***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: A new ambulatory method of monitoring physical activities in Parkinson 's disease ( PD ) patients is proposed based on a portable data -logger with three body-fixed inertial sensors . A group of ten PD patients treated with subthalamic nucleus deep brain stimulation ( STN-DBS ) and ten normal control subjects followed a protocol of typical daily activities and the whole period of the measurement was recorded by video . Walking periods were recognized using two sensors on shanks and lying periods were detected using a sensor on trunk . By calculating kinematics features of the trunk movements during the transitions between sitting and st and ing postures and using a statistical classifier , sit-to-st and ( SiSt ) and st and -to-sit ( StSi ) transitions were detected and separated from other body movements . Finally , a fuzzy classifier used this information to detect periods of sitting and st and ing . The proposed method showed a high sensitivity and specificity for the detection of basic body postures allocations : sitting , st and ing , lying , and walking periods , both in PD patients and healthy subjects . We found significant differences in parameters related to SiSt and StSi transitions between PD patients and controls and also between PD patients with and without STN-DBS turned on . We concluded that our method provides a simple , accurate , and effective means to objective ly quantify physical activities in both normal and PD patients and may prove useful to assess the level of motor functions in the latter The prevalence of falls among neurological patients is unknown , although disturbances of gait and posture are common . Falls may lead to burdens for the patient , the caregivers and the health system . We design ed a prospect i ve study and investigated all patients for a history of falls admitted to a neurological hospital during a 100-day period . Clinical investigation was carried out and several disease specific rating scales were applied . A total of 548 patients were investigated . Of all patients 34 % had fallen once or more often during the last twelve months . A disturbance of gait was blamed for the fall in 55 % , epileptic seizures in 12 % , syncope in 10 % and stroke in 7 % . Intrinsic risk factors for falls were high age , disturbed gait , poor balance and a fear of falling . As extrinsic factors we identified the treatment with antidepressants , neuroleptics and different cardiovascular medications , adverse environmental factors in the patients ' home and the use of walking aids . Within the diagnoses , falls were most frequent in Parkinson 's disease ( 62 % ) , syncope ( 57 % ) and polyneuropathy ( 48 % ) . According to these findings falls in neurological in- patients are twice as frequent as in an age-matched population living in the community . Falls in neurological patients are particularly linked to medication and disorders affecting gait and balance Over an 18-month period , all incident cases of neurological disorders were ascertained prospect ively in an unselected urban population based in 13 general practice s in the London area by a General Practice Linkage Scheme with the National Hospital for Neurology and Neurosurgery . In three of these practice s , the lifetime prevalence of neurological disorders was also assessed . A population of 100 230 patients registered with participating general practice s was followed prospect ively for the onset of neurological disorders . Multiple methods of case finding were used to maintain accuracy . The age- and sex-adjusted incidence rates of neurological disorders were calculated . The lifetime prevalence of neurological disorders was surveyed in 27 658 of the patients . The age- and sex-adjusted incidence rates were calculated for major neurological conditions . [ These are expressed as rates per 100 000 persons per annum , with 95 % confidence intervals ( CI ) in parentheses ] . The commonest of these were first cerebrovascular events , 205 ( CI : 183 , 230 ) ; shingles , 140 ( CI : 104 , 184 ) ; diabetic polyneuropathy , 54 ( CI : 33 , 83 ) ; compressive neuropathies , 49 ( CI : 39 , 61 ) ; epilepsy , 46 ( CI : 36 , 60 ) ; Parkinson 's disease , 19 ( CI : 12 , 27 ) ; peripheral neuropathies , 15 ( CI : 9 , 23 ) ; CNS infections , 12 ( CI : 5 , 13 ) ; post-herpetic neuralgia , 11 ( CI : 6 , 17 ) ; and major neurological injuries , 10 ( CI : 4 , 11 ) . Lifetime prevalence rates are also reported ( expressed as rate per 1000 persons with 95 % CI ) . The most prevalent conditions were : completed stroke , 9 ( CI : 8 , 11 ) ; transient ischaemic attacks , 5 ( CI : 4 , 6 ) ; active epilepsy , 4 ( CI : 4 , 5 ) ; congenital neurological deficit , 3 ( CI : 3 , 4 ) ; Parkinson 's disease , 2 ( CI : 1 , 3 ) ; multiple sclerosis , 2 ( CI : 2 , 3 ) ; diabetic polyneuropathy , 2 ( CI : 1 , 3 ) ; compressive mononeuropathies , 2 ( CI : 2 , 3 ) ; and sub-arachnoid haemorrhage , 1 ( CI : 0.8 , 2 ) . Overall , the onset of 625 neurological disorders was observed per 100 000 population annually . Six percent of the population had at some time had a neurological disorder . This is the first study of the incidence and lifetime prevalence of neurological disorders in recent times ; we found that these disorders give rise to significant morbidity in the community Patients with Parkinson 's disease ( PD ) receive therapies aim ed at addressing a diverse range of motor symptoms . Motor complications in the form of symptom fluctuations and dyskinesias that commonly occur with chronic PD medication use may not be effectively captured by Unified Parkinson 's Disease Rating Scale ( UPDRS ) assessment s performed in the clinic . Therefore , home monitoring may be a viable adjunct tool to provide insight into PD motor symptom response to treatment . In this pilot study , we sought to evaluate the feasibility of capturing PD motor symptoms at home using a computer-based assessment system .  Ten subjects diagnosed with idiopathic PD used the system at home and ten non-PD control subjects used the system in a laboratory . The Kinesia system consists of a wireless finger-worn motion sensor and a laptop computer with software for automated tremor and bradykinesia severity score assessment s. Data from control subjects were used to develop compliance algorithms for rejecting motor tasks performed incorrectly . These algorithms were then applied to data collected from the PD subjects who used the Kinesia system at home to complete motor exams 3 - 6 times per day over 3 - 6 days . Motor tasks not rejected by the compliance algorithms were further processed for symptom severity . PD subjects successfully completed motor assessment s at home , with approximately 97 % of all motor task data files ( 1222/1260 ) accepted . These findings suggest that objective home monitoring of PD motor fluctuations is feasible Objective . To develop an automated and objective method to assess mobility in Parkinson disease ( PD ) patients in daily-life setting s and to investigate whether accelerometer-derived measures discriminate between PD and healthy controls as they walk and simulate activities of daily living ( ADL ) . Methods . Healthy older adults ( 17 ) and patients with PD ( 22 ) wore a triaxial accelerometer on their lower back during short walks ( validation study ) and during a walk around the medical center to simulate daily activities ( ADL simulation ) . The variability ( consistency and rhythmicity ) of stepping was assessed . The patients completed the walks before and after taking their anti-Parkinsonian medications .  Frequency-based acceleration measures included dominant frequency , amplitude ( strength of signal frequency ) , width ( frequency dispersion ) , and slope ( a combination reflecting amplitude and width ) of the main frequency of the power spectral density in the 0.5- to 3.0-Hz b and . A subset of the Unified Parkinson-Disease Rating Scale provided a clinical measure of gait impairment ( UPDRS-Gait5 ) . A PD patient and control wore the sensors for 3 days at home . Results . The width was larger , and the amplitude and slope were smaller in the PD patients compared to the controls in the validation study and ADL simulation ( P < .02 ) . The width decreased , and the amplitude and slope increased when patients took anti-Parkinsonian medications ( P < .007 ) . Significant correlations were observed between acceleration-derived measures and UPDRS-Gait5 . The data obtained at home was similar to the clinic data . Conclusions . Frequency-derived measures are valid and sensitive estimates of stride-to-stride variability that can be used to assess the quality and consistency of walking in patients with PD in real-life setting Our objective was to assess the test-retest reliability of the Unified Parkinson 's Disease Rating Scale ( UPDRS ) . The UPDRS is the most widely used instrument for measuring severity of parkinsonian symptoms in clinical research and in practice . The validity and inter-rater reliability of this scale have been previously studied . We examined the test-retest ( intrarater ) reliability of the UPDRS and derived subscales . Four hundred patients with early-stage Parkinson 's disease ( PD ) who were participating in a multicenter clinical trial were evaluated using the UPDRS on two separate occasions ( screening and baseline visits ) prior to receiving treatment . The same neurologist at each center rated the subjects at both examinations that were , on average , 14.6 + /- 7.6 days apart ( range 3 - 36 days ) . Test-retest reliability was estimated using the intraclass correlation coefficient ( ICC ) for the total UPDRS score , the mental , ADL , and motor subscale scores , and other derived subscale scores . Weighted kappa statistics were calculated for individual UPDRS items . The ICCs for the UPDRS scores were as follows : total score , 0.92 ; mental , 0.74 ; ADL , 0.85 ; motor , 0.90 . ICCs for derived symptom-based scales ranged from 0.69 - 0.88 . Reliability of specific items was generally lower than for summary scales . Reliability was slightly better in patients for whom the testing interval was within 14 days . Based on conventional st and ards , the UPDRS scores were found to have excellent test-retest reliability in this sample of patients with early PD rated by academic movement disorder specialists . The findings are in agreement with previous reports on interrater reliability Gait and mobility problems are prominent features of Parkinson 's Disease ( PD ) , and are difficult to observe clinical ly in early stages of PD . We previously reported that gait changes were measurable in early to mid-stage PD subjects , when we used inertial sensors during an instrumented Timed Up and Go test ( iTUG ) . With the advent of wearable inertial sensors , home assessment of mobility has become possible . We tested six people with early PD and eight control subjects using the iTUG in the home and laboratory . Our objectives were to 1 ) investigate the feasibility of testing subjects at home , and 2 ) compare performance at home versus laboratory . We found that home iTUG testing is feasible and the patients with PD were more affected than the healthy control subjects when tested at home 
    Output:
    
These studies were not only capable of assessing the type , quantity , and quality measures of functional activities , but could also distinguish healthy from non-healthy subjects and /or address disease severity levels .