System for detecting penetration of medical instruments
First Claim
1. In combination, a medical instrument including a tip which is designed to penetrate the wall of an internal cavity of a patient, and a device for detecting when the tip penetrates through said wall, said device comprising:
- a source of a detection signal;
means for coupling said signal to the tip of said medical instrument, said coupling means including a high Q resonant circuit having an initial value of Q when the medical instrument is not in use;
means for providing a return path for said signal so that, in use of the instrument, a circuit is completed through said resonant circuit such that when said tip contacts patient tissue the initial Q of the resonant circuit changes and when the tip penetrates through the patient tissue the Q of the circuit is restored to said initial value; and
detector means for detecting the change in Q of said resonant circuit and for producing an output when changed Q is restored to the initial value thereof so as to indicate that said tip has penetrated through the patient tissue.
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0 Petitions
Accused Products
Abstract
A device is provided for use with a medical instrument including a tip which is designed to penetrate the wall of an internal cavity (e.g., the abdomen) of a patient, for detecting when that tip penetrates through the wall. The device includes a source of a medium frequency detection signal and circuitry for coupling the signal to the tip of the medical instrument. The circuitry includes a transformer forming a high Q resonant circuit having an initial value of Q when the medical instrument is not in use. A return path for the signal provides that, in use of the instrument, a circuit is completed through the resonant circuit such that when the tip contacts patient tissue the initial Q of the resonant circuit changes and when the tip penetrates through the patient tissue of the Q of the circuit is restored to the initial value thereon. A detector detects the change in Q of the resonant circuit and produces an output when changed Q is restored to the initial value thereof so as to indicate that the tip has penetrated through the patient tissue.
114 Citations
20 Claims
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1. In combination, a medical instrument including a tip which is designed to penetrate the wall of an internal cavity of a patient, and a device for detecting when the tip penetrates through said wall, said device comprising:
- a source of a detection signal;
means for coupling said signal to the tip of said medical instrument, said coupling means including a high Q resonant circuit having an initial value of Q when the medical instrument is not in use;
means for providing a return path for said signal so that, in use of the instrument, a circuit is completed through said resonant circuit such that when said tip contacts patient tissue the initial Q of the resonant circuit changes and when the tip penetrates through the patient tissue the Q of the circuit is restored to said initial value; and
detector means for detecting the change in Q of said resonant circuit and for producing an output when changed Q is restored to the initial value thereof so as to indicate that said tip has penetrated through the patient tissue. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
- a source of a detection signal;
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20. In combination, an electrosurgical instrument connected to an electrosurgical generator and including a tip which is designed to penetrate the wall of an internal cavity of a patient, and a device for detecting when the tip penetrates through said wall, said device comprising:
- a source of a detection signal;
means for coupling said signal to the tip of said instrument, said coupling means including a high Q resonant circuit having an initial value of Q when the instrument is not in use;
means for providing a return path for said signal so that, in use of the instrument, a circuit is completed through said resonant circuit such that when said tip contacts patient tissue the initial Q of the resonant circuit changes and when the tip penetrates through the patient tissue the Q of the circuit is restored to said initial value; and
detector means for detecting the change in Q of said resonant circuit and for producing an output, when the changed Q is restored to the initial value thereof indicating that said tip has penetrated through the patient tissue, for cutting off said electrosurgical generator.
- a source of a detection signal;
Specification