7720 results about "Instability" patented technology

An active noise cancellation system includes a series of features for more effective cancellation, greater reliability, and improved stability. A particular feature adapted for headset systems includes locating a residual microphone radially offset from the center of a sound generator to detect a signal more similar to that incident upon the eardrum of the user. In addition, an open back headset design includes perforations on the side of the headset instead of the back, so that the perforations are less susceptible to inadvertent blockage. The system also includes a mechanism for detecting changes in the acoustic characteristics of the environment that may be caused, for example, by pressure exerted upon the earpieces, and that may destabilize the cancellation system. The system automatically responds to such changes, for example, by reducing the gain or the frequency response of the system to preserve stability. The system further includes other methods for detecting imminent instability and compensating, such as detecting the onset of signals within enhancement frequencies characteristic of the onset of instability, and adjusting the gain or frequency response of the system or suppressing the enhanced signals. The system further includes a mechanism for conserving battery life by turning the system off when sound levels are low, or adjusting the power supply to the system to correspond to the current power requirements of the system.

Disclosed herein is a system for rapidly resolving position with centimeter-level accuracy for a mobile or stationary receiver [4]. This is achieved by estimating a set of parameters that are related to the integer cycle ambiguities which arise in tracking the carrier phase of satellite downlinks [5,6]. In the preferred embodiment, the technique involves a navigation receiver [4] simultaneously tracking transmissions [6] from Low Earth Orbit Satellites (LEOS) [2] together with transmissions [5] from GPS navigation satellites [1]. The rapid change in the line-of-sight vectors from the receiver [4] to the LEO signal sources [2], due to the orbital motion of the LEOS, enables the resolution with integrity of the integer cycle ambiguities of the GPS signals [5] as well as parameters related to the integer cycle ambiguity on the LEOS signals [6]. These parameters, once identified, enable real-time centimeter-level positioning of the receiver [4]. In order to achieve high-precision position estimates without the use of specialized electronics such as atomic clocks, the technique accounts for instabilities in the crystal oscillators driving the satellite transmitters, as well as those in the reference [3] and user [4] receivers. In addition, the algorithm accommodates as well as to LEOS that receive signals from ground-based transmitters, then re-transmit frequency-converted signals to the ground.

Provider Link State Bridging (PLSB) expands static configuration of Ethernet MAC forwarding tables by the control plane and utilizes direct manipulation of Ethernet forwarding by a link state routing system. At least one media-access-control (MAC) address for unicast forwarding to the bridge and at least one MAC address for multicast forwarding from the bridge are assigned. Bridges exchange state information by a link state bridging protocol so that a synchronized configured view of the network is shared between nodes. Each node can calculate shortest path connective between peer bridging nodes and populated the appropriate forwarding tables. A reverse path forwarding check is performed on incoming packets to provide loop suppression. During times of network instability the loop suppression can be disabled for unicast packets as identified by the destination MAC address to buffer packets and minimize the impact on traffic flow.

Microvascular complications of diabetes mellitus are closely related to blood glucose levels and fluctuations. The Glycostator statistical package was created to allow patients and health care providers simple access to “glycemic indicators” which permit a “snapshot view” of the effectiveness of the patient's diabetes management program. Glycostator functions provide a simple way of enhancing the information already provided by home blood glucose monitoring devices. To this end, a set of new indices, including one called the Virtual A1c, are computed in a recursive fashion from blood glucose test results to provide a more meaningful day-to-day assessment of glycemic control. All indices can be made available at the meter user interface on request. The displayed indices allow patients to improve glycemic control by identifying problems with blood glucose control and lability that are less easily recognized in traditional blood glucose meter statistical packages. Virtual A1c emulates hemoglobin A1c continuously and provides better day-to-day assessment of long term glycemic control than does the traditional average blood glucose report. The method for computing each of these indices, including the Virtual A1c, allows for their implementation in commercial blood glucose monitors.

A noninvasive patient-specific method is provided to aid in the analysis, diagnosis, prediction or treatment of hemodynamics of the cardiovascular system of a patient. Coronary blood flow and pressure can be predicted using a 3-D patient image-based model that is implicitly coupled with a model of at least a portion of the remaining cardiovascular system. The 3-D patient image-based model includes at least a portion of the thoracic aorta and epicardial coronaries of the patient. The shape of one or more velocity profiles at the interface of the models is enforced to control complex flow features of recirculating or retrograde flow thereby minimizing model instabilities and resulting in patient-specific predictions of coronary flow rate and pressure. The invention allows for patient-specific predictions of the effect of different or varying physiological states and hemodynamic benefits of coronary medical interventions, percutaneous coronary interventions and surgical therapies.

A DC/DC converter includes a pre-regulator stage, which may include a Buck converter, and a post-converter stage, which may include a charge pump. The duty factor of the pre-regulator stage is controlled by a feedback path that extends from the output terminal of the pre-regulator stage or the post-converter stage. The pre-regulator steps the input DC voltage down by a variable amount depending on the duty factor, and the post-converter steps the voltage at the output of the pre-regulator up or down by an positive or negative integral or fractional value. The converter overcomes the problems of noise glitches, poor regulation, and instability, even near unity input-to-output voltage conversion ratios.

A DC/DC converter includes a pre-converter stage, which may include a charge pump, and a post-regulator stage, which may include a boost converter. The duty factor of the post-regulator stage is controlled by a feedback path that extends from the output terminal of the DC/DC converter to an input terminal in the post-regulator stage. The pre-converter steps the input DC voltage up or down by a positive or negative integral or fractional value, and the post-regulator steps the voltage up by a variable amount depending on the duty factor at which the post-regulator is driven. The converter overcomes the problems of noise glitches, poor regulation, and instability, even near unity input-to-output voltage conversion ratios.

Compositions and methods for administering collagen to a human subject have been developed. The collagen-containing lipid vesicles of the invention provide a delivery system for human collagen which eliminates problems associated with chemical and physical instability of the collagen as well as immune responses to non-human collagen.

A disk drive to reduce head instability during disk drive manufacturing is disclosed. The disk drive comprises: a disk; a dynamic flying height (DFH) read/write head; a flying height actuator to control the spacing between the DFH read/write head and the disk; and a controller. The controller controls operations in the disk drive including applying a sloped increasing power between a first voltage and a second voltage to move the DFH read/write head towards the disk.

The invention relates to the technical field of mining safe engineering, and particularly to a stability monitoring method for a cold high-altitude steep slope. According to the stability monitoring method, through field engineering geology, hydrogeology survey, engineering geological rock quality evaluation and rock mechanical parameter determining, the lithologic condition, the rock structure, the hydrogeology condition, the slope shape, earthquake parameters, explosion parameters and the like of the slope are determined. Slope stability analysis and a treatment strategy measure are performed. Furthermore a comprehensive monitoring system and a slope instability criterion are established.

Apparatus and method for measuring spinal instability through the use of a distractor arm assembly having segments pivotal with respect to each other and movable through the movement of a pivotal collar assembly along a centrally positioned jackscrew.

A new geometry ion trap and its use as a mass spectrometer is described. The ion traps can be combined linearly and in parallel to form systems for mass storage, analysis, fragmentation, separation, etc. of ions. The ion trap has a simple rectilinear geometry with a high trapping capacity. It can be operated to provide mass analysis in the mass-selective instability mode as well as the mass-selective stability mode. Arrays of multiple ion traps allow combinations of multiple gas-phase processes to be applied to the trapped ions to achieve high sensitivity, high selectivity and/or higher throughput in the analysis of ions.

An apparatus for selectively positioning intraoral anatomic features of a human patient to enhance upper airway stability for use alone or in combination with positive airway pressure as therapeutic treatment for obstructive sleep apnea and other conditions, such as snoring, which are symptomatic of upper airway instability.

This disclosure describes systems and methods for detecting and quantifying transmission delays associated with distributed sensing and monitoring functions within a ventilatory system. Specifically, the present methods and systems described herein define an event-based delay detection algorithm for determining transmission delays between distributed signal measurement and processing subsystems and a central platform that receives data from these subsystems. It is important to evaluate and quantify transmission delays because dyssynchrony in data communication may result in the misalignment of visualization and monitoring systems or instability in closed-loop control systems. Generally, embodiments described herein seek to quantify transmission delays by selecting a ventilator-based defining event as a temporal baseline and calculating the delay between the inception of the defining event and the receipt of data regarding the defining event from one or more distributed sensing devices.

A digital receiver, that may be used to receive VSB/QAM digital television signals, includes an adaptive fine carrier recovery circuit that compensates for deviations in the carrier frequency or phase. The carrier recovery circuit de-rotates a signal including phase errors. Estimations of phase errors are filtered using a filter whose gain and bandwidth are adjusted adaptively. This allows the carrier recovery circuit to track phase/frequency offset without introducing significant jitter. In one embodiment, the receiver includes a DFE, and the adaptive carrier recovery circuit mitigates instability that might be associated with the DFE.

A system and method for the automatic diagnosis of obstructive sleep apnea in a centralized hospital critical care monitoring system for the monitoring of a plurality of patients in at least one of a critical care, step down, and cardiac ward by telemetry. The system includes a central processor having a display, and a plurality of telemetry unit for mounting with patients, each of the telemetry units has a plurality of sensors for connection with each patient, the telemetry unit is capable of the transmission of multiple signals derived from the sensors to the central processor, in one preferred embodiment the method comprising steps of programming the system to analyze the signals and to automatically identify the presence and severity of obstructive sleep apnea and to provide an indication of the identification.

A signal processing system includes an analog-to-digital delta sigma modulator with a duty cycle modulator and a finite impulse response (FIR) filter in a main loop feedback path of the delta sigma modulator. The duty cycle modulator and FIR filter can provide high performance filtering in the main loop feedback path. To prevent instability in the main loop caused by the duty cycle modulator and FIR filter, the delta sigma modulator also includes a stabilizer loop. Transfer functions of the main loop and the stabilizer loop combine to achieve a target transfer function for the analog-to-digital delta sigma modulator that provides for stable operation of the analog-to-digital delta sigma modulator.

A system and method for processing track identifier errors to mitigate head instability in data storage devices is disclosed. The system and method includes computing a track id differential between an expected track id and a received track id, encoding the expected track id and the received track id, initiating a first action if the track id differential exceeds a pre-determined threshold and the encoded expected track id varies from the encoded received track id by a pre-configured number of bits, and initiating a second action if the track id differential does not exceed the pre-determined threshold or the encoded expected track id does not vary from the encoded received track id by a pre-configured number of bits.

In many systems, computer software is a common source of failure or instability. The proliferation of multiple interacting applications from several different software vendors leads to “emergent” problems that are difficult or impossible to predict or prevent. The problems are compounded by the use of networks, which introduce the added complexity of applications on multiple machines interacting in complex scenarios. As a result, many business and home users are hindered from using software-based systems to their fullest potential. More effective use of these systems can be aided by an application which can provide services for monitoring, diagnosing, and solving problems that occur in the operation of the machines at a customer facility. In the system described herein, a database contains entries with executable code that can make use of these services in order to monitor, diagnose, and solve specific problems. Each entry in the database addresses a specific problem. The executable code is designed to isolate and recognize the problem, and then implement a fix or workaround for that problem. The executable code is designed to completely automate the entire process of detection and resolution of the problem. Further, manual intervention may be employed to complete the diagnosis or solution.