Electronically controlled respirator
First Claim
1. A method of controlling the breathing cycle of a patient comprising:
- determining the total resistance R of the patient'"'"'s lungs;
determining the total compliance C of the patient'"'"'s lungs;
determining the alveolar tidal volume V°
AT of the patient'"'"'s lungs;
delivering oxygen enriched air to the patient for an inspiration period τ
of the breathing cycle at an initial pressure RV°
AT /τ and
increasing the pressure to a pressure ##EQU17## at the end of the inspiration cycle; and
lowering the pressure to a level below RV°
AT /τ
during an expiration period of the breathing cycle.
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Accused Products
Abstract
The breathing cycle of a patient is controlled to achieve proper ventilation and at the same time minimize the work of distension of the lungs. Oxygen enriched air is delivered to the patient during the inspiration period such that the pressure waveform is a ramp function having initial and final values which are dependent on the resistance, compliance and alveolar volume of the lungs. The apparatus includes a source of oxygen enriched air at a regulated pressure and a pneumatically controlled pressure reducing valve for reducing the pressure of the oxygen enriched air for delivery to the patient. The valve is controlled by a transducer which converts an electrical control signal into a pneumatic control signal. The electrical control signal which is generated by an electronic control circuit, is a function of the parameters of the patient'"'"'s lungs.
116 Citations
8 Claims
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1. A method of controlling the breathing cycle of a patient comprising:
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determining the total resistance R of the patient'"'"'s lungs; determining the total compliance C of the patient'"'"'s lungs; determining the alveolar tidal volume V°
AT of the patient'"'"'s lungs;delivering oxygen enriched air to the patient for an inspiration period τ
of the breathing cycle at an initial pressure RV°
AT /τ and
increasing the pressure to a pressure ##EQU17## at the end of the inspiration cycle; and
lowering the pressure to a level below RV°
AT /τ
during an expiration period of the breathing cycle. - View Dependent Claims (2, 3)
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4. A respirator system for ventilating the lungs of a patient in accordance with a breathing cycle having an inspiration period and an expiration period comprising:
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means for providing oxygen enriched air at a regulated pressure; pneumatically controlled pressure reducing valve for reducing the pressure of the oxyen enriched air in accordance with a predetermined pressure waveform for delivery to the patient; transducer means for converting an electrical control signal to a pneumatic control signal to control the pressure reducing valve; and electronic control circuit for generating the electrical control signal as a function of parameters of the lungs. - View Dependent Claims (5, 6, 7, 8)
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Specification