Abstract: A multiple parameter monitoring system for ambulatory human patients utilizes a separate harness to be removably worn by each patient. The harness is adapted to engage the chest of the patient and incorporates a first ECG data sensing device engaging the patient to produce first and second analog voltages having variable magnitudes which are measurements of the body MCL1 and MCL6 data respectively; a second respiratory amplitude sensing device to produce a first analog signal having a variable magnitude which is a measurement of the respiratory amplitude of the patient; and a third temperature sensing device engaging the patient to produce a second analog signal which is a measurement of the temperature of the patient.

Abstract: An oscillator employs a single flat piezo-electric transducer as a frequency determining element. The transducer has first, second and third mutually orthagonal axes. The first and second axes lie in a selected one of first and second planes. The first plane is the plane of the transducer, the second plane is at right angles to the first plane. The third axis is perpendicular to the selected plane. The transducer has different modes of excitation in different planes which have different resonant frequencies. The oscillator has a positive feedback loop containing in series a high pass filter and a low pass filter which together [a] determine one selected mode of excitation of the transducer in the selected plane with an associated resonant frequency whereby the transducer resonates in the selected plane at the associated resonant frequency and [b] also prevent the transducer from being excited along the third axis.

Abstract: An oscillator utilizes a piezo-electric transducer as a frequency determining element. The transducer, when unloaded, has a resonant frequency which determines the oscillation frequency and exhibits a pretermined level of amplitude excursion. A clamping mechanism detachably couples the transducer into engagement with a conduit through which fluid flows. This action increases the loading of the transducer and produces a change of resonant frequency, causing the oscillator frequency to change, and also causing the level of amplitude excursion to change. The amount of oscillator frequency change and the change in excursion level have respective values when the fluid flowing in the conduit past the transducer is bubble free which differ from the respective values when the fluid contains bubbles. Circuitry responsive to the changing amplitude values produces an output signal when a selected one of the bubble free and bubble containing conditions is detected.

Abstract: An oscillator utilizes a piezo-electric transducer as a frequency determining element. The transducer, when unloaded, has a resonant frequency which determines the oscillation frequency and exhibits a predetermined level of amplitude excursion. The transducer, when moved into engagement with a conduit through which fluid flows, becomes loaded and exhibits a change of resonant frequency, whereby the oscillator frequency changes, and also exhibits a change in level of amplitude excursion. The amount of oscillator frequency change and the change in excursion level have respective values when the fluid flowing in the conduit past the transducer is bubble free which differ from the respective values when the fluid contains bubbles. Circuitry responsive to at least one of the changing frequency and amplitude values produces a signal when a selected one of the bubble free and bubble containing conditions is detected.