scholarly journals Development of a Pedal Powered Wheelchair

2009 ◽  
Vol 3 (2) ◽  
Author(s):  
R. Dix ◽  
R. Pal ◽  
D. A. Brown ◽  
M. Makhous
Keyword(s):  
Front Axle ◽  
Metabolic Energy ◽  
Stroke Event ◽  
Powered Wheelchair ◽  
Post Stroke ◽  
Minute Period ◽  
University Of Buffalo ◽  
A Chain ◽  
The University ◽  
6 Minute Walk Test

A first student project to put pedals on a wheelchair for exercise and propulsion was unsuccessful. The need remained and in June of 2005 the “Eureka” event occurred. Seeing a five-year-old on her training-wheel-equipped bicycle suggested that a fifth wheel could be added in the center between the wheelchair's two large rear wheels, and a mast supported by the fifth wheel's axle could extend forward to support a front axle and pedal set. A chain drive completed the propulsion system. There are no pedal-powered wheelchairs currently on the market. Around 2001 a product (EZChair) without retractable pedals was on the market but withdrawn. A team at the University of Buffalo invented and patented a pedal-powered wheelchair in 1993 (US Patent 5,242,179), but it was not commercialized. Also, a Japanese company designed and built a series of fifth-wheel wheelchair designs. Between 2006 and late 2008 we built many prototypes incorporating geometries that permitted retracting the pedal. For compactness a “Pedalong” with three telescoping tubes was built but it proved impossible to secure tightly. In the next design twin telescoping tubes passing above and to the rear of the rear axle provided the desired extension. A clamp at the front of the outer tube provided tightness of the assembly. In the Northwestern research program (see below), there was some success, but awkwardness in operation prevented commercialization. In October 2008 a major design change from a fifth wheel in the center to a powering of the two standard rear wheels was begun. This required a new chain path geometry and addition of a differential to the drive train. With the new design user control, arm-powering and braking through the rear wheels is retained, and chair stability is improved. Twelve individuals with chronic post-stroke hemiplegia (>6 months post-stroke event) participated in a study to examine the metabolic energy expended when participants performed a 6-minute walk test, a 6 minute leg-propelled wheelchair trial (using the Pedalong), and a 6 minute arm-propelled wheelchair trial. VO2, VCO2, and distance traveled were measured using a portable metablic cart system and wheel-based distance measurement system. The Pedalong and walking trials showed equivalent oxygen consumption levels, but manual pushing was, on average, significantly less. All three modes (walking, leg-propelled and arm-propelled) resulting in similar distances traveled within the 6 minute period. The leg-propelled trials generated the greatest amount of VCO2 during expiration compared with the other modes. This means that more of the available oxygen is being utilized (metabolized) during the leg-propelled mode and so, a greater number of calories were being burned during this 6-minute test.

scholarly journals XXIII.—On the Disruptive Discharge of Electricity: An Experimental Thesis for the Degree of Doctor of Science, Department A

1878 ◽  
Vol 28 (2) ◽  
pp. 633-671 ◽  
Author(s):  
Alexander Macfarlane
Keyword(s):  
Copper Wire ◽  
Late Summer ◽  
The Other ◽  
Straight Line ◽  
Summer Session ◽  
The Difference ◽  
A Chain ◽  
The One ◽  
Metallic Parts ◽  
The University

The experiments to which I shall refer were carried out in the physical laboratory of the University during the late summer session. I was ably assisted in conducting the experiments by three students of the laboratory,—Messrs H. A. Salvesen, G. M. Connor, and D. E. Stewart. The method which was used of measuring the difference of potential required to produce a disruptive discharge of electricity under given conditions, is that described in a paper communicated to the Royal Society of Edinburgh in 1876 in the names of Mr J. A. Paton, M. A., and myself, and was suggested to me by Professor Tait as a means of attacking the experimental problems mentioned below.The above sketch which I took of the apparatus in situ may facilitate tha description of the method. The receiver of an air-pump, having a rod capable of being moved air-tight up and down through the neck, was attached to one of the conductors of a Holtz machine in such a manner that the conductor of the machine and the rod formed one conducting system. Projecting from the bottom of the receiver was a short metallic rod, forming one conductor with the metallic parts of the air-pump, and by means of a chain with the uninsulated conductor of the Holtz machine. Brass balls and discs of various sizes were made to order, capable of being screwed on to the ends of the rods. On the table, and at a distance of about six feet from the receiver, was a stand supporting two insulated brass balls, the one fixed, the other having one degree of freedom, viz., of moving in a straight line in the plane of the table. The fixed insulated ball A was made one conductor with the insulated conductor of the Holtz and the rod of the receiver, by means of a copper wire insulated with gutta percha, having one end stuck firmly into a hole in the collar of the receiver, and having the other fitted in between the glass stem and the hollow in the ball, by which it fitted on to the stem tightly. A thin wire similarly fitted in between the ball B and its insulating stem connected the ball with the insulated half ring of a divided ring reflecting electrometer.

Introduction

2018 ◽  
pp. 1-27
Author(s):  
Anushka Singh
Keyword(s):  
Free Speech ◽  
Hate Speech ◽  
Freedom Of Expression ◽  
University Of California ◽  
American Democracy ◽  
Mob Violence ◽  
A Chain ◽  
The Right ◽  
The University ◽  
Public Lecture

On 1 February 2017 at the University of California, Berkeley, USA, mob violence erupted on campus with 1,500 protesters demanding the cancellation of a public lecture by Milo Yiannopoulos, a British author notorious for his alleged racist and anti-Islamic views.1 Consequently, the event was cancelled triggering a chain of reactions on the desirability and limits of freedom of expression within American democracy. The Left-leaning intellectuals and politicians were accused of allowing the mob violence to become a riot on campus defending it in the name of protest against racism, fascism, and social injustice. In defending the rights of the protesters to not allow ‘illiberal’ or hate speech on campus, however, many claimed that the message conveyed was that only liberals had the right to free speech....

scholarly journals Long-Term Effect of Income Level on Mortality after Stroke: A Nationwide Cohort Study in South Korea

2020 ◽  
Vol 17 (22) ◽  
pp. 8348
Author(s):  
Seungmin Jeong ◽  
Sung-il Cho ◽  
So Yeon Kong
Keyword(s):  
Low Income ◽  
Income Group ◽  
Income Level ◽  
High Income ◽  
High Income Group ◽  
Stroke Mortality ◽  
Stroke Event ◽  
Middle Income ◽  
Medical Aid ◽  
Post Stroke

We investigated whether income level has long-term effects on mortality rate in stroke patients and whether this varies with time after the first stroke event, using the National Health Insurance Service National Sample Cohort data from 2002 to 2015 in South Korea. The study population was new-onset stroke patients ≥18 years of age. Patients were categorized into Category (1) insured employees and Category (2) insured self-employed/Medical Aid beneficiaries. Each category was divided into three and four income level groups, retrospectively. The study population comprised of 11,668 patients. Among the Category 1 patients (n = 7720), the low-income group’s post-stroke mortality was 1.15-fold higher than the high-income group. Among the Category 2 patients (n = 3948), the lower income groups had higher post-stroke mortality than the high-income group (middle-income, aOR (adjusted odds ratio) 1.29; low-income, aOR 1.70; Medical Aid beneficiaries, aOR 2.19). In this category, the lower income groups’ post-stroke mortality risks compared to the high-income group were highest at 13–36 months after the first stroke event(middle-income, aOR 1.52; low-income, aOR 2.31; Medical Aid beneficiaries, aOR 2.53). Medical Aid beneficiaries had a significantly higher post-stroke mortality risk than the high-income group at all time points.

News Notes

1927 ◽  
Vol 20 (3) ◽  
pp. 178-179
Keyword(s):  
Mathematics Section ◽  
University Of Buffalo ◽  
The University

Professor Wilfred H. Sherk, of the University of Buffalo, is the new president of the Mathematics Section of the Middle States and Maryland Association of Teachers of Mathematics.

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