Robots in Human Environments: Basic Autonomous Capabilities

This article discusses the basic capabilities needed to enable robots to operate in human-populated environments for accomplishing both autonomous tasks and human-guided tasks. These capabilities are key to many new emerging robotic applications in service, construction, field, underwater, and space. An important characteristic of these robots is the “assistance” ability they can bring to humans in performing various physical tasks. To interact with humans and operate in their environments, these robots must be provided with the functionality of mobility and manipulation. The article presents developments of models, strategies, and algorithms concerned with a number of autonomous capabilities that are essential for robot operations in human environments. These capabilities include: integrated mobility and manipulation, cooperative skills between multiple robots, interaction ability with humans, and efficient techniques for real-time modification of collision-free path. These capabilities are demonstrated on two holonomic mobile platforms designed and built at Stanford University in collaboration with Oak Ridge National Laboratories and Nomadic Technologies.

One- and Two-Dimensional Nuclear Magnetic Resonance Spectroscopy with a Diamond Quantum Sensor

We report on Fourier spectroscopy experiments performed with near-surface nitrogen-vacancy centers in a diamond chip. By detecting the free precession of nuclear spins rather than applying a multipulse quantum sensing protocol, we are able to unambiguously identify the NMR species devoid of harmonics. We further show that, by engineering different Hamiltonians during free precession, the hyperfine coupling parameters as well as the nuclear Larmor frequency can be selectively measured with up to five digits of precision. The protocols can be combined to demonstrate two-dimensional Fourier spectroscopy. Presented techniques will be useful for mapping nuclear coordinates in molecules deposited on diamond sensor chips, en route to imaging their atomic structure.

Dearterialization with mucopexy versus haemorrhoidectomy for grade III or IV haemorrhoids: short-term results of a double-blind randomized controlled trial

AIM

There is scepticism regarding anatomical rationale and Doppler guidance for ligation of haemorrhoidal arteries. The null hypothesis of this randomized controlled trial (RCT) was that there is no difference in pain following dearterialization or haemorrhoidectomy for grade III/IV internal haemorrhoids in a minimum of three quadrants.

METHOD

This was a single-centre, double-blind RCT. Patients were allocated to dearterialization or haemorrhoidectomy. Included haemorrhoids were grade III, prolapsing but reducible; and grade IV, chronic non-incarcerated. The primary end-point was pain. Patients with external component, acute incarcerated grade IV or recurrent haemorrhoids were not included. The interventions were dearterialization (with Doppler guidance and mucopexy) or haemorrhoidectomy. The main outcome measure was the Brief Pain Inventory (BPI).

RESULTS

Twenty dearterialization patients were comparable to 20 haemorrhoidectomy patients for age (P = 0.107), body mass index (P = 0.559), race (P = 0.437), American Society of Anesthesiology score (P = 0.569), comorbidities (P = 0.592), grade (P = 0.096), quadrants (P = 0.222), Fecal Incontinence Quality-of-Life Score (FIQOL; P = 0.388), coping (P = 0.532), depression (P = 0.505), embarrassment (P = 0.842), and Short Form Health Survey (SF-12) physical components (P = 0.337), SF-12 mental components (P = 0.396) and constipation (P = 0.628) scores. Dearterialization patients had shorter operative time (36 vs 54 min, P = 0.043) with less pain (P = 0.011) and urinary retention (P = 0.012). Dearterialization patients had first bowel movement earlier (1.3 vs 4.6 days, P = 0.001), less pain (P = 0.011) and lower pain intensity (P = 0.001). Narcotic requirements were reduced in dearterialization patients (25% vs 100%, P = 0.001), with less medication (4.9 vs 112 pills, P = 0.001) and shorter regimen (0 vs 7 days, P = 0.001). BPI did not differ on days 1, 3, 5, 7 and 14 except for less pain in dearterialization patients. At 3 months, symptomatic relief was the same with no differences in BPI, FIQOL or SF-12.

CONCLUSION

Compared with haemorrhoidectomy, dearterialization led to less pain in grade III/IV haemorrhoids.

Removable esophageal stents have poor efficacy for the treatment of refractory benign esophageal strictures (RBES)

With the recent availability of removable esophageal stents, endoscopic stenting has been utilized to treat refractory benign esophageal strictures (RBES). The objective of this study was to review the feasibility and effectiveness of removable esophageal stents to treat RBES. Patients who received removable esophageal stents for the treatment of RBES at the institution between 2004-2010 using its stent implantation logs and endoscopic database were retrospectively identified. Patient demographics, stricture etiology and location, stent and procedure characteristics, and clinical outcomes were obtained. Twenty-five patients with a mean age of 70 (72% male) underwent initial stent placement; 24 were successful. Overall clinical success was achieved in five of the 19 patients (26%) ultimately undergoing stent removal. RBES etiologies included anastomotic (13), radiation (5), peptic (3), chemotherapy (1), scleroderma (1), and unknown (2). Alimaxx-E (Merit-Endotek, South Jordan, UT, USA) stents were placed in 20 patients and Polyflex (Boston Scientific, Natick, MA, USA) stents were used in five patients. Immediate complications included failed deployment (1) and chest pain (7). Five patients died prior to stent removal. Stent migration was found in 53% (10/19) of patients who underwent stent removal: nine required additional therapy and one had symptom resolution. Out of the nine patients without stent migration, five required additional therapy and four had symptom resolution. Although placement of removable esophageal stents for RBES is technically feasible, it is frequently complicated by stent migration and chest pain. In addition, few patients achieved long-term stricture resolution after initial stenting. In this study, most patients ultimately required repeated stenting and/or dilations to maintain relief of dysphagia.

A double-blind comparative study of Chinese herbal medicine Jinlianqingre Effervescent Tablets in combination with conventional therapy for the treatment of uncomplicated hand, foot, and mouth disease

Chinese herbal medicine Jinlianqingre Effervescent Tablets (JET) are the recommended control measure for uncomplicated hand, foot, and mouth disease (HFMD) by the Ministry of Health of China. However, high-quality evidence to support this recommendation is limited. A total of 288 patients ranging in age from 1 to 13 years were randomly assigned to JET in combination with conventional therapy (mainly including the reduction of temperature by applying physical cooling paste or warm bathing), or conventional therapy with placebo group for 7 days. The objective was to test the hypothesis that JET combination therapy is more effective than conventional therapy for uncomplicated HFMD. A randomized, double-blind, placebo-controlled trial was designed. Our study showed that, compared with conventional therapy, the median time to fever resolution was significantly shorter in the JET combination therapy (8 vs. 80 h; p < 0.0001); the risk of fever resolution increased in the JET combination therapy [hazard ratio, 19.8; 95% confidence interval (CI), 12.8 to 30.7]; the median healing time of rash or oral ulcer was significantly shorter in the JET combination therapy (14 vs. 74 h; p < 0.0001); and the median symptom score for skin or oral mucosa lesions improved more rapidly in the JET combination therapy during the follow-up period. The median duration of hospital stay was 6 days in the JET combination therapy and 7 days in the conventional therapy (p < 0.0001). No significant adverse events and complications were found in both groups. The addition of JET to conventional therapy reduced fever clearance time, healing time of skin or oral mucosa lesions, and duration of hospital stay in children with uncomplicated HFMD.

Imaging the effects of oxygen saturation changes in voluntary apnea and hyperventilation on susceptibility-weighted imaging

BACKGROUND AND PURPOSE

Cerebrovascular oxygenation changes during respiratory challenges have clinically important implications for brain function, including cerebral autoregulation and the rate of brain metabolism. SWI is sensitive to venous oxygenation level by exploitation of the magnetic susceptibility of deoxygenated blood. We assessed cerebral venous blood oxygenation changes during simple voluntary breath-holding (apnea) and hyperventilation by use of SWI at 3T.

MATERIALS AND METHODS

We performed SWI scans (3T; acquisition time of 1 minute, 28 seconds; centered on the anterior commissure and the posterior commissure) on 10 healthy male volunteers during baseline breathing as well as during simple voluntary hyperventilation and apnea challenges. The hyperventilation and apnea tasks were separated by a 5-minute resting period. SWI venograms were generated, and the signal changes on SWI before and after the respiratory stress tasks were compared by means of a paired Student t test.

RESULTS

Changes in venous vasculature visibility caused by the respiratory challenges were directly visualized on the SWI venograms. The venogram segmentation results showed that voluntary apnea decreased the mean venous blood voxel number by 1.6% (P < .0001), and hyperventilation increased the mean venous blood voxel number by 2.7% (P < .0001). These results can be explained by blood CO2 changes secondary to the respiratory challenges, which can alter cerebrovascular tone and cerebral blood flow and ultimately affect venous oxygen levels.

CONCLUSIONS

These results highlight the sensitivity of SWI to simple and noninvasive respiratory challenges and its potential utility in assessing cerebral hemodynamics and vasomotor responses.