Abstract: An inflatable tourniquet cuff includes an inflatable bladder having an outer layer with a predetermined thickness and an inner layer with a thickness that is less than the predetermined thickness of the outer layer. An opening in the bladder allows for the inflation and deflation of the bladder. A fastener system attached to the bladder releasably secures the bladder about a patient's limb so that the thin inner layer is positioned adjacent the patient's skin. The thin layer is relatively flexible in comparison to the thick outer layer and thus expands to a greater degree than the outer layer upon inflation of the bladder.

Abstract: A gas transfer apparatus readily adapted for oxygenating blood includes a housing with a hollow internal chamber having a fiber mat consisting of two sets of intermingled hollow fibers with one set of fibers having micropores formed in the walls thereof and the other set having solid liquid impermeable walls. The housing for the apparatus is designed such that the blood being processed passes substantially uniformly across the entire cross section of the fiber mat whereby a treating gas such as oxygen being directed through the microporous fibers can be diffused into the oxygen deficient blood while excess CO.sub.2 in the blood can cross diffuse into the interior of the fiber and be removed from the apparatus. Simultaneously with the cross diffusion of gas between the microporous fibers and the blood, a thermal conducting fluid such as water is passed through the solid walled fibers to maintain or regulate the temperature of the blood in the apparatus.

Abstract: A blood collection reservoir and filter device includes a generally cylindrical housing and an internal filter medium with the filter medium being retained in spaced relationship from the side wall of the housing so that blood can pass through the filter in a non-traumatized manner and flow smoothly onto a dispersion plate for cascading delivery to the internal surface of the side wall of the housing where it can flow in a non-traumatic manner to an outlet in the bottom wall of the housing. The filter medium includes a defoaming filter layer and a particulate filter layer so that blood removed from a surgical wound can be defoamed and filtered within the device. The filter is elevated within the housing to provide a relatively large temporary storage area where blood can be retained in non-contact with the filter.

Abstract: A tube clamp for dependably occluding the flow of fluid through a deformable tube includes a pair of pin members mounted on a supporting surface adjacent to a pivotal body that includes an edge portion adapted to be pivoted into the space between the pin members to pinch the tube against the pin members, thereby occluding the flow of fluid through the tube.

Abstract: A blood filter device for separating gas bubbles from a flow of blood includes a filter medium in a lower body portion of the device through which the blood must flow before being directed through an outlet tube. An upper cap sealed to the top of the lower body portion includes a blood inlet tube into which a conical dispersion plate is projected so as to decrease the rate of flow of the blood. The rate of flow further decreases as it enters a debubbling chamber in the cap. A top wall of the cap defines a sloped and arched channel around the inlet tube adapted to direct released gas toward a vent tube at the uppermost extent of the sloped top wall.

Abstract: A method of cleaning red blood cells which have been separated from undesirable components of blood in a centrifugal separating chamber includes the steps of pulsating a washing solution through the red blood cells in an alternating high flow rate/low flow rate sequence so as to alternately agitate the red cells for optimal cleaning and stabilize the red cells to prevent a flushing of the cells from the separation chamber.

Abstract: An electronic measuring device utilizes multiple different transducers for supplying signals exhibiting predetermined and typically nonlinear relationships to the multiple input variables sensed by the transducers. The measuring device includes a microcomputer containing stored linearizing information therein relating to the predetermined nonlinear relationship of the signals supplied by the transducers and the variables sensed by the transducers. The microcomputer linearizes each of the signals supplied by the transducers and thereby obtains highly accurate signals indicative of the variables sensed. Depending upon the ultimate determination to be obtained by the device, the linearized signals representative of the input variables may be employed in a polynomial equation calculation conducted by the computer to obtain the output determination.

Abstract: The temperature within a freezer case or refrigeration compartment is operatively determined and controlled by a control system employing a microcomputer which operatively controls a refrigeration system associated with the freezer case. A sensing element is operatively connected to the microcomputer for supplying a signal representative of the freezer compartment temperature. Temperature selector switches establish upper and lower limits of a desired range of temperatures for the freezer case and another selector switch establishes an alarm condition temperature limit. The microcomputer follows a program of comparing the compartment temperature to the upper limit, the lower limit and the alarm condition limit. During normal operation, the microcomputer also controls a refrigerant valve to regulate the compartment temperature within the desired range. If the compartment temperature elevates to the alarm condition limit, the microcomputer energizes a first alarm.

Abstract: A digital thermometer uses a microprocessor computer containing stored information relating to the response characteristics of a transducer to supply a measurement of temperature. The transducer is preferably a thermistor whose resistance varies in a predetermined and nonlinear relation to its temperature. The microprocessor computer includes a read-only memory which has been preprogrammed with piece-wise linearized information approximating the nonlinear relation of resistance and temperature of the thermistor. A current source develops a voltage across the thermistor which is related to the temperature of the thermistor. The voltage across the thermistor is converted into a digital signal, and the digital signal is related to the piece-wise linearized information stored. The temperature equivalent is calculated from a first order algebraic equation determined by the relationship of the digital signal to the stored information.

Abstract: A display unit having a plurality of light emitting segments is directly attached to a circuit board, thereby avoiding use of a separate encapsulated display device. The circuit board is provided with a plurality of electrical conductors permanently attached to its component mounting surface. Electrically conductive leads extend between the light emitting segments of the display unit and the electrical conductors attached to the circuit board. The display unit includes a base supporting member to which the light emitting segments are attached in a desired configuration. The base member is preferably glued with an electrically conductive glue to an electrical conductor attached to the circuit board, thereby simultaneously physically connecting the base member directly and permanently to the circuit board and electrically connecting a common terminal of the light emitting segments to the electrical conductor on the circuit board.

Abstract: A probe of an electronic thermometer, to which a temperature sensing element is attached, is conditioned with heat energy whereby the temperature of the probe is changed to approximately the temperature of the environment whose temperature is to be measured. A thermistor is thermally attached to the probe and provides a measurable electrical characteristic related in a predetermined manner to the temperature experienced by the thermistor. An auxiliary current source supplies a current to the thermistor of sufficient magnitude so that the thermistor acts as a heating element for raising the temperature of the probe. Heat energy is supplied to the probe for a predetermined time or until the temperature of the probe reaches a predetermined limit. The flow of auxiliary current is terminated and the temperature of the probe and its attached thermistor are allowed to equalize to the temperature of the environment.

Abstract: An electronic thermometer providing an improved means for controlling temperature readout. The thermometer incorporates analog-to-digital conversion utilizing a pulse width modulation technique. The temperature of a patient is taken for a given time interval and the last reading thereof is held for another given time interval. An adjustable oscillator provides clock pulses to a frequency divider one output of which triggers a saw tooth generator and other outputs of which are coupled to a decoder driving the display. The saw tooth generator provides an input to a reference comparator and a temperature measurement comparator the former of which receives a reference voltage and the latter of which receives a temperature sensitive voltage derived from circuitry which includes a thermistor.