Through-body TCSPC based real-time tracking to guide interventional medical procedures

基于全身 TCSPC 的实时跟踪指导介入医疗程序

• 批准号: ST/S000763/1
• 负责人: Robert Thomson
• 金额: $ 40.15万
• 依托单位: Heriot-Watt University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FS000763%2F1
• 关键词: Through; body; TCSPC; based; real

The accurate tracking of medical devices is a key clinical requirement that currently requires the use of ionising X-ray radiation and / or contrast agents. These essential procedures have potential long term detrimental effects, especially on babies, and also causes significant disruption (and therefore cost) due to both the need to protect staff and waiting for the availability of, or transport to, X-ray equipment. There are therefore significant clinical drivers to develop alternative tracking methods. Very recently, we have demonstrated a ground breaking approach to tracking medical devices located deep in tissues using single photon imaging [1]. Our approach exploits the fact that if a point source of light is placed inside the body, a tiny fraction of the light will emerge from the body with a close to line-of-sight path. Crucially, these line-of-sight photons (particles of light) hold precise information about the spatial location of the point source inside the tissue, but extracting this information is not trivial. The key to accessing it is the fact that the line-of-sight photons exit the body with a shorter transit time than the more diffuse photons - a fact that allows us to exploit a technique known as time-correlated single-photon counting (TCSPC) to detect and distinguish them from more diffuse photons. In contrast to "normal" cameras, which do not record the arrival time of the photons on the detector array, TCSPC-based imaging relies on using a source of light that produces short pulses of light at precisely known times, together with a single-photon sensitive detector array that can record the arrival times of individual photons. In this manner, TCSPC imaging allows us to design an imaging system that can selectively detect and image the location of the emerging line-of-sight photons before the diffuse photons start to emerge, and this allows us to locate the precise position of the source.Although we have now demonstrated the potential of this technique for medical device tracking, the clinical translation has been hampered by the low fill-factor (how much of the detector array is light-sensitive) of commercially available TCSPC detector arrays. This low fill-factor (~1%) effectively means that we lose 99% of the light reaching the detector array, limiting the maximum frame rate to ~0.05 Hz - too low to provide adequate feedback to the clinician during catheter placement. Recently, through STFC funding, we have demonstrated that so-called "photonic lantern" transitions provide a new and powerful route to addressing the low fill-factor of commercially available SPAD arrays [2]. The overarching goal of this project will therefore be to work with our commercial partners, Photon Force, to exploit this capability, and develop a TCSPC system capable of tracking catheters with video frame rates. We will then work with clinician scientists to translate the technology towards clinical exploitation by demonstrating the tracking capability using relevant models. The results of this project will then be used to support translational clinical studies, and to work with Photon Force to develop a TCSPC tracking system suitable for the medical market.[1] M. G. Tanner et al, Biomed. Opt. Express 8, 4077-4095 (2017)[2] H. K. Chandrasekharan et al. Nat. Commun. 8, 14080 (2017).

医疗器械的准确跟踪是目前需要使用电离X射线辐射和/或造影剂的关键临床要求。这些基本程序具有潜在的长期有害影响，特别是对婴儿，并且由于需要保护工作人员和等待X射线设备的可用性或运输到X射线设备，也会导致显著的中断（以及因此的成本）。因此，有重要的临床驱动因素来开发替代跟踪方法。最近，我们已经证明了一种突破性的方法，可以使用单光子成像来跟踪位于组织深处的医疗设备[1]。我们的方法利用了这样一个事实，即如果将一个点光源放置在体内，那么一小部分光将以接近视线的路径从体内射出。至关重要的是，这些视线光子（光粒子）包含关于组织内点光源空间位置的精确信息，但提取这些信息并不简单。访问它的关键是这样一个事实，即视线光子离开身体的渡越时间比更漫射的光子更短-这一事实使我们能够利用一种称为时间相关单光子计数（TCSPC）的技术来检测和区分它们。与不记录光子到达探测器阵列的时间的“普通”相机相反，基于TCSPC的成像依赖于使用在精确已知的时间产生短脉冲光的光源，以及可以记录单个光子到达时间的单光子敏感探测器阵列。通过这种方式，TCSPC成像使我们能够设计一种成像系统，该系统可以在漫射光子开始出现之前选择性地检测和成像出现的视线光子的位置，这使我们能够定位源的精确位置。商业上可获得的TCSPC检测器阵列的低填充因子（检测器阵列中有多少是光敏的）阻碍了临床转化。这种低填充因子（~1%）实际上意味着我们损失了99%到达探测器阵列的光，将最大帧速率限制为~0.05 Hz -太低，无法在导管放置期间向临床医生提供足够的反馈。最近，通过STFC的资助，我们已经证明所谓的“光子灯笼”转变提供了一种新的强大途径来解决市售SPAD阵列的低填充因子问题[2]。因此，该项目的总体目标将是与我们的商业合作伙伴Photon Force合作，利用这一能力，并开发能够以视频帧速率跟踪导管的TCSPC系统。然后，我们将与临床科学家合作，通过使用相关模型展示跟踪能力，将该技术转化为临床开发。该项目的结果将用于支持转化临床研究，并与Photon Force合作开发适合医疗市场的TCSPC跟踪系统。[1]M. G.坦纳等人，生物医学。Opt. Express 8，4077-4095（2017）[2] H. K. Amarrasekharan等，Nat. Commun. 8，14080（2017）.

项目成果

Laser Machining of a Multicore Fibre for Multipoint in vivo Illumination and Collection

用于多点体内照明和采集的多芯光纤的激光加工

• DOI: 10.1364/translational.2020.tm2b.5
• 发表时间: 2020
• 作者: Chandrasekharan H

Ultrafast laser ablation of a multicore polymer optical fiber for multipoint light emission

• DOI: 10.1364/oe.424494
• 发表时间: 2021-06-21
• 期刊: OPTICS EXPRESS
• 影响因子: 3.8
• 作者: Chandrasekharan，Harikumar K.;McShane，Eunan P.;Tanner，Michael G.
• 通讯作者: Tanner，Michael G.

High resolution TCSPC imaging of diffuse light with a one-dimensional SPAD array scanning system

使用一维 SPAD 阵列扫描系统对漫射光进行高分辨率 TCSPC 成像

• DOI: 10.48550/arxiv.2204.07582
• 发表时间: 2022
• 作者: McShane E

High resolution TCSPC imaging of diffuse light with a one-dimensional SPAD array scanning system.

使用一维 SPAD 阵列扫描系统对漫射光进行高分辨率 TCSPC 成像。

• DOI: 10.1364/oe.461334
• 发表时间: 2022
• 期刊: Optics express
• 影响因子: 3.8
• 作者: McShane EP