Evaluation of a novel navigation platform for laparoscopic liver surgery with organ deformation compensation using injected fiducials

In laparoscopic liver resection, surgeons conventionally rely on anatomical landmarks detected through a laparoscope, preoperative volumetric images and laparoscopic ultrasound to compensate for the challenges of minimally invasive access. Image guidance using optical tracking and registration procedures is a promising tool, although often undermined by its inaccuracy. This study evaluates a novel surgical navigation solution that can compensate for liver deformations using an accurate and effective registration method. The proposed solution relies on a robotic C-arm to perform registration to preoperative CT/MRI image data and allows for intraoperative updates during resection using fluoroscopic images. Navigation is offered both as a 3D liver model with real-time instrument visualization, as well as an augmented reality overlay on the laparoscope camera view. Testing was conducted through a pre-clinical trial which included four porcine models. Accuracy of the navigation system was measured through two evaluation methods: liver surface fiducials reprojection and a comparison between planned and navigated resection margins. Target Registration Error with the fiducials evaluation shows that the accuracy in the vicinity of the lesion was 3.78±1.89 mm. Resection margin evaluations resulted in an overall median accuracy of 4.44 mm with a maximum error of 9.75 mm over the four subjects. The presented solution is accurate enough to be potentially clinically beneficial for surgical guidance in laparoscopic liver surgery.

Use of mixed reality for surgery planning: Assessment and development workflow

Meticulous preoperative planning is an important part of any surgery to achieve high levels of precision and avoid complications. Conventional medical 2D images and their corresponding three-dimensional (3D) reconstructions are the main components of an efficient planning system. However, these systems still use flat screens for visualisation of 3D information, thus losing depth information which is crucial for 3D spatial understanding. Currently, cutting-edge mixed reality systems have shown to be a worthy alternative to provide 3D information to clinicians. In this work, we describe development details of the different steps in the workflow for the clinical use of mixed reality, including results from a qualitative user evaluation and clinical use-cases in laparoscopic liver surgery and heart surgery. Our findings indicate a very high general acceptance of mixed reality devices with our applications and they were consistently rated high for device, visualisation and interaction areas in our questionnaire. Furthermore, our clinical use-cases demonstrate that the surgeons perceived the HoloLens to be useful, recommendable to other surgeons and also provided a definitive answer at a multi-disciplinary team meeting.

The effect of intraoperative imaging on surgical navigation for laparoscopic liver resection surgery

Conventional surgical navigation systems rely on preoperative imaging to provide guidance. In laparoscopic liver surgery, insufflation of the abdomen (pneumoperitoneum) can cause deformations on the liver, introducing inaccuracies in the correspondence between the preoperative images and the intraoperative reality. This study evaluates the improvements provided by intraoperative imaging for laparoscopic liver surgical navigation, when displayed as augmented reality (AR). Significant differences were found in terms of accuracy of the AR, in favor of intraoperative imaging. In addition, results showed an effect of user-induced error: image-to-patient registration based on annotations performed by clinicians caused 33% more inaccuracy as compared to image-to-patient registration algorithms that do not depend on user annotations. Hence, to achieve accurate surgical navigation for laparoscopic liver surgery, intraoperative imaging is recommendable to compensate for deformation. Moreover, user annotation errors may lead to inaccuracies in registration processes.

Thermodynamics of interaction of caffeic acid and quinic acid with multisubunit proteins

Helianthinin is a multisubunit protein from Sunflower seeds. Caffeic acid (CA) and quinic acid (QA) are intrinsic ligands present in sunflower seeds. The mechanism of interaction of these ligands with multisubunit proteins is limited. The present study enables one to understand the mechanism of the interaction of these ligands with the protein helianthinin. From this study, it is shown that CA has two classes of binding sites on helianthinin. The high-affinity class of sites total six from 60+/-10 for both high-affinity and low-affinity sites. Tryptophan, tyrosine and lysine residues of the protein are mainly involved in the interaction with CA. The temperature dependence of the binding in the range 10-45 degrees C can be clearly described by an enthalpy-entropy compensation effect at the low-affinity class of sites, while it is described by positive DeltaC(p)(o) at the high-affinity class of sites. This positive DeltaC(p)(o) has a contribution to the protein stability. The binding strength of CA also has a positive cooperativity at higher protein concentration. QA has two classes of binding sites on the protein based on the strength of the interaction. The interaction of QA with the protein is predominantly described by positive DeltaC(p)(o) for both classes of affinity. This suggests predominance of ionic/hydrogen bonding in the interaction process. Differential scanning calorimetric measurements reveal that the binding of both CA and QA induces destabilisation of the subunit-subunit interaction. Human methaemoglobin (mHb) has two binding sites on the molecule for CA. Both CA and QA decrease the stability of mHb, as indicated by decreased T(m). This destabilisation is also accompanied by dissociation to the monomers with concomitant conformational changes.

Changes in protein metabolism in hemolymph and fat body of the silkworm, Bombyx mori (Lepidoptera: Bombycidae) in response to organophosphorus insecticides toxicity

Changes in protein metabolism were studied in hemolymph and fat body of 5th instar silkworm Bombyx mori exposed to lethal and sublethal doses of fenitrothion and ethion. The total protein content indicated a depletion followed by a concomitant increase in accumulation of free amino acids. Concurrently, the activity of protease in both of the tissues was also increased. A sharp enhancement in the activities of alanine aminotransferase and aspartate aminotransferase paralleled the elevation of glutamate dehydrogenase activity in the tissues studied. All these changes clearly documented the induction of severe proteolysis and transamination of amino acids.

Changes in Na and K ions in mouse liver following in vivo exposure to ultrasound

Mouse liver was exposed in vivo to a continuous and unfocussed ultrasound of 875 KHz at 5, 10 or 15 W/cm2 for 300 sec spread over five days and excised on day 0, 1, 5 and 10 for studying the changes in Na+ and K+ reserves and Na-K-ATPase activity. At 5 and 10 W intensities the change in ionic concentrations and Na-K-ATPase activity were almost in linear. At 15 W intensity the loss of both the ions and suppression of Na-K-ATPase indicated the damage of hepatic tissue caused by high intensity ultrasound. By day 10, all the animals of three exposures showed a normal ionic concentration with an optimum Na-K-ATPase activity in liver indicating the recovery process. The results indicate that ultrasound induces permeability changes in a glandular tissue exposed in vivo.

Ultrasound-induced enhancement of ACh, AChE and GABA in fetal brain tissue of mouse

Pregnant mice were exposed to continuous-wave (CW) ultrasound of 875 kHz frequency at 1 W/cm2 for 300 and 400 s, spread over five days, starting from the sixth day of pregnancy. The neurotransmitters, acetylcholine (ACh) and gamma amino butyric acid (GABA), and the associated enzyme acetylcholinesterase (AChE) levels, were estimated in the exposed fetal brains. Enhanced levels, significant at p < 0.001, were observed in the brains excised on day 10, day 15 and day 20 of gestation compared to sham-exposed and cage-control brains.

Some biochemical changes in mouse after in-vivo irradiation of pancreas with ultrasound

875 KHz continuous wave of ultrasound at 2.5 W/Cm2 intensity revealed certain biochemical and enzymological changes in mouse pancreas and liver following the irradiation of pancreas in-vivo for a total of 300 seconds spread over five days. The sacrifice of the animals was carried out on day 0, day 1, day 5 and day 10. Blood glucose was reduced significantly with concomitant increase in liver glycogen. Glucose-6-phosphatase in liver was decreased significantly while glycogen phosphorylase showed marginal variations. Increased calcium pool in pancreas along with Ca2+ activated ATPase was observed. These alterations were prevalent in all the days of sacrifice and also for more than 10 days after the last exposure. The results are suggestive of ultrasound could stimulate the release of pancreatic secretions.

Transmission of health information on leprosy from children to their families: another approach to health education

A controlled study was carried out in the North Arcot District of Tamil Nadu, South India to determine whether health information given to schoolchildren would influence the knowledge and attitudes of their families concerning leprosy. A total of 41 children and almost all of their household members participated in the study. The study, conducted by questionnaire, involved a pre-test of knowledge and attitude about leprosy of seventh standard students and their families. After one group of children received health education about leprosy and the other received information about tuberculosis, an identical post-test questionnaire was administered to all participants. Although significant improvement in knowledge about leprosy was detected in the leprosy educated group of children compared with controls, no transmission of information on leprosy was detected in the family members of either group. The attitudes of the children who had been educated about leprosy may have been adversely affected by the health education session. The reasons for our failure to detect significant transfer of information about leprosy in this setting are discussed, as well as the need for additional research in this area.

The need for a drug abuse documentation center in India

The problems of alcoholism and drug addiction are major concerns in India. Alcohol and drugs were used in the past to obtain relief from pain and misery and to attain a state of forgetfulness. India is presently facing the problem of increased trafficking in drugs; heroin and hashish are supplied to the west through the subcontinent. Addiction has become a major problem in metropolitan centers. The Ministry of Welfare is responsible for drug abuse prevention programs and the rehabilitation of addicts. The Ministry of Health and Family Welfare is concerned with drug treatment. A deaddiction center, established at the All India Institute of Medical Sciences, became operational in 1988; it is responsible for health manpower training, research, and documentation. India has witnessed an exponential growth in the literature on drug abuse; it is no longer possible for a single library to acquire all of the international literature. There is a clear need to establish a drug abuse information center in India. This paper describes the aims, objectives, and planning for such a center and recommends the establishment of a national center in New Delhi with regional centers in other geographic areas.

Ultrasound induced damages and time bound recovery in mouse liver

Therapeutic ultrasound at 875 kHz at 10 and 15 W/cm2 intensity induced extensive damages in the liver of mouse. Total exposure of 5 min was spread over 5 days. Aqueous medium was avoided by coupling the transducer directly to the skin surface. Mild to extensive damages were noted. Complete distortion of hepatocellular architecture was noted in 15 W irradiated mice. However, there was almost complete recovery by 10th day following the last exposure.

Anthranilate hydroxylase from Aspergillus niger: evidence for the participation of iron in the double hydroxylation reaction

Evidence was obtained for the participation of iron in the double hydroxylation reaction catalyzed by anthranilate hydroxylase from Aspergillus niger (UBC 814). Omission of iron from the growth medium gave inactive preparations of anthranilate hydroxylase which could be reactivated by incubating the enzyme preparations with ferric citrate. The enzyme was susceptible to inhibition by metal chelating agents. The K(i) for o-phenanthroline, which inhibited the enzyme activity non-competitively with respect to anthranilate, was calculated to be 0.9 mM. The inhibition by o-phenanthroline was counteracted by ferric complexes such as ferric-ethylenediaminetetraacetic acid and ferric citrate. Anthranilate afforded protection against inhibition by o-phenanthroline.