A Virtual Reality Application of the Rubber Hand Illusion Induced by Ultrasonic Mid-air Haptic Stimulation

Ultrasonic mid-air haptic technologies, which provide haptic feedback through airwaves produced using ultrasound, could be employed to investigate the sense of body ownership and immersion in virtual reality (VR) by inducing the virtual hand illusion (VHI). Ultrasonic mid-air haptic perception has solely been investigated for glabrous (hairless) skin, which has higher tactile sensitivity than hairy skin. In contrast, the VHI paradigm typically targets hairy skin without comparisons to glabrous skin. The aim of this article was to investigate illusory body ownership, the applicability of ultrasonic mid-air haptics, and perceived immersion in VR using the VHI. Fifty participants viewed a virtual hand being stroked by a feather synchronously and asynchronously with the ultrasonic stimulation applied to the glabrous skin on the palmar surface and the hairy skin on the dorsal surface of their hands. Questionnaire responses revealed that synchronous stimulation induced a stronger VHI than asynchronous stimulation. In synchronous conditions, the VHI was stronger for palmar stimulation than dorsal stimulation. The ultrasonic stimulation was also perceived as more intense on the palmar surface compared to the dorsal surface. Perceived immersion was not related to illusory body ownership per se but was enhanced by the provision of synchronous stimulation.

Uncommon sublingual ulceration in an infant

Sir, An eight-month-old girl was referred to our department with an extensive lingual ulceration. The parents noted that she had habitually bitten her tongue since the release of her first teeth at the age of six months. She was a poor feeder and did not sleep well because of the painful lingual ulceration. There was no family history of developmental disorders or congenital syndromes. Intraoral examination revealed a deep, circular, and extensive ulceration of the whole ventral surface of the tongue with intermittent bleeding in the tongue (Figs. 1a – c). An examination of the rest of the intraoral mucosa revealed that the lower central incisors had recently erupted. However, there were two other ulcerations of the palmar surface of the second and third fingers caused by nocturnal finger biting. Neurological examination noted a lack of pain sensitivity related to peripheral neuropathy diagnosed as congenital insensitivity to pain. Based on the clinical features and the particular site on the ventral surface of the tongue against the lower central incisors and ulcerative lesions of the fingers due to self-biting, the lesion was diagnosed as Riga–Fede disease. Because of the size of the ulceration, significant pain during feeding led to inadequate nutrient intake associated with permanent sleep disturbances. Radical treatment was chosen and the lower central incisors were extracted. Topical corticosteroids were prescribed to help with healing. The term Riga–Fede disease has been used to describe a traumatic ulceration that has occurred on the ventral surface of the tongue in newborn babies and infants. It is most commonly related to neonatal or natal teeth but may also occur in infants after the eruption of the primary lower incisors [1]. This benign ulceration occurs as a result of repetitive mechanical trauma caused to the oral mucosal surfaces by the teeth and is most commonly located on the ventral surface of the tongue against the teeth [1,2]. Riga–Fede disease may reveal an underlying developmental or neurologic disorder, including congenital insensitivities to pain [3]. The case of our patient was associated with congenital insensitivity to pain. Failure to diagnose may lead to dehydration and inadequate nutrient intake in the infant because of the significant pain during feeding. No biopsy is needed. The diagnosis of Riga–Fede disease is based on clinical characteristics [1,2]. Treatment should focus on eliminating the source of trauma. Conservative treatment is attempted at first by grinding the sharp edges of the teeth and placing composite resin in a dome shape or by placing a protective ring. If conservative treatment fails to heal the wounds, radical treatment may be necessary, such as extraction of the teeth [2,3]. We believe that Riga–Fede disease must be recognized by clinicians to avoid misdiagnosis and delayed treatment.

Learning to Combine Local and Global Image Information for Contactless Palmprint Recognition

In the past few years, there has been a leap from traditional palmprint recognition methodologies, which use handcrafted features, to deep-learning approaches that are able to automatically learn feature representations from the input data. However, the information that is extracted from such deep-learning models typically corresponds to the global image appearance, where only the most discriminative cues from the input image are considered. This characteristic is especially problematic when data is acquired in unconstrained settings, as in the case of contactless palmprint recognition systems, where visual artifacts caused by elastic deformations of the palmar surface are typically present in spatially local parts of the captured images. In this study we address the problem of elastic deformations by introducing a new approach to contactless palmprint recognition based on a novel CNN model, designed as a two-path architecture, where one path processes the input in a holistic manner, while the second path extracts local information from smaller image patches sampled from the input image. As elastic deformations can be assumed to most significantly affect the global appearance, while having a lesser impact on spatially local image areas, the local processing path addresses the issues related to elastic deformations thereby supplementing the information from the global processing path. The model is trained with a learning objective that combines the Additive Angular Margin (ArcFace) Loss and the well-known center loss. By using the proposed model design, the discriminative power of the learned image representation is significantly enhanced compared to standard holistic models, which, as we show in the experimental section, leads to state-of-the-art performance for contactless palmprint recognition. Our approach is tested on two publicly available contactless palmprint datasets—namely, IITD and CASIA—and is demonstrated to perform favorably against state-of-the-art methods from the literature. The source code for the proposed model is made publicly available.

Unusual congenital polydactyly in mini-pigs from the breeding group of the Institute of Cytology and Genetics (Novosibirsk, Russia)

The article describes a new phenomenon in the breeding group of mini-pigs at the Institute of Cytology and Genetics (ICG, Novosibirsk): polydactyly (extra digits), which is unusual because the additional digits are situated at the lateral surface of legs or at the lateral and medial ones. This anomaly was first found here in 2017 in adult animals intended for culling due to incorrect positioning of the legs caused by flexor tendon laxity and resulting in weight-bearing on the palmar surface of the proximal phalanges (“bear’s paw”). Therefore, the polydactyly of mini-pigs has a pronounced negative selection effect. A visual survey of the livestock was conducted, and a description of the detected anomaly was compiled. The polydactyly in mini-pigs is a stand-alone trait and is not part of any syndromes. Individuals with polydactyly may have extra digits either on pectoral or on pectoral and pelvic limbs. On thoracic limbs, there may be either one lateral digit or a lateral digit and a medially located rudimentary hooflet. On pelvic limbs, only lateral extra digits can occur. Anatomical and morphological analyses showed that the lateral extra digit is an anatomically complete (“mature”) structure, whereas the medial rudimentary digit consists of only a hooflet without other structures characteristic of normal digits. Cytological examination revealed no specific karyotypic features, except for Robertsonian translocation Rb 16;17 previously reported for the mini-pigs of the same livestock. Cytological findings indicated that the polydactyly and Robertsonian translocation are not linked genetically. Genealogical analysis and results of crosses are consistent with a working hypothesis of recessive inheritance of the trait. Overall, the study shows that this type of polydactyly is anatomically and morphologically unique and not typical of Sus scrofa. In this species, only polydactyly types with medial accessory toes have been described and are usually inherited as a dominant trait with incomplete penetrance. In our case, the results of test crosses indicate recessive inheritance of the trait with varying expression and incomplete penetrance, because of which poorly expressed phenotypes are not visually detectable.

Validation of a Handprint for Clinical Evaluation of Dupuytren’s Contracture

Objective We have developed a handprint-based method for visualizing and quantifying the palmar contact of patients with Dupuytren’s contracture. The purpose of this study was to examine whether the generated handprint was useful for assessing the severity of flexion contracture of the fingers and for evaluating the therapeutic effects of collagenase clostridium histolyticum (CCH) injection for Dupuytren’s contracture. Methods The handprint was created by applying medical-grade ethanol-containing hand sanitizer over the entire palmar surface of the affected hand and then pressing it on thermal paper for word processors. The reliability of the handprint was evaluated through test–retest of 10 healthy volunteers at an interval of 10 days, and the validity of the handprint was assessed using a flexion contracture model in which the little finger was fixed in an Alfence splint. In addition, we obtained handprints of the affected hand in 33 patients with unilateral Dupuytren’s contracture both before CCH injection and at the final observation after injection to investigate the contact area of the hand (CAH) and the length of the hand (LH). The relationships between CAH, LH, total extension deficit angle (TEDA), and patient-reported outcome measures (Japanese Society for Surgery of the Hand Version of the Quick Disability of Arm, Shoulder, and Hand Questionnaire [Quick DASH-JSSH] and Hand20) were examined. Results The test–retest correlation coefficient was 0.9187 (p < 0.001) for CAH and 0.9052 (p < 0.001) for LH, indicating high reliability of the handprint. The ratios of CAH and LH decreased gradually as the contracture angle of the splinted finger increased. The handprint revealed a marked improvement of palmar contact after CCH injection for Dupuytren’s contracture. Furthermore, the ratios of CAH and LH were strongly correlated with TEDA, Quick DASH-JSSH, and Hand20 before treatment. Conclusion Our handprint-based assessment method was extremely useful for clinical evaluation of CCH treatment for Dupuytren’s contracture. Type of Study/Level of Evidence Therapeutic.

Angiolipoma: A Unique Cause of Carpal Tunnel Syndrome

Carpal tunnel syndrome is one of the most common conditions affecting the hand. The majority of cases are idiopathic, with tumours causing less than 3% of cases. We present a unique case of an angiolipoma overlying the carpal tunnel as a cause of median nerve compression. A 54-year-old female presented with signs and symptoms consistent with carpal tunnel syndrome associated with an enlarging lump overlying the carpal tunnel on the palmar surface of her hand. Nerve conduction studies confirmed median neuropathy. The case was successfully treated by surgical excision of the tumour and open carpal tunnel release. Histopathology confirmed the presence of an angiolipoma. The patient had complete resolution of symptoms at the final 6-week follow-up. This case highlights the importance of considering tumours in the differential diagnosis of carpal tunnel syndrome.

COMPARISON OF CYTOLOGICAL CHANGES ON PALMAR SURFACE PRIOR AND POST USAGE OF ALCOHOL BASED HAND SANITIZER IN HEALTH CARE PROFESSIONALS DURING COVID 19 PANDEMIC. A PILOT STUDY

Background: After the outbreak of global pandemic, the novel coronavirus (COVID-19) increased the burden on health care professionals to take action to restrain the virus. WHO recommended hand sanitizers to prevent the spread of the disease. This Pilot study was carried out among 10 volunteered health care professionals to evaluate the effects of frequent use of alcohol based hand sanitizers on palmar surface through PAP test. Aim: Comparison of cytological changes on palmar surface prior and post usage of alcohol based hand sanitizer in health care professionals during covid 19 pandemic. Materials and Methods: PAP test was conducted on the smears taken from palmar surface of both the hands of 10 volunteered health care professionals and evaluated for clinical and cytological parameters. Results and Conclusion: Health care professionals increased their use of hand sanitizers to prevent further spread of novel coronavirus (COVID-19) however use of hand sanitizers have adverse effects on the surface of the skin. The current trend in emerging pandemic like COVID 19, both the general public and among health care professionals, frequent washing with detergents, antimicrobial soaps and hand sanitizers needs careful reassessment in light of the damage done to skin. However further studies have be carried out for adequate protection and minimizing the risk of damage on the skin.