Abstract: A method and apparatus for stimulating a human muscle to produce a controlled response against a dynamic load. Muscle stimulation is achieved through a pair of alternately pulsed stimulation signals which are applied across different pairs of stimulation electrodes. A pulse generating circuit generates the pulsed stimulating signals at a frequency of about 60 Hz across each electrode pair. A position sensor provides a feedback signal to a computer, which in turn generates a stimulation control signal. The pulse generating circuit uses the stimulation control signal for adjusting the amplitude of the stimulation pulses. The pulse width of the stimulation pulses is disclosed as being about 500 microseconds.

Abstract: An exercising method and apparatus for use in the treatment of paralyzed muscles. The method and apparatus make use of a set of transcutaneous electrodes which are placed upon the skin of the subject over muscles which are to be stimulated. A computer controlled stimulator generates a pair of alternately pulsed stimulation signals which are applied across different pairs of stimulation electrodes to produce controlled muscle contraction. Muscle movement is resisted by a dynamic load, and a position sensor provides a feedback signal indicating the movement actually achieved. The computer uses the feedback signal for modifying the control signal applied to the stimulator. The exercise routine is disclosed as being conducted upon the leg of a subject seated in a specially designed exercise chair.

Abstract: A vehicle for transporting a paralyzed person includes a support frame for carrying the person, a plurality of wheels for carrying the support frame, and foot supports movably connected to the support frame for supporting the feet of the person. A drive system connected between the foot supports and at least one of the wheels drives the vehicle in response to movement of the legs of the person. A plurality of stimulation signals are generated and applied to a plurality of electrodes attached to the skin of the person for causing driving movement of the legs. Controls for selectively actuating the signal generator and for controlling the speed of the vehicle are provided.

Abstract: Solubilized cellulosic material is modified through a condensation reaction with organotin halides. The modified products exhibit lower heats of combustion in air than unmodified cellulose, are hydrophobic and resistant to hydrolysis, and inhibit the growth of a variety of common fungi. The modified products are useful as insulation materials, mildew and mold resistant fabrics, and as material for topical bandages.

Abstract: A surface friction tester in the form of a friction sled which may be pulled over a surface to determine the coefficient of friction of that surface. The sled has a friction surface characterizing a vehicle tire tread attached to the bottom of a base plate. The base plate is a part of a sled frame which also has a tongue portion. A straight spring scale attached to the tongue is used to measure the force required to pull the sled over the surface. The friction sled is especially adapted for accident investigations in order to allow the investigator to determine the coefficient of friction of the surfaces upon which skid marks exist and, thus, calculate the vehicle velocity at the time of brake locking on the basis of the skid marks left by the sliding vehicle.

Abstract: A method of preparing tetraketone precursors which are useful in the production of high temperature resistant polyquinoxaline resins. Suitable diketones are oxidized with a halogenating agent, such as cupric halide or hydrogen bromide, and dimethylsulfoxide to produce the corresponding tetraketone. The tetraketones which can be produced by the instant process have the formula: ##STR1## wherein R is hydrogen or an aryl, substituted aryl, heterocyclic or substituted heterocyclic radical and R' is an aryl, substituted aryl, arylalkyl, arylether, arylthioether, arylsulfoxide, arylsulfone, heterocyclic or substituted heterocyclic radical.

Abstract: A polymer lined capillary column for use in gas chromotagraphy has a thin layer of ethoxycarbonyl substituted polyphenylene resin solvent deposited and uniformly coated on the interior surface of the base column as a support for a stationary phase, the resin coated column further including a separate stationary phase with the resin.

Abstract: A method for preparing diketone starting materials useful in synthesizing tetraketone precursors for high temperature resistant polyquinoxaline resins. Dicarboxylic acid derivatives that contain no alpha hydrogens are contacted in the presence of a strong base with an active-hydrogen compound of the type R -- CH.sub.2 -- X where R is an aryl, substituted aryl, heterocyclic or substituted heterocyclic radical and X is a nitrile group or a carboxylic acid functional group. A reaction intermediate is formed having the formula: ##STR1## wherein R and X are as defined in regard to the active-hydrogen compound and R' is the same as R. The reaction intermediate is hydrolyzed and decarboxylated to form the diketone. The diketones produced by the instant invention have the formula: ##STR2## where R and R' are the same as in the reaction intermediate.