Mukul Mukherjee

Electroacupuncture may help motor recovery in chronic stroke survivors: A pilot study

Past studies have suggested that acupuncture may reduce spasticity in stroke survivors. We do not know, however, whether acupuncture may enhance the effect of strength training on motor function. This study compared upper-limb motor functional improvement in chronic stroke survivors who received a combination of acupuncture and strength training with that of subjects who received strength training alone. A total of 10 chronic stroke patients with moderate or severe wrist muscle spasticity were recruited for this study. The study used a crossover design with a random order of either combined electroacupuncture and strength training or strength training alone. Each subject received one of the two types of treatment twice a week for the first 6 weeks and switched to the other for another 6 weeks. Quantitative measurements of wrist spasticity, active wrist extension range of motion, isometric wrist strength, and clinical evaluation with Fugl-Meyer (FM) upper-limb motor scores were conducted before and after either treatment. After the combined treatment, the quantitative spasticity level, active wrist extension range of motion (increased by a mean of 16.3 degrees), and FM upper-limb motor score (increased by a mean of 4.9 points) changed significantly (p < 0.01) but no significant changes were noted in isometric wrist strength. The strength training alone resulted in no significant changes to any measured variable. The results of the current study indicate that the combined acupuncture and strength training treatment reduced muscle spasticity and may have improved motor function for chronic stroke survivors with moderate or severe muscle spasticity.

The impact of environmental noise on robot-assisted laparoscopic surgical performance

BACKGROUND An operating room is a noisy environment. How noise affects performance during robotic surgery remains unknown. We investigated whether noise during training with the da Vinci surgical robot (Intuitive Surgical, Inc., Sunnyvale, CA) would affect the performance of simple operative tasks by the surgeon. METHODS Twelve medical students performed 3 inanimate operative tasks (bimanual carrying, suture tying, and mesh alignment) on the da Vinci Surgical System with or without the presence of noise. Prerecorded noise from an actual operating room was used. The kinematics of the robotic surgical instrument tips and the muscle activation patterns of the subjects were evaluated. RESULTS We found noise effects for all 3 tasks with increases in the time to task completion (23%; P=.046), the total distance traveled (8%; P=.011) of the surgical instrument tips, and the muscle activation volume (87%; P=.015) with the presence of noise. We confirmed that the mesh alignment task was the most difficult task with the greatest time to task completion and the greatest muscle activation volume, whereas the suture tying task and the bimanual carrying could be considered the intermediate and the least difficult task, respectively. The noise effects were significantly greater while performing more difficult tasks. CONCLUSION Our findings demonstrated that noise degraded robotic surgical performance; however, the impact of noise on robotic surgery will depend on the level of difficulty of the task. Subsequent research is required to identify how different types of noise, such as random or rhythmic sounds, affect the performance of operative tasks using robots such as the da Vinci.

The Effect of Music on Robot-Assisted Laparoscopic Surgical Performance

Music is often played in the operating room to increase the surgeon’s concentration and to mask noise. It could have a beneficial effect on surgical performance. Ten participants with limited experience with the da Vinci robotic surgical system were recruited to perform two surgical tasks: suture tying and mesh alignment when classical, jazz, hip-hop, and Jamaican music were presented. Kinematics of the instrument tips of the surgical robot and surface electromyography of the subjects were recorded. Results revealed that a significant music effect was found for both tasks with decreased time to task completion (P = .005) and total travel distance (P = .021) as well as reduced muscle activations ( P = .016) and increased median muscle frequency (P = .034). Subjects improved their performance significantly when they listened to either hip-hop or Jamaican music. In conclusion, music with high rhythmicity has a beneficial effect on robotic surgical performance. Musical environment may benefit surgical training and make acquisition of surgical skills more efficient.

Training program for fundamental surgical skill in robotic laparoscopic surgery

Although the use of robotic laparoscopic surgery has increased in popularity, training protocols for gaining proficiency in robotic surgical skills are not well established. The purpose of this study was to examine a fundamental training program that provides an effective approach to evaluate and improve robotic surgical skills performance using the da Vinci™ Surgical System.

Accuracy and speed trade-off in robot-assisted surgery

Controlling surgical task speed and maintaining accuracy are vital components of robotic surgical skills. This study was designed to investigate the relationship between accuracy and speed for robot‐assisted surgical skills.

Biomechanical analyses of stair-climbing while dual-tasking

Stair-climbing while doing a concurrent task like talking or holding an object is a common activity of daily living which poses high risk for falls. While biomechanical analyses of overground walking during dual-tasking have been studied extensively, little is known on the biomechanics of stair-climbing while dual-tasking. We sought to determine the impact of performing a concurrent cognitive or motor task during stair-climbing. We hypothesized that a concurrent cognitive task will have a greater impact on stair climbing performance compared to a concurrent motor task and that this impact will be greater on a higher-level step. Ten healthy young adults performed 10 trials of stair-climbing each under four conditions: stair ascending only, stair ascending and performing subtraction of serial sevens from a three-digit number, stair ascending and carrying an empty opaque box and stair ascending, performing subtraction of serial sevens from a random three-digit number and carrying an empty opaque box. Kinematics (lower extremity joint angles and minimum toe clearance) and kinetics (ground reaction forces and joint moments and powers) data were collected. We found that a concurrent cognitive task impacted kinetics but not kinematics of stair-climbing. The effect of dual-tasking during stair ascent also seemed to vary based on the different phases of stair ascent stance and seem to have greater impact as one climbs higher. Overall, the results of the current study suggest that the association between the executive functioning and motor task (like gait) becomes stronger as the level of complexity of the motor task increases.

Locomotor Sensory Organization Test: A Novel Paradigm for the Assessment of Sensory Contributions in Gait

Feedback based balance control requires the integration of visual, proprioceptive and vestibular input to detect the body’s movement within the environment. When the accuracy of sensory signals is compromised, the system reorganizes the relative contributions through a process of sensory recalibration, for upright postural stability to be maintained. Whereas this process has been studied extensively in standing using the Sensory Organization Test (SOT), less is known about these processes in more dynamic tasks such as locomotion. In the present study, ten healthy young adults performed the six conditions of the traditional SOT to quantify standing postural control when exposed to sensory conflict. The same subjects performed these six conditions using a novel experimental paradigm, the Locomotor SOT (LSOT), to study dynamic postural control during walking under similar types of sensory conflict. To quantify postural control during walking, the net Center of Pressure sway variability was used. This corresponds to the Performance Index of the center of pressure trajectory, which is used to quantify postural control during standing. Our results indicate that dynamic balance control during locomotion in healthy individuals is affected by the systematic manipulation of multisensory inputs. The sway variability patterns observed during locomotion reflect similar balance performance with standing posture, indicating that similar feedback processes may be involved. However, the contribution of visual input is significantly increased during locomotion, compared to standing in similar sensory conflict conditions. The increased visual gain in the LSOT conditions reflects the importance of visual input for the control of locomotion. Since balance perturbations tend to occur in dynamic tasks and in response to environmental constraints not present during the SOT, the LSOT may provide additional information for clinical evaluation on healthy and deficient sensory processing.

The effect of the partially restricted sit-to-stand task on biomechanical variables in subjects with and without Parkinson's disease

The aim of this study was to explore the electromyographic, kinetic and kinematic patterns during a partially restricted sit-to-stand task in subjects with and without Parkinsons disease (PD). If the trunk is partially restricted, different behavior of torques and muscle activities could be found and it can serve as a reference of the deterioration in the motor performance of subjects with PD. Fifteen subjects participated in this study and electromyography (EMG) activity of the tibialis anterior (TA), soleus (SO), vastus medialis oblique (VMO), biceps femoris (BF) and erector spinae (ES) were recorded and biomechanical variables were calculated during four phases of the movement. Subjects with PD showed more flexion at the ankle, knee and hip joints and increased knee and hip joint torques in comparison to healthy subjects in the final position. However, these joint torques can be explained by the differences in kinematic data. Also, the hip, knee and ankle joint torques were not different in the acceleration phase of movement. The use of a partially restricted sit-to-stand task in PD subjects with moderate involvement leads to the generation of joint torques similar to healthy subjects. This may have important implications for rehabilitation training in PD subjects.

The negative effect of distraction on performance of robot‐assisted surgical skills in medical students and residents

Modern surgical practice often requires multitasking in operating rooms, generally full of distractions. The purpose of this research was to investigate the effect of distraction on robot‐assisted surgical skill performance in medical students and residents.

Stroke Survivors Control the Temporal Structure of Variability During Reaching in Dynamic Environments

Learning to control forces is known to reduce the amount of movement variability (e.g., standard deviation; SD) while also altering the temporal structure of movement variability (e.g., approximate entropy; ApEn). Such variability control has not been explored in stroke survivors during reaching movements in dynamic environments. Whether augmented feedback affects such variability control, is also unknown. Chronic stroke survivors, assigned randomly to a control/experimental group, learned reaching movements in a dynamically changing environment while receiving either true feedback of their movement (control) or augmented visual feedback (experimental). Hand movement variability was analyzed using SD and ApEn. A significant change in variability was determined for both SD and ApEn. Post hoc tests revealed that the significant decrease in SD was not retained after a week. However, the significant increase in ApEn, determined on both days of training, showed significant retention effects. In dynamically changing environments, chronic stroke survivors reduced the amount of movement variability and made their movement patterns less repeatable and possibly more flexible. These changes were not affected by augmented visual feedback. Moreover, the learning patterns characteristically involved the control of the nonlinear dynamics rather than the amount of hand movement variability. The absence of transfer effects demonstrated that variability control of hand movement after a stroke is specific to the task and the environment.