Feasibility of imaging photoplethysmography

Contact and spot measurement have limited the application of photoplethysmography (PPG), thus an imaging PPG system comprising a digital CMOS camera and three wavelength light-emitting diodes (LEDs) is developed to detect the blood perfusion in tissue. With the means of the imaging PPG system, the ideally contactless monitoring with larger field of view and the different depth of tissue by applying multi- wavelength illumination can be achieved to understand the blood perfusion change. Corresponding to the individual wavelength LED illumination, the PPG signals can be derived in the both transmission and reflection modes, respectively. The outcome explicitly reveals the imaging PPG is able to detect blood perfusion in a illuminated tissue and indicates the vascular distribution and the blood cell response to individual wavelength LED. The functionality investigation leads to the engineering model for 3-D visualized blood perfusion of tissue and the development of imaging PPG tomography

A high performance biometric signal and image processing method to reveal blood perfusion towards 3D oxygen saturation mapping

Non-contact imaging photoplethysmography (PPG) is a recent development in the field of physiological data acquisition, currently undergoing a large amount of research to characterize and define the range of its capabilities. Contact-based PPG techniques have been broadly used in clinical scenarios for a number of years to obtain direct information about the degree of oxygen saturation for patients. With the advent of imaging techniques, there is strong potential to enable access to additional information such as multi-dimensional blood perfusion and saturation mapping. The further development of effective opto-physiological monitoring techniques is dependent upon novel modelling techniques coupled with improved sensor design and effective signal processing methodologies. The biometric signal and imaging processing platform (bSIPP) provides a comprehensive set of features for extraction and analysis of recorded iPPG data, enabling direct comparison with other biomedical diagnostic tools such as ECG and EEG. Additionally, utilizing information about the nature of tissue structure has enabled the generation of an engineering model describing the behaviour of light during its travel through the biological tissue. This enables the estimation of the relative oxygen saturation and blood perfusion in different layers of the tissue to be calculated, which has the potential to be a useful diagnostic tool

Feasibility of Imaging Photoplethysmography

Contact and spot measurement have limited the application of photoplethysmography (PPG), thus an imaging PPG system comprising a digital CMOS camera and three wavelength light-emitting diodes (LEDs) is developed to detect the blood perfusion in tissue. With the means of the imaging PPG system, the ideally contactless monitoring with larger field of view and the different depth of tissue by applying multi- wavelength illumination can be achieved to understand the blood perfusion change. Corresponding to the individual wavelength LED illumination, the PPG signals can be derived in the both transmission and reflection modes, respectively. The outcome explicitly reveals the imaging PPG is able to detect blood perfusion in a illuminated tissue and indicates the vascular distribution and the blood cell response to individual wavelength LED. The functionality investigation leads to the engineering model for 3-D visualized blood perfusion of tissue and the development of imaging PPG tomography

Remote simultaneous dual wavelength imaging photoplethysmography: a further step towards 3-D mapping of skin blood microcirculation

This paper presents a camera-based imaging photoplethysmographic (PPG) system in the remote detection of PPG signals, which can contribute to construct a 3-D blood pulsation mapping for the assessment of skin blood microcirculation at various vascular depths. Spot measurement and contact sensor have been currently addressed as the primary limitations in the utilization of conventional PPG system. The introduction of the fast digital camera inspires the development of the imaging PPG system to allow ideally non-contact monitoring from a larger field of view and different tissue depths by applying multi-wavelength illumination sources. In the present research, the imaging PPG system has the capability of capturing the PPG waveform at dual wavelengths simultaneously: 660 and 880nm. A selected region of tissue is remotely illuminated by a ring illumination source (RIS) with dual-wavelength resonant cavity light emitting diodes (RCLEDs), and the backscattered photons are captured by a 10-bit CMOS camera at a speed of 21 frames/second for each wavelength. The waveforms from the imaging system exhibit comparable functionality characters with those from the conventional contact PPG sensor in both time domain and frequency domain. The mean amplitude of PPG pulsatile component is extracted from the PPG waveforms for the mapping of blood pulsation in a 3-D format. These results strongly demonstrate the capability of the imaging PPG system in displaying the waveform and the potential in 3-D mapping of blood microcirculation by a non-contact means

Real-time VLSI architecture for bio-medical monitoring

This paper discusses the architecture and implementation of SSS2, a high-performance real-time signal processing system developed with a hybrid ESL/RTL methodology and targeted to biomedical image processing. Traditional methodologies, as well as new tools, such as Cebatech's C2R untimed-C synthesizer have been employed in the design of the system. The SSS2 platform specifies a parametric number of scalar processing elements, based on multiple 32-bit Sparc-compliant engines, augmented with LE2, an ESL-designed 2-way LIW/SIMD accelerator. LE2, which is purely designed in C, exposes a consistent interface to its SIMD datapath directly which is directly derived from the C-source of open-source image processing codes. It is synthesized to Verilog RTL with C2R. Behaviorally-synthesized SIMD datapaths are then 'plugged-in' into the exposed LE2 datapath interface. The LE2 memory interface can be either a cache- based configurable vector load/store unit or a multi-banked, multi-channel streaming local memory system. Results drawn from this work strongly suggest a shift towards a hybrid approach in designing multi-core systems for high bandwidth streaming and for dealing with large scale medical image transfers and non-linear bio-signal processing algorithms

Innovations towards personalised biomedical photonic devices

The paper demonstrates the progress made in biomedical photonics engineering at Loughborough University since 1998. Research, development of concepts and innovation of products for principal use in healthcare can be traced back to the initial clinical request for a device to measure oxygen saturation in the peripheral tissues. Since then a directed path of progress, which has involved a systematic investigation of component technologies, has been followed. Latterly, the research has been directed at placing the devices developed at the point of care, which is often in the home setting rather than in a controlled clinical environment. Knowledge transfer of ideas and concepts through to translational research that utilises results can also be represented via the developed innovation platform

Systems modelling of EMT cell signalling pathways in heart valve development

Systems modelling of EMT cell signalling pathways in heart valve developmen

Innovation for personalization: A healthcare case study

This paper describes a research and innovation platform for the development of ideas relating to the investigation of blood perfusion in peripheral tissue. The Loughborough Innovation Platform for Health Technologies (LIPHT) can be used to demonstrate the use of the research and innovation pipe-line in more than one dimension. For this paper the first dimension considered is that of `blue sky' idea through to their exploitation for the benefit of users and at the same time creating a wealth stream; the second dimension is the changing market as the ideas develop - from a hospital-based instrument operated by clinicians through to a point and click device for the use by the knowledgeable layman in the community. The starting point for these developments is a medical device known to many people as the `finger clip' that measures arterial blood oxygen saturation; the end point is an optical device capable of imaging blood perfusion

Innovation for personalization: a healthcare case study

This paper describes a research and innovation platform for the development of ideas relating to the investigation of blood perfusion in peripheral tissue. The Loughborough Innovation Platform for Health Technologies (LIPHT) can be used to demonstrate the use of the research and innovation pipe-line in more than one dimension. For this paper the first dimension considered is that of `blue sky' idea through to their exploitation for the benefit of users and at the same time creating a wealth stream; the second dimension is the changing market as the ideas develop - from a hospital-based instrument operated by clinicians through to a point and click device for the use by the knowledgeable layman in the community. The starting point for these developments is a medical device known to many people as the `finger clip' that measures arterial blood oxygen saturation; the end point is an optical device capable of imaging blood perfusion