instability

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Related to detrusor instability: neurogenic bladder

instability

1. tendency to variable or unpredictable behaviour
2. Physics a fast growing disturbance or wave in a plasma

instability

[‚in·stə′bil·əd·ē]
(control systems)
A condition of a control system in which excessive positive feedback causes persistent, unwanted oscillations in the output of the system.
(physics)
A property of the steady state of a system such that certain disturbances or perturbations introduced into the steady state will increase in magnitude, the maximum perturbation amplitude always remaining larger than the initial amplitude.

instability

In a structure, the sudden loss of stiffness that limits its load-carrying capability, and in some cases results in the structure’s failure.

instability

instabilityclick for a larger image
i. A state of the atmosphere in which a parcel of air will continue to rise, if for any reason, it is pushed up. Any instability in the atmosphere means turbulent conditions exist. The environmental lapse rate (ELR) in this case will be higher than both dry and saturated adiabatic lapse rates. Dry adiabatic lapse rate (DALR) is the rate of decrease of temperature with height of a parcel of dry air lifted adiabatically. Its value is 3°/1000 ft. Saturated adiabatic lapse rate (SALR) is the lapse rate of a parcel of saturated air and its value is 1.5°/1000 ft.
ii. A tendency of a body to continue moving away from its original state when disturbed by an external force and to continue after that force has been withdrawn.
iii. The failure of structures, such as the buckling of plates and panels under compression, and the failure of struts under end loads.
References in periodicals archive ?
Efficacy of trospium chloride in patients with detrusor instability. BJU Int 2000;85:659-64.
With 2 years of experience using this drug, it has proven effective in reducing detrusor instability without significant side effects.
Before patients were included in the study they underwent a physical examination, with assessment of cognitive function by the Folstein Mini Mental State Evaluation (MMSE) and detrusor instability was diagnosed by water cystometry, filling at 1 ml/s, using the criteria of the International Continence Society [11].
The results of this study also underline some important points in relation to the treatment of detrusor instability. The median dose of oxybutnin remained at or returned to 2.5 mg bd, the starting level, at the end of the study, although the protocol allowed upward titration of dose at each assessment until a satisfactory therapeutic response had been achieved, or until side-effects required a reduction or limited further increase.
Phasic detrusor instability (PDI) (Figure 1B), is characterized by urgency of micturition and/or urge incontinence, normal or increased bladder sensation and phasic bladder contractions occurring spontaneously during bladder filling or being provoked by rapid filling, coughing, jumping or other external mechanical stimuli.
The history and physical examination are still the mainstays for evaluating suspected outflow obstruction, but urodynamics can determine the patient's bladder compliance, detrusor instability, or voiding characteristics.
Additional urodynamic testing theoretically could be helpful in identifying patients whose incontinence symptoms are due to detrusor instability alone because in these patients merely adding an anti-incontinence procedure to the prolapse repair would not improve incontinence symptoms, Dr.
There's detrusor instability, stress incontinence, and abdominal pressure when voiding," he said.
African American women are more likely to have detrusor instability (DI), while whites are more likely to have genuine stress incontinence (GSI), said Dr.
The main value of urodynamic testing (UDT) is its sensitivity for detecting detrusor instability, said Dr.
In a separate study of 200 women with stress incontinence and/or detrusor instability, pelvic muscle exercises were as effective in reducing incontinence episodes as bladder training or the exercises and bladder training combined (Am.J.
Patients were excluded from participation if they presented with detrusor instability, internal sphincter dysfunction, overflow incontinence, inflammatory bowel disease, idiopathic fecal incontinence, or a history of rectal surgery.