Publications by authors named "Ryan Downey"

Background: Surgical dogma suggests that enhanced recovery (ERAS) pathways are not feasible in the non-elective setting. This study challenges that dogma with the implementation of ERAS in non-elective colorectal surgery.

Methods: Single center review of all colorectal operations was performed following implementation of ERAS in non-elective colorectal surgery.

View Article and Find Full Text PDF

Objective: To evaluate the perioperative as well as early oncological outcomes of patients undergoing robotic retroperitoneal lymph node dissection for treatment of testicular cancer.

Methods: We conducted a prospective consecutive case series of patients undergoing robotic assisted retroperitoneal lymph node dissection for metastatic testicular cancer between May 2018 and July 2021 at our institution. Data were collected on patient and tumour characteristics, intraoperative and postoperative parameters, and functional and oncological outcomes.

View Article and Find Full Text PDF

The goal of this study was to test a novel approach (iCanClean) to remove non-brain sources from scalp EEG data recorded in mobile conditions. We created an electrically conductive phantom head with 10 brain sources, 10 contaminating sources, scalp, and hair. We tested the ability of iCanClean to remove artifacts while preserving brain activity under six conditions: , , , , , and .

View Article and Find Full Text PDF

Mobile brain imaging with high-density electroencephalography (EEG) can provide insight into the cortical processes involved in complex human walking tasks. While uneven terrain is common in the natural environment and poses challenges to human balance control, there is limited understanding of the supraspinal processes involved with traversing uneven terrain. The primary objective of this study was to quantify electrocortical activity related to parametric variations in terrain unevenness for neurotypical young adults.

View Article and Find Full Text PDF

Accuracy of electroencephalography (EEG) source localization relies on the volume conduction head model. A previous analysis of young adults has shown that simplified head models have larger source localization errors when compared with head models based on magnetic resonance images (MRIs). As obtaining individual MRIs may not always be feasible, researchers often use generic head models based on template MRIs.

View Article and Find Full Text PDF

Aging is associated with declines in walking function. To understand these mobility declines, many studies have obtained measurements while participants walk on flat surfaces in laboratory settings during concurrent cognitive task performance (dual-tasking). This may not adequately capture the real-world challenges of walking at home and around the community.

View Article and Find Full Text PDF

A bag-valve-mask (BVM) is a portable handheld medical device commonly used in airway management and manual ventilation. Outside of the operating theatre, BVM devices are often used to pre-oxygenate spontaneously breathing patients before intubation to reduce the risk of hypoxaemia. Pre-oxygenation is considered adequate when the end-tidal expiratory fraction of oxygen is greater than 0.

View Article and Find Full Text PDF

Motion artifacts hinder source-level analysis of mobile electroencephalography (EEG) data using independent component analysis (ICA). iCanClean is a novel cleaning algorithm that uses reference noise recordings to remove noisy EEG subspaces, but it has not been formally tested in a parameter sweep. The goal of this study was to test iCanClean’s ability to improve the ICA decomposition of EEG data corrupted by walking motion artifacts.

View Article and Find Full Text PDF

We developed a method for altering terrain unevenness on a treadmill to study gait kinematics. Terrain consisted of rigid polyurethane disks (12.7 cm diameter, 1.

View Article and Find Full Text PDF

Thoracic aortic aneurysms and thoracoabdominal aneurysms are often found incidentally. Complications include dissection or rupture. Most of the thoracic aortic aneurysms and thoracoabdominal aneurysms develop in patients with risk factors for atherosclerosis.

View Article and Find Full Text PDF

Graduate students intending to pursue an academic career in the sciences have much to gain by learning to teach science but often have limited training opportunities. In response to this need, we designed a one-semester course, Learning Design in Science Education (LDSE), in which students receive formal training in pedagogical theory with role model demonstration of current best practices in active learning. Building from previous descriptions of similar courses, we added a practical experience for the students to utilize their new skills to design and teach a mini science course at the end of the semester.

View Article and Find Full Text PDF

Researchers can improve the ecological validity of brain research by studying humans moving in real-world settings. Recent work shows that dual-layer EEG can improve the fidelity of electrocortical recordings during gait, but it is unclear whether these positive results extrapolate to non-locomotor paradigms. For our study, we recorded brain activity with dual-layer EEG while participants played table tennis, a whole-body, responsive sport that could help investigate visuomotor feedback, object interception, and performance monitoring.

View Article and Find Full Text PDF

An 89-year-old man with a history of a malignant giant cell tumor of soft parts in the right thigh with recurrent/metastatic tumor in the right pelvis was found to have pulmonary nodules concerning for metastatic disease. Subsequent PET/CT unexpectedly demonstrated a right lower quadrant intussusception with a hypermetabolic mass serving as a lead point. Pathology of the resected mass causing the intussusception was compatible with a metastasis from the patient's malignant giant cell tumor of soft parts.

View Article and Find Full Text PDF

Robot-assisted laparoscopic prostatectomy requires a pneumoperitoneum combined with steep Trendelenburg positioning, and these conditions can be associated with impairment of cerebral autoregulation. The objective of this study was to determine if choice of anaesthetic agent affects the preservation of cerebral autoregulation during robot-assisted laparoscopic prostatectomy. We randomly assigned 30 patients to maintenance of general anaesthesia with either propofol or sevoflurane.

View Article and Find Full Text PDF

Background Solid small renal masses (SRMs) (≤4 cm) represent benign and malignant tumors. Among SRMs, clear cell renal cell carcinoma (ccRCC) is frequently aggressive. When compared with invasive percutaneous biopsies, the objective of the proposed clear cell likelihood score (ccLS) is to classify ccRCC noninvasively by using multiparametric MRI, but it lacks external validation.

View Article and Find Full Text PDF

This survey was designed to investigate levels of stress, anxiety and depression, and to identify factors exacerbating or relieving stress in anaesthesia trainees within the Australian and New Zealand College of Anaesthetists training scheme. In addition, the survey investigated levels of personal healthcare, some working conditions, and reports of bullying and reported discrimination along with stigmatisation of mental health issues in this cohort. Psychological distress was assessed using the Kessler psychological distress scale (K10).

View Article and Find Full Text PDF

Dementia syndromes present a diagnostic challenge given their overlapping clinical features and insidious presentations. Cerebral 2-deoxy-2-[F-18]fluoroglucose (FDG) positron emission tomography (PET) is a functional imaging modality commonly used in the evaluation of dementia. While its role in the clinical assessment of dementia is evolving, FDG PET allows for qualitative and quantitative characterization of major dementia syndromes and variants by means of detecting distinct patterns of cortical hypometabolism.

View Article and Find Full Text PDF

The purpose of this study was to develop and evaluate a new, open-source MR-compatible device capable of assessing unipedal and bipedal lower extremity movement with minimal head motion and high test-retest reliability. To evaluate the prototype, 20 healthy adults participated in two magnetic resonance imaging (MRI) visits, separated by 2-6 months, in which they performed a visually guided dorsiflexion/plantar flexion task with their left foot, right foot, and alternating feet. Dependent measures included: evoked blood oxygen level-dependent (BOLD) signal in the motor network, head movement associated with dorsiflexion/plantar flexion, the test-retest reliability of these measurements.

View Article and Find Full Text PDF

Motion and muscle artifacts can undermine signal quality in electroencephalography (EEG) recordings during locomotion. We evaluated approaches for recovering ground-truth artificial brain signals from noisy EEG recordings. We built an electrical head phantom that broadcast four brain and four muscle sources.

View Article and Find Full Text PDF

A 75-year-old man presented with bleeding ileostomy stoma 20 years after total colectomy and end ileostomy for chronic ulcerative colitis. On physical examination, the stoma was mass-like and firm with friable mucosa. Wedge biopsy of the ileostomy stoma revealed well-differentiated neuroendocrine tumor (intermediate grade).

View Article and Find Full Text PDF

Objective: The objective of this paper was to develop and test a novel control algorithm that enables stroke survivors to pedal a cycle in a desired cadence range despite varying levels of functional abilities after stroke.

Methods: A novel algorithm was developed which automatically adjusts 1) the intensity of functional electrical stimulation (FES) delivered to the leg muscles, and 2) the current delivered to an electric motor. The algorithm automatically switches between assistive, uncontrolled, and resistive modes to accommodate for differences in functional impairment, based on the mismatch between the desired and actual cadence.

View Article and Find Full Text PDF

Central command (CC) and the exercise pressor reflex (EPR) regulate blood pressure during exercise. We previously demonstrated that experimental stimulation of the CC and EPR pathways independently contribute to the exaggerated pressor response to exercise in hypertension. It is known that CC and EPR modify one another functionally.

View Article and Find Full Text PDF