摘要:
A defibrillator circuit for generating a rectangular waveform across a patient from capacitively stored energy and employing a plurality of capacitors initially chargeable to a common voltage and thereafter sequentially switchable into parallel relation with one another so as to raise the voltage supplied to an H-bridge circuit from a point of decay back to said common voltage.
摘要:
Disclosed is a battery powered, hand-held self-contained electronic tonometer with a digital readout for displaying pressure in millimeters of mercury. The tonometer includes a transducer which is a solid state pressure sensitive element and which produces a voltage proportional to intraocular pressure. An electrical waveform is produced by gently bringing the transducer in contact with the cornea. The waveform is converted to a digital signal and processed by a single chip microprocessor. The baseline of a reference signal is nulled by equalizing the charges on two capacitors on the inputs of two differential amplifiers. Equalizing the differential inputs of the two amplifier stages results in a gain of zero and removes any carrier signal. Microprocessor software detects the baseline condition established by equalizing the differential inputs. The microprocessor then looks for a series of valid measurements and calculates the average intraocular pressure along with an estimate of reliability. This average value and the reliability indicator are displayed on a liquid crystal display.
摘要:
A defibrillator module is described which includes a cardiac sensor, a pulse generator and a controller that generates commands responsive to intrinsic cardiac signals for the operation of said pulse generator. The defibrillator module synergistic and arranged so that it can be coupled to a generic patient monitor so that the two can share certain functions. For example, operational parameters and other signals indicative of the operation of the defibrillator module can be shown to the clinician by the patient monitor. Data between the defibrillator module and the patient monitor is exchanged using either a standard or a customized protocol.
摘要:
Disclosed is a digital ultrasonic instrument for measuring the corneal thickness (often referred to as a pachymeter) and for measuring the axial length of the eye (often referred to as a biometric ruler). A number representing corneal thickness or axial length is displayed digitally on a liquid crystal display. The pachymeter incorporates a 20 MHz solid phase piezoelectric transducer, a microprocessor, a gate array, a hybrid analog receiver circuit, a liquid crystal display and four batteries. When axial length is measured, the instrument operates as a biometric ruler, a 10 MHz transducer is used and the software in the microprocessor is modified. Ultrasonic echoes generated by the transducer and various interfaces in the eye are sampled at the rate of 40 MHz which results in equal or greater sensitivity, resolution and accuracy as compared to other pachymeters and biometric rulers currently available. The 40 MHz sample rate is accomplished by use of a grey code counter and a binary counter, each of which is sampled twice after an ultrasonic echo is detected. The two grey code samples are compared to determine a valid sample period. A counter value obtained during a valid sample period is recorded in a shift register and compared to subsequent counter values corresponding to subsequent ultrasonic echoes. The apparatus for correlating ultrasonic echoes with particular counter values assures that the counter will be sampled at a point in time when the counter is stable as opposed to being in a state of transition. The apparatus allows for a counter accuracy of 25 ns.
摘要:
A defibrillator module is described which includes a cardiac sensor, a pulse generator and a controller that generates commands responsive to intrinsic cardiac signals for the operation of said pulse generator. The defibrillator module synergistic and arranged so that it can be coupled to a generic patient monitor so that the two can share certain functions. For example, operational parameters and other signals indicative of the operation of the defibrillator module can be shown to the clinician by the patient monitor. Data between the defibrillator module and the patient monitor is exchanged using either a standard or a customized protocol.
摘要:
A defibrillator module is described which includes a cardiac sensor, a pulse generator and a controller that generates commands responsive to intrinsic cardiac signals for the operation of said pulse generator. The defibrillator module synergistic and arranged so that it can be coupled to a generic patient monitor so that the two can share certain functions. For example, operational parameters and other signals indicative of the operation of the defibrillator module can be shown to the clinician by the patient monitor. Data between the defibrillator module and the patient monitor is exchanged using either a standard or a customized protocol.
摘要:
A power supply for an implantable cardioverter-defibrillator for subcutaneous positioning between the third rib and the twelfth rib and using a lead system that does not directly contact a patient's heart or reside in the intrathoracic blood vessels and for providing anti-tachycardia pacing energy to the heart, comprising a capacitor subsystem for storing the anti-tachycardia pacing energy for delivery to the patient's heart; and a battery subsystem electrically coupled to the capacitor subsystem for providing the anti-tachycardia pacing energy to the capacitor subsystem.
摘要:
A power supply for an implantable cardioverter-defibrillator for subcutaneous positioning between the third rib and the twelfth rib and using a lead system that does not directly contact a patient's heart or reside in the intrathoracic blood vessels and for providing anti-bradycardia pacing energy to the heart, comprising a capacitor subsystem for storing the anti-bradycardia pacing energy for delivery to the patient's heart; and a battery subsystem electrically coupled to the capacitor subsystem for providing the anti-bradycardia pacing energy to the capacitor subsystem.