Hearing aid malfunction detection system

A malfunction detection system for detecting malfunctions in electrical signal processing circuits is disclosed. Malfunctions of a hearing aid in the form of frequency distortion and/or inadequate amplification by the hearing aid amplifier, as well as weakening of the hearing aid power supply are detectable. A test signal is generated and a timed switching circuit periodically applies the test signal to the input of the hearing aid amplifier in place of the input signal from the microphone. The resulting amplifier output is compared with the input test signal used as a reference signal. The hearing aid battery voltage is also periodically compared to a reference voltage. Deviations from the references beyond preset limits cause a warning system to operate

Noise-induced inhibitory suppression of malfunction neural oscillators

Motivated by the aim to find new medical strategies to suppress undesirable neural synchronization we study the control of oscillations in a system of inhibitory coupled noisy oscillators. Using dynamical properties of inhibition, we find regimes when the malfunction oscillations can be suppressed but the information signal of a certain frequency can be transmitted through the system. The mechanism of this phenomenon is a resonant interplay of noise and the transmission signal provided by certain value of inhibitory coupling. Analyzing a system of three or four oscillators representing neural clusters, we show that this suppression can be effectively controlled by coupling and noise amplitudes.Comment: 10 pages, 14 figure

Valve malfunction detection apparatus

A detection system is provided for sensing a malfunction of a valve having an outlet connected to an end of a first pipe through which pressurized fluid may be flowed in a downstream direction away from the valve. The system includes a bypass pipe connected at its opposite ends to the first pipe and operative to bypass a portion of the fluid flow therethrough around a predetermined section thereof. A housing is interiorly divided by a flexible diaphragm into first and second opposite chambers which are respectively communicated with the first pipe section and the bypass pipe, the diaphragm being spring-biased toward the second chamber. The diaphragm housing cooperates with check valves and orifices connected in the two pipes to create and maintain a negative pressure in the first pipe section in response to closure of the valve during pressurized flow through the first pipe. A pressure switch senses the negative pressure and transmits a signal indicative thereof to a computer. Upon cessation of the signal while the valve is still closed, the computer responsively generates a signal indicating that the valve, or another portion of the detection system, is leaking

Development of monitoring techniques by acoustical means for mechanical checkouts Final report, 15 May - 30 Sep. 1965

Automated pattern recognition devices using sonic signature data for detecting S3D and F-1 engine valve malfunction

An application of adaptive learning to malfunction recovery

A self-organizing controller is developed for a simplified two-dimensional aircraft model. The Controller learns how to pilot the aircraft through a navigational mission without exceeding pre-established position and velocity limits. The controller pilots the aircraft by activating one of eight directional actuators at all times. By continually monitoring the aircraft's position and velocity with respect to the mission, the controller progressively modifies its decision rules to improve the aircraft's performance. When the controller has learned how to pilot the aircraft, two actuators fail permanently. Despite this malfunction, the controller regains proficiency at its original task. The experimental results reported show the controller's capabilities for self-organizing control, learning, and malfunction recovery

‘Twiddling’ of the pacemaker resulting in lead dislodgement

Twiddler’s syndrome is a rare condition in which patient manipulation of the pulse generator within its pocket may result in coiling of the lead and lead dislodgement, thereby causing pacemaker malfunction. Retraction of the electrode may cause phrenic nerve stimulation resulting in diaphragmatic stimulation and a sensation of abdominal pulsations. As the leads are further wrapped around the generator, rhythmic arm twitching may occur as a result of pacing of the brachial plexus.1 Twiddler’s syndrome was first described by Bayliss et al in 1968 as a complication of pacemaker implantation.2 It has also been reported with implantable cardioverter-defibrillators (ICDs)3 and cardiac resynchronisation therapy (CRT).4 This is a case report of an elderly lady with Twiddler’s syndrome resulting in pacemaker malfunction secondary to lead retraction, who emphatically denied any manipulation of her device. She subsequently underwent lead repositioning and appropriate counselling.peer-reviewe

Is it possible to check micro ginning fiber quality preservation performance using reference seed-cotton materials?

In sub-Saharian countries, simple micro-gin, without seed-cotton cleaner nor lint-cleaner, is often used as a reference device for characterizing the performance of industrial gin plants for fiber quality preservation. It is however useful to check if this micro-gin itself is properly set and maintained. Reference seed-cotton materials, well homogenized with known variability level, and available in large quantities, may serve the purpose of monitoring the performance of the micro-gin in order to detect any malfunction or any drift. Therefore, it is expected that any deviation in SITC results on ginned reference seed-cotton materials from predetermined data would alert on altered ginning conditions. This experiment demonstrates the feasibility of setting mean values and confidence intervals on measured SITC characteristics on fiber samples, to later detect any malfunction or drift that may occur in practices, settings, or degradation in a micro-gin

Communications system for zero-g simulation tests in water

System connects seven observers, diver, and spare station, and utilizes public address system with underwater speakers to provide two-way communications between test subject and personnel in control of life support, so that test personnel are warned immediately of malfunction in pressure suit or equipment

Building graph-based programming strategies for reconfigurable photonic circuits

We have developed a graph representation of programmable photonic mesh circuits that can be used by pathfinding algorithms. We modified the Dijkstra algorithm to observe only physically possible connections in the graph, demonstrating flexible rerouting in case of node malfunction