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Cao Q, Deng R, Pan Y, Liu R, Chen Y, Gong G, Zou J, Yang H, Han D. Robotic wireless capsule endoscopy: recent advances and upcoming technologies. Nat Commun 2024; 15:4597. [PMID: 38816464 PMCID: PMC11139981 DOI: 10.1038/s41467-024-49019-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 05/21/2024] [Indexed: 06/01/2024] Open
Abstract
Wireless capsule endoscopy (WCE) offers a non-invasive evaluation of the digestive system, eliminating the need for sedation and the risks associated with conventional endoscopic procedures. Its significance lies in diagnosing gastrointestinal tissue irregularities, especially in the small intestine. However, existing commercial WCE devices face limitations, such as the absence of autonomous lesion detection and treatment capabilities. Recent advancements in micro-electromechanical fabrication and computational methods have led to extensive research in sophisticated technology integration into commercial capsule endoscopes, intending to supersede wired endoscopes. This Review discusses the future requirements for intelligent capsule robots, providing a comparative evaluation of various methods' merits and disadvantages, and highlighting recent developments in six technologies relevant to WCE. These include near-field wireless power transmission, magnetic field active drive, ultra-wideband/intrabody communication, hybrid localization, AI-based autonomous lesion detection, and magnetic-controlled diagnosis and treatment. Moreover, we explore the feasibility for future "capsule surgeons".
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Affiliation(s)
- Qing Cao
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Runyi Deng
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yue Pan
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Ruijie Liu
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yicheng Chen
- Sir Run-Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, 310016, China
| | - Guofang Gong
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jun Zou
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Huayong Yang
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Dong Han
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China.
- School of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, China.
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Mohamed MA, Abd El-Rahman MK, Mousavi MPS. Electrospun nanofibers: promising nanomaterials for biomedical applications. ELECTROCHEMISTRY 2023:225-260. [DOI: 10.1039/bk9781839169366-00225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023] Open
Abstract
With the rapid development of nanotechnology and nanomaterials science, electrospun nanofibers emerged as a new material with great potential for a variety of applications. Electrospinning is a simple and adaptable process for generation of nanofibers from a viscoelastic fluid using electrostatic repulsion between surface charges. Electrospinning has been used to manufacture nanofibers with low diameters from a wide range of materials. Electrospinning may also be used to construct nanofibers with a variety of secondary structures, including those having a porous, hollow, or core–sheath structure. Due to many attributes including their large specific surface area and high porosity, electrospun nanofibers are suitable for biosensing and environmental monitoring. This book chapter discusses the different methods of nanofiber preparations and the challenges involved, recent research progress in electrospun nanofibers, and the ways to commercialize these nanofiber materials.
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Affiliation(s)
- Mona A. Mohamed
- Pharmaceutical Chemistry Department, Egyptian Drug Authority Giza Egypt
- Biomedical Engineering University of Southern California Los Angeles USA
| | - Mohamed K. Abd El-Rahman
- Analytical Chemistry Department, Faculty of Pharmacy Cairo University, Kasr-El Aini Street Cairo 11562 Egypt
| | - Maral P. S. Mousavi
- Analytical Chemistry Department, Faculty of Pharmacy Cairo University, Kasr-El Aini Street Cairo 11562 Egypt
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Chen Y, Liu Y, Li Y, Wang G, Chen M. An Energy-Efficient ASK Demodulator Robust to Power-Carrier-Interference for Inductive Power and Data Telemetry. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2022; 16:108-118. [PMID: 35104224 DOI: 10.1109/tbcas.2022.3146559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Wireless power and datatelemetry based on amplitude-shift keying (ASK) modulation over dual inductive links has been widely adopted in biomedical implants. Due to the mutual inductance between the power and data links, the large power-carrier-interference (PCI) will inevitably cause low signal-to-interference ratio (SIR) of the received signal, thereby increasing the bit-error-rate (BER) of the ASK demodulation. In this paper, an innovative high energy-efficient ASK demodulator robust to PCI has been proposed. Thanks to the proposed sampling-and-subtraction (SAS) architecture, the demodulator is capable of withstanding PCI with an amplitude up to 2.5 times as the data carrier without the need for any high-order filters. The prototype has been implemented with 180 nm standard CMOS process, occupying a core area of 0.51 mm 2. The experimental results show that with 1 Mbps data rate and 13.56 MHz carrier frequency, the typical BER is less than 1.3×10 -3, while the energy efficiency is 280 pJ/bit, showing 7.5× improvement compared to the prior works. The energy-efficient robustness to PCI demonstrates the potential of the technique to be applied to retina prostheses as well as various kinds of ultra-low-power implantable biomedical devices.
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A low noise cascaded amplifier for the ultra-wide band receiver in the biosensor. Sci Rep 2021; 11:22592. [PMID: 34799638 PMCID: PMC8605013 DOI: 10.1038/s41598-021-02122-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/10/2021] [Indexed: 11/21/2022] Open
Abstract
This paper presents the design of an Ultra-Wide Band (UWB) Low Noise cascaded Amplifier (LNA) used for biomedical applications. The designed structure uses a technique which is based on the inductances minimization to reduce the LNA surface while maintaining low power consumption, low noise and high stability, linearity and gain. To prove its robustness, this technique was studied theoretically, optimized and validated through simulation using the CMOS 0.18 µm process. The LNA achieves a maximum band voltage gain of about 17.5 dB at [1-5] GHz frequency band, a minimum noise figure of 2 dB, IIP3 of + 1dBm and consumes only 13mW under a 2 V power supply. It is distinguished by its prominent figure of merit of 0.68.
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Wearable Textile Antenna with a Graphene Sheet or Conductive Fabric Patch for the 2.45 GHz Band. ELECTRONICS 2021. [DOI: 10.3390/electronics10212571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Textile patch antennas of simple rectangular, triangular, and circular shape, for operation in the 2.4–2.5 GHz free industrial, scientific, and medical (ISM) band, are designed in this paper. Thirty-six patch antenna prototypes have been fabricated by engaging different patch geometries, patch materials, and substrate materials. Each patch antenna is designed after optimization by a genetic algorithm, which evolves the initial dimensions and feeding position of the prototype’s microstrip counterpart to the final optimal geometrical characteristics of the wearable prototype (with the originally selected shape and materials). The impact of the design and fabrication details on antenna performance were thoroughly investigated. Graphene sheet patches were tested against conductive fabric and copper sheet ones, while denim and felt textile substrates were competing. The comparative study between a large number of different graphene, all, and copper textile prototypes, which revealed the excellent suitability of graphene for wearable applications, is the main contribution of this paper. Additional novelty elements are the compact, flexible, and easy-to-fabricate structure of the proposed antennas, as well as the use of state-of-the-art conductive materials and commercially available fabrics and the extensive investigation of many prototypes in various bending conditions. Simulations and measurements of the proposed antennas are in very good agreement. All fabricated prototypes are characterized by flexibility, light weight, mechanical stability, resistance to shock, bending and vibrations, unhindered integration to clothes, low-cost implementation, simple, time-saving, and industry-compatible fabrication process, and low specific absorption rate (SAR) values (computed using rectangular and voxel models); the graphene prototypes are additionally resistant to corrosion, and the circular ones have very good performance under bending conditions. Many antenna prototypes demonstrate interesting characteristics, such as relatively wide bandwidth, adequate gain, firm radiation patterns, coverage of the ISM band even under bending, and very low SAR values. For example, the circular graphene patch (with 55.3 mm diameter attached upon a 165.9 × 165.9 mm) felt substrate CGsF1 prototype accomplishes 109 MHz measured bandwidth, 5.45 dBi gain, 56% efficiency, full coverage of the ISM band under bending, and SAR less than 0.003 W/Kg.
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Sun L, Cheng C, Wang S, Tang J, Xie R, Wang D. Bioinspired, Nanostructure-Amplified, Subcutaneous Light Harvesting to Power Implantable Biomedical Electronics. ACS NANO 2021; 15:12475-12482. [PMID: 34355573 DOI: 10.1021/acsnano.1c03614] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Implantable biomedical electronics hold immense promise for in vivo personalized healthy monitoring and even precise therapeutic intervention. Tremendous miniaturization of indwelling modules enables implanted biomedical devices to perform multiple functions with ultralow power consumption but exacerbates the technical challenges of supplying effective power to the devices in vivo. In this Perspective, we summarize new developments in transmitting near-infrared light from sunlight or a light-emitting diode into subcutaneously implanted photovoltaic cells, in which the light utilization efficiency can be amplified with the aid of nanostructured rear reflectors. Considering the many natural examples of nanostructure-induced structural coloration displayed by submarine animals, we wish to open up new prospects of bioinspired, nanostructure-amplified, subcutaneous light harvesting to power implanted biomedical electronics.
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Affiliation(s)
- Lu Sun
- Department of Polymer Science, College of Chemistry, Jilin University, Changchun 130012, China
| | - Chongling Cheng
- State Key Lab of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
| | - Shun Wang
- College of Chemistry and Materials Engineering, Institute of New Materials and Industrial Technologies, Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou University, Wenzhou 325035, China
| | - Jun Tang
- Department of Polymer Science, College of Chemistry, Jilin University, Changchun 130012, China
| | - Renguo Xie
- State Key Lab of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
| | - Dayang Wang
- State Key Lab of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
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Lyu H, Babakhani A. A 13.56-MHz -25-dBm-Sensitivity Inductive Power Receiver System-on-a-Chip With a Self-Adaptive Successive Approximation Resonance Compensation Front-End for Ultra-Low-Power Medical Implants. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2021; 15:80-90. [PMID: 33373302 PMCID: PMC9215201 DOI: 10.1109/tbcas.2020.3047827] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Battery-less and ultra-low-power implantable medical devices (IMDs) with minimal invasiveness are the latest therapeutic paradigm. This work presents a 13.56-MHz inductive power receiver system-on-a-chip with an input sensitivity of -25.4 dBm (2.88 μW) and an efficiency of 46.4% while driving a light load of 30 μW. In particular, a real-time resonance compensation scheme is proposed to mitigate resonance variations commonly seen in IMDs due to different dielectric environments, loading conditions, and fabrication mismatches, etc. The power-receiving front-end incorporates a 6-bit capacitor bank that is periodically adjusted according to a successive-approximation-resonance-tuning (SART) algorithm. The compensation range is as much as 24 pF and it converges within 12 clock cycles and causes negligible power consumption overhead. The harvested voltage from 1.7 V to 3.3 V is digitized on-chip and transmitted via an ultra-wideband impulse radio (IR-UWB) back-telemetry for closed-loop regulation. The IC is fabricated in 180-nm CMOS process with an overall current dissipation of 750 nA. At a separation distance of 2 cm, the end-to-end power transfer efficiency reaches 16.1% while driving the 30-μW load, which is immune to artificially induced resonance capacitor offsets. The proposed system can be applied to various battery-less IMDs with the potential improvement of the power transfer efficiency on orders of magnitude.
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Kirtania SG, Elger AW, Hasan MR, Wisniewska A, Sekhar K, Karacolak T, Sekhar PK. Flexible Antennas: A Review. MICROMACHINES 2020; 11:E847. [PMID: 32933077 PMCID: PMC7570180 DOI: 10.3390/mi11090847] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/25/2020] [Accepted: 09/04/2020] [Indexed: 11/25/2022]
Abstract
The field of flexible antennas is witnessing an exponential growth due to the demand for wearable devices, Internet of Things (IoT) framework, point of care devices, personalized medicine platform, 5G technology, wireless sensor networks, and communication devices with a smaller form factor to name a few. The choice of non-rigid antennas is application specific and depends on the type of substrate, materials used, processing techniques, antenna performance, and the surrounding environment. There are numerous design innovations, new materials and material properties, intriguing fabrication methods, and niche applications. This review article focuses on the need for flexible antennas, materials, and processes used for fabricating the antennas, various material properties influencing antenna performance, and specific biomedical applications accompanied by the design considerations. After a comprehensive treatment of the above-mentioned topics, the article will focus on inherent challenges and future prospects of flexible antennas. Finally, an insight into the application of flexible antenna on future wireless solutions is discussed.
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Affiliation(s)
- Sharadindu Gopal Kirtania
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, WA 98686, USA; (S.G.K.); (A.W.E.); (M.R.H.); (A.W.); (T.K.)
| | - Alan Wesley Elger
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, WA 98686, USA; (S.G.K.); (A.W.E.); (M.R.H.); (A.W.); (T.K.)
| | - Md. Rabiul Hasan
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, WA 98686, USA; (S.G.K.); (A.W.E.); (M.R.H.); (A.W.); (T.K.)
| | - Anna Wisniewska
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, WA 98686, USA; (S.G.K.); (A.W.E.); (M.R.H.); (A.W.); (T.K.)
| | - Karthik Sekhar
- Department of ECE, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Vadapalani Campus, No.1, Jawaharlal Nehru Road, Vadapalani, Chennai, TN 600026, India;
| | - Tutku Karacolak
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, WA 98686, USA; (S.G.K.); (A.W.E.); (M.R.H.); (A.W.); (T.K.)
| | - Praveen Kumar Sekhar
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, WA 98686, USA; (S.G.K.); (A.W.E.); (M.R.H.); (A.W.); (T.K.)
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Yadav A, Kumar Singh V, Kumar Bhoi A, Marques G, Garcia-Zapirain B, de la Torre Díez I. Wireless Body Area Networks: UWB Wearable Textile Antenna for Telemedicine and Mobile Health Systems. MICROMACHINES 2020; 11:mi11060558. [PMID: 32486291 PMCID: PMC7344568 DOI: 10.3390/mi11060558] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/18/2020] [Accepted: 05/29/2020] [Indexed: 11/21/2022]
Abstract
A compact textile ultra-wideband (UWB) antenna with an electrical dimension of 0.24λo × 0.24λo × 0.009λo with microstrip line feed at lower edge and a frequency of operation of 2.96 GHz is proposed for UWB application. The analytical investigation using circuit theory concepts and the cavity model of the antenna is presented to validate the design. The main contribution of this paper is to propose a wearable antenna with wide impedance bandwidth of 118.68 % (2.96–11.6 GHz) applicable for UWB range of 3.1 to 10.6 GHz. The results present a maximum gain of 5.47 dBi at 7.3 GHz frequency. Moreover, this antenna exhibits Omni and quasi-Omni radiation patterns at various frequencies (4 GHz, 7 GHz and 10 GHz) for short-distance communication. The cutting notch and slot on the patch, and its effect on the antenna impedance to increase performance through current distribution is also presented. The time-domain characteristic of the proposed antenna is also discussed for the analysis of the pulse distortion phenomena. A constant group delay less than 1 ns is obtained over the entire operating impedance bandwidth (2.96–11.6 GHz) of the textile antenna in both situations, i.e., side by side and front to front. Linear phase consideration is also presented for both situations, as well as configurations of reception and transmission. An assessment of the effects of bending and humidity has been demonstrated by placing the antenna on the human body. The specific absorption rate (SAR) value was tested to show the radiation effect on the human body, and it was found that its impact on the human body SAR value is 1.68 W/kg, which indicates the safer limit to avoid radiation effects. Therefore, the proposed method is promising for telemedicine and mobile health systems.
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Affiliation(s)
- Ashok Yadav
- Department of ECE, Krishna Engineering College, Ghaziabad 201007, India;
| | - Vinod Kumar Singh
- Department of Electrical Engineering, S.R. Group of Institutions, Jhansi 284002, U.P., India;
| | - Akash Kumar Bhoi
- Department of Electrical and Electronics Engineering, Sikkim Manipal Institute of Technology, Sikkim Manipal University, Majhitar 737136, Sikkim, India
- Correspondence: (A.K.B.); (B.G.-Z.)
| | - Gonçalo Marques
- Instituto de Telecomunicações, Universidade da Beira Interior, 6201-001 Covilhã, Portugal;
| | - Begonya Garcia-Zapirain
- eVIDA Research Group, University of Deusto. Avda/Universidades 24, 48007 Bilbao, Spain
- Correspondence: (A.K.B.); (B.G.-Z.)
| | - Isabel de la Torre Díez
- Department of Signal Theory and Communications, and Telematics Engineering University of Valladolid, Paseo de Belén 15, 47011 Valladolid, Spain;
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Valencia D, Thies J, Alimohammad A. Frameworks for Efficient Brain-Computer Interfacing. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:1714-1722. [PMID: 31613780 DOI: 10.1109/tbcas.2019.2947130] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
One challenge present in brain-computer interface (BCI) circuits is finding a balance between real-time on-chip processing in-vivo and wireless transmission of neural signals for off-chip in-silico processing. This article presents three potential frameworks for investigating an area- and energy-efficient realization of BCI circuits. The first framework performs spike detection on the filtered neural signal on a brain-implantable chip and only transmits detected spikes wirelessly for offline classification and decoding. The second framework performs in-vivo compression of the on-chip detected spikes prior to wireless transmission for substantially reducing wireless transmission overhead. The third framework performs spike sorting in-vivo on the brain-implantable chip to classify detected spikes on-chip and hence, even further reducing wireless data transmission rate at the expense of more signal processing. To alleviate the on-chip computation of spike sorting and also utilizing a more area- and energy-effective design, this work employs, for the first time, to the best of our knowledge, an artificial neural network (ANN) instead of using relatively computationally-intensive conventional spike sorting algorithms. The ASIC implementation results of the designed frameworks are presented and their feasibility for efficient in-vivo processing of neural signals is discussed. Compared to the previously-published BCI systems, the presented frameworks reduce the area and power consumption of implantable circuits.
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Qian W, Qian C. Wirelessly Powered Signal Regeneration to Improve the Remote Detectability of an Inductive Pressure Sensor. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:1011-1020. [PMID: 31352353 PMCID: PMC6879186 DOI: 10.1109/tbcas.2019.2930651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Chronic pressure monitoring by wireless and batteryless sensors are desirable for maintaining proper function of biomedical implants. Compared to capacitive, piezoelectric, and piezoresistive sensors, inductive sensors are less susceptible to capacitance fluctuation in the environment, and they can convert loading pressure into inductance changes for wireless detection as resonance frequency shifts. However, inductive sensors normally require the use of ferromagnetic materials for frequency tuning; their frequency responses are harder to detect over larger distance separations. Without using ferromagnetic materials, we will utilize two coaxially coupled resonators whose mutual inductance (and thus resonance frequency) is modulated by the thickness of an elastic substrate that can deform under pressure loading. By modifying one of the coupled resonators into a parametric resonator that contains nonlinear capacitors and an extra conductor across its virtual grounds, the sensor can utilize wireless pumping power to enlarge backscattered signals whose peak response frequency is linearly correlated with the loading pressure. This linear relation is observable beyond the near-field region, even though the distance separation between the sensor and the measurement loop is ten-fold the sensor's circuit dimension. This novel concept of wirelessly powered signal regeneration will improve the remote detectability and operation flexibility of various physiological sensors.
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Affiliation(s)
- Wei Qian
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, 48824, USA
| | - Chunqi Qian
- Department of Radiology, Michigan State University, East Lansing, MI, 48824, USA
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Daoud D, Daoud M, Ghorbel M, Hamida AB. Design of Dual Band Wireless Power and Data Through RF Transmission for Biomedical Implants. BIONANOSCIENCE 2018. [DOI: 10.1007/s12668-017-0472-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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13
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Modified Hermite Pulse-Based Wideband Communication for High-Speed Data Transfer in Wireless Sensor Applications. JOURNAL OF LOW POWER ELECTRONICS AND APPLICATIONS 2017. [DOI: 10.3390/jlpea7040030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kumeria T, McInnes SJP, Maher S, Santos A. Porous silicon for drug delivery applications and theranostics: recent advances, critical review and perspectives. Expert Opin Drug Deliv 2017; 14:1407-1422. [DOI: 10.1080/17425247.2017.1317245] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Tushar Kumeria
- School of Chemical Engineering, The University of Adelaide, Adelaide, Australia
| | - Steven J. P. McInnes
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, Mawson Lakes, Australia
| | - Shaheer Maher
- School of Chemical Engineering, The University of Adelaide, Adelaide, Australia
- Faculty of Pharmacy, Assiut University, Assiut, Egypt
| | - Abel Santos
- School of Chemical Engineering, The University of Adelaide, Adelaide, Australia
- Institute for Photonics and Advanced Sensing (IPAS), The University of Adelaide, Adelaide, Australia
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), The University of Adelaide, Adelaide, Australia
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15
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Issa DB, Hajri M, Kachouri A, Samet M, Samet H. Reconfigurable UWB Transceiver for Biomedical Sensor Application. BIONANOSCIENCE 2017. [DOI: 10.1007/s12668-016-0384-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nagaraj S, Rassam FG. Improved Noncoherent UWB Receiver for Implantable Biomedical Devices. IEEE Trans Biomed Eng 2016; 63:2220-5. [PMID: 26841381 DOI: 10.1109/tbme.2015.2511538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
GOAL The purpose of this paper is to describe a novel noncoherent receiver architecture to improve the error performance of impulse-radio ultrawideband (IR-UWB) in bioimplanted devices. IR-UWB receivers based on energy detection are popular in biomedical applications owing to the low implementation cost/complexity and the high data rates that UWB can potentially support. Implanted devices suffer from severe frequency-dependent attenuation due to human blood and tissues, while most receivers in the literature are designed based on commonly used indoor wireless channel models. METHOD We propose a novel receiver design that is based on judiciously combining the energies in different bands of the signal spectrum with a weighted linear combiner. We derive the optimum coefficients of the combiner. RESULTS The receiver retains almost all of the advantages of a conventional noncoherent detector, but can also compensate for attenuation properties of blood/tissue. The receiver design can be adapted to different implantation depths by simply varying the combiner weights. The receiver can also be considered to be a simple form of equalizer for noncoherent reception. Our simulations show about 2-dB improvement over other commonly used receivers. SIGNIFICANCE This receiver design is significant in that it can enhance critical battery life of implanted transmitters.
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Wu T, Xu J, Lian Y, Khalili A, Rastegarnia A, Guan C, Yang Z. A 16-Channel Nonparametric Spike Detection ASIC Based on EC-PC Decomposition. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2016; 10:3-17. [PMID: 25769170 DOI: 10.1109/tbcas.2015.2389266] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In extracellular neural recording experiments, detecting neural spikes is an important step for reliable information decoding. A successful implementation in integrated circuits can achieve substantial data volume reduction, potentially enabling a wireless operation and closed-loop system. In this paper, we report a 16-channel neural spike detection chip based on a customized spike detection method named as exponential component-polynomial component (EC-PC) algorithm. This algorithm features a reliable prediction of spikes by applying a probability threshold. The chip takes raw data as input and outputs three data streams simultaneously: field potentials, band-pass filtered neural data, and spiking probability maps. The algorithm parameters are on-chip configured automatically based on input data, which avoids manual parameter tuning. The chip has been tested with both in vivo experiments for functional verification and bench-top experiments for quantitative performance assessment. The system has a total power consumption of 1.36 mW and occupies an area of 6.71 mm (2) for 16 channels. When tested on synthesized datasets with spikes and noise segments extracted from in vivo preparations and scaled according to required precisions, the chip outperforms other detectors. A credit card sized prototype board is developed to provide power and data management through a USB port.
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Bahrami H, Mirbozorgi SA, Ameli R, Rusch LA, Gosselin B. Flexible, Polarization-Diverse UWB Antennas for Implantable Neural Recording Systems. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2016; 10:38-48. [PMID: 25794394 DOI: 10.1109/tbcas.2015.2393878] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Implanted antennas for implant-to-air data communications must be composed of material compatible with biological tissues. We design single and dual-polarization antennas for wireless ultra-wideband neural recording systems using an inhomogeneous multi-layer model of the human head. Antennas made from flexible materials are more easily adapted to implantation; we investigate both flexible and rigid materials and examine performance trade-offs. The proposed antennas are designed to operate in a frequency range of 2-11 GHz (having S11 below -10 dB) covering both the 2.45 GHz (ISM) band and the 3.1-10.6 GHz UWB band. Measurements confirm simulation results showing flexible antennas have little performance degradation due to bending effects (in terms of impedance matching). Our miniaturized flexible antennas are 12 mm×12 mm and 10 mm×9 mm for single- and dual-polarizations, respectively. Finally, a comparison is made of four implantable antennas covering the 2-11 GHz range: 1) rigid, single polarization, 2) rigid, dual polarization, 3) flexible, single polarization and 4) flexible, dual polarization. In all cases a rigid antenna is used outside the body, with an appropriate polarization. Several advantages were confirmed for dual polarization antennas: 1) smaller size, 2) lower sensitivity to angular misalignments, and 3) higher fidelity.
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Kwack WG, Lim YJ. Current Status and Research into Overcoming Limitations of Capsule Endoscopy. Clin Endosc 2016; 49:8-15. [PMID: 26855917 PMCID: PMC4743729 DOI: 10.5946/ce.2016.49.1.8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 12/13/2022] Open
Abstract
Endoscopic investigation has a critical role in the diagnosis and treatment of gastrointestinal (GI) diseases. Since 2001, capsule endoscopy (CE) has been available for small-bowel exploration and is under continuous development. During the past decade, CE has achieved impressive improvements in areas such as miniaturization, resolution, and battery life. As a result, CE is currently a first-line tool for the investigation of the small bowel in obscure gastrointestinal bleeding and is a useful alternative to wired enteroscopy. Nevertheless, CE still has several limitations, such as incomplete examination and limited diagnostic and therapeutic capabilities. To resolve these problems, many groups have suggested several models (e.g., controlled CO2 insufflation system, magnetic navigation system, mobile robotic platform, tagging and biopsy equipment, and targeted drug-delivery system), which are in development. In the near future, new technological advances will improve the capabilities of CE and broaden its spectrum of applications not only for the small bowel but also for the colon, stomach, and esophagus. The purpose of this review is to introduce the current status of CE and to review the ongoing development of solutions to address its limitations.
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Affiliation(s)
- Won Gun Kwack
- Department of Internal Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Korea
| | - Yun Jeong Lim
- Department of Internal Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Korea
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Thotahewa KMS, Redoute JM, Yuce MR. A UWB wireless capsule endoscopy device. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:6977-80. [PMID: 25571601 DOI: 10.1109/embc.2014.6945233] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Wireless capsule endoscopy (WCE) presents many advantages over traditional wired endoscopic methods. The performance of WCE devices can be improved using high-frequency communication systems such as Impulse Radio-Ultra-Wideband (IR-UWB) to enable a high data rate transmission with low-power consumption. This paper presents the hardware implementation and experimental evaluation of a WCE device that uses IR-UWB signals in the frequency range of 3.5 GHz to 4.5 GHz to transmit image data from inside the body to a receiver placed outside the body. Key components of the IR-UWB transmitter, such as the narrow pulse generator and up-conversion based RF section are described in detail. This design employs a narrowband receiver in the WCE device to receive a control signal externally in order to control and improve the data transmission from the device in the body. The design and performance of a wideband implantable antenna that operates in the aforementioned frequency range is also described. The operation of the WCE device is demonstrated through a proof-of-concept experiment using meat.
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Wu T, Yang Z. A multichannel integrated circuit for neural spike detection based on EC-PC threshold estimation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:779-82. [PMID: 24109803 DOI: 10.1109/embc.2013.6609616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In extracellular neural recording experiments, spike detection is an important step for information decoding of neuronal activities. An ASIC implementation of detection algorithms can provide substantial data-rate reduction and facilitate wireless operations. In this paper, we present a 16-channel neural spike detection ASIC. The chip takes raw data as inputs, and outputs three data streams simultaneously: field potentials down sampled at 1.25 KHz, band-pass filtered neural data, and spiking probability maps sampled at 40 KHz. The functionality and the performance of the chip have been verified in both in-vivo and benchtop experiments. Fabricated in a 0.13 µm CMOS process, the chip has a peak power dissipation of 85 µW per channel and achieves a data-rate reduction of 98.44%.
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22
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Ebrazeh A, Mohseni P. 30 pJ/b, 67 Mbps, Centimeter-to-Meter Range Data Telemetry With an IR-UWB Wireless Link. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2015; 9:362-369. [PMID: 25134088 DOI: 10.1109/tbcas.2014.2328492] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This paper reports an energy-efficient, impulse radio ultra wideband (IR-UWB) wireless link operating in 3-5 GHz for data telemetry over centimeter-to-meter range distances at rates extended to tens of Mbps. The link comprises an all-digital, integrated transmitter (TX) fabricated in 90 nm 1P/9M CMOS that incorporates a waveform-synthesis pulse generator and a timing generator for on-off-keying (OOK) pulse modulation and phase scrambling. The link also incorporates an energy-detection receiver (RX) realized with commercial off-the-shelf (COTS) components that performs radio-frequency (RF) filtering, amplification, logarithmic power detection for data demodulation and automatic level control for robust operation in the presence of distance variations. Employing a miniaturized, UWB, chip antenna for the TX and RX, wireless transmission of pseudo-random binary sequence (PRBS) data at rates up to 50 Mbps over 10 cm-1 m is shown. Further, employing a high-gain horn antenna for the RX, wireless transmission of PRBS data at rates up to 67 Mbps over 50 cm-4 m is shown with a TX energy consumption of 30 pJ/b (i.e., power consumption of 2 mW) from 1.2 V. The measured bit error rate (BER) in both cases is < 10(-7) . Results from wireless recording of the background current of a carbon-fiber microelectrode (CFM) in one fast-scan cyclic voltammetry (FSCV) scan using the IR-UWB link are also included, exhibiting excellent match with those obtained from a conventional frequency-shift-keyed (FSK) link at ~433 MHz.
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23
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Kuan YC, Lo YK, Kim Y, Chang MCF, Liu W. Wireless gigabit data telemetry for large-scale neural recording. IEEE J Biomed Health Inform 2015; 19:949-57. [PMID: 25823050 DOI: 10.1109/jbhi.2015.2416202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Implantable wireless neural recording from a large ensemble of simultaneously acting neurons is a critical component to thoroughly investigate neural interactions and brain dynamics from freely moving animals. Recent researches have shown the feasibility of simultaneously recording from hundreds of neurons and suggested that the ability of recording a larger number of neurons results in better signal quality. This massive recording inevitably demands a large amount of data transfer. For example, recording 2000 neurons while keeping the signal fidelity ( > 12 bit, > 40 KS/s per neuron) needs approximately a 1-Gb/s data link. Designing a wireless data telemetry system to support such (or higher) data rate while aiming to lower the power consumption of an implantable device imposes a grand challenge on neuroscience community. In this paper, we present a wireless gigabit data telemetry for future large-scale neural recording interface. This telemetry comprises of a pair of low-power gigabit transmitter and receiver operating at 60 GHz, and establishes a short-distance wireless link to transfer the massive amount of neural signals outward from the implanted device. The transmission distance of the received neural signal can be further extended by an externally rendezvous wireless transceiver, which is less power/heat-constraint since it is not at the immediate proximity of the cortex and its radiated signal is not seriously attenuated by the lossy tissue. The gigabit data link has been demonstrated to achieve a high data rate of 6 Gb/s with a bit-error-rate of 10(-12) at a transmission distance of 6 mm, an applicable separation between transmitter and receiver. This high data rate is able to support thousands of recording channels while ensuring a low energy cost per bit of 2.08 pJ/b.
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24
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Poon CCY, Lo BPL, Yuce MR, Alomainy A, Hao Y. Body Sensor Networks: In the Era of Big Data and Beyond. IEEE Rev Biomed Eng 2015; 8:4-16. [DOI: 10.1109/rbme.2015.2427254] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Xu F, Yan G, Zhao K, Lu L, Gao J, Liu G. A wireless capsule system with ASIC for monitoring the physiological signals of the human gastrointestinal tract. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2014; 8:871-880. [PMID: 25608285 DOI: 10.1109/tbcas.2013.2296933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper presents the design of a wireless capsule system for monitoring the physiological signals of the human gastrointestinal (GI) tract. The primary components of the system include a wireless capsule, a portable data recorder, and a workstation. Temperature, pH, and pressure sensors; an RF transceiver; a controlling and processing application specific integrated circuit (ASIC); and batteries were applied in a wireless capsule. Decreasing capsule size, improving sensor precision, and reducing power needs were the primary challenges; these were resolved by employing micro sensors, optimized architecture, and an ASIC design that include power management, clock management, a programmable gain amplifier (PGA), an A/D converter (ADC), and a serial peripheral interface (SPI) communication unit. The ASIC has been fabricated in 0.18- μm CMOS technology with a die area of 5.0 mm × 5.0 mm. The wireless capsule integrating the ASIC controller measures Φ 11 mm × 26 mm. A data recorder and a workstation were developed, and 20 cases of human experiments were conducted in hospitals. Preprocessing in the workstation can significantly improve the quality of the data, and 76 original features were determined by mathematical statistics. Based on the 13 optimal features achieved in the evaluation of the features, the clustering algorithm can identify the patients who lack GI motility with a recognition rate reaching 83.3%.
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26
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Mehmood I, Sajjad M, Baik SW. Mobile-cloud assisted video summarization framework for efficient management of remote sensing data generated by wireless capsule sensors. SENSORS (BASEL, SWITZERLAND) 2014; 14:17112-45. [PMID: 25225874 PMCID: PMC4208216 DOI: 10.3390/s140917112] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/05/2014] [Accepted: 09/09/2014] [Indexed: 12/22/2022]
Abstract
Wireless capsule endoscopy (WCE) has great advantages over traditional endoscopy because it is portable and easy to use, especially in remote monitoring health-services. However, during the WCE process, the large amount of captured video data demands a significant deal of computation to analyze and retrieve informative video frames. In order to facilitate efficient WCE data collection and browsing task, we present a resource- and bandwidth-aware WCE video summarization framework that extracts the representative keyframes of the WCE video contents by removing redundant and non-informative frames. For redundancy elimination, we use Jeffrey-divergence between color histograms and inter-frame Boolean series-based correlation of color channels. To remove non-informative frames, multi-fractal texture features are extracted to assist the classification using an ensemble-based classifier. Owing to the limited WCE resources, it is impossible for the WCE system to perform computationally intensive video summarization tasks. To resolve computational challenges, mobile-cloud architecture is incorporated, which provides resizable computing capacities by adaptively offloading video summarization tasks between the client and the cloud server. The qualitative and quantitative results are encouraging and show that the proposed framework saves information transmission cost and bandwidth, as well as the valuable time of data analysts in browsing remote sensing data.
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Affiliation(s)
- Irfan Mehmood
- College of Electronics and Information Engineering, Sejong University, Seoul 143-747, Korea.
| | - Muhammad Sajjad
- College of Electronics and Information Engineering, Sejong University, Seoul 143-747, Korea.
| | - Sung Wook Baik
- College of Electronics and Information Engineering, Sejong University, Seoul 143-747, Korea.
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27
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Goodarzy F, Skafidas ES, Gambini S. Feasibility of Energy-Autonomous Wireless Microsensors for Biomedical Applications: Powering and Communication. IEEE Rev Biomed Eng 2014; 8:17-29. [PMID: 25137732 DOI: 10.1109/rbme.2014.2346487] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this review, biomedical-related wireless miniature devices such as implantable medical devices, neural prostheses, embedded neural systems, and body area network systems are investigated and categorized. The two main subsystems of such designs, the RF subsystem and the energy source subsystem, are studied in detail. Different application classes are considered separately, focusing on their specific data rate and size characteristics. Also, the energy consumption of state-of-the-art communication practices is compared to the energy that can be generated by current energy scavenging devices, highlighting gaps and opportunities. The RF subsystem is classified, and the suitable architecture for each category of applications is highlighted. Finally, a new figure of merit suitable for wireless biomedical applications is introduced to measure the performance of these devices and assist the designer in selecting the proper system for the required application. This figure of merit can effectively fill the gap of a much required method for comparing different techniques in simulation stage before a final design is chosen for implementation.
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28
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Tan J, Liew WS, Heng CH, Lian Y. A 2.4 GHz ULP reconfigurable asymmetric transceiver for single-chip wireless neural recording IC. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2014; 8:497-509. [PMID: 25073126 DOI: 10.1109/tbcas.2013.2290533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This paper presents a 2.4 GHz ultra-low-power (ULP) reconfigurable asymmetric transceiver and demonstrates its application in wireless neural recording. Fabricated in 0.13 μm CMOS technology, the transceiver is optimized for sensor-gateway communications within a star-shaped network, and supports both the sensor and gateway operation modes. Binary phase-shift keying (BPSK) modulation with high data rate (DR) of 1 to 8 Mbps is used in the uplink from sensor to gateway, while on-off keying (OOK) modulation with low DR of 100 kbps is adopted in the downlink. A fully integrated Class-E PA with moderate output power has also been proposed and achieves power efficiency of 53%. To minimize area usage, inductor reuse is adopted between PA and LNA, and eliminates the need of lossy T/R switch in the RF signal path. When used as sensor, the transceiver with frequency locked phase-locked loop (PLL) achieves TX (BPSK) power efficiency of 28% @ 0 dBm output power, and RX (OOK) sensitivity of -80 dBm @ 100 kbps while consuming only 780 μW . When configured as gateway, the transceiver achieves sensitivity levels of -92, -84.5, and -77 dBm for 1, 5, and 8 Mbps BPSK, respectively. The transceiver is integrated with an 8-channel neural recording front-end, and neural signals from a rat are captured to verify the system functionality.
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29
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Bahrami H, Mirbozorgi SA, Rusch LA, Gosselin B. Biological channel modeling and implantable UWB antenna design for neural recording systems. IEEE Trans Biomed Eng 2014; 62:88-98. [PMID: 25055379 DOI: 10.1109/tbme.2014.2339836] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ultrawideband (UWB) short-range communication systems have proved to be valuable in medical technology, particularly for implanted devices, due to their low-power consumption, low cost, small size, and high data rates. Neural activity monitoring in the brain requires high data rate (800 kb/s per neural sensor), and we target a system supporting a large number of sensors, in particular, aggregate transmission above 430 Mb/s (∼512 sensors). Knowledge of channel behavior is required to determine the maximum allowable power to 1) respect ANSI guidelines for avoiding tissue damage, and 2) respect FCC guidelines on unlicensed transmissions. We utilize a realistic model of the biological channel to inform the design of antennas for the implanted transmitter and the external receiver under these requirements. Antennas placement is examined under two scenarios having contrasting power constraints. Performance of the system within the biological tissues is examined via simulation and experiment. Our miniaturized antennas, 12 mm ×12 mm, need worst-case receiver sensitivities of -38 and -30.5 dBm for the first and second scenarios, respectively. These sensitivities allow us to successfully detect signals transmitted through tissues in the 3.1-10.6-GHz UWB band.
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30
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Karargyris A, Koulaouzidis A. Capsule-odometer: A concept to improve accurate lesion localisation. World J Gastroenterol 2013; 19:5943-5946. [PMID: 24124345 PMCID: PMC3793153 DOI: 10.3748/wjg.v19.i35.5943] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 07/28/2013] [Accepted: 08/20/2013] [Indexed: 02/06/2023] Open
Abstract
In order to improve lesion localisation in small-bowel capsule endoscopy, a modified capsule design has been proposed incorporating localisation and - in theory - stabilization capabilities. The proposed design consists of a capsule fitted with protruding wheels attached to a spring-mechanism. This would act as a miniature odometer, leading to more accurate lesion localization information in relation to the onset of the investigation (spring expansion e.g., pyloric opening). Furthermore, this capsule could allow stabilization of the recorded video as any erratic, non-forward movement through the gut is minimised. Three-dimensional (3-D) printing technology was used to build a capsule prototype. Thereafter, miniature wheels were also 3-D printed and mounted on a spring which was attached to conventional capsule endoscopes for the purpose of this proof-of-concept experiment. In vitro and ex vivo experiments with porcine small-bowel are presented herein. Further experiments have been scheduled.
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31
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Kim K, Yun S, Lee S, Nam S, Yoon YJ, Cheon C. A design of a high-speed and high-efficiency capsule endoscopy system. IEEE Trans Biomed Eng 2011; 59:1005-11. [PMID: 22207636 DOI: 10.1109/tbme.2011.2182050] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This paper presents a high-speed and high-efficiency capsule endoscopy system. Both a transmitter and a receiver were optimized for its application through an analysis of the human body channel. ON-OFF keying modulation is utilized to achieve low power consumption of the in-body transmitter. A low drop output regulator is adopted to prevent performance degradation in the event of a voltage drop in the battery. The receiver adopts superheterodyne structure to obtain high sensitivity, considering the link budget from the previous analysis. The receiver and transmitter were fabricated using the CMOS 0.13-μm process. The output power of the transmitter is -1.6 dB·m and its efficiency is 27.7%. The minimum sensitivity of the receiver is -80 dB·m at a bit error ratio (BER) of 3 × 10 (-6). An outer wall loop antenna is adopted for the capsule system to ensure a small size. The integrated system is evaluated using a liquid human phantom and a living pig, resulting in clean captured images.
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Affiliation(s)
- Kihyun Kim
- Applied Electromagnetics Laboratory, School of Electrical Engineering, Seoul National University, Seoul, Korea.
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Gosselin B. Recent advances in neural recording microsystems. SENSORS (BASEL, SWITZERLAND) 2011; 11:4572-97. [PMID: 22163863 PMCID: PMC3231370 DOI: 10.3390/s110504572] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 04/03/2011] [Accepted: 04/25/2011] [Indexed: 11/16/2022]
Abstract
The accelerating pace of research in neuroscience has created a considerable demand for neural interfacing microsystems capable of monitoring the activity of large groups of neurons. These emerging tools have revealed a tremendous potential for the advancement of knowledge in brain research and for the development of useful clinical applications. They can extract the relevant control signals directly from the brain enabling individuals with severe disabilities to communicate their intentions to other devices, like computers or various prostheses. Such microsystems are self-contained devices composed of a neural probe attached with an integrated circuit for extracting neural signals from multiple channels, and transferring the data outside the body. The greatest challenge facing development of such emerging devices into viable clinical systems involves addressing their small form factor and low-power consumption constraints, while providing superior resolution. In this paper, we survey the recent progress in the design and the implementation of multi-channel neural recording Microsystems, with particular emphasis on the design of recording and telemetry electronics. An overview of the numerous neural signal modalities is given and the existing microsystem topologies are covered. We present energy-efficient sensory circuits to retrieve weak signals from neural probes and we compare them. We cover data management and smart power scheduling approaches, and we review advances in low-power telemetry. Finally, we conclude by summarizing the remaining challenges and by highlighting the emerging trends in the field.
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Affiliation(s)
- Benoit Gosselin
- Electrical and Computer Engineering Department, Université Laval, 1065 avenue de la Médecine, Québec, G1V 0A6, Canada.
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