Biomedical Engineering Reference
In-Depth Information
improvements obtained with medication without any negative side effects (Birbaumer and
Cohen 2007).
These groundbreaking studies highlighted the possibility of modifying cognitive
functions, paving the road for new applications of BCI technology. One of the most recent
directions concerning clinical applications is the use of a BOLD regulation-based BCI
to treat emotional disorders such as psychopathy and schizophrenia (Birbaumer et al.
2005, 2008). Several studies have shown that it is possible to control emotion-related brain
activity using real-time fMRI (rt-fMRI) (Weiskopf et al. 2003, 2004a, 2004b; Phan et al. 2004;
Caria et al. 2007). In a typical experiment, subjects try to increase and decrease the BOLD
response from a region of interest. The BOLD response is usually displayed on a screen
giving feedback to the subjects with a delay of approximately 1-3 s. By using this protocol,
several studies have already explored the feasibility of self-regulation of different brain
regions. The regulation of the BOLD response from premotor and motor areas can lead
to changes in the motor response speed, whereas from parahippocampal areas it can lead
to changes in explicit memory performance (Weiskopf et al. 2004b, 2007). The regulation
of the anterior cingulate region leads to decrease of pain (deCharms et al. 2005). Finally,
regulation of the anterior insula can lead to changes in negative emotional responses
(Caria et al. 2007; Lee et al. 2011) as face perception (Ruiz et al. 2011).
The feasibility of a NIRS-BCI was exploited by measuring oxygenated and deoxygenated
hemoglobin changes during left- and right-hand motor imagery in five healthy subjects
(Sitaram et al. 2007). By using a Hidden Markov Model (HMM) algorithm, Sitaram and
colleagues successfully classified the imagery of the two hands with an accuracy of 89%.
17.7 Assistive Technologies and BCI
BCIs represent one of the most pioneering fields in AT. Therefore, it is necessary to consider
the complexity of the assignment process of ATs. As recently pointed out, BCIs might be
seen as an AT in the area of information and communication technologies (AT ICT) (Millán
et al. 2010): “AT ICT products are understood to be devices for helping a person to receive,
send, produce and/or process information in different forms” (ISO 2007). According to
this definition, BCIs should be considered as ATs that support daily life activities. It is
important to match person and technology to avoid dissatisfaction and abandonment
(Louise-Bender Pape et al. 2002). It is widely accepted that personal factors can serve as
significant barriers and facilitators to the use of AT (Scherer et al. 2011). The predisposition
to the use of technology could depend on personal and psychosocial characteristics, such
as users' personality, quality of life, abilities, and beliefs (Scherer et al. 2005). ATs are not
considered as deficit compensation systems, but they involve personal well-being and
social participation. Only considering the use in a real environment could it be possible
to meet the needs of its intended users and to entail the consideration of a broad range
of functional and nonfunctional attributes (Stephanidis et al. 1998). The notion of quality
integrates the traditional concept of usability (Abran et al. 2003) and includes aspects that
are not easily measurable on the basis of performance criteria.
The proper BCI should be assessed based on the individual needs and specifics of the
health conditions of the patient (Nijboer et al. 2010). Although it was shown that ALS
patients can use SCPs (Birbaumer et al. 1999), P300 (Sellers and Donchin 2006), and
SMRs (Kübler et al. 2005), it has still not been demonstrated that completely locked-in
