Capsule Device Research Articles

Achieving Ultrasound-Excited Emission with Organic Mechanoluminescent Materials.

Unlike traditional photoluminescence (PL), mechanoluminescence (ML) achieved under mechanical excitation demonstrates unique characteristics such as high penetrability, spatial resolution, and signal-to-background ratio (SBR) for bioimaging applications. However, bioimaging with organic mechanoluminescent materials remains challenging because of the shallow penetration depth of ML with short emission wavelengths and the absence of a suitable mechanical force to generate ML in vivo. To resolve these issues, the present paper reports the achievement of ultrasound (US)-excited fluorescence and phosphorescence from purely organic luminogens for the first time with emission wavelengths extending to the red/NIR region, with the penetrability of the US-excited emission being considerably higher than that of PL. Consequently, US-excited subcutaneous phosphorescence imaging can be achieved using a mechanoluminescent-luminogen-based capsule device with a quantified intensity of 9.15 ± 1.32 × 104 p s-1 cm-2 sr-1 and an SBR of 24. Moreover, the US-excited emission can be adequately tuned using the packing modes of the conjugated skeletons, dipole orientation of mechanoluminescent luminogens, and strength and direction of intermolecular interactions. Overall, this study innovatively expands the kind of excitation sources and the emission wavelengths of organic mechanoluminescent materials, paving the way for practical biological applications based on US-excited emission.

The environmental impact of small-bowel capsule endoscopy.

The environmental impact of endoscopy, including small-bowel capsule endoscopy (SBCE), is a topic of growing attention and concern. This study aimed to evaluate the greenhouse gas (GHG) emissions (kgCO2) generated by an SBCE procedure. Life cycle assessment methodology (ISO 14040) was used to evaluate three brands of SBCE device and included emissions generated by patient travel, bowel preparation, capsule examination, and video recording. A survey of 87 physicians and 120 patients was conducted to obtain data on travel, activities undertaken during the procedure, and awareness of environmental impacts. The capsule itself (4 g) accounted for < 6 % of the total product weight. Packaging (43-119 g) accounted for 9 %-97 % of total weight, and included deactivation magnets (5 g [4 %-6 %]) and paper instructions (11-50 g [up to 40 %]). A full SBCE procedure generated approximately 20 kgCO2, with 0.04 kgCO2 (0.2 %) attributable to the capsule itself and 18 kgCO2 (94.7 %) generated by patient travel. Capsule retrieval using a dedicated device would add 0.98 kgCO2 to the carbon footprint. Capsule deconstruction revealed materials (e. g. neodymium) that are prohibited from environmental disposal; 76 % of patients were not aware of the illegal nature of capsule disposal via wastewater, and 63 % would have been willing to retrieve it. The carbon impact of data storage and capsule reading was negligible. The carbon footprint of SBCE is mainly determined by patient travel. The capsule device itself has a relatively low carbon footprint. Given that disposal of capsule components via wastewater is illegal, retrieval of the capsule is necessary but would likely be associated with an increase in device-related emissions.

Recent Advances in Omeprazole Drug Delivery Systems and Advantages of Magnetic Formulation - A Review

This review presents about the new diverse drug delivery technologies of omeprazole and also to explore it advantages by formulating omeprazole into magnetic tablets. The first marketed proton pump inhibitor was the omeprazole which irreversibly alter the H+/K+ ATPase activity therefore inhibiting the secretion of gastric acid. The gastric parietal cells are responsible for the gastric acid secretion. It is an agent used to prevent infections like stomach ulcers caused by Helicobacter pylori and also diseases such as Zollinger-Ellison syndrome, Acid Related Dyspepsia. Nowadays, there are many researchers who have been working to enhance the dissolution, bioavailability of drug, therapeutic efficacy and patient compliance of the various formulations of the proton pump inhibitors. The development of various formulations up to date can be favourable for the drugs to reach their target site and results in effective drug action on its receptor. Even though reaching their target site, it couldn’t differentiate the normal cells and infected cells on the target site. Hence if we give it as a magnetic formulation, it can be controlled by external magnetic field to reach their target site without being acted upon the other sites. Keywords: Omeprazole; Chemistry; Nanoparticle; Microparticle; In situ gel; Capsule device; Targeted delivery; Magnetic system Running title: Recent advances in omeprazole drug delivery systems.

Influence of the CleaRing intraocular open capsule device on refractive predictability in cataract surgery.

The marked improvement in cataract surgery and intraocular lens (IOL) quality has led to a decline in posterior capsular opacification (PCO) incidence; however, PCO remains a common complication of cataract surgery. The CleaRing intraocular capsule open device (IOCD) decreases PCO incidence. We aimed to investigate the influence of the CleaRing IOCD on refractive predictability in cataract surgery. We conducted this prospective pilot study at the Wolfson Medical Center, Holon, Israel. Ten eyes of patients who underwent cataract surgery and insertion of an IOL after IOCD implantation into the capsular bag were included. All patients completed 12 months of follow-up, including refraction, measurement of uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), slit-lamp biomicroscopy, and ultrasound biomicroscopy. All the surgeries were uneventful, with no postoperative complications. The IOL was centred in the device and bag in all cases. The mean prediction error at 1 and 12 months postoperatively was +0.28 ± 0.32 D and +0.50 ± 0.32 D, respectively. The mean UDVA was 0.17 ± 0.13 and 0.15 ± 0.11 logMAR, and the mean CDVA was 0.04 ± 0.10 and 0.04 ± 0.06 logMAR, respectively. The manifest refractive cylinders at 12 months postoperatively were compatible with corneal astigmatism. Implantation of the IOCD resulted in a slight, predicted, and stable hyperopic shift with a low standard deviation. The standard deviation of the prediction error demonstrated excellent refractive accuracy and predictability using the IOCD, which was as low as 0.32 D at the 12-month follow-up.

Release of ranibizumab using a porous poly(dimethylsiloxane) capsule suppressed laser-induced choroidal neovascularization via the transscleral route

The administration of anti-vascular endothelial growth factor drugs in the posterior eye segment with sustained release through less invasive methods is a challenge in the treatment of age-related macular disease. We developed a flexible capsule device using porous poly(dimethylsiloxane) (PDMS) that was able to release ranibizumab. The porous PDMS sheet was fabricated by salt-leaching of a micro-sectioned PDMS sheet containing salt microparticles. Observation with scanning electron microscopy revealed that the pore densities could be adjusted by the concentration of salt. The in vitro release study showed that the release rate of fluorescein isothiocyanate-tagged albumin could be adjusted based on the pore density of the porous PDMS sheet. Ranibizumab could be released in a sustained-release manner for 16 weeks. The device was implanted on the sclera; its efficacy in terms of the suppression of laser-induced choroidal neovascularization (CNV) in rats was compared with that of monthly intravitreal injections of ranibizumab. At 8 and 18 weeks after implantation, the CNV area was significantly reduced in rats that received the ranibizumab-releasing device compared with those that received the placebo device. However, although monthly intravitreal injections of ranibizumab reduced CNV for 8 weeks, this reduction was not sustained for 18 weeks. In conclusion, we demonstrated a novel controlled-release device using a porous PDMS sheet that could suppress CNV via a less invasive transscleral route versus intravitreal injections. This device may also reduce the occurrence of side effects associated with frequent intravitreal injections.Graphical

A compact and wideband MIMO antenna for high-data-rate biomedical ingestible capsules

Due to recent advancements in complementary metal-oxide-semiconductor (CMOS) cameras, transferring high resolution images and videos are possible in wireless capsule endoscopy. High-data-rates communication is required for such data, which is possible using multiple-input-multiple-output (MIMO) antennas. In this paper, a low-sized, compact, high-data-rate, highly isolated two-element MIMO antenna with a large bandwidth has been proposed at 2.45 GHz for wireless capsule endoscopy. The geometry of the antenna (5times 4.2 times 0.12,hbox {mm}^{3}) is kept small using meandered geometry, defected ground structure, and high permittivity of the substrate. A wider bandwidth of 620 MHz (2.15–2.77 GHz) is achieved by exciting dual-modes of the antenna using defected ground structure. Furthermore, a lower mutual coupling between the antennas (30.1 dB at 2.45 GHz) is realized, despite the small edge-to-edge gap of 0.5 mm, using combination of defected ground structure and I-shaped stub. Keeping in mind of system level configuration, this antenna is simulated and measured inside a capsule device by considering effects of the other components and the device itself. The practical measurements are performed by inserting the capsule device (containing the MIMO antenna) inside minced meat. To check the safety and effectiveness of the proposed MIMO antenna, it’s specific absorption rate (SAR) and link budget are calculated and validated. In addition, the 2times 2 channel specifications are verified which shows satisfactory performance. This antenna has high channel capacity (approx 8.2 ,hbox {bps/Hz} at hbox {SNR} = 20 ,hbox {dB}) than single-input-single-output (SISO) antennas, thus, is a suitable choice for high-data-rate capsule endoscopic devices. To the best of the authors’ knowledge, this is the first implantable MIMO antenna reported so far with such lower dimension and wider bandwidth.

Designing an “all-in-one” microextraction capsule device for the liquid chromatographic-fluorescence determination of doxorubicin and its metabolites in rat plasma

In this study, an “all-in-one” microextraction device was designed and fabricated for the extraction of doxorubicin and its two metabolites from rat plasma prior to their determination by high performance liquid chromatography coupled to fluorescence detector. A sol-gel-based sorbent was synthesized in situ and incorporated within two conjoined porous polypropylene tubes together with a cylindrical magnetic bar in order to avoid the need of an external stirring bar. Among other sorbents investigated, the moderately polar sol-gel poly(tetrahydrofuran) was found to be advantageous due to its high affinity toward the target analytes. Systematic investigation of the critical parameters affecting the adsorption and the desorption step was carried out. Due to the “built-in” filtration mechanism of the porous microextraction capsules, the isolation of the analytes was performed directly in the plasma matrix without any previous sample pretreatment (i.e., protein precipitation, centrifugation, etc.). The proposed method was validated in terms of linearity, accuracy, precision, specificity, sensitivity, and stability according to the FDA guidelines. The limits of detection ranged between 1 – 2 ng mL−1 while the lower limits of quantitation of the analytes were calculated as 10 ng mL−1. The accuracy (% relative error) was found within -9.7 – 15.3% under both intra- and inter-day conditions. The precision was better than 13.4% in all cases. ComplexGAPI index was employed to present the green attributes of the developed protocol from the preparation of the microextraction device to the final determination of the analytes. Finally, the applicability of the fabricated stand-alone extraction device was demonstrated in the analysis of the target analytes in rat plasma after intravenous administration of doxorubicin in order to assess its pharmacokinetic profile.

Wireless power transfer system for deep-implanted biomedical devices

In this paper, a dual-band implantable rectenna is proposed for recharging and operating biomedical implantable devices at 0.915 and 2.45 GHz. The rectenna system consists of a compact dual-band antenna based on a meandered-resonator as well as efficient dual-band rectifier circuit. Both components (antenna and rectifier) are integrated inside a capsule device to simulate and experimentally validate the rectenna. The antenna occupies lower volume (5 times 5.25 times 0.25 hbox {mm}^{3}), where compactness is achieved using meandered geometry and a slotted ground plane. It maintains quasi-omnidirectional radiation patterns and peak realized gains of −22.1 dBi (915 MHz) and −19.6 dBi (2.45 GHz); thus, its capability is enhanced to harvest the ambient energy from multiple directions. Moreover, a dual-band rectifier is designed using a dual-branch matching network (an L-matching network and open-circuited stub in each branch) with a radio frequency (RF) to direct current (DC) conversion efficiency of 79.9% for the input power of 1 dBm (lower band: 0.915 GHz) and 72.8% for the input power of 3 dBm (upper band: 2.45 GHz). To validate the concept of the rectenna, the implantable antenna and rectifier are fabricated and attached together inside a capsule device, with the measured results verifying the simulated responses. The proposed rectenna efficiently rectifies two RF signals and effectively superimposes on a single load, thus, providing a distinct advantage compared to single-band rectennas. To the best of the authors’ knowledge, this is the first-ever implantable rectenna to perform dual-band RF signal rectification.

A High Data Rate Implantable MIMO Antenna for Deep Implanted Biomedical Devices

In this article, a compact multiple-input multiple-output (MIMO) implantable antenna based on meandered resonators is proposed for use in medical implantable devices. Such devices require compactness and high data rates. Regarding compactness, the antenna has a size of <inline-formula> <tex-math notation="LaTeX">$5.35\times 6.2 \times 0.12$ </tex-math></inline-formula> mm³ (operating frequency of 2.45 GHz) which is one of the smallest sizes reported in the literature for this class of antennas. This compactness is achieved using the meandered resonators and slots in the ground plane. For high data rates, the proposed antenna is of MIMO configuration and consists of two probe-fed elements that share the same ground plane and are placed at a distance (edge-to-edge) of 0.4 mm from each other. This configuration reduces multipath distortion and achieves seamless communications with high data rates as evident from conducted link budget analysis and MIMO channel studies. The <i>ex vivo</i> measurements (S-parameters, gain, and radiation patterns) are performed on the proposed antenna when placed inside a capsule and implanted in minced meat. A bandwidth of 320 MHz and isolation of 28 dB are achieved at the design frequency along with omni-directional radiation patterns with a peak realized gain of &#x2212;20.5 dBi. Specific absorption rate (SAR) analysis and input power studies are performed to ensure patient&#x2019;s safety. The result shows that the antenna has a safe 10 g SAR of 402.8 W/kg at an input power of 1 W. Also, the capsule device can be operated at a safe power level of 3.97 mW, which is far greater than the maximum allowable power limit (<inline-formula> <tex-math notation="LaTeX">$25~\mu \text{W}$ </tex-math></inline-formula>).

Novel 3D capsule device to restrict kidney volume expansion on polycystic kidney progression: feasibility study in a rat model.

Cystogenesis in polycystic kidney disease (PKD) is likely accelerated by various renal insults, including crystal deposition, that activate renal tubule obstruction and dilation. We developed a capsule-based device that can be applied to cystic kidneys to restrict tubular lumen dilatation and cyst expansion. Kidney capsule devices were designed from computed tomography images of wild-type and Cy/+ rats. Capsule devices were surgically implanted on kidneys in six surgical sessions over a period of 14months in 7 wild-type rats of 6.5-8weeks (3 sham operations, 2 right, 2 left) and 6 Cy/+ rats of 6.5weeks (2 sham, 3 left, 1 bilateral). After surgery, the rats were followed for 5.4-12.4weeks' growth and sacrificed to retrieve the kidneys. During the follow-up, serum creatinine was measured and retrieved kidneys were weighed. Histological analysis including cystic area measurement and immunohistochemistry was performed. Morphometric capsule devices were configured and developed by an image processing technique and produced using a 3D printer. Encapsulated Cy/+ kidneys (n = 5; mean weight 3.64g) were consistently smaller in size (by 21-36%; p < 0.001) than unencapsulated Cy/+ kidneys (n = 7; mean weight 5.52g). Encapsulated Cy/+ kidneys (mean %cyst area: 29.4%) showed smaller histological cystic area (by 28-58%; p < 0.001) than unencapsulated Cy/+ kidneys (mean %cyst area 48.6%). Cell proliferation and macrophages were also markedly reduced in encapsulated Cy/+ kidneys, compared to unencapsulated Cy/+ kidneys. We report a pilot feasibility study for the application of a novel morphometric 3D capsule device to the Cy/+ rat model showing restricted kidney volume expansion on polycystic kidney disease progression.

Ultrasound mediated delivery of quantum dots from a proof of concept capsule endoscope to the gastrointestinal wall

Biologic drugs, defined as therapeutic agents produced from or containing components of a living organism, are of growing importance to the pharmaceutical industry. Though oral delivery of medicine is convenient, biologics require invasive injections because of their poor bioavailability via oral routes. Delivery of biologics to the small intestine using electronic delivery with devices that are similar to capsule endoscopes is a promising means of overcoming this limitation and does not require reformulation of the therapeutic agent. The efficacy of such capsule devices for drug delivery could be further improved by increasing the permeability of the intestinal tract lining with an integrated ultrasound transducer to increase uptake. This paper describes a novel proof of concept capsule device capable of electronic application of focused ultrasound and delivery of therapeutic agents. Fluorescent markers, which were chosen as a model drug, were used to demonstrate in vivo delivery in the porcine small intestine with this capsule. We show that the fluorescent markers can penetrate the mucus layer of the small intestine at low acoustic powers when combining microbubbles with focused ultrasound during in vivo experiments using porcine models. This study illustrates how such a device could be potentially used for gastrointestinal drug delivery and the challenges to be overcome before focused ultrasound and microbubbles could be used with this device for the oral delivery of biologic therapeutics.

Results of using the AssiAnchor capsule device for subluxated crystalline lenses.

Purpose:To describe our results with the AssiAnchor capsule device in cases of subluxated crystalline lenses.Methods:This was a retrospective consecutive case series. Seven eyes of four patients with subluxated crystalline lenses underwent lensectomy/phacoemulsification with intraocular lens (IOL) implantation using the AssiAnchor capsule device in the Kaplan medical center, ophthalmology department. Three patients had Marfan syndrome and one patient had experienced blunt trauma. Demographic data were collected as well as parameters of pre- and postoperative distance visual acuity and refraction, intra-, and postoperative complications, and IOL stability and centration.Results:Six out of the seven surgical procedures were uneventful with in-the-bag implantation of the IOL. In the first surgery, a tear of the capsular bag lead to IOL exchanging and fixating to the AssiAnchor and to the iris. In the traumatic cataract case, two AssiAnchors were used. A capsular tension ring was implanted in six out of seven surgeries. The average follow-up time was 9.5 ± 6.8 months. All the IOLs were stable and well centered except for the first IOL that exhibited a slight temporal, but not clinically significant, decentration. The distance visual acuity and the refractive parameters improved significantly in all cases.Conclusion:We found the AssiAnchor capsule device an effective tool with a short learning curve for treating subluxated lenses.

Miniaturized Dual-Band Circularly Polarized Implantable Antenna for Capsule Endoscopic System

This study proposes a miniaturized dual-band antenna with a circular-polarization characteristic for a wireless-capsule endoscopic system operating in the industrial, scientific, and medical bands: 915 and 2450 MHz. The proposed capsule device is intended for deep-tissue implantation with the standard dimensions of 26×11 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The key features of the proposed antenna are its CP characteristic at both bands, satisfactory gain values, and a smallest volume ( 6.5×6.5×0.05=2.11 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) with a via-less ground plane compared with the state-of-the-art device. The CP wave performance and the miniaturization of the antenna are achieved via the introduction of slots accompanied by meandered line segments in a radiating patch and open-end slots in a ground plane. Furthermore, the proposed antenna offers a reasonable axial ratio (AR) of <; 3 dB at the desired frequency bands. The circularly polarized radiator attains the AR bandwidths (BWs) of 33.0% and 8.67% and the measured -10 dB impedance BWs of 13.63% and 6.28% at 915 and 2450 MHz, respectively. The measurements of the reflection coefficient and radiation pattern are performed using a fabricated prototype of the proposed antenna system in a saline solution and minced pork. Finally, the safety considerations and link budget calculations are evaluated to analyze the performance of the proposed capsule device. Due to the AR BW, impedance BW, and ease of fabrication, the proposed antenna system is a suitable candidate for use in endoscopic applications.

Long-Term Effect of Novel Morphometric 3D Capsule Device to Constrain Growth in Polycystic Kidney: Comparison Between Wild-Type, Cy/+, and PCK Rat Models

Long-Term Effect of Novel Morphometric 3D Capsule Device to Constrain Growth in Polycystic Kidney: Comparison Between Wild-Type, Cy/+, and PCK Rat Models

Robustness to misalignment of low-cost, compact quantitative phase imaging architectures.

Non-interferometric approaches to quantitative phase imaging could enable its application in low-cost, miniaturised settings such as capsule endoscopy. We present two possible architectures and both analyse and mitigate the effect of sensor misalignment on phase imaging performance. This is a crucial step towards determining the feasibility of implementing phase imaging in a capsule device. First, we investigate a design based on a folded 4f correlator, both in simulation and experimentally. We demonstrate a novel technique for identifying and compensating for axial misalignment and explore the limits of the approach. Next, we explore the implications of axial and transverse misalignment, and of manufacturing variations on the performance of a phase plate-based architecture, identifying a clear trade-off between phase plate resolution and algorithm convergence time. We conclude that while the phase plate architecture is more robust to misalignment, both architectures merit further development with the goal of realising a low-cost, compact system for applying phase imaging in capsule endoscopy.

Asymptomatic Tracheal Aspiration of Capsule Endoscopy in a Patient Without Dysphagia.

CASE REPORT An 84-year-old man with a significant history of hypertension, coronary artery disease, congestive heart failure, and osteoarthritis was referred for an evaluation of iron deficiency anemia. Previous upper endoscopy and colonoscopy were unrevealing. The patient had no history of dysphagia and reported no swallowing problems. The decision was made to perform small bowel wireless capsule endoscopy. The patient swallowed the capsule device without any complaints. As per standard protocol, the live viewer was checked before patient discharge. Aspiration of capsule endoscopy on the live viewer was suspected after physician evaluation (Figure 1). This image remained unchanged despite asking the patient to cough. Nine minutes later, the patient was asked to cough, and with a firm hand thrust maneuver to his midback, the capsule was expulsed. The patient remained asymptomatic. The recorded capsule images were reviewed, which demonstrated images of the capsule entering the trachea and settling at the level of the carina before expulsion (Video 1, watch the video at https://links.lww.com/ACGCR/A15).Figure 1.: Capsule endoscopy showing the (A) epiglottis, (B) respiratory tract, (C) tracheal rings anteriorly and trachealis muscle posteriorly, and (D) carina and both the main bronchus.Capsule endoscopy is a relatively safe procedure used to study obscure gastrointestinal bleeding when upper and lower endoscopies are unrevealing. However, this study is contraindicated in patients with strictures, bowel obstruction, difficulty swallowing, pacemakers, and pregnancy. It is important to screen patients for difficulty with swallowing before the wireless capsule study. To avoid capsule retention, the alternative would be direct postpyloric placement of the wireless capsule using a capsule deployment device. Swallowing dysfunction could potentially lead to aspiration of the wireless capsule device although this is a relatively rare complication. There have been previously reported cases in the literature of tracheal aspiration of wireless capsule endoscopy devices, but most of them were overtly symptomatic.1–5 Our case highlights the importance of a rare complication that can occur in patients without dysphagia and can be completely asymptomatic after capsule tracheal aspiration. Some case reports conclude or suggest that capsule endoscopy should be introduced by a delivery system in elderly patients. The reason being that these groups are at relatively higher risk of neurological diseases that could potentially impair the swallowing process.6 It is interesting that most of the reported cases were patients older than 60 years, and it is rather alarming that it can be associated with changes in the swallowing mechanisms of otherwise healthy aging adults. This is known as presbyphagia.7 In turn, the subtle changes associated with presbyphagia can lead to intermittent impaired deglutition. Especially in elderly patients, one must recognize that impaired deglutition remains a hidden threat that can lead to a complication while swallowing the capsule device. Our patient was referred to speech and swallow for further evaluation of deglutition. Therefore, it is strongly recommended that all staff involved in this procedure should be alerted to the potential risk of capsule tracheal aspiration. Major complications could occur as a consequence of capsule aspiration requiring emergent intubation and removal of the foreign body by bronchoscopy. Furthermore, prompt recognition and proper management of this complication are warranted before the patient is discharged. We proposed an algorithm approach to follow in the event of aspiration of a capsule device as an attempt to minimize complications of this uncommon event (Figure 2).1–6Figure 2.: An algorithm approach to follow in the event of aspiration of capsule endoscopy.DISCLOSURES Author contributions: FM Arroyo-Mercado wrote the manuscript and is the article guarantor. M. Martinez revised the manuscript. Financial disclosure: None to report. Informed consent was obtained for this case report.

Radio Frequency Backscatter Communication for High Data Rate Deep Implants

In this paper, we study the radio frequency (RF) backscatter for high data rate wireless communication with deep medical implants. The radar approach permits remote reading of the implant’s information. This means that the active transmitter is removed from the implant that results in significant power saving. We customize our design for wireless capsule endoscopy (WCE) application, which is used for streaming high data rate video signals for improved visualization of the gastrointestinal tract. An efficient antenna system is designed and integrated into the WCE prototype that generates large radar cross section (RCS) using a self-resonant antenna geometry. The antenna is reconfigurable using an active microwatt switch, which is controlled by the data stream. The switch alters the antenna RCS for an efficient modulation of the incident electromagnetic (EM) wave transmitted from outside the body. The antenna design considers the specific conditions of wave propagation in the biological environments and antenna loading with the lossy tissues. Polarization diversity using bistatic on-body reader antennas is used for communicating with the implant device. The on-body antennas can direct EM energy to the capsule device for improving the backscatter link performance. The feasibility study is demonstrated using numerical computations and experimentally validated in a liquid phantom and in-vivo animal experiments. A reliable backscatter data connectivity of 1 and 5 Mb/s is measured for the capsule in the gastrointestinal tract for the depths up to 10 cm using an acceptable level of RF radiations.

Formulation and Evaluation of Pulsatile Drug Delivery of Lovastatin

In the present study, an attempt was made to develop the pulsatile drug delivery of Lovastatin to reduce plasma cholesterol levels and to prevent cardiovascular diseases. Formaldehyde treated Capsule bodies were used for the preparation of pulsincaps. It was sealed with unhardened cap of the capsule. The microspheres were prepared by emulsion solvent evaporation technique. Hydrogel plug (karaya gum and lactose in 1:1 ratio) having 4.5kg/cm2 hardness and 100 mg weight was placed in the capsule opening and found that it was satisfactory to retard the drug release in small intestinal fluid and to eject out the plug in colonic fluid and releasing the microspheres into colonic fluid after a lag time criterion of 5 hours. The sealed capsules were completely coated by dip coating method with 5% cellulose acetate phthalate to prevent variable gastric emptying. Optimized microsphere formulations were selected based on dissolution studies. Dissolution studies of pulsatile capsule device in media with different pH (1.2, 7.4 and6.8) showed that drug release in colon could be modulated by optimizing the concentration of polymers in the microspheres. Drug–polymer interaction studies indicated no interaction in between the drug and the polymer. Among all the formulations Lovastatin microspheres prepared with Ethyl cellulose, in 1:3 ratio shown prolonged release for a period of 11 hours. The obtained results showed the capability of the system in delaying drug release for a programmable period of time and to deliver the drug in the early morning hours when cholesterol synthesis are more prevalent.

WITHDRAWN: The Role of capsule endoscopy and device assisted enteroscopy for small bowel lesions in hereditary hemorrhagic telangiectasia.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

A Magnetic Soft Endoscopic Capsule-Inflated Intragastric Balloon for Weight Management.

Overweight and obesity have been identified as a cause of high risk diseases like diabetes and cancer. Although conventional Intragastric Balloons (IGBs) have become an efficient and less invasive method for overweight and obesity treatment, the use of conventional tools such as catheter or endoscope to insert and remove the IGBs from the patient’s body causes nausea, vomiting, discomfort, and even gastric mucous damage. To eliminate these drawbacks, we develop a novel magnetic soft capsule device with gas-filled balloon inflation. The balloon is made from a thin and biocompatible material that can be inflated to a desired volume using biocompatible effervescent chemicals. In addition, both the outer balloon and inner capsule are designed to be soft and chemical resistance. The soft capsule shell is fabricated using scaffold-solvent approach while the outer balloon utilizes a novel fabrication approach for 3D spherical structure. A prototype of the proposed capsule and balloon is given. Experiments are successfully carried out in stimulated gastric environment and fresh porcine stomach to validate the effectiveness and reliability of the proposed approach.