A technique for measuring contact force distribution in minimally invasive surgical procedures

1997 ◽  
Vol 211 (4) ◽  
pp. 309-316 ◽  
Author(s):  
P N Brett ◽  
R S W Stone
Keyword(s):  
Contact Force ◽  
Low Cost ◽  
Working Environment ◽  
Tactile Sense ◽  
Sensory Data ◽  
New Methods ◽  
Minimally Invasive Surgical ◽  
Software Algorithms ◽  
Contact Force Distribution ◽  
Sense Of Touch

This paper investigates new methods for measuring forces and tactile sense as a contribution towards relaying the sense of touch to the surgeon. The approach used is to determine a distribution of contact force using a small number of sensory outputs to detect the bending of a surface of known behaviour. Software algorithms have been produced to interpret the contacting force from sensory data, and have achieved a bandwidth of 30 Hz and an accuracy of 2 per cent. The sensor construction is of sufficiently low cost to produce a disposable unit and uses materials that are compatible with the invasive working environment.

scholarly journals Overview of Plant-Derived Vaccine Antigens: Dengue Virus

2011 ◽  
Vol 14 (3) ◽  
pp. 400 ◽  
Author(s):  
Ravindra B Malabadi ◽  
Advaita Ganguly ◽  
Jaime A Teixeira da Silva ◽  
Archana Parashar ◽  
Mavanur R Suresh ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Dengue Virus ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Low Cost ◽  
Current Status ◽  
Human Immune Deficiency Virus ◽  
Dengue Vaccine ◽  
New Methods ◽  
Vaccine Antigens

ABSTRACT - This review highlights the advantages and current status of plant-derived vaccine development with special reference to the dengue virus. There are numerous problems involved in dengue vaccine development, and there is no vaccine against all four dengue serotypes. Dengue vaccine development using traditional approaches has not been satisfactory in terms of inducing neutralizing antibodies. Recently, these issues were addressed by showing a very good response to inducing neutralizing antibodies by plant-derived dengue vaccine antigens. This indicates the feasibility of using plant-derived vaccine antigens as a low-cost method to combat dengue and other infectious diseases. The application of new methods and strategies such as dendritic cell targeting in cancer therapy, severe acute respiratory syndrome, tuberculosis, human immune deficiency virus, and malaria might play an important role. These new methods are more efficient than traditional protocols. It is expected that in the near future, plant-derived vaccine antigens or antibodies will play an important role in the control of human infectious diseases. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals THE ROLE OF EDUCATIONAL TECHNOLOGY IN EFFECTIVE LEARNING AND TEACHING IN SCHOOLS AND COLLEGES IN NIGERIA

1986 ◽  
Vol 1 (1) ◽  
pp. 12
Author(s):  
A K Yusuf
Keyword(s):  
Educational Technology ◽  
Low Cost ◽  
Educational Resource ◽  
Learning And Teaching ◽  
Effective Learning ◽  
New Methods ◽  
Research Findings

This paper outlines briefly, some views of the term “ Educational Technology” and its role generally in the field of education as evident from research findings. The urgent need for low-cost educational technology for schools and colleges in Nigeria is discussed. Attention is also drawn to the need to re-orient the teacher to his task, if new methods and media are to be used successfully. Finally, it is further suggested that future use of the achieved methods and media may differ radically depending among other things on the objectives to be achieved and the en­try behaviour of the students, particularly when we employ the low-cost educational technology for effective learning hnd teaching. The importance of an Educational Resource Centre, and Teachers’ Resource Centre are among other things strongly suggested.

scholarly journals Investigating the relationship between indoor environment and workplace productivity in naturally and mechanically ventilated office environments

2019 ◽  
Vol 41 (3) ◽  
pp. 280-304
Author(s):  
Rajat Gupta ◽  
Alastair Howard ◽  
Sahar Zahiri
Keyword(s):  
Environmental Conditions ◽  
Indoor Environment ◽  
Low Cost ◽  
Environmental Parameters ◽  
Working Environment ◽  
The Other ◽  
Mechanically Ventilated ◽  
Workplace Productivity ◽  
Office Environments ◽  
The Relationship

This paper uses a case study-based approach to empirically investigate the relationship between indoor environment and workplace productivity in two contrasting office environments: one naturally ventilated, the other mechanically ventilated. Environmental parameters were continuously monitored over 19 months. Transverse and longitudinal surveys recorded occupants’ perception of their working environment and self-reported productivity, while performance tasks (numerical and proofreading) measured cognitive capability as proxy for measured productivity. Indoor temperatures and CO2 concentrations were found to be higher and more variable in the naturally ventilated office. However, the correlation between occupant perception of their indoor environment and perceived productivity was stronger in the mechanically ventilated office. Occupants of the naturally ventilated office were found to be more tolerant of their environment than their counterparts in the mechanically ventilated office. Task performance was affected by indoor environmental conditions such as indoor temperature and CO2 concentration. Interestingly in the naturally ventilated office, the median scores were up to 12% higher for tests conducted at CO2 concentrations <1400 ppm, compared to those conducted above 1400 ppm, whereas in the mechanically ventilated office, this threshold was only 1000 ppm. The study showed that higher concentrations of CO2 were associated with lower task scores and longer task durations, reinforcing the need for good levels of ventilation in workspaces. It was found that occupants in NV workspaces were able to adapt to a broader range of environmental conditions. Therefore, controlling the indoor environment within narrow ranges (expending significant amounts of energy in the process) may not always be necessary to improve comfort and productivity. On the other hand, controlling indoor environment within a narrow range – as is common in MV workspaces – may be counterproductive, creating occupants who are less tolerant of small changes in their environmental conditions. The study also demonstrates occupant surveys can provide useful feedback on perceived comfort and productivity at relatively low cost. Insights from such surveys can be used to improve indoor environment in workspaces.

Choosing the Optimal Contact Force Distribution for Multi-Limbed Mobile Robots With Three Feet Contact

2003 ◽  
Author(s):  
Dennis W. Hong ◽  
Raymond J. Cipra
Keyword(s):  
Contact Force ◽  
Dimensional Space ◽  
Contact Point ◽  
Optimal Solution ◽  
Solution Space ◽  
Contact Forces ◽  
Force Distribution ◽  
Normal Vector ◽  
Optimization Criteria ◽  
Contact Force Distribution

One of the inherent problems of multi-limbed mobile robotic systems is the problem of multi-contact force distribution; the contact forces and moments at the feet required to support it and those required by its tasks are indeterminate. A new strategy for choosing an optimal solution for the contact force distribution of multi-limbed robots with three feet in contact with the environment in three-dimensional space is presented. The optimal solution is found using a two-step approach: first finding the description of the entire solution space for the contact force distribution for a statically stable stance under friction constraints, and then choosing an optimal solution in this solution space which maximizes the objectives given by the chosen optimization criteria. An incremental strategy of opening up the friction cones is developed to produce the optimal solution which is defined as the one whose foot contact force vector is closest to the surface normal vector for robustness against slipping. The procedure is aided by using the “force space graph” which indicates where this solution is positioned in the solution space to give insight into the quality of the chosen solution and to provide robustness against disturbances. The “margin against slip with contact point priority” approach is also presented which finds an optimal solution with different priorities given to each foot contact point for the case when one foot is more critical than the other. Examples are presented to illustrate certain aspects of the method and ideas for other optimization criteria are discussed.

Meeting the contraceptive and AIDS prevention needs of people living on a dollar a day

2001 ◽  
Vol 13 (8) ◽  
pp. 739 ◽  
Author(s):  
Malcolm Potts
Keyword(s):  
Developing Countries ◽  
Young People ◽  
Research And Development ◽  
Hiv Transmission ◽  
Low Cost ◽  
Female Sterilization ◽  
Full Cost ◽  
New Methods ◽  
Health Infrastructure ◽  
Aids Pandemic

The new millennium sees the largest cohort of young people in history entering its fertile years. Many of these people are too poor to pay the full cost of modern contraception, but the money available for subsidizing their needs is exceedingly limited. The AIDS pandemic is placing additional, unprecedented demand on already overstretched resources. Existing methods of contraception that are well established and off-patent can be produced in bulk at low cost, and will remain the backbone of future programmes. The use of misoprostol as an abortifacient is likely to spread rapidly. New methods must take into account the limitations of the health infrastructure in developing countries and the imperative of low cost. Given the constraints of money, skills and facilities, it is essential to set realistic priorities for future contraceptive research and development. It is suggested that the greatest needs are for a woman-controlled method of preventing HIV transmission and for a non-surgical method of female sterilization.

scholarly journals Feasibility Study of Multi Inertial Measurement Unit

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 74 ◽  
Author(s):  
Ariel Larey ◽  
Eliel Aknin ◽  
Itzik Klein
Keyword(s):  
Inertial Measurement Unit ◽  
Inertial Sensors ◽  
Low Cost ◽  
Software Tool ◽  
Experimental Results ◽  
Measurement Unit ◽  
Outlier Rejection ◽  
Inertial Measurement ◽  
Navigation Solution ◽  
Sensory Data

An inertial measurement unit (IMU) typically has three accelerometers and three gyroscopes. The output of those inertial sensors is used by an inertial navigation system to calculate the navigation solution–position, velocity and attitude. Since the sensor measurements contain noise, the navigation solution drifts over time. When considering low cost sensors, multiple IMUs can be used to improve the performance of a single unit. In this paper, we describe our designed 32 multi-IMU (MIMU) architecture and present experimental results using this system. To analyze the sensory data, a dedicated software tool, capable of addressing MIMUs inputs, was developed. Using the MIMU hardware and software tool we examined and evaluated the MIMUs for: (1) navigation solution accuracy (2) sensor outlier rejection (3) stationary calibration performance (4) coarse alignment accuracy and (5) the effect of different MIMUs locations in the architecture. Our experimental results show that 32 IMUs obtained better performance than a single IMU for all testcases examined. In addition, we show that performance was improved gradually as the number of IMUs was increased in the architecture.

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