Applied Bionics and Biomechanics - Volume 3, issue 1

Authors: Rutten, W. L. C. | Ruardij, T. G. | Marani, E. | Roelofsen, B. H.

Article Type: Research Article

Abstract: One type of future, improved neural interface is the “cultured probe”. It is a hybrid type of neural information transducer or prosthesis, for stimulation and/or recording of neural activity. It would consist of a microelectrode array (MEA) on a planar substrate, each electrode being covered and surrounded by a local circularly confined network (“island”) of cultured neurons. The main purpose of the local networks is that they act as biofriendly intermediates for collateral sprouts from the in vivo system, thus allowing for an effective and selective neuron–electrode interface. As a secondary purpose, one may envisage future information processing applications of …these intermediary networks. In this paper, first, progress is shown on how substrates can be chemically modified to confine developing networks, cultured from dissociated rat cortex cells, to “islands” surrounding an electrode site. Additional coating of neurophobic, polyimide-coated substrate by triblock-copolymer coating enhances neurophilic-neurophobic adhesion contrast. Secondly, results are given on neuronal activity in patterned, unconnected and connected, circular “island” networks. For connected islands, the larger the island diameter (50, 100 or 150 μm), the more spontaneous activity is seen. Also, activity may show a very high degree of synchronization between two islands. For unconnected islands, activity may start at 22 days in vitro (DIV), which is two weeks later than in unpatterned networks. Show more

Keywords: Cultured neuronal networks, network patterning, network activity, MEA, multi electrode array, neurophilic/neurophobic substrate coating, neuronal synchronization

DOI: 10.1533/abbi.2004.0027

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 1-7, 2006

Authors: Bogen, D.

Article Type: Research Article

Abstract: We describe the initial development of an artificial phonological loop (APL), a new technology to assist individuals with impairment of the working memory system. The phonological loop, along with the visuospatial sketchpad, is one of the two slave short-term memory subsystems that comprise working memory, a cognitive function closely associated with the control of attention. In the phonological loop, phonological (speech) information lasting for 1–2 second is maintained active by repetitive, subvocal (silent speech) rehearsal. Deficits in working memory, specifically in the phonological loop, occur in many disorders, including attention-deficit disorder and Alzheimer's disease. In these disorders, it appears that …the ability for phonological rehearsal is intact, but the regulation or triggering of the rehearsal process is inadequate, thus causing the contents of working memory to be lost. The purpose, then, of the APL is to facilitate the phonological loop by artificially extending the duration of phonological rehearsals. The APL mimics the natural phonological loop by providing audible vocal echoes to take the place of subvocal rehearsals. In this system, the user talks to him/herself in short (1–2 second) phrases; the device records these phrases, stores them in electronic memory, and then repeats— i.e., echoes—the phrases multiple times over an extended period. Two versions of this device have been developed: the Echo-APL and the Rearticulation-APL. In the Echo-APL, only echoing is involved. In the Rearticulation-APL, however, the user re-vocalizes (rearticulates) the phrase in response to an audible cue. The device repeats the cue until it detects (hears) the re-vocalization. Future research and development of the APL will require extensive testing and careful evaluation of possible echo-schedules: the predefined program controlling inter-echo time intervals and echo-amplitude (echo loudness). The APL essentially exteriorizes the silent phonological loop and makes it audible. It is a system that helps the user to “talk to him/herself” to keep ideas in mind. Show more

Keywords: Assistive technology, working memory, short-term memory, phonological loop, attention, attention-deficit disorder

DOI: 10.1533.abbi.2005.0013

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 9-21, 2006

Authors: Negrete-Martínez, J.

Article Type: Research Article

Abstract: In this article we describe a new robot control architecture on the basis of self-organization of self-inhibiting modules. The architecture can generate a complex behaviour repertoire. The repertoire can be performance-enhanced or increased by modular poly-functionality and/or by addition of new modules. This architecture is illustrated in a robot consisting of a car carrying an arm with a grasping tool. In the robot, each module drives either a joint motor or a pair of wheel motors. Every module estimates the distance from a sensor placed in the tool to a beacon. If the distance is smaller than a previously measured …distance, the module drives its motor in the same direction of its prior movement. If the distance is larger, the next movement will be in the opposite direction; but, if the movement produces no significant change in distance, the module self-inhibits. A self-organization emerges: any module can be the next to take control of the motor activity of the robot once one module self-inhibits. A single module is active at a given time. The modules are implemented as computer procedures and their turn for participation scheduled by an endless program. The overall behaviour of the robot corresponds to a reaching attention behaviour. It is easily switched to a running-away attention behaviour by changing the sign of the same parameter in each module. The addition of a “sensor-gain attenuation reflex” module and of a “light-orientation reflex” module provides an increase of the behavioural attention repertoire and performance enhancement. Since scheduling a module does not necessarily produce its sustained intervention, the architecture of the “brain” is actually providing action induction rather than action selection. Show more

Keywords: Modular robot control, self-inhibiting modules (SIMs), self-organization, action induction, brain theory

DOI: 10.1533.abbi.2005.0061

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 23-27, 2006

Authors: Gu, J. J. | Meng, M. | Cook, A. | Liu, P. X.

Article Type: Research Article

Abstract: Loss of an eye is a tragedy for a person, who may suffer psychologically and physically. This paper is concerned with the design, sensing and control of a robotic prosthetic eye that moves horizontally in synchronization with the movement of the natural eye. Two generations of robotic prosthetic eye models have been developed. The first generation model uses an external infrared sensor array mounted on the frame of a pair of eyeglasses to detect the natural eye movement and to feed the control system to drive the artificial eye to move with the natural eye. The second generation model removes …the impractical usage of the eye glass frame and uses the human brain EOG (electro-ocular-graph) signal picked up by electrodes placed on the sides of a person's temple to carry out the same eye movement detection and control tasks as mentioned above. Theoretical issues on sensor failure detection and recovery, and signal processing techniques used in sensor data fusion, are studied using statistical methods and artificial neural network based techniques. In addition, practical control system design and implementation using micro-controllers are studied and implemented to carry out the natural eye movement detection and artificial robotic eye control tasks. Simulation and experimental studies are performed, and the results are included to demonstrate the effectiveness of the research project reported in this paper. Show more

Keywords: Robotic eye, sensing and control, biomedical signal, sensor failure detection, electrode placement

DOI: 10.1533/abbi.2005.0024

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 29-41, 2006

Authors: Goldsmith, P. | Wynd, S. | Kawchuk, G.

Article Type: Research Article

Abstract: The precision and programmability of robotic manipulators makes them suitable for biomechanics research, particularly when an experimental procedure must be accurately repeated multiple times. This paper describes a robotic system used to investigate biomechanical mechanisms of stroke in humans. A parallel robot manipulator is used to reproduce chiropractic manipulations on animal subjects using a 3-D vision system. An algorithm for calibrating the system is proposed and tested on the robot. An iterative learning control scheme is then introduced to improve positional accuracy. Experimental results demonstrate that the calibration procedure and learning scheme are both effective.

Keywords: Robotics, biomedical robots, chiropractic, robot calibration, vision-based motion control

DOI: 10.1533/abbi.2004.0042

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 43-48, 2006

Authors: Fish, F. E.

Article Type: Research Article

Abstract: In recent years, the biomimetic approach has been utilized as a mechanism for technological advancement in the field of robotics. However, there has not been a full appreciation of the success and limitations of biomimetics. Similarities between natural and engineered systems are exhibited by convergences, which define environmental factors, which impinge upon design, and direct copying that produces innovation through integration of natural and artificial technologies. Limitations of this integration depend on the structural and mechanical differences of the two technologies and on the process by which each technology arises. The diversity of organisms that arose through evolutionary descent does …not necessarily provide all possible solutions of optimal functions. However, in instances where organisms exhibit superior performance to engineered systems, features of the organism can be targeted for technology transfer. In this regard, cooperation between biologists and engineers is paramount. Show more

Keywords: Biomimetics, drag reduction, aquatic locomotion, swimming, thrust production, evolution

DOI: 10.1533/abbi.2004.0028

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 49-60, 2006

Authors: Hara, E. H.

Article Type: Research Article

Abstract: In this article, the hearing process is considered from a system engineering perspective. For those with total hearing loss, a cochlear implant is the only direct remedy. It first acts as a spectrum analyser and then electronically stimulates the neurons in the cochlea with a number of electrodes. Each electrode carries information on the separate frequency bands (i.e., spectrum) of the original sound signal. The neurons then relay the signals in a parallel manner to the section of the brain where sound signals are processed. Photonic and tactile hearing systems displaying the spectrum of sound are proposed as alternative paths …to the section of the brain that processes sound. In view of the plasticity of the brain, which can rewire itself, the following conjectures are offered. After a certain period of training, a person without the ability to hear should be able to decipher the patterns of photonic or tactile displays of the sound spectrum and learn to ‘hear’. This is very similar to the case of a blind person learning to ‘read’ by recognizing the patterns created by the series of bumps as their fingers scan the Braille writing. The conjectures are yet to be tested. Designs of photonic and tactile systems displaying the sound spectrum are outlined. Show more

Keywords: Photonic and tactile hearing systems, brain plasticity, sound frequency spectrum, photonic display, tactile display

DOI: 10.1533/abbi.2005.0035

Citation: Applied Bionics and Biomechanics, vol. 3, no. 1, pp. 61-66, 2006