Impact of audit and feedback on antipsychotic prescribing in schizophrenia

Objective  To examine the impact of audit and feedback on antipsychotic prescribing for schizophrenia outpatients over 4.5 years.
Methods  Clinical files in three mental health services caring for outpatients in Auckland, New Zealand were reviewed at two time-points (March 2000, October 2004). After the first audit, feedback was provided to all three services. Baseline prescribing variations between services were found for antipsychotic combinations and second-generation antipsychotic (SGA) prescribing, in particular clozapine. In two services audit and feedback continued with two interim reviews (October 2001, March 2003). Specific feedback and interventions targeting clozapine use were introduced in both services. No further audit or feedback occurred in the third service until the final audit. Data were collected (patient characteristics, diagnosis, antipsychotic treatment) and analysed at each audit.
Results  Three prescribing variables (antipsychotic monotherapy, SGA and clozapine use) were consistent with practice recommendations at the final audit (85.7%, 82.7% and 34.5% respectively) and had changed in the desired direction for all three services over the 4.5 years. At baseline there were differences between the three services. One service had baseline prescribing variables closest to recommendations, was actively involved in audit, and improved further. The second service, also actively involved in audit had baseline prescribing variables further from recommendations but improved the most. The service not involved in continuing audit and feedback made smaller changes, and SGA and clozapine use at endpoint were significantly lower despite at baseline being comparable to the service which improved the most.
Conclusions  This study found audit and feedback to be an effective intervention in closing the gap between recommended and routine clinical practice for antipsychotic prescribing in schizophrenia.     

Force-detecting gripper and force feedback system for neurosurgery applications

Purpose For the application of less invasive robotic neurosurgery to the resection of deep-seated tumors, a prototype system of a force-detecting gripper with a flexible micromanipulator and force feedback to the operating unit will be developed. Methods Gripping force applied on the gripper is detected by strain gauges attached to the gripper clip. The signal is transmitted to the amplifier by wires running through the inner tube of the manipulator. Proportional force is applied on the finger lever of the operating unit by the surgeon using a bilateral control program. A pulling force experienced by the gripper is also detected at the gripper clip. The signal for the pulling force is transmitted in a manner identical to that mentioned previously, and the proportional torque is applied on the touching roller of the finger lever of the operating unit. The surgeon can feel the gripping force as the resistance of the operating force of the finger and can feel the pulling force as the friction at the finger surface. Results A basic operation test showed that both the gripping force and pulling force were clearly detected in the gripping of soft material and that the operator could feel the gripping force and pulling force at the finger lever of the operating unit. Conclusions A prototype of the force feedback in the microgripping manipulator system has been developed. The system will be useful for removing deep-seated brain tumors in future master–slave-type robotic neurosurgery.     

The effects of age and feedback on isometric knee extensor force control abilities

OBJECTIVE: To investigate the effects of age and feedback on submaximal isometric force control abilities in the knee extensors. DESIGN: Analysis of a force control task in a quasi-experimental design. BACKGROUND: The ability to control submaximal strength is important to accomplish activities of daily living. The purpose of this study was to investigate the effects of age, feedback, and force level on force control ability in knee extension, which is often used to accomplish daily activities. METHODS: The performance of an isometric force control task was measured in young (mean age 26, SD 2.7 yrs) and older (mean age 72, SD 2.0 yrs) adult healthy male participants. Each participant maintained a steady force in knee extension at two levels of force (20% and 60% MVC) with and without visual bandwidth feedback. Age, force level, and feedback effects were examined on the dependent variables of force variability, bias, and time in bandwidth. RESULTS: Both groups were fairly accurate at accomplishing the task, particularly at the lower force level. The higher force was harder to control, particularly when feedback was absent. The absence of feedback did not affect variability during force control. Older adults performed with less variability and a higher safety margin. Both groups performed better in time spent in bandwidth and safety margin with visual feedback, compared to the no-feedback condition. CONCLUSIONS: Healthy older and younger adults performed quite similarly regardless of feedback being provided or not. The intermittent feedback condition may have been more closely aligned with a no feedback condition rather than a continuous feedback condition. RELEVANCE: Clinical evaluation of submaximal force control ability may be useful for delineating impairments in motor skill and measuring outcomes of intervention programs. To be useful in the clinic, force control assessments must be both sensitive and specific to underlying impairments. The current study investigated the normal range of force control variability to allow the detection of true impairments.     

视觉反馈增益对力量输出影响的fMRI研究

目的 运用全脑fMRI技术研究视觉反馈增益在运动功能执行中的调节作用.方法 设计快、慢两种变化速度的力量跟踪任务,在高低不同的两种视觉反馈增益下令15名正常受试者做右手握力运动,同时接受BOLD-fMRI扫描;采用t检验分析获得不同运动状态与静息状态信号对比的脑功能图,对比观察脑皮层兴奋区的异同.结果 四种模式握力运动均可激活初级躯体感觉运动区(SMC)、双侧前运动区(PMC)、辅助运动区(SMA)、小脑、基底节(BG)和对侧后顶叶(PPC)等.随着反馈增益的提高:S1、PPC、PMC、小脑等激活强度、范围均降低,BG恰好相反;SMA激活强度提高但范围缩小,M1表现不明显.结论 视觉反馈增益对力量输出有显著影响,不同增益所激活的脑区不同.PPC、PMC、小脑、基底节等参与调节过程.     

Impact of nonlinear distortion on acoustic radiation force elastography

High-intensity focused ultrasound (HIFU) produces an acoustic radiation force that induces tissue displacement, which can be measured by monitoring time shifts in the backscattered signals from interrogation pulses. If the pulse occurs simultaneously with the HIFU, the arrival time of the backscatter will be biased because nonlinearity associated with the HIFU changes the local sound speed. Measurements of the pressure field using 1.1 MHz HIFU and a 7.5 MHz pulse in water exhibited a nonlinearly induced apparent displacement (NIAD) that varied with the HIFU pressure, propagation distance and the timing of the pulse relative to the HIFU. Nonlinear simulations employing the KZK equation predicted NIADs that agreed with measurements. Experiments with chicken breast demonstrated a NIAD with magnitude similar to that expected from the radiation force. Finally it was shown that if two pulses were fired with different phases relative to the HIFU, then upon averaging, the NIAD could be mitigated.     

肌电控制前臂假手握力反馈装置

本文研究了利用电阻应变片测量假手握力及采用电刺激方法实现假手握力反馈的原理与反馈装置的实现,并对如何达到良好的反馈效果及实际应用的问题进行了讨论。实验结果表明:本文所采用的方法简便易行,反馈信号的特征明显,反馈效果良好。本文所述方法可应用于各种类型的电动假手,构成感觉反馈系统。     

Extended physiologic taction: design and evaluation of a proportional force feedback system

In both robot teleoperation and prosthetics, the feeding back of touch information to the human operator in a physiologically compatible manner is an important problem. Most research in feedback systems for prosthetic devices has concentrated on electrotactile or vibrotactile stimulation of the skin. While these techniques can transmit information to the user, the user does not have the same sensation as if he were grasping an object in his natural hand. The present research investigates a third method of stimulation using direct force. In the sense of Simpson's Extended Physiologic Proprioception (EPP), it is called: Extended Physiologic Taction (EPT). The EPT system produces a one-to-one correspondence of touch sensation to user stimulation. The EPT system applies a force on the surface of the skin of the operator proportional to the grip force applied at the terminal device, or applies a vibration to the operator proportional to the vibration at the terminal device. A method of quantifying grip controllability has also been developed. A prototype was built and tested using a myoelectrically-controlled prosthetic terminal device as the remote gripping device. Quantifiable comparisons can be made between different feedback and gripping systems as well as comparisons between artificial terminal devices and the natural hand. Results are reported of improved grip control and of improved ability to manipulate objects when using the EPT system.     

Discrete bandwidth visual feedback increases structure of output as compared to continuous visual feedback in isometric force control tasks

BACKGROUND: Performance variability measures provide a partial picture of force control ability. Nonlinear analyses can reveal important information related to the randomness and complexity of the data, providing a more complete picture of the physiological process. METHODS: We investigated the effects of visual feedback on the structure and performance of the force output from isometric force control tasks. Twelve young volunteers completed isometric force control tasks using two types of visual feedback: discrete bandwidth (+/-4% maximal voluntary contraction) and continuous line matching. We determined force signal variability (standard deviation), self-similarity (fractal dimension), and complexity (approximate entropy). Analyses of variance (feedback x muscle group x force level) were conducted and P values less than 0.05 were considered significant. FINDINGS: The force signal in discrete bandwidth feedback, compared to continuous line matching, had significantly a higher standard deviation (P=.000): 2.18 Nm (SD 1.98) vs. 0.99 Nm (SD 0.91); lower fractal dimension (P=.000): 1.07 (SD 0.04) vs. 1.16 (SD 0.04); and lower approximate entropy (P=.000): 0.12 (SD 0.07) vs. 0.26 (SD 0.09). INTERPRETATION: The greater self-similarity (lower fractal dimension) and greater regularity (lower approximate entropy) of the discrete bandwidth, compared to the continuous line matching, may indicate a process that required more kinesthetic (intrinsic) feedback to modulate force. Clinicians may choose to employ visual feedback paradigms that target the use of intrinsic feedback during rehabilitation. Discrete bandwidth feedback may be useful for delineating impairments in motor skill and measuring outcomes of intervention programs.     

Impact of health consequences feedback on patients acceptance of advice about alcohol consumption

Methods: 281 patients identified as hazardous drinkers were offered advice about alcohol consumption. During the experimental period patients' were given feedback as to the health consequences.

Results: Introduction of feedback led to a 23% increase in the proportion of patients who were willing to accept brief advice.

Conclusions: Feedback provision should be included as part of Screening and Brief intervention programmes to increase the number of patients that may benefit from an intervention.

     

Hippocrate: a safe robot arm for medical applications with force feedback

We have developed a robotic system to assist doctors when they are moving ultrasonic probes on a patient's skin while exerting a given effort. The probes are used to monitor arteries for cardiovascular disease prevention, namely to reconstruct the three-dimensional profile of arteries. A preliminary feasibility study making use of an industrial robot has been made to validate the force control scheme. It has proven the interest of the robotized approach for such medical applications where force control is needed. In order to comply with safety constraints, a dedicated robotic system 'Hippocrate' has been designed. This paper describes the arm and the controller architectures, with emphasis on design strategies selected to meet safety requirements. Preliminary in vivo results are presented as well as a possible new application of Hippocrate as a tool for reconstructive surgery.     

Objective concurrent feedback on force parameters improves performance of lumbar mobilisation, but skill retention declines rapidly

ObjectiveTo determine the optimum practice for students to apply lumbar mobilisations with force parameters consistent with an experienced therapist.DesignThirty physiotherapy students attended three practice sessions over two weeks where they performed lumbar mobilisations on a fellow student. Students viewed feedback on their applied forces (measured using an instrumented treatment table) in real-time on a computer screen. Performance was tested before and after feedback at each practice session and at follow up sessions one week and three months later.Outcome measuresA greater accuracy in manual force application was defined as a smaller difference between each student-applied force parameter (mean peak force (N), force amplitude (N), and oscillation frequency (Hz)), and that previously applied by an expert. Test data from each session was analysed using Friedman's and Wilcoxon signed rank tests to determine student learning and retention.ResultsStudents were more accurate after feedback at Session 1 (median difference between student and expert force parameters 7.7 N, IQR 3.2–15.3) than before feedback (median 17.5, IQR 7.3–33.6, P < 0.001). Increased practice improved performance, with the greatest accuracy after feedback at Session 3 (median 7.0, IQR 3.5–11.9, P < 0.01). Retention however was poor, with performance at follow-up sessions no different to baseline.ConclusionsStudents apply more consistent and accurate mean peak force, force amplitude and oscillation frequency after practising with objective, concurrent feedback. Additional practice sessions further improve performance, however retention is poor.     

Rehabilitation of activities of daily living in virtual environments with intuitive user interface and force feedback

Purpose: To investigate the feasibility of using a virtual rehabilitation system with intuitive user interface and force feedback to improve the skills in activities of daily living (ADL).

Method: A virtual training system equipped with haptic devices was developed for the rehabilitation of three ADL tasks – door unlocking, water pouring and meat cutting. Twenty subjects with upper limb disabilities, supervised by two occupational therapists, received a four-session training using the system. The task completion time and the amount of water poured into a virtual glass were recorded. The performance of the three tasks in reality was assessed before and after the virtual training. Feedback of the participants was collected with questionnaires after the study.

Results: The completion time of the virtual tasks decreased during the training (p?<?0.01) while the percentage of water successfully poured increased (p?=?0.051). The score of the Borg scale of perceived exertion was 1.05 (SD?=?1.85; 95% CI?= 0.18–1.92) and that of the task specific feedback questionnaire was 31 (SD?= 4.85; 95% CI?= 28.66–33.34). The feedback of the therapists suggested a positive rehabilitation effect. The participants had positive perception towards the system.

Conclusions: The system can potentially be used as a tool to complement conventional rehabilitation approaches of ADL.

• Implications for rehabilitation

• Rehabilitation of activities of daily living can be facilitated using computer-assisted approaches.

• The existing approaches focus on cognitive training rather than the manual skills.

• A virtual training system with intuitive user interface and force feedback was designed to improve the learning of the manual skills.

• The study shows that system could be used as a training tool to complement conventional rehabilitation approaches.

     

Use of visual force feedback to improve digit force direction during pinch grip in persons with stroke: a pilot study

Seo NJ, Fischer HW, Bogey RA, Rymer WZ, Kamper DG. Use of visual force feedback to improve digit force direction during pinch grip in persons with stroke: a pilot study.

Objective

To investigate whether visual feedback of digit force directions for the index fingertip and thumb tip during repeated practice of grip force production can correct the digit force directions for persons with stroke during grip assessments. Following stroke, the paretic fingers generate digit forces with a higher than normal proportion of shear force to compression force during grip. This misdirected digit force may lead to finger-object slip and failure to stably grasp an object.

Design

A case series.

Setting

Laboratory.

Participants

Persons (N=11) with severe chronic hand impairment after stroke.

Interventions

Four training sessions during which participants practiced directing the index finger and thumb forces in various target directions during pinch using visual feedback.

Main Outcome Measure

Digit force direction during pinch and clinical hand function scores were measured before and immediately after the training.

Results

Study participants were able to redirect the digit force closer to the direction perpendicular to the object surface and increase their hand function scores after training. The mean ratio of the shear force to the normal force decreased from 58% to 41% (SD, 17%), the mean Box and Block Test score increased from 1.4 to 3.4 (SD, 2.0), and the mean Action Research Arm Test score increased from 10.8 to 12.1 (SD, 1.3) (P<.05 for all 3 measures).

Conclusions

Repeated practice of pinch with visual feedback of force direction improved grip force control in persons with stroke. Visual feedback of pinch forces may prove valuable as a rehabilitation paradigm for improving hand function.     

Impact of population management with direct physician feedback on care of patients with type 2 diabetes

OBJECTIVE: Population-level strategies may improve primary care for diabetes. We designed a controlled study to assess the impact of population management versus usual care on metabolic risk factor testing and management in patients with type 2 diabetes. We also identified potential patient-related barriers to effective diabetes management. RESEARCH DESIGN AND METHODS: We used novel clinical software to rank 910 patients in a diabetes registry at a single primary care clinic and thereby identify the 149 patients with the highest HbA(1c) and cholesterol levels. After review of the medical records of these 149 patients, evidence-based guideline recommendations regarding metabolic testing and management were sent via e-mail to each intervention patient's primary care provider (PCP). Over a 3-month follow-up period, we assessed changes in the evidence-based management of intervention patients compared with a matched cohort of control patients receiving usual care at a second primary care clinic affiliated with the same academic medical center. RESULTS: In the intervention cohort, PCPs followed testing recommendations more often (78%) than therapeutic change recommendations (36%, P = 0.001). Compared with the usual care control cohort, population management resulted in a greater overall proportion of evidence-based guideline practices being followed (59 vs. 45%, P = 0.02). Most intervention patients (62%) had potential barriers to effective care, including depression (35%), substance abuse (26%), and prior nonadherence to care plans (18%). CONCLUSIONS: Population management with clinical recommendations sent to PCPs had a modest but statistically significant impact on the evidence-based management of diabetes compared with usual care. Depression and substance abuse are prevalent patient-level adherence barriers in patients with poor metabolic control.     

Ray-casting based evaluation framework for haptic force feedback during percutaneous transhepatic catheter drainage punctures

Purpose

   Development of new needle insertion force feedback algorithms requires comparison with a gold standard method. A new evaluation framework was formulated and tested on needle punctures for percutaneous transhepatic catheter drainage (PTCD).

Methods

   Needle insertion is an established procedure for minimally invasive interventions in the liver. Up-to-date, needle insertions are precisely planned using 2D axial CT slices from 3D data sets. To provide a 3D virtual reality and haptic training and planning environment, the full segmentation of patient data is often a mandatory step. To lessen the time required for manual segmentation, we propose direct haptic volume-rendering based on CT gray values and partially segmented patient data. The core contribution is a new force output evaluation method driven by a ray-casting technique that defines paths from the skin to target structures, i.e., the right hepatic duct near the juncture with the common hepatic duct. A ray-casting method computes insertion trajectories from the skin to the duct considering no-go structures and plausibility criteria. A rating system scores each trajectory. Finally, the best insertion trajectories are selected that reach the target. Along the selected paths, force output comparison between a reference system and the new haptic force output algorithm is carried out, quantified and visualized.

Results

   The evaluation framework is presented along with an exemplary study of the liver using the atlas data set from a reference patient. In a comparison of our reference method to a newer algorithm, force outputs are found to be similar in 99 % of the paths.

Conclusion

   The proposed evaluation framework allows reliable detection of problematic PTCD trajectories and provides valuable hints to improve force feedback algorithm development.     

Finger-attachment device for the feedback of gripping and pulling force in a manipulating system for brain tumor resection

Purpose

Development and evaluation of an effective attachment device for a bilateral brain tumor resection robotic surgery system based on the sensory performance of the human index finger in order to precisely detect gripping- and pulling-force feedback.

Methods

First, a basic test was conducted to investigate the performance of the human index finger in the gripping- and pulling-force feedback system. Based on the test result, a new finger-attachment device was designed and constructed. Then, discrimination tests were conducted to assess the pulling force and the feedback on the hardness of the gripped material.

Results

The results of the basic test show the application of pulling force on the side surface of the finger has an advantage to distinguish the pulling force when the gripping force is applied on the finger-touching surface. Based on this result, a finger-attachment device that applies a gripping force on the finger surface and pulling force on the side surface of the finger was developed. By conducting a discrimination test to assess the hardness of the gripped material, an operator can distinguish whether the gripped material is harder or softer than a normal brain tissue. This will help in confirming whether the gripped material is a tumor. By conducting a discrimination test to assess the pulling force, an operator can distinguish the pulling-force resistance when attempting to pull off the soft material. Pulling-force feedback may help avoid the breaking of blood pipes when they are trapped in the gripper or attached to the gripped tissue.

Conclusion

The finger-attachment device that was developed for detecting gripping- and pulling-force feedback may play an important role in the development of future neurosurgery robotic systems for precise and safe resection of brain tumors.