Apparatus and method for discriminating flow of blood in a cardiovascular system

A method for discriminating cardiovascular blood flow, comprising the steps of:

• implanting a first electrode in a blood flow path of the cardiovascular system;
• implanting a second electrode such that an ionically conductive path exists between said first and second electrodes;
• implanting a reference electrode such that an ionically conductive path exists between said first and reference electrodes;
• detecting cardiac fibrillation, whereby, if fibrillation is detected, a state of substantially no flow of blood at said first electrode can be assumed;
• delivering a reference electrical shock between said first and second electrodes at a time when there is substantially no flow of blood at said first electrode;
• subsequently delivering a defibrillating electrical shock between said first and second electrodes;
• sensing in the time domain a reference electrical potential between said first and reference electrodes following delivery of said reference electrical shock;
• sensing in the time domain a test electrical potential between said first and reference electrodes following delivery of said defibrillation electrical shock;
• analyzing and comparing said test electrical potential to said reference electrical potential, and
• determining, on the basis of said comparison, whether blood is flowing following delivery of said defibrillation electrical shock.

A method of discriminating flow of blood in a cardiovascular system of a body, comprising the steps of:

• disposing a first electrode in a blood flow path of the cardiovascular system;
• disposing a second electrode such that an ionically conductive path exists through the body between said first electrode in a blood flow path and said second electrode,
• imposing an electrical potential on said first electrode by connecting a voltage source between said first electrode in the blood flow path and said second electrode;
• disconnecting said voltage source from said first electrode after said electrical potential has been imposed;
• allowing the electrical potential on said first electrode to discharge at least partially;
• sensing the discharging electrical potential in the time domain following said step of imposing an electrical potential by
• disposing a reference electrode such that an ionically conductive path exists through the body between said first electrode in a blood flow path and said reference electrode, and
• sensing the potential of the electrode in a blood flow path relative to the potential of said reference electrode;
• and
• analyzing said sensed electrical potential to discriminate flow of blood, wherein said step of disposing a second electrode and said step of disposing a reference electrode are performed independently by implanting separate components comprising said second and reference electrodes, respectively.

An apparatus for discriminating flow of blood in a cardiovascular system, comprising:

• a first implantable electrode configured for implanting in a blood flow path of the cardiovascular system;
• a second implantable electrode configured for implanting in the body such that an ionically conductive path exists through the body between the first and second electrodes;
• a reference implantable electrode configured for implanting in the body such that an ionically conductive path exists through the body between the first and reference electrodes in which said second electrode and said reference electrode are electrically non-common at separate locii;
• means for sensing cardiac parameters from which the state of flow of blood at said first electrode can be deduced;
• means in electrical communication with said first and second electrodes for delivering a reference shock between said first and second electrodes at a time when the state of flow of blood at said first electrode is known, and for subsequently delivering a test shock between said first and second electrodes;
• means for sensing in the time domain a reference electrical potential between said first electrode and said reference electrode following delivery of said reference shock, and for sensing in the time domain a test electrical potential between said first electrode and said reference electrode following delivery of said test shock;
• and
• means for analyzing and comparing said sensed reference electrical potential and said sensed test electrical potential., and for determining on the basis of said comparison the state of flow of blood following delivery of said test shock.