US 4,526,177 A · Electronic anatomical probe

Abstract

A wire sensing coil is sealed in the tip of an elongate, rigid, plastic probe, and is connected by a coaxial cable releasably to a housing containing a fixed frequency, crystal-controlled oscillator, the output of which is applied through a high impedance resistor and the cable to the coil. The number of turns in the coil and the cable length are carefully selected so that the coil remains tuned to the frequency of the oscillator, except when the tip of the probe approaches a metal object, at which time the voltage drop across the coil decreases. The housing also contains an audible alarm, and a sensing circuit which detects the voltage drop across the coil, and which energizes the alarm when the voltage across the coil drops below a preset or predetermined level. The housing also contains a rechargable battery for supplying power to the oscillator and alarm circuits, and a recharging circuit for recharging the battery. A manually operable switch on the housing connects the battery to the oscillator when the switch is in its ON position, and connects the recharging circuit to the battery when in its OFF position.

Claims20

Dependent claims

An electronic anatomical probe device, comprising

a housing having thereon a manually operable switch movable between ON and OFF positions, respectively,
a solid state, fixed frequency oscillator secured in said housing,
a DC power supply means in said housing for energizing said oscillator when said switch is in its ON position,
a tubular probe having a tip end disposed to be inserted in a wound or the like,
a wire sensing coil sealed in the tip end of said probe,
means connecting said coil to the output of said oscillator, including an elongate, coaxial cable secured at one end in said probe to said coil, and releasably connected at its opposite end to said housing and to the output of said oscillator,
said coil and said connecting means being tuned to the frequency of the output of said oscillator, whereby when energized thereby, the voltage drop across said coil remains constant until the coil approaches a metallic object,
means in said housing for sensing the voltage drop across said coil, and
alarm means connected to said sensing means and operable thereby to provide a warning signal in response to a predetermined change in said voltage drop across said coil.

6 more elements

A device for detecting metal objects in a human or animal body, comprising

a housing having mounted therein a fixed frequency oscillator, and a power supply means for energizing said oscillator,
a probe assembly including a rigid, tubular probe having a wire sensing coil secured in one end thereof, and an elongate, coaxial cable secured at one end in said probe to said coil, and releasably connected at its opposite end to said housing operatively to couple the output of said oscillator to said coil,
said probe assembly being approximately tuned to the frequency of the output of said oscillator, whereby the voltage drop created across said coil by said oscillator output remains substantially constant until said coil approaches a metallic object, and
alarm means in said housing connected by said cable to said coil and operative to provide a warning signal when the value of the voltage drop across said coil decreases to a predetermined value below the maximum value capable of being created across said coil by said oscillator output,
said coil having an inductance operative normally to cause the voltage drop across said coil to have a value which is less than said maximum value and greater than said predetermined value, and which steadily decreases as said coil approaches a metallic object.

2 more elements

Dependencies are inferred from the claim text.

Electronic anatomical probe

Life of this patent

Electronic anatomical probe

Life of this patent

Abstract

Claims20