Abstract: A medical device known as an implantable therapeutic substance delivery device is configured for implanting in humans to deliver a therapeutic substance such as pharmaceutical compositions, genetic materials, and biologics to treat a variety of medical conditions such as pain, spasticity, cancer, and many other conditions. The infusion device incorporates a stepper motor that controls the infusion flow rate during the service life of the device. The stepper motor is controlled by continuously varying electrical pulse parameters based on the continuously decreasing power source voltage during the service life of the substance delivery device. In particular the stepper motor electrical pulse parameters, especially duty cycle, are selected to efficiently compensate for decreasing battery voltage thereby optimizing the motor performance while maximizing the power source service life.

Abstract: A medical device known as an implantable therapeutic substance delivery device is configured for implanting in humans to deliver a therapeutic substance such as pharmaceutical compositions, genetic materials, and biologics to treat a variety of medical conditions such as pain, spasticity, cancer, and many other conditions. The infusion device incorporates a stepper motor that controls the infusion flow rate during the service life of the device. The stepper motor is controlled by continuously varying electrical pulse parameters based on the continuously decreasing power source voltage during the service life of the substance delivery device. In particular the stepper motor electrical pulse parameters, especially duty cycle, are selected to efficiently compensate for decreasing battery voltage thereby optimizing the motor performance while maximizing the power source service life.

Abstract: A system for insertion of a fiber optic diagnostic sensor into the human body. The sensor is of the type which functions by emission of light into the body and reception of light reflected from the body. In particular, the system is intended for use with fiber optic reflectance oximeters. The fiber optic sensor is inserted into an introducer catheter, and coupled to monitoring equipment and activated as the sensor is advanced through the introducer catheter. By appropriately filtering or otherwise processing the signal indicative of reflected light received by the sensor, its position relative to the end of the introducer catheter can be determined. This allows for accurate insertion of the fiber optic sensor, regardless of the length of the introducer catheter and regardless of the length and/or number of fittings or manifolds through which the fiber optic sensor must pass.

Abstract: A fiber-optic sensor for measuring a parameter of a test fluid, including a chemical sensor, incorporating a dye composition which displays changes in its optical properties correlated to changes in the parameter to be measured. The sensor is coupled to an apparatus including a light source, and means for measuring light received from said sensor at three different peak wavelengths. The first wavelength is chosen such that the optical characteristics of the dye with respect to that wavelength do not change significantly with changes in the parameter to be measured. The second and third wavelengths are chosen such that optical characteristics of the dye with respect to these wavelengths do change along with changes in the parameter to be measured, and also change as a function of temperature. The light received from the sensor at first, second and third wavelengths is compared to determine the temperature of the test fluid and to provide a temperature correction for the parameter to be measured.

Abstract: A multiple wavelength light source and a method of constructing a multiple wavelength light source. The light source includes a plurality of light emitting diodes mounted to a substrate, located closely adjacent to one another. A single optical fiber is mounted to the substrate, appropriately positioned to provide a desired ratio of wavelengths at a desired amplitude.

Abstract: A two fiber reflectance oximeter and hematocrit detector and a method of use are disclosed. The tips of the optical fibers employed are beveled at an angle optimized to minimize internal reflections, allowing the use of the fibers to simultaneously perform transmitting and receiving functions.