OBJECTIVES
To evaluate the intraexaminer and interexaminer reliability of rehabilitative ultrasound imaging (RUSI) in obtaining thickness measurements of the transversus abdominis (TrA) and lumbar multifidus muscles at rest and during contractions.


DESIGN
Single-group repeated-measures reliability study.


SETTING
University and orthopedic physical therapy clinic.


PARTICIPANTS
A volunteer sample of adults (N=30) with current nonspecific low back pain (LBP) was examined by 2 clinicians with minimal RUSI experience.


INTERVENTIONS
Not applicable.


MAIN OUTCOME MEASURES
Thickness measurements of the TrA and lumbar multifidus muscles at rest and during contractions were obtained by using RUSI during 2 sessions 1 to 3 days apart. Percent thickness change was calculated as thickness(contracted)-thickness(rest)/thickness(rest). Intraclass correlation coefficients (ICC) were used to estimate reliability.


RESULTS
By using the mean of 2 measures, intraexaminer reliability point estimates (ICC(3,2)) ranged from 0.96 to 0.99 for same-day comparisons and from 0.87 to 0.98 for between-day comparisons. Interexaminer reliability estimates (ICC(2,2)) ranged from 0.88 to 0.94 for within-day comparisons and from 0.80 to 0.92 for between-day comparisons. Reliability estimates comparing measurements by the 2 examiners of the same image (ICC(2,2)) ranged from 0.96 to 0.98. Reliability estimates were lower for percent thickness change measures than the corresponding single thickness measures for all conditions.


CONCLUSIONS
RUSI thickness measurements of the TrA and lumbar multifidus muscles in patients with LBP, when based on the mean of 2 measures, are highly reliable when taken by a single examiner and adequately reliable when taken by different examiners.

Reliability of rehabilitative ultrasound imaging of the transversus abdominis and lumbar multifidus musculature

In this paper, a novel technique of collocating a millimeter-wave end-fire 5G beam steerable array antenna with a low-frequency planar inverted-F antenna (PIFA) is presented. In this technique, the low-frequency antenna can be transparent by using some grating strips between the low- and high-frequency antennas. A quad-element mm-wave array with end-fire radiation patterns operating in 22–31 GHz is integrated with a dual-band low-frequency PIFA in a mobile terminal. The novelty of this paper is the collocation of a high-frequency end-fire 5G antenna array with an old-generation low-frequency antenna, such as 4G in small space in the mobile terminal, without interfering with the radiation pattern and impedance matching of both low- and high-frequency antennas. The proposed 5G antenna covers 22–31 GHz and can scan ±50° with the scan loss of better than 3 dB. The coverage efficiency of the proposed mm-wave 5G antenna is better than 50% and 80% for a minimum gain of 4 and 0 dBi in 22–31 GHz, respectively. The gain of the high-frequency antenna array is better than 9.5 dBi at 28 GHz. The low-frequency antenna covers some practical 4G LTE bands from 740–960 MHz and 1.7–2.2 GHz bands. The measured results in both low and high frequencies agree well with the simulations.

/pdf/integrated-millimeter-wave-wideband-end-fire-5g-beam-2tphrhbmnb.pdf

Integrated Millimeter-Wave Wideband End-Fire 5G Beam Steerable Array and Low-Frequency 4G LTE Antenna in Mobile Terminals

A novel design for a radio-frequency identification (RFID) tag antenna mounted on a metallic plane is presented. The tag antenna has a rectangular radiating plate with a Z-shaped slot, which enables it to function like a half-wavelength slot resonator and a dipole-type ground radiator. A conjugate match to an Alien Higgs-3 chip with an impedance of 8 – j 142 $\Omega$ at 925 MHz is obtained by etching a half-wavelength slot resonator in the center of the rectangular radiating plate ( $120 \text{ mm}\times60\text{ mm}$ ). The tag antenna resistance and inductive reactance can be matched to the desired chip impedance by simply tuning the length and width of the Z-slot resonator. The space between the half-wavelength resonant radiating plate (dipole-type ground radiator) and the metallic plane enhances the antenna gain by increasing the reflection from the metallic plane. A horizontal electric dipole placed above the perfectly flat electric metallic plane enables a maximum gain of 8.7 dBi over a short distance, which is fourfold higher than that of an isolated half-wavelength dipole. Tests of an RFID reader with an effective isotropic radiated power of 4.0 W showed that the maximum read coverage of the proposed tag antenna mounted on a metallic plane exceeded 10 m. Measurement data were in good agreement with the simulation results.

Gain Enhancement of Ground Radiation Antenna for RFID Tag Mounted on Metallic Plane

The stacked inverted-F antenna with two hybrid shorting strips placed close to the antenna's feeding strip can provide two wide operating bands to cover long-term evolution/wireless wide-area network operation (698-960/1710-2690 MHz) in the tablet device. The antenna's lower and higher bands are, respectively, contributed by the longer and shorter arms of the antenna. The two hybrid shorting strips include an inductive shorting strip (chip-inductor-loaded strip) and a capacitive shorting strip which capacitively couples to the antenna's shorter arm. The longer arm is also coupled through a chip inductor to the feeding strip such that the longer arm has a decreased resonant length for the low-band operation and, on the other hand, has very small effects on the high-band operation, which is mainly contributed by the shorter arm. The feeding strip is also embedded with a chip capacitor such that an internal high-pass matching circuit formed by the inductive shorting strip and the capacitive feeding strip is obtained to greatly widen the antenna's low-band bandwidth, with small effects on the high-band operation. On the other hand, the capacitive shorting strip is added to greatly enhance the bandwidth of the antenna's higher band, with small effects on the low-band operation. Two wide operating bands are hence easily obtained and adjusted. The antenna can also be recessed in a small ground clearance of 10 × 35 mm 2
 inside the tablet device such as a tablet computer in this study. Details of the proposed antenna are presented.

Small-Size Stacked Inverted-F Antenna With Two Hybrid Shorting Strips for the LTE/WWAN Tablet Device

An inherently non-resonant capacitive coupling element antenna for mobile handsets is presented. The compact antenna includes a simple coupling element with a novel multi-band matching circuit for simultaneous 698-960 and 1710-2690 MHz operation. Experimental results show that the antenna performs strongly in comparison to the current state-of-the-art in mobile terminal antennas, and that the non-resonant antenna is a competitive choice for mobile terminals.

Inherently non-resonant multi-band mobile terminal antenna

An innovative antenna radiation method for exciting a dipole-type radiation mode in the ground plane of mobile devices is proposed. This method is based on a capacitively loaded slot placed at the centre of the ground plane. The ground plane is 50 × 15 mm in length and width, respectively, which is the size typically used in USB dongles and headsets. The −10 dB impedance bandwidth is 12.9% at 2.4 GHz, fully covering the WiMax, Wi-Fi and Bluetooth frequency bands.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/el.2012.4520

Ground radiation method using slot with coupling capacitors

A loop-type ground antenna with wide-band operation is proposed for USB dongle applications. The solution for improving the bandwidth is based on a resonant feeding circuit that includes both an inductor and a capacitor. By choosing an appropriate ratio of the inductance to the capacitance, the impedance bandwidth (VSWR < 2) is 21.8% at 2.2 GHz, sufficient bandwidth to cover both the WCDMA and WiMax frequency bands.

Bandwidth enhancement of ground antenna using resonant feeding circuit

Proposed is a novel mobile handset antenna with a double planar inverted-E (PIE) feed structure that achieves a wide impedance bandwidth. The antenna is designed by inserting two branch capacitors in the feed structure of a conventional planar inverted-F antenna. In the lower and higher frequency bands, the proposed antenna has a very wide impedance bandwidth characteristic, from 698 to 990 MHz, and from 1710 to 2170 MHz under a voltage standing wave ratio of 3:1 with good efficiency.

Mobile handset antenna with double planar inverted-E (PIE) feed structure

A planar inverted-F antenna (PIFA) is presented, which has a dual-resonance feed structure that enhances impedance bandwidth considerably. The proposed antenna fully covers LTE13/GSM850/GSM900 without significant modification of the antenna element fabricated in a small ground clearance. The antenna's impedance bandwidth under VSWR = 3:1 is 733-974 MHz, with a good realised efficiency.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/el.2013.1432

PIFA with dual-resonance feed structure for enhancement of impedance bandwidth

PURPOSE: The purpose of this study was to investigate the effects of a supplementary Ki-hap technique and verbal encouragement on the activation of abdominal muscles during performance of crunch exercise in healthy subjects. METHODS: 93 subjects were randomly allocated to three group, crunch exercise group (CG), crunch exercise with Ki-hap group (CKG), and crunch exercise with Ki-hap and verbal encouragement group (CKVG), with 31 subjects in each group, respectively. The interventions were conducted over three trials in each group, and measurements were performed on each subject by one examiner in three trials. The activation of rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles were evaluated using electromyography (EMG) during performance of crunch exercise with non-Ki-hap, Ki-hap and Ki-hap combined with verbal encouragement. RESULTS: Our results showed a significantly greater increase in the EMG patterns of all muscles during performance of crunch exercise in the CKG (p

http://www.koreascience.or.kr:80/article/JAKO201617338765169.pdf

Influence of the Supplementary Ki-hap Technique and Verbal Encouragement on Abdominal Muscle Activation during Crunch Exercise in Healthy Subjects: A Pilot Randomized Controlled Trial

H. H. Kim

Papers

Ground radiation method using slot with coupling capacitors

Bandwidth enhancement of ground antenna using resonant feeding circuit

Mobile handset antenna with double planar inverted-E (PIE) feed structure

PIFA with dual-resonance feed structure for enhancement of impedance bandwidth

Influence of the Supplementary Ki-hap Technique and Verbal Encouragement on Abdominal Muscle Activation during Crunch Exercise in Healthy Subjects: A Pilot Randomized Controlled Trial