic acids from white blood cells and the phospholipids impurities are not detected. The blocking of reactive sulfhydryl groups in hemoglobin by a sulfhydryl reagent is performed in an oxygenated environment. Flowthrough column chromatography is used to remove different plasma protein impurities. N-acetyl cysteine is added to the α-α cross-linked tetrameric hemoglobin solution to maintain a low level of met-hemoglobin. The stabilized hemoglobin is preserved in an infusion bag with aluminum overwrap to prevent formation of inactive met-hemoglobin from oxygen intrusion. The product finds use in tissue oxygenation and cancer treatment.