Force Control Issues in Upper and Lower Limbs in Parkinson's Disease and Freezing of Gait.

Parkinson's Disease (PD) has been found to cause force control deficits in upper and lower limbs. About 50% of patients with advanced PD develop a debilitating symptom called freezing of gait (FOG), which has been linked to force control problems in the lower limbs, and some may only have a limited response to the gold standard pharmaceutical therapy, levodopa, resulting in partially levodopa-responsive FOG (PLR-FOG). There has been limited research on investigating upper-limb force control in people with PD with PLR-FOG, and without FOG. In this pilot study, force control was explored using an upper-and-lower-limb haptics-enabled robot in a reaching task while people with PD with and without PLR-FOG were on their levodopa medication. A healthy control group was used for reference, and each cohort completed the task at three different levels of assistance provided by the robot. Similar significant proportional force control deficits were found in the upper and lower limbs in patients with PLR-FOG versus those without FOG. Some aspects of force control were found to be retained, including an ability to increase or decrease force in response to changes in resistance while completing a reaching task. Overall, these results suggest there are force control deficits in both the upper and lower limbs in people with PLR-FOG.

Colonic displacement as a marker of endoscopic skill: development of a novel tool for endoscopy training.

BACKGROUND: Colonoscopy is a technically challenging procedure. The colonoscope is prone to forming loops in the colon, which can lead patient discomfort and even perforation. We hypothesized that expert endoscopists use techniques to avoid loop formation, identify and straighten loops earlier, and thus exert less force. METHODS: Using a commercially available physical colon simulator model (Kyoto Kagaku), electromagnetic tracking markers (NDI Medical) were placed along the mobile segments of the colon (sigmoid, transverse) to measure the degree of displacement of the colon as the scope was advanced to the cecum. The colon model was set for each participant to simulate a redundant alpha loop in the sigmoid colon. Gastroenterology and surgical trainees and attendings were assessed. Demographic data were collected for each participant. RESULTS: Seventy-five participants were enrolled in the study. There were 17 (22.7%) attending physicians, and 58 (77.3%) trainees. Attending physicians advanced the scope to the cecum faster. The mean time required for procedure completion was 360.5 s compared to 178.4 s for the trainee and attending groups respectively (mean difference: 182.1 s, 95% CI: 93.0, 269.7; p = 0.0002). Attending physicians exerted significantly lower mean colonic displacement than trainees. The mean colonic displacement was 79.8 mm for the trainee group and 57.9 mm for the attending group (mean difference: 21.9 mm, 95% CI: 2.6, 41.2; p = 0.04). Those who used torque steering caused lower maximum colonic displacement than those who used knob steering. CONCLUSION: Attending physicians advance the scope during colonoscopy in a manner that results in significantly less colonic displacement than resident trainees. Although prior studies have shown a difference in force application between endoscopists and inexperienced students, ours is the first to differentiate across varying degrees of endoscopic skill. Future studies will define metrics for incorporation into endoscopic training curricula, focusing on techniques that encourage safety and comfort for patients.

Development and evaluation of stem cell collection procedure diagrams to support the education and recruitment of committed stem cell donors.

BACKGROUND: Diagrams which allow potential unrelated stem cell donors to visualize the stem cell collection process were hypothesized to support the recruitment and education of committed stem cell donors. STUDY DESIGN AND METHODS: A series of bone marrow and peripheral blood stem cell collection procedure diagrams were developed, featuring young adult male donors of varied ethnic backgrounds. Post-implementation, surveys were conducted to evaluate stakeholder perspective on the diagrams' utility. A quality improvement project was conducted at five stem cell drives from 2017 to 2018 at which recruiters did or did not show the diagrams to potential donors. Following the drives, registrants were invited to complete a survey exploring their experience, knowledge and attitude towards donation. RESULTS: The diagrams were implemented in Canada in 07/2016. Of 293 participating registrants (24·7% non-Caucasian males) recruited at five drives between 2017 and 2018, 76% (n = 197) were shown the diagrams. Participants who were shown the diagrams were significantly more likely to report that the recruiters appeared very knowledgeable (89% vs. 76%, P = 0·019) and to report improved self-reported knowledge of stem cell donation (P = 0·010) compared to participants not shown the diagram. Data are also shown demonstrating that stakeholders in donor recruitment used and valued the diagrams and that use of the diagrams was associated with improved donor recruitment outcomes in Canada. CONCLUSION: This report is the first evaluation of stem cell collection diagrams in the literature. The diagrams are relevant to donor registries, recruitment organizations and transplant centres worldwide, and their use may support efforts to educate and recruit committed, ethnically diverse donors.

Does Dual-Task Gait Differ in those with Late-Life Depression versus Mild Cognitive Impairment?

OBJECTIVES: To compare the dual-task gait performance of older adults with Late-Life Depression (LLD) versus Mild Cognitive Impairment (MCI). DESIGN: Cross-sectional study with three matched groups: LLD, MCI and non-depressed and cognitively intact (NDCI). SETTING: LLD group participants were recruited from geriatric psychiatry clinics in London, Ontario. Matched participants meeting criteria for the MCI or NDCI groups were previously recruited for other research studies from geriatric clinics and the community. PARTICIPANTS: Individuals aged 60-85 who met criteria for mild-moderate LLD (N=23) without a diagnosis of a neurocognitive disorder. MEASUREMENTS: Participants completed questionnaires regarding mood, cognition and physical activity. Gait speed was recorded using an electronic walkway during simple and dual-task gait (walking while naming animals aloud). Dual-task cost (DTC) is the percentage change in gait speed between simple and dual-task gait. It is a clinically relevant indicator of fall risk and is strongly associated with cognitive decline. For comparison, 23 MCI and 23 NDCI participants, matched with respect to age, sex and comorbidities, were randomly selected from existing research databases. RESULTS: Each group had 8 males and 15 females, with mean age of 69.0-69.6 years. The mean (±SD) DTC of the NDCI, LLD and MCI groups were statistically different at 2.4±11.4%, 11.8±9.9% and 22.2±16.7%, respectively. CONCLUSION: Older adults with LLD perform worse on dual-task gait than NDCI; however, they are less impaired than those with MCI. The elevated DTC seen in LLD is likely because of underlying executive dysfunction that is less significant than in those with MCI.

An autoclavable wireless palpation instrument for minimally invasive surgery.

Minimally invasive surgery prevents surgeons from manually palpating organs to locate subsurface tumors and other structures. One solution is to use ultrasound; however, it is not always reliable. Various minimally invasive surgery instruments that provide tactile feedback have been proposed to augment ultrasound sensing for tumor localization; however, current designs have limitations such as cumbersome wiring, difficulty in manipulation, lack of sterilizability and high cost. This paper presents a novel, autoclavable, wireless, hand-held palpation instrument that uses a custom, low-cost, disposable tactile sensor to provide tactile and kinesthetic force feedback. The use of a replaceable, disposable tactile sensor avoids deterioration in sensor performance due to repeated autoclaving. The instrument features a passive joint in the end effector that allows the sensor to self-align to the palpation surface in a wide range of orientations. All of the electronics are packaged in a removable module that allows the rest of the instrument to be easily cleaned and autoclaved. Two versions of the tactile sensor, using piezoresistive sensing and capacitive sensing respectively, have been designed for use with this instrument. The instrument is shown to be able to detect 6 mm diameter spherical tumors at a depth of 9-10 mm in ex vivo tissue samples.