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; 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).

准确跟踪医疗设备是当前需要使用电离X射线辐射和 /或对比剂的关键临床要求。这些基本程序具有潜在的长期有害影响，尤其是对婴儿的影响，并且由于需要保护员工的需求以及等待X射线设备的可用性或运输，也会造成重大破坏（因此成本）。因此，有重要的临床驱动因素来开发替代跟踪方法。最近，我们已经展示了一种使用单光子成像[1]在组织深处跟踪医疗设备的破碎方法。我们的方法利用了这样一个事实，即，如果将光源放置在体内，则一小部分光线将从人体中出现，并靠近视线路径。至关重要的是，这些视线光子（光的颗粒）具有有关组织内部源的空间位置的精确信息，但是提取此信息并不是一件容易的事。访问它的关键是，视线线光子比更漫射的光子较短的传输时间退出身体 - 这一事实使我们能够利用一种称为时间相关的单光子计数（TCSPC）的技术，可以检测并区分更多的散射光子。与“正常”摄像机相反，该相机未记录光子在检测器阵列上的到达时间，基于TCSPC的成像依赖于使用光源在精确已知的时间上产生短脉冲脉冲的光源，以及可以记录单个光子的到达时间的单光敏感检测器阵列。通过这种方式，TCSPC成像使我们能够设计一个成像系统，该系统可以在弥漫性光子开始出现之前，可以选择性地检测和图像新出现的视线光子的位置，这使我们能够确切的源位置。可商购的TCSPC检测器阵列的光敏）。这种低填充因子（〜1％）有效地意味着我们损失了达到检测器阵列的99％的光线，将最大帧速率限制在〜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资金，我们证明了所谓的“光子灯笼”过渡为解决市售Spad阵列的低填充因子提供了新的强大途径[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，以利用此功能，并开发能够跟踪具有视频帧速率的导管的TCSPC系统。然后，我们将与临床医生合作，通过使用相关模型证明跟踪能力来将技术转化为临床开发。然后，该项目的结果将用于支持翻译临床研究，并与Photon Force合作开发适合医疗市场的TCSPC跟踪系统。[1] M. G. Tanner等人，Biomed。选择。 Express 8，4077-4095（2017）[2] H. K. Chandrasekharan等。纳特。社区。 8，14080（2017）。