Abstract: A pulse oximeter includes a capacitive d.c. blocking element to separate the time varying red and infra-red components of a light source transmitted through or reflected form the blood from the composite light signals. The magnitudes of the signal amplitudes are then digitized and converted for use as independent variables applied to a ROM based look-up table to determine blood oxygen saturation.

Abstract: A tamper-proof package includes a vessel, closure and locking member having downwardly and outwardly extending tabs of a contrasting color welded to the vessel. The tabs are frangible to break upon twisting of the cap to provide visibly contrasting evidence of tampering observable from above the package.

Abstract: Apparatus for arming and disarming a vehicle alarm in response to locking and unlocking of an entranceway to the vehicle has a cylinder mounted in the housing and adapted to be rotated relative thereto by the turning of a key inserted therein in one direction for locking said entranceway and the opposite direction for unlocking said entranceway. A slidable member signals that the alarm has been armed. The alarm is armed and disarmed by the movement of a first cam fixedly mounted on one of the cylinder and the housing and a plurality of switches fixedly mounted on the other of the housing and the cylinder. The first cam engages one of the switches to arm the alarm when the cylinder is rotated to one position and engages another of the switches to disarm the alarm when the cylinder is rotated to another position. A second cam freely mounted in circumscribing relationship to the cylinder rotates upon the turning of said cylinder with an unauthorized key thereby actuating another switch to sound the alarm.

Abstract: A container or receptacle for a freezer comprises a flexible polymeric material having the shape and contour of the freezer and is adapted to be inserted into and attached to the freezer which may then be used in a conventional manner. Frost builds up on the container rather than on the walls of the freezer. To defrost the freezer, the contents are removed, and the container is removed and replaced with another container; or the removed container is flexed to remove the frost therefrom, and replaced in the freezer.

Abstract: A copy holder used on a desk to hold work consisting of papers or other graphic materials for viewing by a typist or terminal operator has a lip for placement under a terminal or typewriter. A sentence page guide is frictionally journalled and longitudinally slidable on a cylindrical guide strip rod offset from the copy holder plate which supports the work. A swing eye rod extending from the copy holder plate is journalled in one end of a spring holder arm which is hollow and contains two inserts urged apart by an intermediate coil spring to frictionally hold the copy holder plate in position. The other end of the spring holder arm is frictionally pivotally mounted on a base.

Abstract: The calibration of a polarographic oxygen sensor (20) at zero oxygen concentration is accomplished by providing an oxygen-free liquid environment at the sensor active surface. This is accomplished electrolytically by depleting a thin film of electrolyte (24) of oxygen to zero concentration with an oxygen-reducing cathode (6), and complementary anode (4), connected via a battery (10) and switch (12). The sensor (20) is placed into close proximity with the electrodes (4,6) and the oxygen in the electrolyte (24) reduced while its concentration is measured by the sensor (20). A low steady-state signal for the sensor provides the zero oxygen concentration calibration point.

Abstract: An improved nasal cannula is made of a soft pliable material and has two hollow tubular prongs which are ribbed to prevent significant closure of the airways through the prongs upon bending of the prongs and a base adapted to receive a soft strip of foam-like material which can be attached to a skull cap for securing the prongs of the cannula in the nasal passages of a patient.

Abstract: A skate has a wheel rotatably mounted on an axle with a light emitting element mounted on the wheel for making the wheel illuminative when an electrical potential is applied to the light emitting element. The electrical potential can be supplied by a battery installed within the wheel through a switch which can be actuated by rotating a cap movably mounted on the hub of the wheel or contacts actuated by centrifugal force upon rotation of the wheel. The rotor and stator of an electrical generator can be mounted on the axle and wheel to generate the electrical potential in an embodiment which does not require a battery.

Abstract: An improved apparatus for non-invasive measurement of transcutaneous carbon dioxide pressure employs a skin engaging sensor including pH and reference electrodes and a temperature sensor. The temperature sensor produces an output signal voltage having a characteristic which can be the same as or the complement of the voltage-temperature characteristic of the deviation voltage component of the pH-reference electrode voltage attributable to temperature deviation effects on the sensor as well as on the skin. An error signal voltage produced at the output of the temperature sensor is combined with the voltage measured across the pH and reference electrodes to provide a corrected voltage having a magnitude indicative of transcutaneous carbon dioxide pressure at a predetermined reference temperature without need to heat the skin or electrode or otherwise control their temperatures.

Abstract: An adapter to be connected between a respirator and a patient artificial airway has an axial bore communicating between the respirator and artificial airway and one or more sloping bores communicating between the axial bore and the periphery of the adapter body to provide one or more respective access openings leading to the bore through which a suction catheter can be inserted. Means for sealing the access openings from the ambient environment when a suction catheter is not in use is provided by an access closure means which includes a member movable on the adapter body and an elastomeric sealing means which is compressed about each access opening to form an airtight seal when the access closure means is in a position to cover the access openings. Each access opening can accept a catheter for insertion through the axial bore and into the artificial airway when the access closure means is in a position to expose the access opening.

Abstract: An apparatus and method for measuring and monitoring blood oxygen content and local perfusion factor. A transcutaneous gas measurement probe is heated by application of an electric current to a semi-conductor device housed therein. The heat developed in a semi-conductor device heats the probe to a constant temperature under the control of a temperature monitoring and regulating circuit and the amount of power applied to the semi-conductor device is measured by multiplying the current conducted through the semiconductor device by the voltage across it to provide a measurement of local perfusion factor. An alerting device is provided to signal when blood oxygen content and local perfusion factor are outside a predetermined acceptable range.

Abstract: A fixation ring for a transcutaneous gas sensor probe adapted to be removably mounted on the probe with a bore in the ring communicating with the electrodes of the probe. The fixation ring includes a membrane mounted therein which is tensioned in cooperation with the probe when the fixation ring is attached to the probe at which time the membrane permits only gases to which it is permeable to pass through the bore in the fixation ring and into an ion solution in contact with the electrodes of the probe. A cap member removably mountable on the fixation ring is provided with a resilient disc for depressing the membrane to prevent excessive ion solution and any entrapped air from accumulating adjacent to the electrodes.