Advances in wireless technology offer innovative solutions for diagnostic and potentially therapeutic endoscopy.
Rise in prevalence of diseases that require endoscopy procedures, like cancer and gastrointestinal diseases, is one of the prime reasons that drives the growth of endoscopy equipment market. The global endoscopy equipment market is projected to reach USD 35.2 billion by 2024 from an estimated USD 25.6 billion in 2019 at a CAGR of 6.6 percent, predicts Markets and Markets. Growth in baby-boomer generation with high risk of targeted diseases, rise in awareness about novel endoscopy equipment, and patient preference for the minimally invasive nature of endoscopy equipment propel market growth. Modern endoscopy techniques have revolutionized the examination and treatment of upper gastrointestinal tract (including esophagus, stomach, and duodenum), and the colon. Increase in adoption of innovative endoscopy equipment, such as capsule endoscopes and robot-assisted endoscopy along with ultra-high-definition visualization systems, further augments the market growth. However, the dearth of skilled physicians and endoscopists, high cost of the sophisticated endoscopy equipment, and infections caused by a few endoscopes impede market growth.
Indian market dynamics
The Indian endoscopy equipment in 2018 is estimated at Rs 725 crore, with the rigid endoscopes segment estimated at Rs 385 crore and the flexible endoscopes segment at Rs 320 crore. Capsules contributed Rs 14 crore and balloon another Rs 6 crore. In unit terms, it is estimated that in 2018, 600 numbers of flexible and 2500 numbers of rigid endoscopes were sold in the Indian market.
The flexible segment is dominated by Olympus, with Fujifilm, Karl Storz, and Pentax being aggressive players. Other players include Auhoa and J Mitra.
Karl Storz, Olympus, and Stryker are aggressive players in the rigid category. Other brands that are present are Richard Wolf and Surgdent.
Capsule endoscopes are dominated in India by Medtronics, although globally some of the notable industry players include Olympus Corporation, CapsoVision, Chongqing Jinshan, RF System, Fujifilm, Given Imaging Ltd., and IntroMedic.
Balloon-assisted enteroscopy allows advancement of a long endoscope into the small intestine for both diagnostic and therapeutic purposes. In India, double-balloon enteroscopy is catered to largely by Fujifilm and the single-balloon enteroscopy largely by Olympus.
The small intestine, which used to be called the dark continent, was long regarded as being difficult to diagnose and treat due to challenges with endoscope insertion. Balloon endoscopes and manually operated spiral overtubes that appeared in the 2000s made it possible to shorten the small intestine by pleating, which made deep enteroscopy easier. However, many of these systems require two operators and can be very difficult to operate, often resulting in long procedure times. In order to overcome these challenges, in 2011 Olympus wholly acquired US-based Spirus Medical, which possessed special technology for motorized spiral overtubes. By integrating this technology with its own, Olympus has now developed the new PowerSpiral enteroscopy system. In March 2019, Olympus launched this product in Indian hospitals.
In February 2019, Aohua announced its Indian marketing service center in Mumbai, in anticipation that the Indian market’s demand would increase for endoscopic diagnosis and treatment over the years.
The Asian Institute of Gastroenterology, Hyderabad, procured endoscopes for about Rs 25 crore in 2018. The facility was established as a new concept of daycare unit where major endoscopic surgical procedures could be done on an outpatient basis without resorting to hospitalization. Since then the institute has become one of the largest referral centers in Asia for therapeutic endoscopy. Patients are referred from not only most cities in India but also from surrounding countries like Sri Lanka, Bangladesh, Malaysia, and Nepal.
The future is wireless, indeed
Advances in wireless technology offer innovative solutions for diagnostic and potentially therapeutic endoscopy. The development of capsule endoscopy allows the investigation of the gastrointestinal tract overcoming the limits of traditional instruments, more comfortably and less stressfully for the patient.
A variety of wireless endoscopes are available for the examination of the small and large bowel, of the lower esophagus, and (if magnetically guided) even of the stomach. However, the industry has not yet reached the ultimate targets of this technology – mini-robots for pan-endoscopy and interventional endoscopy. The major obstacles to achieving these goals are limited battery power, lack of capsule control and guidance through the digestive tract, accurate localization of the ingested device, enhancement of image quality, and development of biopsy and drug-delivery systems.
Energy, energy, energy – the prerequisite to achieve the aforementioned goals. Today, the deliverable power supply to the capsules is about 25 mW and it is estimated that future mini-robots will require more than 550 mW to fulfill our expectations. Therefore, either power supply must be increased or new technology developed that requires minimum energy to perform the required tasks.
Many innovative solutions are under investigation ex-vivo to overcome the limited battery life of the commercially available capsules. Among them, the wireless power transmission technology that transfers power from a transmitter (outside of the body) to a receiver (within the capsule) in the form of electromagnetic waves based on inductive coupling is the most promising solution for the delivery of safe, stable, and sufficient energy. While a portable transmitter has recently been developed, issues such as misalignment between the transmitter and receiver magnetic fields, and efficient power transmission through biological tissues need to be solved; thus, successful testing in humans is pending. On the other hand, taking advantage of nanotechnology medicine, new miniature devices incorporated in capsules and new technologies, like the field programmable gate array (FPGA) and the application-specific circuit (ASCI), are expected to consume less energy. Indeed, an ASCI-based prototype micro-robot has been shown to consume less energy than the commercially available capsules.
The mobility, localization, and orientation of wireless capsules in the digestive tract are unpredictable and largely undetectable (the latter two), so far. The active locomotion systems under development are divided in those with internal (within the capsule), external, and mixed actuators. Within the first group, friction force-based mechanisms (worm-like, paddle/legged, crawler mobility) predominate; however, high energy requirements, hostile shape for the intestine, and capture of the majority of the endoscope space make their use questionable.
The future of the active locomotion of the wireless robot seems to be the magnet. External locomotion actuators take advantage of an external magnetic field, coupled with a permanent magnet within the capsule to propel the device. Perhaps a hybrid locomotion system that combines internal and external actuators may eventually prevail. Currently, research focuses on the development of a safe, low-power-consuming system that will offer proper endoscope velocity and ability to move backwards–forwards, and to stop under real time control.
Exact localization of the capsule endoscope in the digestive tract is of imperative importance for accurate localization of the detected lesions and potential therapy application in real time. The existing capsule route 2-D tracking software is inaccurate and its use is limited in clinical practice. Magnetic field strength-based and electromagnetic wave-based methods are currently under investigation to resolve the issue of device localization, the former giving promising results. However, none of these methods can provide information regarding the distance that the robot has traveled from a landmark (e.g., pylorus) to the detected lesion.
Another challenge for active capsule endoscopes is to incorporate mechanisms that allow tissue sampling. Several prototypes have been tested ex vivo, but their clinical utility is limited by unprecise targeting, difficulty navigating to the target, and obtaining single sample capacity. Recently, the combination of a magnetically actuated soft-capsule robot that has abilities for advanced functions (e.g., localized drug delivery) with self-folding microgrippers – which have already been used in vivo to obtain biopsy in pig’s bile duct – offers the next sweet dream option for accurate active biopsy capsule operation, albeit with many limitations.
The ultimate challenge for the future endoscopy robot is active drug delivery. The major problem to overcome is limited capsule space, where two principal mechanisms should be incorporated – an anchoring system to guide capsule positioning and a drug-release mechanism to control the dose and the frequency of the released drug by remote actuation. Researchers have suggested mechanical systems using micro motors embedded in the capsule and a specific legged mechanism to attach the wall of the gastrointestinal tract. Magnetically actuated mechanisms have been tested to control the active drug release; however, a lot of work has to be done yet. 9 Part of this work has been incorporated in two European projects – the nano-based capsule endoscopy with molecular imaging and optical biopsy and the versatile endoscopic capsule for gastrointestinal tumor recognition and therapy design intending to create new capsules with therapeutic and diagnostic capabilities.
Regarding higher image resolution, the closest to expectations prototype is a low-energy ASCI model that supports light- and auto-fluorescence imaging at 24 frames/sec, 400×400 (almost double the existing) image resolution, and an efficient image-compressing module. The device has successfully been tested in pigs; however, attenuation of the signal transmitted through biological tissues has still to be addressed.
Is the ideal future micro-robot still far away and how long is far? During the last 5 years, major technological achievements have been accomplished in the field of endoscopic micro-robots, promising that the future of endoscopy is wireless, indeed!