Abstract: Disclosed is an improved drainage catheter for insertion into and retention in the bladder of the human body, and a novel stylet for use in inserting the catheter through the urethra and into the bladder. The catheter is formed of an elongate flexible cannula having a free and unobstructed open end adapted to be inserted into the bladder to permit drainage of waste material from the bladder and to facilitate the insertion of diagnostic instrumentation into the bladder. The end of the catheter in the bladder can expand to widen the opening and cause the open end to lie lower in the bladder. The stylet is an elongate flexible member adapted to be inserted into the cannula prior to the cannula being inserted into the urethra. The cannula and the stylet have cooperating stop means to prevent the stylet from passing through the cannula beyond a predetermined point so that the stylet can be used to push the cannula through the urethra and insert the open end into the bladder.

Abstract: Disclosed is an improved drainage catheter for insertion into and retention in the bladder of the human body, and a novel stylet for use in inserting the catheter through the urethra and into the bladder. The catheter is formed of an elongate flexible cannula having a free and unobstructed open end adapted to be inserted into the bladder to permit drainage of waste material from the bladder and to facilitate the insertion of diagnostic instrumentation into the bladder. The end of the catheter in the bladder can expand to widen the opening and cause the open end to lie lower in the bladder. The stylet is an elongate flexible member adapted to be inserted into the cannula prior to the cannula being inserted into the urethra. The cannula and the stylet have cooperating stop means to prevent the stylet from passing through the cannula beyond a predetermined point so that the stylet can be used to push the cannula through the urethra and insert the open end into the bladder.

Abstract: A system for controlling the concentration of developer solution, which includes a toner concentrate and a carrier, to be substantially equal to a predetermined concentration. The system, which is used in conjunction with a photocopying apparatus, comprises a source of light directed through the solution and a photosensor, on which the light source is focused, that generates an output signal proportional to the amount of light reaching it. A reference signal generator produces a reference signal substantially equal to the photosensor output signal that corresponds to the predetermined solution concentration. A comparator receives both the photosensor output and the reference signals and produces an error signal proportional to the difference between the two. The error signal is used to modulate the amount of time during which a servo mechanism is operated to add toner concentrate to the solution and thereby control solution concentration.

Abstract: A device for indicating when the level of developer solution in an electrostatic photocopying machine falls to a predetermined level comprises a source of light and a photosensor on which the light source is focused. The photosensor generates a light intensity signal that is related in a known way to the magnitude of light incident on it. Both the light source and photosensor are mounted in a housing, which has a bottom formed to rest firmly on the bottom of the tank that holds the developer solution, and, therefore, are mounted in fixed, spaced relation relative to each other as well as to the housing bottom. A bracket, which includes a spring, supports the housing in the developer solution tank with the housing and tank bottoms in firm interengagement to establish the predetermined developer solution level equal to the distance between the tank bottom and photosensor.