Abstract: A unitary multilumen cranial bolt for use in multimodal monitoring of a plurality of physiological parameters in brain tissue incorporates a plurality of lumens, each lumen directing a catheter borne sensor through a bore hole in the cranium and into brain tissue of a patient. The lumens are configured to cause the catheters to splay outward as they enter the cranial cavity and reach their intended depth of penetration. Each lumen is associated with a guide. The guides are adapted for use with introducers that enable fragile and/or flexible sensors to be introduced into brain tissue. Each catheter borne sensor can be positioned and repositioned within brain tissue independently of all other sensors.

Abstract: An edema monitor uses patient-specific measurements of tissue conductivity and tissue perfusion and an empirically developed perfusion coefficient of thermal conductivity to obtain tissue intravascular water and tissue extravacular water components of tissue total water. Edema is an excess of tissue extravacular water. A value for edema is obtained by deducting from the obtained value for tissue extravacular water a normal value for tissue extravacular water.

Abstract: A unitary multilumen cranial bolt for use in multimodal monitoring of a plurality of physiological parameters in brain tissue incorporates a plurality of lumens, each lumen directing a catheter borne sensor through a bore hole in the cranium and into brain tissue of a patient. The lumens are configured to cause the catheters to splay outward as they enter the cranial cavity and reach their intended depth of penetration. Each lumen is associated with a guide. The guides are adapted for use with introducers that enable fragile and/or flexible sensors to be introduced into brain tissue. Each catheter borne sensor can be positioned and repositioned within brain tissue independently of all other sensors.

Abstract: Methods and apparatus for determining blood flow in tissue are disclosed. The methods and apparatus are used to establish a baseline for both thermal properties of the tissue and non-physiologic conditions. Periodic changes in either or both constituents of the baseline are determined and, when the changes correspond to a need for a new baseline, a new baseline is established.

Abstract: A unitary multilumen cranial bolt for use in multimodal monitoring of a plurality of physiological parameters in brain tissue incorporates a plurality of lumens, each lumen directing a catheter borne sensor through a bore hole in the cranium and into brain tissue of a patient. The lumens are configured to cause the catheters to splay outward as they enter the cranial cavity and reach their intended depth of penetration. Each lumen is associated with a guide. The guides are adapted for use with introducers that enable fragile and/or flexible sensors to be introduced into brain tissue. Each catheter borne sensor can be positioned and repositioned within brain tissue independently of all other sensors.

Abstract: The system assesses the endothelial function of a subject. Particularly, peripheral tissue perfusion measurements taken in a subject are compared to reference perfusion data and the comparison yields the assessment of endothelial function. The reference may be data indicative of peripheral tissue perfusion in a healthy person. Also, peripheral tissue perfusion measurements taken in a subject when perfusion is in an unperturbed state (the reference) can be compared to perfusion measurements taken promptly after a challenge to normal or unperturbed tissue perfusion of the subject.

Abstract: An edema monitor uses patient-specific measurements of tissue conductivity and tissue perfusion and an empirically developed perfusion coefficient of thermal conductivity to obtain tissue intravascular water and tissue extravascular water components of tissue total water. Edema is an excess of tissue extravascular water. A value for edema is obtained by deducting from the obtained value for tissue extravascular water a normal value for tissue extravascular water.

Abstract: The system assesses the endothelial function of a subject. Particularly, peripheral tissue perfusion measurements taken in a subject are compared to reference perfusion data and the comparison yields the assessment of endothelial function. The reference may be data indicative of peripheral tissue perfusion in a healthy person. Also, peripheral tissue perfusion measurements taken in a subject when perfusion is in an unperturbed state (the reference) can be compared to perfusion measurements taken promptly after a challenge to normal or unperturbed tissue perfusion of the subject.

Abstract: Methods and apparatus for determining blood flow in tissue are disclosed. The methods and apparatus are used to establish a baseline for both thermal properties of the tissue and non-physiologic conditions. Periodic changes in either or both constituents of the baseline are determined and, when the changes correspond to a need for a new baseline, a new baseline is established.

Abstract: Methods and apparatus for determining blood flow in tissue are disclosed. The methods and apparatus are used to establish a baseline for both thermal properties of the tissue and non-physiologic conditions. Periodic changes in either or both constituents of the baseline are determined and, when the changes correspond to a need for a new baseline, a new baseline is established.

Abstract: The system assesses the endothelial function of a subject. Particularly, peripheral tissue perfusion measurements taken in a subject are compared to reference perfusion data and the comparison yields the assessment of endothelial function. The reference may be data indicative of peripheral tissue perfusion in a healthy person. Also, peripheral tissue perfusion measurements taken in a subject when perfusion is in an unperturbed state (the reference) can be compared to perfusion measurements taken promptly after a challenge to normal or unperturbed tissue perfusion of the subject.

Abstract: Methods and apparatus for determining blood flow in tissue are disclosed. The methods and apparatus are used to establish a baseline for both thermal properties of the tissue and non-physiologic conditions. Periodic changes in either or both constituents of the baseline are determined and, when the changes correspond to a need for a new baseline, a new baseline is established.

Abstract: Disclosed are methods and apparatus for determining blood flow in tissue. Particularly methods and apparatus are disclosed for establishing baseline thermal properties for the tissue and providing one or more steps for periodically determining changes in the tissue thermal properties that correspond to a need for a new baseline and establishing the new baseline.

Abstract: A technique is disclosed for determining blood flow in a living body by changing the thermal energy level in the venous blood flow path and determining temperatures in both the venous and arterial blood flow paths. Blood flow is calculated as a function of the change in energy level and the temperature differences in the venous and arterial blood flow paths.

Abstract: Disclosed are methods and apparatus for determining blood flow in tissue. Particularly methods and apparatus are disclosed for establishing baseline thermal properties for the tissue and providing one or more steps for periodically determining changes in the tissue thermal properties that correspond to a need for a new baseline and establishing the new baseline.

Abstract: Oxygen partial pressure and temperature are measured in living tissue by inserting a thin probe into living tissue. The probe includes a plurality of spatially separated thermal sensors secured to the probe substrate. A plurality of oxygen sensors is positioned along the length of the probe substrate and each oxygen sensor is associated with and positioned adjacent to or is an integral part of one of the thermal sensors. Electrical parameters of the sensors located on the probe are measured and used to determine oxygen partial pressure and to determine temperature at each of a plurality of sites along the probe.