Terahertz Sensors for Industrial Automation

Saturday, August 30, 2014

Teraview- Terahertz intraoperative breast cancer probe


http://euroscan.org.uk/technologies/technology/view/2768

Source agency:
NIHR-HSC
Date of Submission:
29/08/2014
Date of Printing:
30/08/2014
Disclaimer:
This report is work in progress and should not be used for external distribution without permission from the originating agency. Users should be aware that reports are based on information available at the time of research and often on a limited literature search.

Technology, Company & Licensing

Technology name:
Terahertz
Technology - description:
An intraoperative imaging probe based on terahertz (THz) light has been developed by TeraView Ltd to aid identification and excision of cancerous tissue during breast cancer surgery.

The probe is intended to be used on women aged 18-90 years who are undergoing wide local excision, re-excision or sentinel node biopsy for breast cancer. It has been designed to help surgeons identify and differentiate between malignant and benign breast and lymph node tissue and can be used at the site of the surgical incision or on excised tissue. The company claim the probe will assist surgeons to achieve complete surgical excision of tumours, including margins of cancerous tissue.

Based on Terahertz Pulsed Imaging (TPI™) core technology, the hand held Terahertz probe scans the tissue and produces and detects pulses of THz. Information from the reflected light is analysed by a custom algorithm to assess the spectral fingerprint of the tissue and differentiate malignant from benign tissue. This information is processed into 3D images by TeraView’s TPI™ software.
Company or developer:
TeraView Ltd
Reason for database entry:
Existing methods used to assess tumour margins intraoperatively, include specimen x-ray mammography and palpation. These methods can however, be unreliable, requiring the surgeon to guess if the tumour has been entirely removed. Histopathological examination of the excised tumour, although more reliable, can only be performed post-operatively and is a time consuming process, requiring 5-7 days for analysis.
Technology - stage in early warning process:
Assessment complete
Technology - stage of development:
Nearly established
Licensing, reimbursement and other approval:
The company anticipate launch for private and NHS clinical use following CE marking in 2015.
Technology - type(s):
Diagnostics, Device
Technology - use(s):
Diagnostic

Patient Indication & Setting

Patient indications:
Breast cancer surgery
Disease description and associated mortality and morbidity:
Number of Patients:
Technology - specialities(s):
Radiology, imaging & nuclear medicine, Oncology & radiotherapy
Technology - setting(s):
General hospital and ambulatory care, Specialist hospital
Setting - further information:

Impact

Alternative and/or complementary technology:
Additive and substitution
Current Technology:
Existing methods used to assess tumour margins intraoperatively, include specimen x-ray mammography and palpation. These methods can however, be unreliable, requiring the surgeon to guess if the tumour has been entirely removed. Histopathological examination of the excised tumour, although more reliable, can only be performed post-operatively and is a time consuming process, requiring 5-7 days for analysis.
Health Impact:
The company state the ability of the probe to identify and differentiate sorts of tissues is based on the sensitivity of Terahertz light to variations in tissue water content. They also claim the probe offers a less invasive and low energy option for high resolution breast cancer imaging. The company claim a key innovative feature of the probe is its ability to assist with the identification of cancerous tissue in real-time. The company state the probe will allow the surgeon to check for cancerous tissue at the site of incision and in the excised tissue, during surgery. Being able to do this in real time may reduce incidence and associated costs of re-excision and additional follow-up surgery, as claimed by the company. As a consequence, this may also reduce waiting times for first-time surgery.

If clinical and cost effectiveness can be demonstrated, the Terahertz intraoperative probe may offer an additional imaging option for selected patients. 
Diffusion:
Cost, infrastructure and economic consequences:
Ethical, social, legal, political and cultural impact:

Evidence & Policy

Clinical evidence and safety:
Economic evaluation:
Ongoing research:
TPI- in vivo study in breast cancer and sentinel lymph nodes: In vivo evaluation of Terahertz Pulse Imaging of breast cancer and sentinel lymph nodes. [Online]
http://public.ukcrn.org.uk/Search/StudyDetail.aspx?StudyID=13598 Accessed 24th July 2014. 
Ongoing or planned HTA:
Web link:
http://www.hsc.nihr.ac.uk/topics/terahertz-intraoperative-breast-cancer-probe/
References and sources:
Ashworth PC, Pickwell-MacPherson E, Provenzano E et al. Terahertz pulsed spectroscopy of freshly excised human breast cancer. Optics Express 2009; 17(15):12444-12454. http://www.ncbi.nlm.nih.gov/pubmed/19654646

Calvin Y, Shuting Fan, Yiwen S et al. The potential of terahertz imaging for cancer diagnosis: A review of investigations to date. Quantitative imaging in medicine and surgery 2012;2(1): 33-45.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3496499/

Fitzgerald AJ, Wallace VP, Jimenez-Linan M et al. Terahertz pulsed imaging of human breast tumours. Radiology 2006;239(2):533-540. http://www.ncbi.nlm.nih.gov/pubmed/16543586

Fitzgerald AJ, Pinder S, Purushotham AD et al. Classification of terahertz-pulsed imaging data from excised breast tissue. Journal of biomedical optics 2012;17(1). http://www.ncbi.nlm.nih.gov/pubmed/22352655

Pickwell-Macherson E and Wallace VP. Terahertz pulsed imaging- A potential medical imaging modality? Photodiagnosis and photodynamic therapy 2009;6(2):128-134. http://www.ncbi.nlm.nih.gov/pubmed/19683214 
Notes:
Another intraoperative imaging probe is the MarginProbe® system, which has been developed by Dune Medical devices. The system became commercially available following CE marking in 2006. MarginProbe® is not currently distributed in the UK.
Other technologies for the identification of cancerous tissue currently in early development include: a heads up goggle display by Washington University, the Artemis fluorescence camera and C-dots system by Quest Medical and Cornell University and the iKnife surgical tool by Medimass and Imperial College London, which can also cut the identified cancerous tissue. 

Friday, August 29, 2014

Abstract-A review of terahertz sources





R A Lewis
Institute for Superconducting and Electronic Materials and School of Physics, University of Wollongong, Wollongong NSW 2522, Australia 
http://iopscience.iop.org/0022-3727/47/37/374001
Bibliometric data set the scene by illustrating the growth of terahertz work and the present interest in terahertz science and technology. After locating terahertz sources within the broader context of terahertz systems, an overview is given of the range of available sources, emphasizing recent developments. The focus then narrows to terahertz sources that rely on surface phenomena. Three are highlighted. Optical rectification, usually thought of as a bulk process, may in addition exhibit a surface contribution, which, in some cases, predominates. Transient surface currents, for convenience often separated into drift and diffusion currents, are well understood according to Monte Carlo modelling. Finally, terahertz surface emission by mechanical means—in the absence of photoexcitation—is described.

Abstract-Terahertz spectroscopy of quantum 2D electron systems


James Lloyd-Hughes

University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, UK 

Terahertz time-domain spectroscopy permits the coherent motion of charges to be examined in a diverse range of two-dimensional semiconductor heterostructures. Studies of the THz conductivity and magnetoconductivity of two-dimensional quantum systems are reviewed, including cyclotron resonance spectroscopy and the transverse conductivity in the Hall and quantum Hall regimes. Experiments are described that demonstrate quantum phenomena at THz frequencies, principally coherent control and enhanced light–matter coupling in electromagnetic cavities.

Abstract-Rapid scanning terahertz time-domain magnetospectroscopy with a table-top repetitive pulsed magnet



G. Timothy Noe, II, Qi Zhang, Joseph Lee, Eiji Kato, Gary L. Woods, Hiroyuki Nojiri, and Junichiro Kono  »View Author Affiliations

Applied Optics, Vol. 53, Issue 26, pp. 5850-5855 (2014)
http://dx.doi.org/10.1364/AO.53.005850

We have performed terahertz time-domain magnetospectroscopy by combining a rapid scanning terahertz time-domain spectrometer based on the electronically controlled optical sampling method with a table-top minicoil pulsed magnet capable of producing magnetic fields up to 30 T. We demonstrate the capability of this system by measuring coherent cyclotron resonance oscillations in a high-mobility two-dimensional electron gas in GaAs and interference-induced terahertz transmittance modifications in a magnetoplasma in lightly doped n-InSb.
© 2014 Optical Society of America

Abstract-Structural control of metamaterial oscillator strength and electric field enhancement at terahertz frequencies




The design of artificial nonlinear materials requires control over internal resonant charge densities and local electric field distributions. We present a MM design with a structurally controllable oscillator strength and local electric field enhancement at terahertz frequencies. The MM consists of a split ring resonator (SRR) array stacked above an array of closed conducting rings. An in-plane, lateral shift of a half unit cell between the SRR and closed ring arrays results in an increase of the MM oscillator strength by a factor of 4 and a 40% change in the amplitude of the resonant electric field enhancement in the SRR capacitive gap. We useterahertz time-domain spectroscopy and numerical simulations to confirm our results. We show that the observed electromagnetic response in this MM is the result of image chargesand currents induced in the closed rings by the SRR.