Development of a master-slave 3D printed robotic surgical finger with haptic feedback.

Robotic surgery started nearly 30 years ago. It has achieved telepresence and the performance of repetitive, precise, and accurate tasks. The "master-slave" robotic system allows control of manipulators by surgeon at distant site. Robotic surgical fingers were developed to allow surgeons to move them with accuracy through sensors fixed on surgeon's hand. Also, haptic sensors were developed to allow transmission of sensation from robotic finger to surgeon's finger. A complete system of a, 3D printed by a stereolithography (SLA) 3D printer, robotic surgical finger with haptic feedback system is proposed. The developed system includes a master glove that controls the motion of a 3DOF robotic slave finger while getting haptic feedback of force/pressure exerted on it. The precise control of the slave robotic finger was achieved by applying a Proportional Integral and Derivative (PID), fast and robust, control algorithm using an Arduino based hardware and software module. The individual joint angles, metacarpophalangeal joint (MCP) and proximal interphalangeal joint (PIP), and wrist were measured using rotatory and inertial sensors respectively. The degree of movement for MCP, PIP, and Wrist joints were measured to be 0-86°, 0-71°, and 0-89° respectively. Motion to the robotic finger is mimicked by a glove motion requiring minimal learning curve for the device. The collected data for the slave motion is in good agreement with the master-glove motion data. The vibro-tactile haptic feedback system was developed to distinguish between three different materials to mimic human flesh, tumor, and bone. The master-slave system using robotic surgical finger with good simultaneous movement to surgeon's finger and good haptic sensation will provide the surgeon with the opportunity to perform finger dissection in laparoscopic and robotic surgery, as it used to be in open surgery. 3D bio printing will make this process even cheaper with the added advantage of making surgical tools locally according to the need of the surgery. An ongoing work is to develop silicone based 8 mm robotic surgical finger with multiple type haptic feedback.

A Comparative Study to Evaluate the Essential Work of Fracture to Measure the Fracture Toughness of Quasi-Brittle Material.

In the present work, three different woven composite laminates were fabricated using the hand lay-up method. The woven reinforcement fibres were carbon fibres (CFRP), glass fibres (GFRP-W) and (GFRP-R) in combination with epoxy resin. Then, the central notch specimen tensile test (CNT) was used to measure the fracture toughness and the corresponding surface release energy (GIC). Then, the data were compared with the essential work of fracture (we) values based on the stored energy of the body to obtain a new standard fracture toughness test for composite laminates using relatively simple techniques. In addition to an extended finite element model, XFEM was implemented over a central notch specimen geometry to obtain a satisfactory validation of the essential work of fracture concepts. Therefore, the average values of (GIC) were measured with CNT specimens 25.15 kJ/m2, 32.5 kJ/m2 and 20.22 kJ/m2 for CFRP, GFRP-W and GFRP-R, respectively. The data are very close as the percentage error for the surface release energy measured by the two methods was 0.83, 4.6 and 5.16 for carbon, glass and random fibre composite laminates, respectively. The data for the fracture toughness of XFEM are also very close. The percentage error is 4.6, 5.25 and 2.95 for carbon, glass and random fibre composite laminates, respectively. Therefore, the fundamental work of the fracture concept is highly recommended as a fracture toughness test for composite laminates or quasi-brittle Material.

An Analysis of the Risk Factors for the Development of Parastomal Hernia: A Single Institutional Experience.

OBJECTIVES:  To study the frequency of risk factors affecting the development of parastomal hernias in patients undergoing stoma formation. STUDY DESIGN: A retrospective descriptive cross-sectional study. Duration of Study: This study was conducted at the Department of General Surgery between January 2017 to December 2020. METHODOLOGY:  A total of 163 patients aged between 20 and 100 years and who required a stoma formation were included in the study. The patients with incomplete data and those lacking post-operative imaging were excluded. According to this selection criteria, 80 patients were excluded. The data was collected for all patients from the hospital database. This included patient's demographic information, co-morbidities, pre-surgery patient characteristics, an indication of stoma formation, the location of stoma exit, type of surgery, associated comorbidities, subcutaneous fat thickness, and type of stoma formed. Data were analyzed using IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp. RESULTS:  The mean age was 68.46 ± 16.50 years, with males in the majority: 48 (57.8%). Most of the patients, 53 (63.8%), had malignant disease. Post-stoma formation, a total of 38 (45.9%) patients developed parastomal hernias, mostly involving the sigmoid colon (n=62, 74.7%). However, there was a statistically significant relationship between paroxysmal sympathetic hyperactivity (PSH) incidence with non-trans-rectus stomas (trans-oblique n=07, junctional n=28) (OR 3.04, CI 1.23-7.5, p=0.014). Furthermore, malignancy was also not an independent predictor of PSH (OR 0.408, CI 0.15-1.2, p=0.056). All other risk factors included in this study were nonsignificant. CONCLUSION:  Our study shows that the incidence of parastomal hernias is rising with a high rate demonstrated in our patients. There was no statistically significant association between patient-related preoperative and operative factors with increased risk of parastomal hernias in our population except for a non-trans-rectus stoma, which was identified as an independent risk factor for parastomal hernias. Based on our findings, we would recommend a trans-rectus stoma over all other stoma sites. However, a much larger study is needed to validate this finding further.

Intra-thoracic Symptomatic Gallstones in a Right-Sided Post-traumatic Diaphragmatic Hernia: A Case Report.

Herniation of abdominal contents through the diaphragm into the thoracic cavity can occur after blunt abdominal injury, resulting in a permanently acquired diaphragmatic hernia. Their clinical presentation is varied and non-specific, which can go unnoticed for a long duration. A 27-year-old male presented with right upper quadrant pain and right-sided pleuritic chest pain for the past 20 days. His past medical history included high-impact blunt trauma a few years back. His workup revealed a right-sided diaphragmatic hernia through which the gallbladder had herniated into the thoracic cavity, along with liver and hepatic flexure of the colon. The gallbladder contained gallstones which were the cause of his symptoms. The patient was managed successfully with a laparotomy and repair of the diaphragmatic hernia and cholecystectomy. After blunt abdominal trauma, right-sided diaphragmatic injury is less common because most of the trauma is absorbed by the liver, providing a protective effect. The sign and symptoms of acquired diaphragmatic hernia lack sensitivity and specificity, due to which many cases remain undiagnosed and are incidentally picked up on chest auscultation where bowel sounds are audible in the chest, and breath sounds on the affected side are absent, whereas patients have complaints of respiratory difficulty and recurrent pneumonia. Chest and abdominal imagining in the form of chest X-rays and abdominal ultrasound can help diagnose. The case we present was a unique presentation of acquired right-sided diaphragmatic hernia resulting in herniation of the gallbladder in the right-sided chest and leading to acute cholecystitis. The treatment modality is surgical repair of the diaphragm. Any patient presenting with unusual symptoms of pneumonia or abdominal pain should be investigated, especially patients with a history of blunt abdominal trauma.

De Garengeot's hernia in an elderly woman as a diagnostic challenge: a review of literature.

De Garengeot's hernia is the presence of an appendix in a femoral hernia and can be a rare cause of an acute groin swelling. Here, we present a case report of an elderly woman who was referred to us with a short history of a painful, tender lump in the right groin associated with nausea and vomiting. Her inflammatory markers were raised, and to establish a final diagnosis, an urgent CT scan was requested which showed a blind ending tubular structure in a hernia sac. She was taken to the theatre for urgent exploration of the groin which revealed that it was a femoral hernia, the sac of which contained gangrenous appendix, the base of which could not be accessed through the groin incision and, therefore, a lower midline laparotomy incision was made and a formal appendicectomy was done.