Roshan Dsouza

Dermascope guided multiple reference optical coherence tomography

In this paper, we report the feasibility of integrating a novel low cost optical coherence tomography (OCT) system with a dermascope for point-of-care applications. The proposed OCT system is based on an enhanced time-domain optical coherence tomographic system, called multiple reference OCT (MR-OCT), which uses a single miniature voice coil actuator and a partial mirror for extending the axial scan range. The system can simultaneously register both the superficial dermascope image and the depth-resolved OCT sub-surface information by an interactive beam steering method. A practitioner is able to obtain the depth resolved information of the point of interest by simply using the mouse cursor. The proposed approach of combining a dermascope with a low cost OCT provides a unique powerful optical imaging modality for a range of dermatological applications. Hand-held dermascopic OCT devices would also enable point of care and remote health monitoring.

3D nondestructive testing system with an affordable multiple reference optical-delay-based optical coherence tomography

Optical coherence tomography (OCT) is emerging as a powerful noncontact imaging technique, allowing high-quality cross-sectional imaging of scattering specimens nondestructively. However, the complexity and cost of current embodiments of an OCT system limit its use in various nondestructive testing (NDT) applications at resource-limited settings. In this paper, we demonstrate the feasibility of a novel low-cost OCT system for a range of nondestructive testing (NDT) applications. The proposed imaging system is based on an enhanced time-domain OCT system with a low cost and small form factor reference arm optical delay, called multiple reference OCT (MR-OCT), which uses a miniature voice coil actuator and a partial mirror for extending the axial scan range. The proposed approach is potentially a low-cost, compact, and unique optical imaging modality for a range of NDT applications in a low-resource setting. Using this method, we demonstrated the capability of MR-OCT to perform cross-sectional and volumetric imaging at 1200 A-scans per second.

Assessment of curing behavior of light‐activated dental composites using intensity correlation based multiple reference optical coherence tomography

Monitoring the curing kinetics of light‐activated resin is a key area of research. These resins are used in restorative applications and particularly in dental applications. They can undergo volumetric shrinkage due to poor control of the depth dependent curing process, modulated by the intensity and duration of the curing light source. This often results in the formation of marginal gaps, causing pain and damage to the restoration site. In this study, we demonstrate the capabilities of a correlation method applied using a multiple references optical coherence tomography (MR‐OCT) architecture to monitor the curing of the resin.

Multiple reference optical coherence tomography (MR-OCT) system

We describe a multiple reference OCT (MR-OCT) system which is radically different from existing optical coherence tomography (OCT) systems. Complete scans of a target from surface to depth are accomplished by simultaneously acquiring the scan in multiple segments using a virtually solid state design that is inherently miniature, robust and low cost; in short, ideal for use in applications characterized by high volumes, difficult operating environments and constrained acquisition and operating budgets.

The how and why of a

Optical Coherence Tomography (OCT) is the fastest growing medical imaging modality with more than

10 optical coherence tomography system

1Bln worth of scans ordered and over

In vivo microcirculation imaging of the sub surface fingertip using correlation mapping optical coherence tomography (cmOCT)

400M worth of equipment shipped in 2010, just nine years after its commercialization. It is at various stages of acceptance and approvals for eye care, coronary care and skin cancer care and is spreading rapidly to other medical specialties. Indeed, it is the leading success of translation of biophotonics science into clinical practice. Significant effort is being made to provide sufficient evidence for efficacy across a broad range of applications, but more needs to be done to radically reduce the cost of OCT so that it can spread to underserved markets and address new, fast growing opportunities in mobile health monitoring. Currently, a clinical OCT system ranges in price from ~

Comparing an FFT filter for multiple reference optical coherence tomography (MR-OCT) with an Chebychev and an elliptic filter

50k to ~

Evaluation of a polarization sensitive multiple reference optical coherence tomography system

150k, typically is housed on a bedside trolley, runs off AC power, and requires skilled, extensively trained technicians to operate. The cost, size, and skill level required keep this wonderful technology beyond the reach of mainstream primary care, much less individual consumers seeking to monitor their health on a routine basis outside of typical clinical settings and major urban medical centers. Beyond the first world market, there are 6.5 billion people with similar eye and skin cancer care needs which cannot be met by the current generation of large, expensive, complex, and delicate OCT systems. This paper will describe a means to manufacture a low cost, compact, simple, and robust OCT system, using parts and a configuration similar to a CD-ROM or DVD pickup unit (see figure 1). Essentially, this system—multiple reference OCT (MR-OCT)—is based on the use of a partial mirror in the reference arm of a time domain OCT system to provide multiple references, and hence A-scans, at several depths simultaneously (see figure 2). We have already shown that a system based on this configuration can achieve an SNR of greater than 90 dB, which is sufficient for many medical imaging and biometry applications.

The impact of relative intensity noise on the signal in multiple reference optical coherence tomography

We describe a novel application of correlation mapping optical coherence tomography (cmOCT) for sub-surface fingerprint biometric identification. Fingerprint biometrics including automated fingerprint identification systems, are commonly used to recognise the fingerprint, since they constitute simple, effective and valuable physical evidence. Spoofing of biometric fingerprint devices can be easily done because of the limited information obtained from the surface topography. In order to overcome this limitation a potentially more secure source of information is required for biometric identification applications. In this study, we retrieve the microcirculation map of the subsurface fingertip by use of the cmOCT technique. To increase probing depth of the sub surface microcirculation, an optical clearing agent composed of 75% glycerol in aqueous solution was applied topically and kept in contact for 15 min. OCT intensity images were acquired from commercial research grade swept source OCT system (model OCT1300SS, Thorlabs Inc. USA). A 3D OCT scan of the fingertip was acquired over an area of 5x5 mm using 1024x1024 A-scans in approximately 70 s. The resulting volume was then processed using the cmOCT technique with a 7x7 kernel to provide a microcirculation map. We believe these results will demonstrate an enhanced security level over artificial fingertips. To the best of our knowledge, this is the first demonstration of imaging microcirculation map of the subsurface fingertip.