A technical concept of a computer game for patients with Parkinson's disease – a new form of PC-based physiotherapy

Background: At present, there are no meaningful and sophisticated computer games that simultaneously allow the treatment of movement disorders such as Parkinson's syndrome. In particular, there are no systems to consider the severity of the disease and the physical skills of the patient.

Methods: A computer game using the Microsoft Kinect as markerless sensor for the 3?D recognition of the patient’s movement was developed to support the rehabilitation. The scenario of a basketball game was created after determining that the movement like throwing a ball and the correct posture of the body are important. A study based on system usability was performed with 15 patients to evaluate the system.

Results: The technical feasibility of a computer-assisted training system for supporting patients with Parkinson‘s disease has been demonstrated. No markers on the patient are required for movement detection and allow a user-friendly handling. Regarding the usability study, the patients were accepting of such a system and its at-home use and symptoms like ‘freezing’ and the Pisa syndrome can be treated.

Conclusions: The physiotherapist can be assisted by the developed rehabilitation system. An objective measurement of the patient’s training progress delivers valuable information to adjust the training sessions for every patient individually. Due to its modular character, the system can also be applied to other diseases or sports injuries and offers the basis for further development.     

Endoscopy in Barrett's oesophagus: adherence to standards and neoplasia detection in the community practice versus hospital setting

Objective. Potential process differences between hospital and community‐based endoscopy for Barrett’s oesophagus have not been examined. We aimed at comparing adherence to guidelines and neoplasia detection rates in medical centres (MC) and community practices (CP). Design. Retrospective analysis. Setting. All histologically confirmed Barrett cases seen over a 3‐year period in six MC and 19 CP covering a third of all upper gastrointestinal endoscopies (n = 126 000) performed annually in Berlin, Germany. Main outcome measure. Rate of relevant neoplasia (high‐grade intraepithelial neoplasia or more) in both settings in relation to adherence to standards. Results. Of 1317 Barrett cases, 66% were seen in CP. CP patients had a shorter mean Barrett length (2.6 cm vs. 3.8 cm; P < 0.001) with fewer biopsies taken during an examination (2.5 vs. 4.1 for Barrett length ≤2 cm; P < 0.001). CPs also provided fewer complete esophagogastroduodenoscopy documentation (25.1% vs. 57.8%, P < 0.001). Neoplasias were found more commonly in MCs compared to CPs (9.2% vs. 0.8%; P < 0.001). However, on exclusion of all referred patients with known neoplasia (65%) or those examined for other reasons (27.5%), the detection rate at MCs decreased to 1.3%, not different from the one seen at CPs (0.8%, P = 0.43). Only 13% were found during surveillance, but 57% were diagnosed at an early stage. Conclusions. Referral bias and not better adherence to guidelines could explain the higher neoplasia prevalence in Barrett’s oesophagus at hospital centres. Despite a generally poor adherence to guidelines, most neoplasias found were at an early and potentially curable stage.     

Position Control and Force Estimation Method for Surgical Forceps Using SMA Actuators and Sensors

Minimally invasive surgery is increasingly used in many medical operations because of the benefits for the patients. However, for the surgeons, accessing the situs through a small incision or natural orifice comes with a reduction of the degrees of freedom of the instrument. Due to friction of the mechanical coupling, the haptic feedback lacks sensitivity that could lead to damage of the tissue. The approach of this work to overcome these problems is to develop a control concept for position control and force estimation with shape memory alloys (SMA) which could offer haptic feedback in a novel handheld instrument. The concept aims to bridge the gap between manually actuated laparoscopic instruments and surgical robots. Nickel-titanium shape memory alloys are used for actuation because of their high specific energy density. The work includes the manufacturing of a functional model as a proof of concept comprising the development of a suitable forceps mechanism and electronic circuit for position control and gripping force measurement, as well as designing an ergonomic user interface with haptic force feedback.     

Media for Dimensional Stabilization of Rubber Compounds during Additive Manufacturing and Vulcanization

The current article proposes a concept for the additive manufacturing of rubber components using extrusion-based 3D printing, in which an additional medium is added to ensure the maintenance of shape within the elastomeric structure during the additive manufacturing process and in the subsequent vulcanization process. Specific requirements for the dimensional stabilization of the media were defined and suitable media were derived. Silicone rubber, molding sand, and plaster were examined in experimental vulcanization tests for their suitability as possible media with regard to shape retention. Selected rubber geometries made of NBR were embedded in these media to undergo the vulcanization process. The results show a significant influence of the media on the heating times. All media were able to ensure that the rubber geometries maintained their shape during vulcanization. Nevertheless, some side effects were found. The silicone rubber did not cure properly around the rubber sample. Therefore, it was difficult to remove it from the rubber after vulcanization. The molding sand caused an increased surface roughness on the rubber. Plaster changed the glossy surfaces at the beginning to a matte one after vulcanization and residuals were difficult to remove. However, all media can serve as stabilization media with specific changes.     

Cocaine-Dependent Acquisition of Locomotor Sensitization and Conditioned Place Preference Requires D1 Dopaminergic Signaling through a Cyclic AMP,NCS-Rapgef2, ERK,and Egr-1/Zif268 Pathway

Elucidation of the mechanism of dopamine signaling to ERK that underlies plasticity in dopamine D1 receptor-expressing neurons leading to acquired cocaine preference is incomplete. NCS-Rapgef2 is a novel cAMP effector, expressed in neuronal and endocrine cells in adult mammals, that is required for D1 dopamine receptor-dependent ERK phosphorylation in mouse brain. In this report, we studied the effects of abrogating NCS-Rapgef2 expression on cAMP-dependent ERK→Egr-1/Zif268 signaling in cultured neuroendocrine cells; in D1 medium spiny neurons of NAc slices; and in either male or female mouse brain in a region-specific manner. NCS-Rapgef2 gene deletion in the NAc in adult mice, using adeno-associated virus-mediated expression of cre recombinase, eliminated cocaine-induced ERK phosphorylation and Egr-1/Zif268 upregulation in D1-medium spiny neurons and cocaine-induced behaviors, including locomotor sensitization and conditioned place preference. Abrogation of NCS-Rapgef2 gene expression in mPFC and BLA, by crossing mice bearing a floxed Rapgef2 allele with a cre mouse line driven by calcium/calmodulin-dependent kinase IIα promoter also eliminated cocaine-induced phospho-ERK activation and Egr-1/Zif268 induction, but without effect on the cocaine-induced behaviors. Our results indicate that NCS-Rapgef2 signaling to ERK in dopamine D1 receptor-expressing neurons in the NAc, but not in corticolimbic areas, contributes to cocaine-induced locomotor sensitization and conditioned place preference. Ablation of cocaine-dependent ERK activation by elimination of NCS-Rapgef2 occurred with no effect on phosphorylation of CREB in D1 dopaminoceptive neurons of NAc. This study reveals a new cAMP-dependent signaling pathway for cocaine-induced behavioral adaptations, mediated through NCS-Rapgef2/phospho-ERK activation, independently of PKA/CREB signaling.SIGNIFICANCE STATEMENT ERK phosphorylation in dopamine D1 receptor-expressing neurons exerts a pivotal role in psychostimulant-induced neuronal gene regulation and behavioral adaptation, including locomotor sensitization and drug preference in rodents. In this study, we examined the role of dopamine signaling through the D1 receptor via a novel pathway initiated through the cAMP-activated guanine nucleotide exchange factor NCS-Rapgef2 in mice. NCS-Rapgef2 in the NAc is required for activation of ERK and Egr-1/Zif268 in D1 dopaminoceptive neurons after acute cocaine administration, and subsequent enhanced locomotor response and drug seeking behavior after repeated cocaine administration. This novel component in dopamine signaling provides a potential new target for intervention in psychostimulant-shaped behaviors, and new understanding of how D1-medium spiny neurons encode the experience of psychomotor stimulant exposure.     

Surgical stent planning: simulation parameter study for models based on DICOM standards

Purpose  

Endovascular Aneurysm Repair (EVAR) can be facilitated by a realistic simulation model of stent-vessel-interaction. Therefore, numerical feasibility and integrability in the clinical environment was evaluated.     

Concept of patient-specific shape memory implants for the treatment of orbital floor fractures

Purpose

We will aim to develop implants made of a Ni-Ti shape memory alloy which can be applied for the treatment of midface fractures, such as isolated orbital floor fractures. These can then be implanted in a compressed form and unfold automatically in the body. With the help of newly developed application instruments, the implants can be applied along transnasal and transantral approaches into the maxillary sinus. Our objective is to evaluate the operation process and the functionality of these implants, already in a pre-investigation by an experienced surgeon on a phantom.

Methods

The functionality of the surgical procedure and an implant prototype were both evaluated with the help of a realistic phantom. The minimally invasive application was carried out using the transnasal and transantral approach. Instruments and implant were rated individually on a scale, from ?2 (not at all) to +2 (very good) for vaious criteria, such as the implants functionality or the ergonomics of the entire procedure. For a geometric comparison between the manufactured implant and the planned target geometry, the implants were scanned by micro-computed tomography. CAD models were derived from the scans by using reverse engineering.

Results

Both the implants and the application procedure were assessed as good; thus, the implant concept is suitable for further development.

Conclusions

Implants made of shape memory alloys could allow in the future and allow less invasive access to treat orbital floor fractures. The implant design has to be modified that the implant can be stabilized and fixed with screws or a suture to avoid dislocation or implant loosening. The complication rates and risks of conventional orbital reconstructions should be lowered by this new method.

     

Investigation into the Hybrid Production of a Superelastic Shape Memory Alloy with Additively Manufactured Structures for Medical Implants

The demographic change in and the higher incidence of degenerative bone disease have resulted in an increase in the number of patients with osteoporotic bone tissue causing. amongst other issues, implant loosening. Revision surgery to treat and correct the loosenings should be avoided, because of the additional patient stress and high treatment costs. Shape memory alloys (SMA) can help to increase the anchorage stability of implants due to their superelastic behavior. The present study investigates the potential of hybridizing NiTi SMA sheets with additively manufactured Ti6Al4V anchoring structures using laser powder bed fusion (LPBF) technology to functionalize a pedicle screw. Different scanning strategies are evaluated, aiming for minimized warpage of the NiTi SMA sheet. For biomechanical tests, functional samples were manufactured. A good connection between the additively manufactured Ti6Al4V anchoring structures and NiTi SMA substrate could be observed though crack formation occurring at the transition area between the two materials. These cracks do not propagate during biomechanical testing, nor do they lead to flaking structures. In summary, the hybrid manufacturing of a NiTi SMA substrate with additively manufactured Ti6Al4V structures is suitable for medical implants.     

Appropriateness of Colonoscopy in the Era of Colorectal Cancer Screening: A Prospective,Multicenter Study in a Private-Practice Setting (Berlin Colonoscopy Project 1, BECOP 1)

Purpose The introduction of reimbursement for screening colonoscopy in Germany more than one year ago raised concerns that the consequent workload might lead to underuse of diagnostic colonoscopy for symptomatic patients. Available appropriateness criteria for diagnostic colonoscopy have been rarely tested in a realistic outpatient setting. This study was designed to test current appropriateness criteria for diagnostic colonoscopy to better select patients and potentially provide more capacity for screening cases. Secondary goals were yield and quality control in both the diagnostic and screening cases. Methods A prospective study was initiated in 39 private-practice offices to collect data on consecutive colonoscopies conducted during a 6-day study period. A detailed questionnaire was developed to define indications and symptoms, and all findings at colonoscopy were recorded. Colonoscopies were further analyzed and stratified into a screening and a diagnostic group. In the diagnostic group, indications were assessed according to the current guidelines for appropriateness (American Society for Gastrointestinal Endoscopy, European Panel for the Appropriateness of Gastrointestinal Endoscopy), and the results were correlated with the percentage of relevant findings (tumors, inflammatory conditions). Results During the study period, 1,397 colonoscopies (57 percent screening, 43 percent diagnostic) were analyzed (male/female ratio = 39/61 percent; mean age, 61 years). Fourteen percent and 37 percent, respectively, of the 605 diagnostic colonoscopies were regarded as inappropriate relative to the criteria of the American Society for Gastrointestinal Endoscopy and the European Panel for the Appropriateness of Gastrointestinal Endoscopy. However, the percentage of relevant inflammatory and neoplastic findings (polyps, cancer, inflammatory bowel disease, benign strictures) was only 5 to 10 percent higher in the appropriate group than in the inappropriate group. On the basis of these data, a hypothetical model for selecting appropriate indications was developed: if patients older than aged 50 years with pain, bleeding, and diarrhea, but not constipation, are regarded as having an appropriate indication, such an approach would save 20 percent of colonoscopies in these main indication groups (bleeding, pain, diarrhea, constipation), with a hypothetical miss rate for relevant findings (as defined above) of 5 percent. Conclusions Currently used appropriateness criteria for diagnostic colonoscopy increase the yield of relevant findings but lead to a miss rate for relevant findings in the range of 10 to 15 percent. Simple selection criteria based on age and symptoms could be more suitable and should be tested in a larger group of patients. *For members participating in this study, see the Appendix. Supported by unrestricted grants from Olympus Co. Europe/Hamburg and Falk Foundation/Freiburg, Germany.