中国国际医疗器械设计与制造技术展览会(Medtec China)2021

专注于为医疗器械研发与生产服务

2022年12月7-9日 | 苏州国际博览中心B1-E1号馆

Can Vagus Nerve Stimulation Treat Stroke?

2021-12-29

To say Austin, Texas-based MicroTransponder had a breakthrough year in 2021 is no exaggeration. In fact, the “breakthrough” nomenclature comes courtesy of FDA, which granted the Vivistim System Breakthrough Device Designation and then pre-market device approval for its Vivistim Paired VNS vagus nerve stimulation device in August.

The device utilizes a small implant in the upper chest with electrodes located on the left side of the neck, next to the vagus nerve to improve upper extremity function after ischemic stroke. In addition to the FDA approval, it also received the best new product of the year designation from industry publication Neurotech Reports in November. The vagus nerve stimulation (VNS), delivered in small pulses, is paired with traditional rehabilitation exercises performed under the supervision of a therapist.

The theory behind Vivistim is that the VNS enhances the process of neuroplasticity as recovering stroke patients’ rehab exercises rewire the brain. MicroTransponder says the device is “ideal for chronic ischemic stroke survivors who have not regained arm and hand function six months after their stroke and are considered to have moderate to severe deficits by their physician.”

The foundational pre-clinical technology behind the Vivistim was developed over the past decade at the University of Texas at Dallas’s Texas Biomedical Device Center; MicroTransponder chief scientific officer Navzer Engineer received his PhD at the university. One of the center’s researchers, Seth Hays, worked on the technology but has no connection to MicroTransponder.

“There is an idea that has been around for decades now, that if you have a neurological injury, one way you might be able to recover after that is to drive neuroplasticity or synaptic plasticity—changes in the circuits that remain after the injury,” Hays said. He and his colleagues opted for a VNS-based approach because stimulation of the cervical vagus nerve releases neuromodulators associated with that plasticity.

“The concept behind this was to look at a time when a patient was doing an exercise,” he said. “At that time, the circuits controlling the arm are active. If you do that in concurrence with VNS you are also releasing the neuromodulators with the idea it will promote synaptic plasticity in those active circuits.”

The effectiveness of the device, measured by the Upper Extremity Fugl-Meyer Assessment (FMA-UE), a stroke-specific measure of motor impairment, was demonstrated in a study published in The Lancet in April. The FDA announcement of the approval summarized the study’s results: Patients in the treatment group had an average score increase of 5 points, whereas patients in the control group had an average score increase of 2.4 points. Additionally, 47.2 percent of those in the treatment group saw an improvement of 6 or more points in the FMA-UE score 90 days post-therapy as compared with 23.6 percent in the control group.

The FDA approval allows MicroTransponder executives to launch concerted sales efforts, but they are also in the early stage of strategizing how best to be the first-of-its-kind platform to market.

“When you think about new technology coming to market, obviously an FDA approval is critical,” Richard Foust, the company’s chief commercial officer, said. “The next aspect is really understanding what is the state of healthcare—and that always comes down to how will this be paid for and is there a big enough need in the marketplace?

“The positive story we have is that there are CPT codes in place today that talk about a vagus nerve, specifically a cranial nerve. And that gives us a very good grounding of how we will be positioning our product. There is still work to be done, because we don’t have a coverage decision, but what we have is a silence on the decision, so we are not starting with a non-coverage decision.”

What is ‘Clinically Meaningful?’

The launch of the Vivistim also presents an opportunity for the neuroscience community to discuss the ramifications of existing measurements of post-stroke rehabilitation and how the definitions of functional improvement are dependent upon who is doing the defining. That discussion was primed in part by a commentary in Stroke in July by Gert Kwakkel, chair of neurorehabilitation at Amsterdam University Medical Center in the Netherlands, and Bruce Dobkin, M.D., medical director of the UCLA Neurologic Rehabilitation and Research Program.

Kwakkel and Dobkin said the Lancet study’s authors’ overall interpretation of their results as being clinically significant in the effectiveness of VNS could be interpreted to be “too optimistic” to call it a novel treatment option. However, Kwakkel and Dobkin also introduced a central confounder about how clinically meaningful improvements are defined: “Unfortunately, there is no clear consensus on a definition for a clinically meaningful improvement, otherwise called a clinically important difference, in part, because the concept may be defined from different perspectives, including clinicians, patients, statisticians, healthcare economists, and stakeholders.”

In an email exchange with MD+DI, Kwakkel elaborated on the amorphous boundaries of what “meaningful” is in stroke rehab: “Patients, for example, may report improvements in their self-reported well-being after a therapy without any measurable improvements in their activities and vice versa,” he said. “In the same way, improvement in, for example, a patient’s ability to perform a meaningful task may occur without any improvements in the underlying neurological impairments by using compensation strategies (and vice versa). With that, this key question needs always to be refined into ‘meaningful improvement in terms of what?’”

“Gert got at something that is core to the whole field,” Hays said. “You could call it a conflict, l guess, but it’s just a discussion about what does it mean? Certainly, families of survivors know what they have gone through. What does it mean to have something that’s clinically meaningful? It’s surprisingly difficult to define. So some of this will probably be post hoc—did people perceive it was helpful to them in their life? And that is a holistic discussion.”

On the other hand, Hays said, self-perceptions of improvement are problematic if a developer wants to bring something to market: “It’s hard to convince the FDA that ‘Hey, these people said this really helped them’ because they are looking at a quantitative measure—which of course they need to—but there will be some balance that needs to be struck between the more qualitative measures and the more quantitative ones.”

A Growing Market for Stroke Care

MicroTransponder’s Foust said the dynamics of stroke treatment offer innovative rehabilitation technologies a sizeable market. For instance, he said, the number of hospitals with specialized stroke care has grown from about 500 to more than 2,000 in the past decade, and emergency treatment modalities such as TPA being given in ambulances en route to emergency rooms means more people are surviving strokes.

However, Foust added, the increased number of survivors is not matched by those who recover more fully: “It doesn’t seem as though the technologies that are saving people’s lives are reducing impairments,” he said. “They go through a typical rehabilitation regimen, and about 50 percent recover and the other 50 percent have varying levels of impairment.”

The Vivistim, he said, is intended for those patients with those long-term impairments who are motivated enough to undergo the implantation surgery. The payoff, he said, is that the therapy can continue not only in outpatient rehab centers, but the patients themselves can activate the device at home by swiping a magnet over the device up to eight times a day while practicing activities of daily living that are important to them. “Our technology is specifically for after they have gone through that six-month rehabilitation process, because we want to make sure that everything that is available at lower cost and non-invasive is done. At the point of which, if they don’t cross that threshold, there is another option for them now, and that is really the target market.”

And, according to Hays, the FDA approval means the uses for paired VNS and rehab are not limited by any means to stroke; UT-Dallas researchers and others are already working on projects to expand its utility.

“One of the important things that came out of the study was that pairing VNS with rehab is safe,” Hays said, “and has a ton of application. There is no reason it is limited to stroke. We are trying it with spinal cord injury patients now. Another study we have ongoing with some collaborators is pairing it with cognitive therapy for PTSD.

“The idea is the same, that VNS is enhancing these neuromodulators and that is basically potentiating the effects of rehab. I think you’ll see a bunch of new applications coming out for something like this, probably within the next 10 10 years."

Article source: Qmed and MD+DI

 

伴随着人工智能兴起,起步较晚的国产医疗机器人正在加快发展,逐步扩大应用场景。5月26日,第十一届中国生物产业大会在武汉光谷发布本土健康企业的7项最新成果,首先推介的便是武汉兰丁公司的宫颈癌检测智能机器人。

 

《每日经济新闻》记者在大会现场了解到,多家企业正在推广医疗机器人,应用范围涵盖胃镜检查、腹腔手术、美容抗衰等,并且已有成熟产品进入国内医院,打破进口机器人在医院应用的垄断局面。

 

 

据主办方介绍,“LANDING”机器人通过筛查样本拨片进行自动化诊断,每月有108万例的样本检测能力,效率远远超过人工。目前,武汉兰丁公司与阿里巴巴的合作,使“LANDING”机器人在中国各地基层终端收集的大量细胞特征参数及数据,在云平台上完成分析诊断工作。

 

 

科技颠覆想象力,机器人在医疗领域的应用范围更加广泛。《每日经济新闻》记者注意到,多家企业在生物产业大会上重点推介医疗机器人产品。

 

患者吞下一粒胶囊,在胃里变成机器人进行螺旋式扫描,将检查图像实时传输至医生电脑,这便是安翰光电技术(武汉)有限公司研制的磁控胶囊胃镜机器人。该公司展位负责人程先生介绍,目前全国已有1000多家医疗机构应用了胶囊胃镜机器人,包括三甲医院、大型体检中心等,涵盖专业医疗和常规健康体检领域,年消耗量达50万粒。

 

据了解,这粒胶囊仅重5G,但包含了80多项科技创新专利,集成400多个精密元器件。上述负责人表示,在检查方面,胃镜机器人可以替代传统的电子胃镜,不过电子胃镜可以做小型的腔镜手术、切片等,胶囊机器人还不具备这些功能,但在进一步研发中。

 

苏州康多机器人有限公司则在大会上重点推介腹腔镜手术机器人系统,该公司展位负责人张辉介绍,这款手术机器人由医生控制台、支撑臂、手术器械三部分组成,通过机器人操作可以起到防止手抖、放大病灶视野等精确治疗的效果。

 

其实,在“机器换人”升级过程中,国产医疗机器人起步虽晚,但发展很快,不少上市公司将其作为下一风口进行布局。

 

2015年,制造装备公司楚天科技(行情300358,诊股)(300358,SZ)表示正在研发医药机器人和医疗机器人,一年后,首台医药无菌生产智能机器人下线,步入医药装备4.0时代;2017年11月,科大讯飞(行情002230,诊股)(002230,SZ)研发的医疗机器人“智医助理”通过临床执业医师综合笔试,目前已进入合肥基层卫生中心,辅助全科医生进行诊疗;2017年,埃斯顿(行情002747,诊股)(002747,SZ)收购美国Barrett 30%股权,全面进军康复医疗机器人市场,并计划与Barrett共同出资在中国境内成立一家新的合公司。

 

国产机器人拥有成本优势 在多家企业布局的背后,是医疗机器人巨大的市场潜力。普华永道中国发布的《医疗机器人宏观应用趋势与研究方向》显示,2014年,全球医疗机器人的市场价值是26亿美元,到2020年预计会达到76亿美元。

 

人均可支配收入的增加会促使高质量医疗需求的增长,而医疗机器人正好有出血少、精准度更高,恢复快的优势。整个发展趋势显示医疗机器人市场潜力巨大。

 

目前,国内医院的医疗机器人仍依赖进口,最为广泛应用的就是美国直觉外科公司制造的达芬奇手术机器人,2016年国内手术量突破1.5万台。

 

但是,进口医疗机器人价格昂贵,使得医疗费用也居高不下,如一台达芬奇机器人在国内售价2000万元左右,附带长期的耗材费用。

 

“进口机器人就算不用,一年的保养费都得80~100万元,每天开机费用就达1万元左右。”张辉表示,国外的机器人设备,主要包括维修费、保养费、耗材费等费用,所以价格居高不下。

 

随着国产医疗机器人发力,这一局面有望打破。此前,楚天科技研发的医药无菌生产机器人定价500万~600万元,而国际同类机器人定价800万~1000万元左右。

 

张辉告诉《每日经济新闻》记者,国产医疗机器人的优势是小型化、便捷化,还有国内的服务体系,针对三甲医院、县级医院等机构,可以实现分级应用,因此价格应该会比进口设备低一半左右,降低医疗成本。

 

来源:每日经济新闻

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