A medical instrument includes a noninvasive pulse transducer which senses heart beats of a human subject. Based upon pulse signals from the transducer, the instrument provides visual stimulae which allow the human subject to voluntarily synchronize the subject's respiration cycles with the subject's heart beats. At the same time, the instrument determines and stores the instantaneous beat-to-beat heart rate for each beat of the respiratory cycles. After a predetermined number of synchronized res...

Concretions, such as kidney stones, are nonsurgically fragmented by apparatus which produces focused shock waves. A truncated ellipsoidal reflector is positioned against the patient such that one focus thereof is coincident with the concretion. The reflector is filled with a liquid medium having an acoustical impedance similar to living tissue. A laser beam is focused at the remaining focus, thereby producing a shock wave which is coupled through the liquid medium and the patient's tissue and fo...

A noninvasive device for photoelectrically measuring a property of arterial blood is provided. Light that contacts living tissue with arterial blood is converted into a pair of electrical signals. The electrical signals are processed to provide information of the amplitude of the measured signals and are further processed to produce a final output signal that is substantially a square function of a ratio between the electrical signals representative of the amplitudes.

Apparatus and method for noninvasive fragmentation of body concretions. The apparatus has an integral unit including an ultrasonic locating transducer and positioning structure. The concretion is localized with ultrasonics and then shattered upon generation of a shockwave, using a relfector with first and second foci. A spark gap at the first focus generates the shockwave which propagates to the second focus coincident with the concretion. The ultrasonic tranducer is positioned so that an axis o...

A non-invasive method for continuously monitoring blood and tissue oxygenation of a human fetus prior to and during labor and delivery. A specialized NMR spectrometer, whose static-field magnet is large enough to admit the abdomen of a pregnant woman at term, obtains resonance signals from a spatial region within the mother that includes the fetus. Resonance signals originating from the oxygen-transport protein hemoglobin are continuously obtained and analyzed. Signals originating from the speci...

A method and apparatus for monitoring the cardiac output of living subjects. Carotid pulse waveforms and femoral pulse waveforms are measured and converted to digitized signals. The carotid pulse signal or waveform is applied as a voltage to the simulated aorta circuit and the circuit component values varied to develop a waveform output best matching the femoral pulse electrical waveform.

The invention comprises methods for noninvasively monitoring physiological characteristics of a patient's blood. Determinations of blood constituent concentrations may be made by comparing absorbance of radiation at varying parameters, such as path length and blood pressure. Preferably, changes in pressure are effected by changing the height of the probes relative to the patient's heart. Determinations of blood pH may be made by comparing absorbance of the blood at different wavelengths. The tem...

The invention provides improved devices, methods, and systems for shrinking of collagenated tissues, particularly for treating urinary incontinence in a noninvasive manner by directing energy to a patient's own support tissues. This energy gently heats fascia and other collagenated support tissues, causing them to contract. The energy will preferably be applied between a pair of large plate electrodes having cooled flat electrode surfaces. Such cooled plate electrodes are capable of directing el...

A method and apparatus for determining the mean arterial blood pressure (MAP) of a subject during tonometric conditions. In one embodiment, the apparatus comprises one or more pressure and ultrasound transducers placed over the radial artery of a human subject's wrist, the latter transmitting and receiving acoustic energy so as to permit the measurement of blood velocity during periods of variable compression of the artery. During compression, the ultrasound velocity waveforms are recorded and p...

A respiratory gas analyzer for measuring the metabolic activity and the cardiac output of a subject includes a bi-directional flow meter and a capnometer sensor interconnected by conduits and valving between a mouthpiece and a source of respiratory gasses which may be a controlled source or the atmosphere. A pass-through carbon dioxide scrubber may be plugged into the conduits and the valving controlled so that upon inhalation by the subject gasses are passed through the flow meter to the mouthp...