Apparatus and method for ascertaining cardiac output and other parameters
First Claim
1. Apparatus for ascertaining cardiac output of the heart of a patient having arteries having arterial blood therein supplied by the heart and veins having venous blood therein being returned to the heart which extend into a forearm of the patient comprising a control and display module, a venous probe adapted to be inserted into a vein in the forearm of the patient and coupled into the control and display module and providing an electrical signal representing the dissolved oxygen in the venous blood in the vein, an arterial probe adapted to be inserted into an artery in the forearm of the patient and coupled into the control and display module for providing an electrical output signal representing the dissolved oxygen in the arterial blood in the artery, the control and display module having a visible display, the control and display module having electronics therein including a microprocessor for receiving the electrical output signals from the venous probe and the arterial probe and providing a continuous in vivo cardiac output on the display and utilizing in connection therewith an arterial venous oxygen differential equation which includes an adjustment factor for adjusting for venous blood being sampled in the forearm of the patient rather than mixed venous blood in the pulmonary artery of the patient.
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Accused Products
Abstract
Apparatus for ascertaining cardiac output of the heart of a patient comprising a control and display module. A venous probe is inserted into a vein in the forearm of the patient and is coupled into the control and display module and provides an electrical signal representing the dissolved oxygen in the venous blood. An arterial probe is inserted into an artery in the forearm of the patient and is coupled into the control and display module and provides an electrical output signal representing the dissolved oxygen in the arterial blood. The control and display module has a visible display that provides a continuous in vivo cardiac output that utilizes an arterial venous oxygen differential equation which includes an adjustment factor for adjusting for venous blood being sampled rather than mixed venous blood in the pulmonary artery of the patient.
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Citations
15 Claims
- 1. Apparatus for ascertaining cardiac output of the heart of a patient having arteries having arterial blood therein supplied by the heart and veins having venous blood therein being returned to the heart which extend into a forearm of the patient comprising a control and display module, a venous probe adapted to be inserted into a vein in the forearm of the patient and coupled into the control and display module and providing an electrical signal representing the dissolved oxygen in the venous blood in the vein, an arterial probe adapted to be inserted into an artery in the forearm of the patient and coupled into the control and display module for providing an electrical output signal representing the dissolved oxygen in the arterial blood in the artery, the control and display module having a visible display, the control and display module having electronics therein including a microprocessor for receiving the electrical output signals from the venous probe and the arterial probe and providing a continuous in vivo cardiac output on the display and utilizing in connection therewith an arterial venous oxygen differential equation which includes an adjustment factor for adjusting for venous blood being sampled in the forearm of the patient rather than mixed venous blood in the pulmonary artery of the patient.
- 8. A probe for use in ascertaining cardiac output and other parameters in connection with a control and display module comprising a cannula, an oxygen sensor assembly mounted in the cannula, the cannula being gas permeable in the vicinity of the oxygen sensor assembly, said oxygen sensor assembly including a buffer solution disposed in the cannula and first and second electrodes disposed in the buffer solution and providing a first electrical output, a carbon dioxide sensor assembly disposed in the cannula proximal of the oxygen sensor assembly, the cannula being gas permeable in the vicinity of the carbon dioxide sensor assembly, the carbon dioxide sensor assembly providing a second electrical output, means for isolating the carbon dioxide sensor assembly from the oxygen sensor assembly so that the measurements of one sensor assembly do not interfere with the other sensor assembly and conductor means connected to the oxygen sensor assembly and to the carbon dioxide sensor assembly and supplying the first and second electrical outputs through the cannula to the control and display module.
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12. A probe for use in ascertaining cardiac output and other parameters in connection with a control and display module comprising a cannula, an oxygen sensor assembly mounted in the cannula, said oxygen sensor assembly including a buffer solution disposed in the cannula and first and second electrodes disposed in the buffer solution and providing an electrical output, one of the first and second electrodes being provided with a coiled distal extremity to maximize contact with the buffer solution, conductor means connected to the sensor assembly and supplying the electrical output through the cannula to the control and display module.
- 14. A method for ascertaining cardiac output of the heart of a patient having arteries having arterial blood therein supplied by the heart and veins having venous blood therein being returned to the heart which extend into a forearm of the patient comprising the steps of providing an electrical signal representing the dissolved oxygen in the venous blood in a vein of the forearm of the patient, providing an electrical signal representing the dissolved oxygen in the arterial blood in an artery in the forearm of the patient, using the electrical signals to provide a continuous in vivo cardiac output by utilizing an arterial venous oxygen differential equation which includes an adjustment factor for adjusting for venous blood being sampled in the forearm of the patient rather than in the mixed venous blood in the pulmonary artery of the patient.
Specification