Influence of verbal instruction on gait training in Parkinson's disease: a randomized controlled trial

OBJECTIVE

Verbal instruction is one of the most commonly used methods that therapists use to correct walking pattern for people with Parkinson's disease (PD). This study aimed to compare the long-term training effects of two different verbal instructions that either asked the participants to 'take big steps' or 'strike the ground with the heel' on walking ability in individuals with PD.

DESIGN

Forty-five participants with PD were randomized into the big-step (BIG) or heel strike (HS) group. The participants underwent 12 sessions of treadmill and overground gait training. Throughout the interventions, the BIG group received an instruction to 'take big steps,' while the HS group received an instruction to 'strike the ground with your heel.' The primary outcome was gait performance, including velocity, stride length, cadence, and heel strike angle. The participants were assessed before, immediately after, and 1-month after training.

RESULTS

Both groups showed significant improvements in gait performance after training. The HS group showed continuous improvements in velocity and stride length during the follow-up period; however, the BIG group showed slightly decreased performance.

CONCLUSION

A verbal instruction emphasizing heel strike can facilitate long-term retention of walking performance in people with PD.

Influences of Aerobic Exercise on Motor Sequence Learning and Corticomotor Excitability in People With Parkinson's Disease

BACKGROUND

People with Parkinson's disease (PD) are known to have motor learning difficulties. Although numerous studies have demonstrated that a single bout of aerobic exercise (AEX) can facilitate motor learning in non-disabled adults, the same beneficial effect in PD is unknown. Furthermore, associated neuroplastic changes have not been investigated.

OBJECTIVES

This study aimed to determine whether a single bout of aerobic exercise (AEX) can facilitate motor sequence learning in people with PD and to investigate the associated neurophysiological changes.

METHODS

Thirty individuals with PD were recruited and randomized into the exercise group (PD + AEX) and non-exercise group (PD - AEX). At the first visit, corticomotor excitability was assessed using transcranial magnetic stimulation (TMS). All participants then performed a serial reaction time task (SRTT) followed by 20 minutes of moderately-high intensity aerobic exercise (AEX) for the PD + AEX group or rest for the PD - AEX group. The SRTT and TMS were reevaluated at 3 time points: immediately after aerobic exercise (AEX) or rest, on the second day after practice (D2), and a week after practice (D7).

RESULTS

Both groups showed improvement throughout practice. At retention, the PD + AEX group showed improved SRTT performance on D7 compared to D2 (P = .001), while the PD - AEX group showed no change in performance. TMS results showed that the PD + AEX group had significantly higher corticomotor excitability than the PD - AEX group on D7.

CONCLUSION

A single session of aerobic exercise (AEX) could enhance motor sequence learning and induce neuroplastic changes. Clinicians can consider providing aerobic exercise (AEX) after motor task training for people with PD.

CLINICAL REGISTRATION

NCT04189887 (ClinicalTrials.gov).

Reliability of using foot-worn devices to measure gait parameters in people with Parkinson's disease

BACKGROUND

Recent advances in technology have warranted the use of wearable sensors to monitor gait and posture. However, the psychometric properties of using wearable devices to measure gait-related outcomes have not been fully established in patients with Parkinson's disease (PD).

OBJECTIVE

This study aimed to investigate the test-retest reliability of body-worn sensors for gait evaluation in people with PD. Additionally, the influence of disease severity on the reliability was determined.

METHODS

Twenty individuals with PD were recruited. During the first evaluation, the participants wore inertial sensors on their shoes and walked along a walkway thrice at their comfortable walking speed. The participants were then required to return to the lab after 3-5 days to complete the second evaluation with the same study procedure. Test-retest reliability of gait-related outcomes were calculated. To determine whether the results would be affected by disease severity, reliability was re-calculated by subdividing the participants into early and mid-advanced stages of the disease.

RESULTS

The results showed moderate to good reliability (ICC = 0.64-0.87) of the wearable sensors for gait assessment in the general population with PD. Subgroup analysis showed that the reliability was higher among patients at early stages (ICC = 0.71-0.97) compared to those at mid-advanced stages (ICC = 0.65-0.81) of PD.

CONCLUSIONS

Wearable sensors could reliably measure gait parameters in people with PD, and the reliability was higher among individuals at early stages of the disease compared to those at mid-advanced stages. Absolute reliability values were calculated to act as references for future studies.

Corticomotor Excitability Changes Associated With Freezing of Gait in People With Parkinson Disease

Background and Purpose

Freezing of gait (FOG) is a debilitating gait disorder in people with Parkinson’s disease (PD). While various neuroimaging techniques have been used to investigate the pathophysiology of FOG, changes in corticomotor excitability associated with FOG have yet to be determined. Research to date has not concluded if changes in corticomotor excitability are associated with gait disturbances in this patient population. This study aimed to use transcranial magnetic stimulation (TMS) to investigate corticomotor excitability changes associated with FOG. Furthermore, the relationship between corticomotor excitability and gait performances would be determined.

Methods

Eighteen participants with PD and FOG (PD + FOG), 15 without FOG (PD − FOG), and 15 non-disabled adults (Control) were recruited for this study. Single and paired-pulse TMS paradigms were used to assess corticospinal and intracortical excitability, respectively. Gait performance was measured by the 10-Meter-Walk test. Correlation analysis was performed to evaluate relationships between TMS outcomes and gait parameters.

Results

Compared with the Control group, the PD + FOG group showed a significantly lower resting motor threshold and reduced short intracortical inhibition (SICI). Correlation analysis revealed a relationship between resting motor evoked potential and step length, and between SICI and walking velocity in the Control group. While the silent period correlated with step length in the PD − FOG group, no significant relationship was observed in the PD + FOG group.

Discussion and Conclusion

Compared to the Control group, the PD + FOG group exhibited reduced corticomotor inhibition. Distinct correlations observed among the three groups suggest that the function of the corticomotor system plays an important role in mediating walking ability in non-disabled adults and people with PD − FOG, while people with PD + FOG may rely on neural networks other than the corticomotor system to control gait.

Effects of rhythmic auditory cueing on stepping in place in patients with Parkinson's disease

BACKGROUND

Stepping in place (SIP) is a useful locomotor training intervention. The purpose of this study was to investigate the effects of single auditory-cued SIP training on cortical excitability, rhythmic movements and walking ability in patients with Parkinson's disease(PD).

METHODS

Cross-over randomized control trial. Each participant completed two interventions with at least one-week washout period in between: (1) SIP with concurrent auditory cues (AC condition) and (2) SIP without auditory cues (NC condition).

RESULTS

In the primary outcome, the cortical silent period (CSP) duration increased (P = .005), whereas short intracortical inhibition (SICI) decreased after training (P = .001). Freezers demonstrated enhanced inhibition in the resting motor threshold and CSP duration. SICI and intracortical facilitation were modulated in both groups under the AC condition. In the secondary outcomes, the stepping variability decreased significantly (AC: P = .033; NC: P = .009), whereas walking cadence increased after training (AC: P = .019; NC: P = .0023).

CONCLUSIONS

Auditory-cued SIP training improved the lower-limb movement variability and modulated the cortical excitability in patients with PD. Freezers may benefit more from this training than nonfreezers.

Standard early rehabilitation and lower limb transcutaneous nerve or neuromuscular electrical stimulation in acute stroke patients: a randomized controlled pilot study

OBJECTIVE

We investigated adding lower limb transcutaneous nerve stimulation or neuromuscular electrical stimulation to standard early rehabilitation in acute stroke patients.

DESIGN

An assessor-blinded, randomized controlled pilot study.

SETTING

A medical stroke center.

SUBJECTS

First-stroke patients aged 20-80 years admitted to the stroke center within 24 hours post stroke.

INTERVENTIONS

A total of 42 participants were randomly assigned to groups: transcutaneous nerve stimulation + standard early rehabilitation, neuromuscular electrical stimulation + standard early rehabilitation, or standard early rehabilitation-only. Transcutaneous nerve or neuromuscular electrical stimulation was delivered to the affected tibialis anterior and quadriceps muscles for 30 minutes a day, five days per week for two weeks.

MAIN MEASURES

The Postural Assessment Scale for Stroke Patients, the Functional Independence Measure, and three mobility milestones, namely, sitting for >five minutes, standing for >one minute, and walking ⩾50 m, were evaluated, respectively, at baseline, at the two-week post-intervention, and at two-week follow-up.

RESULTS

Significant differences existed in the Postural Assessment Scale for Stroke Patients scores between the transcutaneous nerve stimulation and standard early rehabilitation-only groups measured at two-weeks post-intervention (mean (SD) = 31.38 (5.39) and 18.00 (8.65), respectively) and at the two-week follow-up (34.08 (2.69) and 26.14 (7.77), respectively). A higher proportion of participants could walk ⩾50 m independently in the transcutaneous nerve stimulation group than in the standard early rehabilitation-only group at the two-week post-intervention (P = 0.013) and two-week follow-up (P = 0.01) marks.

CONCLUSION

Two weeks of transcutaneous nerve stimulation added to standard early rehabilitation improved postural stability and walking in acute stroke patients.

Effects of Extracorporeal Shock Wave-Mediated Transdermal Local Anesthetic Drug Delivery on Rat Caudal Nerves

Cavitation plays a substantial role in the clinical effects of extracorporeal shock wave therapy (ESWT). It is also generally accepted as a major mechanism in sonophoresis. To identify the enhancing effect of extracorporeal shock wave-mediated transdermal drug delivery, 24 Wistar rats were randomly assigned to four groups: (i) topical application of a eutectic mixture of local anesthetics (EMLA); (ii) 1-MHz ultrasound; (iii) ESWT pre-treatment combined with EMLA application; (iv) ESWT concurrent with EMLA application on rat tails. The degree of anesthesia was assessed using the amplitude and latency of sensory nerve action potentials within 5 min after a 60-min EMLA application. The results indicated that ESWT pre-treatment and concurrent ESWT accelerated the anesthetic effects of the EMLA cream on the tail nerve (p < 0.05). This finding might indicate that shock wave-mediated transdermal drug delivery is possible during the ESWT period.

Reliability of lower extremity muscle strength measurements with handheld dynamometry in stroke patients during the acute phase: a pilot reliability study

[Purpose] No literature has described a suitable method for measuring muscle strength in a supine position during acute phase after stroke. This study investigated the feasibility and reliability of using a commercial handheld dynamometer to measure the muscle strengths of the hip flexor, knee extensor, and dorsiflexor in the supine position with a modified method for patients at a stroke intensive care center within 7 days of stroke onset. [Subjects and Methods] Fifteen persons with acute stroke participated in this cross-sectional study. For each patient, the muscle strengths of the hip flexors, knee extensors, and dorsiflexors were measured twice by two testers on the same day. Each patient was re-tested at the same time of day one day later. Inter-rater and test-retest reliability were then determined by the intraclass correlation coefficients (ICCs). [Results] For the three muscle groups, the inter-rater reliability ICCs were all 0.99 and the test-retest reliability ICCs were greater than 0.85. The investigated method thus has good inter-rater reliability and high agreement between the test-retest measurements, with acceptable measurement errors. [Conclusion] The modified method using a handheld dynamometer to test the muscle strength of acute stroke patients is a feasible and reliable method for clinical use.

Football APP based on smart phone with FES in drop foot rehabilitation

BACKGROUND

Long-term, sustained progress is necessary in drop foot rehabilitation. The necessary inconvenient body training movements, the return trips to the hospital and repetitive boring training using functional electrical stimulation (FES) often results in the patient suspending their training. The patient's drop foot rehabilitation will not progress if training is suspended.

OBJECTIVE

A fast spread, highly portable drop foot rehabilitation training device based on the smart phone is presented. This device is combined with a self-made football APP and feedback controlled FES. The drop foot patient can easily engage in long term rehabilitation training that is more convenient and interesting.

METHODS

An interactive game is established on the smart phone with the Android system using the originally built-in wireless communications. The ankle angle information is detected by an external portable device as the game input signal. The electrical stimulation command to the external device is supplemented with FES stimulation for inadequate ankle efforts.

RESULTS

After six-weeks training using six cases, the results indicated that this training device showed significant performance improvement (p< 0.05) in the patient's ankle dorsiflexion strength, ankle dorsiflexion angle, control timing and Timed Up and Go.

CONCLUSIONS

Preliminary results show that this training device provides significant positive help to drop foot patients. Moreover, this device is based on existing and universally popular mobile processing, which can be rapidly promoted. The responses of clinical cases also show this system is easy to operate, convenient and entertaining. All of these features can improve the patient's willingness to engage in long term rehabilitation.

Assistive Control System for Upper Limb Rehabilitation Robot

This paper presents an assistive control system with a special kinematic structure of an upper limb rehabilitation robot embedded with force/torque sensors. A dynamic human model integrated with sensing torque is used to simulate human interaction under three rehabilitation modes: active mode, assistive mode, and passive mode. The hereby proposed rehabilitation robot, called NTUH-ARM, provides 7 degree-of- freedom (DOF) motion and runs subject to an inherent mapping between the 7 DOFs of the robot arm and the 4 DOFs of the human arm. The Lyapunov theory is used to analyze the stability of the proposed controller design. Clinical trials have been conducted with six patients, one of which acts as a control. The results of these experiments are positive and STREAM assessment by physical therapists also reveals promising results.

Low-cost tele-assessment system for home-based evaluation of reaching ability following stroke

OBJECTIVE

Tele-assessment techniques can provide healthcare professionals with easily accessible information regarding patients' clinical progress. Recently, kinematic analysis systems have been used to assess rehabilitative outcomes in stroke patients. Kinematic systems, however, are not compatible with tele-assessment. The objective of our study was to develop a tele-assessment system for acquiring kinematic data of forward reaching movements in stroke patients, with an emphasis on cost-effectiveness, portability, and ease of use.

MATERIALS AND METHODS

We selected four healthy control participants and eight hemiplegic stroke patients for our study. The stroke patients were classified as Brunnstrom stage III, stage IV, or stage V. Our tele-assessment system used two three-axes accelerometers, a potentiometer, a multifunctional data acquisition card, and two computers. A standardized kinematic system was applied simultaneously to validate the measurements recorded by our tele-assessment system during five repetitions of forward reaching movements.

RESULTS

The correlation coefficients of the reaching displacement, velocity, and acceleration measurements obtained using our tele-assessment system and the standardized kinematic system were 0.956, 0.896, and 0.727, respectively. Differences in the maximum reaching distance and the maximum reaching velocity of forward reaching movements were observed among the study groups. There were no significant differences in the time required to complete the testing session among the study groups.

CONCLUSIONS

Our tele-assessment system is valid for the evaluation of upper-extremity reaching ability in stroke patients. Further research is needed to investigate the feasibility of the use of the tele-assessment system in patients' homes.

Reducing anterior tibial translation by applying functional electrical stimulation in dynamic knee extension exercises: quantitative results acquired via marker tracking

BACKGROUND

Pain that accompanies anterior cruciate ligament deficiency during dynamic knee extension exercises is usually caused by excessive anterior tibial translation, which can be restricted if the anterior cruciate ligament was intact.

METHODS

A functional electrical stimulator is incorporated with a training device to induce hamstring contractions during certain degrees of knee extension to replicate effects similar to those generated by an intact anterior cruciate ligament and to reduce anterior tibial translation. By using a camera that tracks markers placed on bony prominences of the femur and tibia, the anterior tibial translations corresponding to various settings were determined by customized image processing procedures.

FINDINGS

In the electrical stimulation sessions, the knee extensions with electrical stimulation feedback induced significantly (n=6, P<.05) less anterior tibial translation over the range of 20 to 50° when compared to those using the standard isokinetic shank restraint. Likewise, the knee extensions with an anti-shear device that blocks tibia displacement mechanically also induced significantly (n=6, P<.05) less anterior tibial translation, but over a different range of knee extension (30 to 70°).

INTERPRETATION

Despite the fact that both the electrical stimulator and the anti-shear device assisted in reducing anterior tibial translation, the tendency of the curves generated with the functional electrical stimulation was generally more similar to those generated when using the standard isokinetic shank restraint.

A modified multi-channel EMG feature for upper limb motion pattern recognition

The EMG signal is a well-known and useful biomedical signal. Much information related to muscles and human motions is included in EMG signals. Many approaches have proposed various methods that tried to recognize human motion via EMG signals. However, one of the critical problems of motion pattern recognition is that the performance of recognition is easily affected by the normalization procedure and may not work well on different days. In this paper, a modified feature of the multi-channel EMG signal is proposed and the normalization procedure is also simplified by using this modified feature. To recognize motion pattern, we applied the support vector machine (SVM) to build the motion pattern recognition model. In training and validation procedures, we used the 2-DoF exoskeleton robot arm system to do the designed pose, and the multi-channel EMG signals were obtained while the user resisted the robot. Experiment results indicate that the performance of applying the proposed feature (94.9%) is better than that of conventional features. Moreover, the performances of the recognition model, which applies the modified feature to recognize the motions on different days, are more stable than other conventional features.

Dosage of neuromuscular electrical stimulation: is it a determinant of upper limb functional improvement in stroke patients?

OBJECTIVE

To investigate the predictors related to upper extremity functional recovery, with special emphasis on neuromuscular electrical stimulation dose-response in patients after stroke.

SUBJECTS

Ninety-five patients with stroke who received a 4-week neuromuscular electrical stimulation intervention.

DESIGN

Prospective predictive analysis.

METHODS

The change score of the Action Research Arm Test (ARAT) was used as the main outcome. Baseline subject characteristics, stroke-related data, and intervention-related data were collected. Multiple linear regression analysis was applied to identify the potential predictors related to main outcome.

RESULTS

The regression model revealed that the initial Fugl-Meyer upper limb score was the most important predictor for ARAT change score post-test, followed by time since stroke onset and location of stroke lesion. At 2-month follow-up, the neuromuscular electrical stimulation dosage became a significant determinant in addition to the above predictors.

CONCLUSION

Initial motor severity and lesion location were the main predictors for upper limb functional improvement in stroke patients. Neuromuscular electrical stimulation dosage became a significant determinant for upper limb functional recovery after stroke at 2-month follow-up. More intensive neuromuscular electrical stimulation therapy during early rehabilitation is associated with better upper limb motor function recovery after stroke.

Clinical effects of combined bilateral arm training with functional electrical stimulation in patients with stroke

Cerebral vascular disease (or stroke) is the main cause of disabilities in adults. Upper-limb dysfunction after stroke usually exists, leading to severe limits of motor capabilities as well as daily activities. Therefore, effective treatment interventions for upper-limb rehabilitation after stroke are needed. Based on the neurophysiological evidence and clinical measures, combined bilateral arm training (BAT) with functional electric stimulation (FES) could improve hand function in stroke patients. In this study, we attempt to combine BAT with FES applying to the post-stroke paretic arm. A linear guide platform with FES feedback control was developed to execute the training of bilateral reaching movements. 35 stroke subjects were recruited and divided into two groups (BAT with FES and BAT alone). 23 participants completed this experiment with 3-week intervention. According to our preliminary results, a favorable trend toward improvement in experimental group (BAT with FES) existed after treatment and at follow-up. Further analysis would be conducted to investigate the kinematic change on motor performance. Moreover, various treatment doses as well as more functional approaches would also be considered for better effects of upper limb rehabilitation after stroke.

H-reflex, muscle voluntary activation level, and fatigue index of flexor carpi radialis in individuals with incomplete cervical cord injury

BACKGROUND

Individuals with incomplete spinal cord injury (SCI) are predisposed to muscle fatigue during voluntary exercise. However, the origin of fatigue is unclear.

OBJECTIVE

The authors examined the motoneuron excitability, muscle activation level, and fatigue properties of the flexor carpi radialis muscle, just below the level of injury.

METHODS

Nine individuals with chronic, incomplete cervical cord injury and 9 age-matched healthy individuals were recruited. The authors tested maximum voluntary contraction (MVC), motoneuron excitability by the maximum amplitude of the H-reflex (Hmax at C-7), and muscle voluntary activation level measured by the interpolated twitch technique. Subjects were fatigued by repetitive maximal voluntary isometric wrist flexion. General fatigue index (GFI), central fatigue index (CFI), and peripheral fatigue index (PFI) of flexor carpi radialis were examined before, during, and immediately after exercise.

RESULTS

The Hmax in the SCI group was significantly higher (P = .0028) than in controls. The MVC (P < .001) and voluntary activation level (P = .016) in the SCI group were significantly lower. The GFI and CFI decreased in both the SCI and the non-SCI groups. The PFI in the SCI group was significantly higher (ie, less fatigue) than that in controls at 30 repetitive contractions.

CONCLUSIONS

In individuals with incomplete SCI, the deficit in central drive is an important source of muscle weakness and fatigue in the muscle below the level of injury.

In vivo photoacoustic micro-imaging of microvascular changes for Achilles tendon injury on a mouse model

Since neovascularization has been reported that it is associated with tendinopathy, assessments of vascularity are important for both diagnosis and treatment estimation. Photoacoustic imaging, taking the advantages of good ultrasonic resolution and high optical absorption contrast, has been shown a promising tool for vascular imaging. In this study, we explore the feasibility of photoacoustic micro-imaging in noninvasive monitoring of microvascular changes in Achilles tendon injuries on a mouse model in vivo. During collagenase-induced tendinitis, a 25-MHz photoacoustic microscope was used to image microvascular changes in Achilles tendons of mice longitudinally up to 23 days. In addition, complementary tissue structural information was revealed by collateral 25-MHz ultrasound microscopy. Morphological changes and proliferation of new blood vessels in Achilles tendons were observed during and after the acute inflammation. Observed microvascular changes during tendinitis were similar to the findings in the literatures. This study demonstrates that photoacoustic imaging can potentially be a complementary tool for high sensitive diagnosis and assessment of treatment performance in tendinopathy.

An agile enterprise regulation architecture for health information security management

Information security management for healthcare enterprises is complex as well as mission critical. Information technology requests from clinical users are of such urgency that the information office should do its best to achieve as many user requests as possible at a high service level using swift security policies. This research proposes the Agile Enterprise Regulation Architecture (AERA) of information security management for healthcare enterprises to implement as part of the electronic health record process. Survey outcomes and evidential experiences from a sample of medical center users proved that AERA encourages the information officials and enterprise administrators to overcome the challenges faced within an electronically equipped hospital.

Effects of using relaxation breathing training to reduce music performance anxiety in 3rd to 6th graders

The current study examined the effects of applying relaxation breathing training (RBT) as a means to reduce music performance anxiety (MPA) in young, talented musicians. A group of 59 young musicians from 3rd to 6th grade participated in this study, and all of them started RBT twice a week for 2 months prior to the examination. Four tests--2 mos, 1 mos, half an hour and 5 min before the examination--were conducted to examine the level of MPA after the application of RBT. Results show that the degree of MPA 5 min before the trial was lower than the degree of performance anxiety half an hour before the jury (t = -3.683, p < 0.01), which indicated that the RBT was associated with a decrease in MPA. Although a series of RBT exercises was applied, results indicated that when approaching the date of examination, the degree of performance anxiety still increased and reached its maximum half an hour before the jury. The recommendation for future studies is to combine the application of RBT with other methods to expand its effect in reducing MPA.

Thermal effect of sonophoresis for accelerating the analgesic effect of local anesthetics on rat tail nerve

Sonophoresis is an ultrasound transdermal drugs delivery system. The eutectic mixture of local anesthetics (EMLA) has been used clinically for anesthesia but requires at least one hour to take effect and lacks of analgesia's objective assessment. We proposed that sonophoresis could reduce the duration of EMLA analgesia effect onset and be assessed by sensory conduction studies. Thirty Wistar adult rats were randomized into normal, control, ultrasound-, and heat-treatment groups. Normal group was received no EMLA cream or ultrasound and heat treatment. The control group received the EMLA cream on the rat tail at 3.5 cm distal to the rat tail base for local anesthesia of tail nerve. Ultrasound- and heat-treatment groups were received ultrasound with different parameters and heat treatment, respectively, before EMLA cream applied. Sensory conduction studies of tail nerve were made before and after treatment every 5 min at least for 60 min in all rats. There was no significant difference between the EMLA control group and heat treatment group. All rats in ultrasound-treatment group exhibit significant difference with EMLA control group and heat-treatment group in time for decreased 20% SNCV except for the 2 W/cm(2), 25 min, 20% in ultrasound-treatment group having no significant difference with heat-treatment group. There was no significant difference between ultrasound-treatment subgroups. In the decrease of amplitude, only the 2 W/cm(2), 5 min, 100% and the 2 W/cm(2), 10 min, 50% in ultrasound-treatment group had significant difference between EMLA control and heat-treatment groups. We have objectively examined the sonophoresis effect of ultrasound by investigating the effects of EMLA. Applying ultrasound for 5 min reduces the onset time of EMLA analgesia from 60 min to less than 20 min. Ultrasound sonophoresis of analgesic drugs is potentially useful in the treatment of carpal tunnel syndrome, tooth extraction, and other applications of analgesia.

In vivo imaging of blood flow in the mouse Achilles tendon using high-frequency ultrasound

OBJECTIVE

Achilles tendinitis is a common clinical problem with many treatment modalities, including physical therapy, exercise and therapeutic ultrasound. However, evaluating the effects of current therapeutic modalities and studying the therapeutic mechanism(s) in vivo remains problematic. In this study, we attempted to observe the morphology and microcirculation changes in mouse Achilles tendons between pre- and post-treatment using high-frequency (25 MHz) ultrasound imaging. A secondary aim was to assess the potential of high-frequency ultrasound in exploring therapeutic mechanisms in small-animal models in vivo.

METHODS

A collagenase-induced mouse model of Achilles tendinitis was adopted, and 5 min treatment of continuous-mode low-frequency (45 kHz) ultrasound with 47 mW/cm(2) maximum intensity and 16.3 cm(2) effective beam radiating area was applied. The B-mode images showed no focal hypoechoic regions in normal Achilles tendons either pre- or post-treatment. The Doppler power energy and blood flow rate were measured within the peritendinous space of the Achilles tendon.

CONCLUSION

An increase in the microcirculation was observed soon after the low-frequency ultrasound treatment, which was due to immediate induction of vascular dilatation. The results suggest that applying high-frequency Doppler imaging to small-animal models will be an invaluable aid in explorations of the therapeutic mechanism(s). Our future work includes using imaging to assess microcirculation changes in tendinitis between before and after treatment over a long time period, which is expected to yield useful physiological data for future human studies.

Electrophysiological and functional effects of shock waves on the sciatic nerve of rats

Extracorporeal shockwave therapy (ESWT) has been applied in lithotripsy and treatments of musculoskeletal disorders over the past decade, but its effects on peripheral nerves remain unclear. This study investigated the short-term effects of shockwaves on the sciatic nerve of rats. The nerves were surgically exposed and then stimulated with shockwaves at three intensities. We evaluated the motor nerve conduction velocity (MNCV) of treated sciatic nerves before, immediately after (day 0) and at 1, 4, 7 and 14 d after shockwave treatment. Two functional tests-the sciatic functional index and the withdrawal reflex latency-were evaluated before and at 1, 4, 7 and 14 d after shockwave application. The rats were sacrificed on days 0, 1, 4, 7 and 14 for morphologic observation. The degassed treatment group received high-intensity shockwave treatment using degassed normal saline as the contact medium, and MNCV was measured before and on days 0, 1, 4, 7 and 14. The sham group received the same procedure as the treatment groups (i.e., the surgical operation to expose the sciatic nerve) but with no shockwave treatment. The control group received no surgical operation or shockwave treatment. The results showed moderate decrease in the MNCV after shockwave treatment and damage to the myelin sheath of large-diameter myelinated fibers. The effect was largest (reduction to 60.9% of baseline MNCV) and of longest duration (7 to 14 d) in the high-intensity group. There were no significant changes in functional tests. These results indicated that direct application of shockwaves can induce reversible segmental demyelination in large-diameter fibers, with the electrophysiological changes being positively correlated with the intensity of the shockwaves.

Monitoring and Transmission via Wireless Network for an Assistive Device

Owing to the increasing number of disabled individuals, technical aids are acting more aggressively in the era of modern medicine. The M3S (Multiple Master Multiple Slave) system developed for the physically challenged, utilizes intelligent transmission and integration mechanisms to arrange all hooked-up devices with proper control. To overcome certain limitations of the system (e.g. distance), an RF (Radio Frequency) wireless module would be in charge of the wireless communication between a remote bus and a local bus. It is demonstrated here as assistance for parking assistive vehicles (e.g. powered wheelchair) located in a remote region, which also includes monitoring and usage of accessorial data transmissions shown in our man-machine interface.

Safety assurance of assistive devices based on a two-level checking scheme

The increasing number of physically challenged individuals has boosted the demand of powered wheelchairs. This paper is on the subject of a DSP (Digital Signal Processors) based assistive system, which is associated with a two-level checking scheme. The assistive system takes on the M3S (Multiple Master Multiple Slave) regulation for the assurance of safety. The CAN (Control Area Networks) embedded module in the DSP provides robust transmission of information within the system. The hardware interfaces based on the two-level checking scheme is implemented in input devices (e.g. joystick, head control apparatus) and in output devices (e.g. manipulator, prime mover motors).

Use of M3S for mobile/local controls over a remote/fixed environment

The M3S (Multiple Master Multiple Slave) is an intelligent transmission system for the disabled. This integrated system combines technical aids for mobility, manipulation, environment control and communication. However, signals must be transmitted by a RF (Radio Frequency) module to overcome critical limitations of the CAN Bus (e.g. length). Appliances in different rooms are attached to different "remote" M3S Busses, while the user's "local" M3S Bus controls these remote links by manipulating all output devices on the remote end with input devices on the local end. Signals may also be transferred singly through remote M3S Busses, allowing the neighborhood remote Busses to interface between origin and destination.

Development of a monitoring system for keyboard users' performance

To precisely evaluate the typing performance of a VDT user, a program named KBlog was developed to record the typing activity under the Microsoft Windows operating system. This program is small and simply framed in order to avoid overloading of the operating system. Without interfering with the typing task, this program can record the time of every pressing and releasing movement of each keystroke at the millisecond level. The accuracy and reliability of KBlog was tested by comparing time intervals recorded by KBlog to time intervals of keyboard output electrical signals recorded by an oscilloscope. In the regression analysis on these two indicators, results of high correlation coefficients of almost 1.000 and intercepts within acceptable levels of around 1 ms indicated sufficient accuracy and reliability of this program. Further applications are discussed in this paper concerning both laboratory and field researches.

The comparison of electromyographic pattern classifications with active and passive electrodes

Electromyographic (EMG) signals are usually acquired using surface electrodes, and they commonly serve as the control sources of myoelectric prosthetic limbs. The use of passive electrodes and amplifiers with adjustable gain is very popular in laboratories for the development of new control strategies. However, active electrodes without conductive jelly are used in most clinical applications of myoelectric hand control. There remains an important question: Are there any differences between using active and passive electrodes in EMG pattern classifications? Autoregressive and cepstral coefficients were used to evaluate recognition rates via both types of electrodes. The results showed that the estimated recognition rates in the passive electrodes were comparable to those in the active ones (averaged recognition rate, 88.5 vs. 85.84% in the autoregressive coefficients, and 84.84 vs. 83.5%, in the cepstral coefficients, respectively). Aside from the lack of significant statistical differences between them, the results imply that the differences between the recognition rates via these electrodes could be negligible. This would be helpful for the myoelectric control of assistive devices.

A problem-based e-Learning prototype system for clinical medical education

The purpose of this system is to establish virtual medical school (VMS) as the platform of e-learning center, which integrates collaborative and self-directed learning environment by virtual group, classroom and library, and automatically converts valuable clinical case from Hospital Information System (HIS) database into virtual patient by online authoring tools for problem-based e-learning. In this system, the VMS provides a problem-based e-learning environment, and utilizes HIS to capture and store valuable clinical cases. All medical students and residents now have the opportunity to learn from these typical cases online. The VMS at National Taiwan University has the potential to develop into a national medical education network for the meditation and provision of comprehensive medical resources. The system will use the international standard SCORM 1.2 to develop teaching material and assist with the HL7 v2.4, CDA v1.0 standards to connect Electronic Medical Record (EMR) systems in the hospital. It can provide resources sharing among medical centers by using high transportation ability of Grid Computing integrated with the broadband video platform, Access Grid, and personal multiple point videoconference platform, Multi-video, to popularize the application of e-learning in clinical medical education.

SEMG-controlled telephone interface for people with disabilities

This paper proposes the development of a surface electromyographic (SEMG)-controlled telephone interface for the disabled. The system is composed of three major components: (1) a SEMG receiving/signal-processing module; (2) a row-column scanning interface for the telephone dialling pad; and (3) a main controller, the Intel-8951 microprocessor. The design concept was based on the idea of using a SEMG generated by the disabled and converting it into a trigger pulse. This could allow convenient control of the dialing motion in the row-column scanning keys of a telephone dialling pad. People with disabilities are competent for certain kinds of work such as being a telephone operator. The increase of opportunities to perform a job for the disabled would help them live independently.

A radio controller using speech for the blind

This article describes a low-cost, portable real-time DSP-based speech controller system to provide radio interface control command applications for the blind. The system recognizes spoken Mandarin Chinese words on a DSP chip (TMS320C31) using a hidden Markov model. The function of the radio set, which includes a tuner, tape, and compact disc, were evaluated under both noisy and noiseless environments. Four subjects took part in the experiment and achieved 83 and 90% mean recognition rates under noisy and noiseless conditions, respectively. In addition, because this system is based on a DSP chip, it can easily be programmed to execute speaker-independent algorithms.

Isokinetic elbow joint torques estimation from surface EMG and joint kinematic data: using an artificial neural network model

Because the relations between electromyographic signal (EMG) and anisometric joint torque remain unpredictable, the aim of this study was to determine the relations between the EMG activity and the isokinetic elbow joint torque via an artificial neural network (ANN) model. This 3-layer feed-forward network was constructed using an error back-propagation algorithm with an adaptive learning rate. The experimental validation was achieved by rectified, low-pass filtered EMG signals from the representative muscles, joint angle and joint angular velocity and measured torque. Learning with a limited set of examples allowed accurate prediction of isokinetic joint torque from novel EMG activities, joint position, joint angular velocity. Sensitivity analysis of the hidden node numbers during the learning and testing phases demonstrated that the choice of numbers of hidden node was not critical except at extreme values of those parameters. Model predictions were well correlated with the experimental data (the mean root-mean-square-difference and correlation coefficient gamma in learning were 0.0290 and 0.998, respectively, and in three different speed testings were 0.1413 and 0.900, respectively). These results suggested that an ANN model can represent the relations between EMG and joint torque/moment in human isokinetic movements. The effect of different adjacent electrode sites was also evaluated and showed the location of electrodes was very important to produce errors in the ANN model.

A neuro-control system for the knee joint position control with quadriceps stimulation

A neuro-control system was designed to control the knee joint to move in accordance with the desired trajectory of movement through stimulation of quadriceps muscle. This control system consisted of a neural controller and a fixed parameter proportional-integral-derivative (PID) feedback controller, which was designated as a neuro-PID controller. A multilayer feedforward time-delay neural network was used and trained as an inverse model of the functional electrical stimulation (FES)-induced quadriceps-lower leg system for direct feedforward control. The training signals for neural network learning were obtained from experimentation using a low-pass filtered random sequence to reveal the plant characteristics. The Nguyen-Widrow method was used to initialize the neural connection weights. The conjugate gradient descent algorithm was then used to modify these connection weights so as to minimize the errors between the desired outputs and the network outputs. The knee joint angle was controlled with only small deviations along the desired trajectory with the aid of the neural controller. In addition, the PID feedback controller was utilized to compensate for the residual tracking errors caused by disturbances and modeling errors. This control strategy was evaluated on one able-bodied and one paraplegic subject. The neuro-PID controller showed promise as a position controller of knee joint angle with quadriceps stimulation.

Real-time implementation of electromyogram pattern recognition as a control command of man-machine interface

The purpose of this study was to develop a real-time electromyogram (EMG) discrimination system to provide control commands for man-machine interface applications. A host computer with a plug-in data acquisition and processing board containing a TMS320 C31 floating-point digital signal processor was used to attain real-time EMG classification. Two-channel EMG signals were collected by two pairs of surface electrodes located bilaterally between the sternocleidomastoid and the upper trapezius. Five motions of the neck and shoulders were discriminated for each subject. The zero-crossing rate was employed to detect the onset of muscle contraction. The cepstral coefficients, derived from autoregressive coefficients and estimated by a recursive least square algorithm, were used as the recognition features. These features were then discriminated using a modified maximum likelihood distance classifier. The total response time of this EMG discrimination system was achieved about within 0.17 s. Four able bodied and two C5/6 quadriplegic subjects took part in the experiment, and achieved 95% mean recognition rate in discrimination between the five specific motions. The response time and the reliability of recognition indicate that this system has the potential to discriminate body motions for man-machine interface applications.