Recent Patents on Biomedical Engineering (Discontinued) - Volume 6, Issue 2, 2013

Advances in micro-electro-mechanical systems (MEMS), solid-state, wireless, and battery technologies have made possible the development of a new generation of portable, low-power, wireless, and high-capacity movement sensors with significant potential in a variety of medical applications. This article includes a review of recent patents focused on novel wearable movement sensors appropriate for biomedical applications involving motion capture, activity recognition, and objective analysis of movement disorders. The paper focuses on the technical challenges associated with the hardware design of these devices in the context of movement disorders, and the solutions disclosed in patents and patent applications. Additionally, the paper provides a discussion of future developments and the outstanding technical challenges that would need to be overcome for the widespread use of movement sensors in research and clinical settings. Our patent search revealed that a total of 958 issued patents and 664 patent applications have been published by the United States Patent & Trademark Office (USPTO) in subclass US600/595 (body monitoring). Since 2007, 34 patents were issued and 342 patent applications were published (378 patent publications) in this subclass, indicating that nearly 25% of the patented or patent pending developments in movement monitoring occurred in the last 3.5 years. Despite the significant developments in this area, none of the patent publications analyzed disclosed wearable movement sensors that overcome some of the most significant technical challenges such as the problem of wireless synchronization of sampling times among multiple sensors. Consequently, valuable intellectual property remains to be developed and claimed in future patents in this technical field.

This article provides a brief review of recent patents focused on detection and quantification of human tremor. Tremor is the most common type of involuntary movement. The paper provides a discussion of recent patent publications that include disclosure directed to methods, apparatuses or systems for objective detection and quantification of tremor. Our patent search strategy reveals that over 63% of the patent publications in the technical field of body monitoring have occurred in the last 10 years, and the last 3 years account for 30% of the statutory protection effort. Despite the significant developments in this area, no single instrument or methodology has become accepted as a gold standard for quantifying tremor or dominated most applications. The results of the search and review reveal that patent applications published in the last 3 years are not directed specifically to novel methods for detection and quantification of tremor. All instruments currently available and disclosed in recent patents present some disadvantages, and the best instrument depends on the application requirements to determine the tradeoffs between cost, precision, duration, portability, and ease of use. No dominant design has emerged. New instruments are continuing to be developed and it is expected that statutory protection in this technical field will continue to expand.

Gait disturbance is an important symptom of Parkinson’s disease (PD). This paper presents a review of patents reported in the area of computerized gait disorder analysis. The feasibility of marker-less vision based systems has been examined for ‘at-home’ self-evaluation of gait taking into account the physical restrictions of patients arising due to PD. A three tier review methodology has been utilized to synthesize gait applications to investigate PD related gait features and to explore methods for gait classification based on symptom severities. A comparison between invasive and non-invasive methods for gait analysis revealed that marker-free approach can provide resource efficient, convenient and accurate gait measurements through the use of image processing methods. Image segmentation of human silhouette is the major challenge in the marker-free systems which can possibly be comprehended through the use of Microsoft Kinect application and motion estimation algorithms. Our synthesis further suggests that biorhythmic features in gait patterns have potential to discriminate gait anomalies based on the clinical scales.

This review focuses on recent innovations and patents with the aim to allow people with movement disorders to control their environment. This particularly includes different technologies for input devices to control computers and other electronic equipment used by persons with movement disorders, enabling the empowerment of this user group. The control of such devices can be the key to social inclusion and mean improved social contact with others, access of information or possibility to work. In this paper, several patents and innovations are described that enable such control, divided into the groups; Input devices in form of switches and touchscreens, Inertia and inclinometer sensors, Voice control and Gesture control. Also methods allowing monitoring and classification of physical activity, i.e. assisting to alarm in case of a fall and systems assisting in rehabilitation at home, are included, as are video games aimed to promote physical activity.

A major problem with the clinical management of fluctuating movement disorders, e.g. Parkinson’s disease (PD), is the large variability in manifestation of symptoms among patients. In this condition, frequent measurements which account for both patient-reported and objective assessments are needed in order to capture symptom fluctuations, with the purpose to optimize therapy. The main focus of this paper is to present a mobile-based system for enabling remote monitoring of PD patients from their home environment conditions. The system consists of a patient diary section for collecting patient-based self-assessments, a motor test section for collecting fine motor movements through upper limb motor tests, and a scheduler for restricting operation to a multitude of predetermined limited time intervals. The system processes and compiles time series data into different summary scores representing symptom severity. In addition, the paper presents a review of recent inventions which were filed after year 2000 in the field of telemedicine applications. The review includes a summary of systems and methods which enable remote symptom assessments of patients, not necessarily suffering from movement disorders, through repeated measurements and which take into account their subjective and/or objective health indicators. The findings conclude that there are a small number of inventions which collect subjective and objective health measures in telemedicine settings. Consequently, there is a lack of mechanisms that combine these two types of information into scores to provide a more in-depth assessment of the patient’s general health, their motor and non-motor symptom fluctuations and treatment effects. The paper also provides a discussion concerning different approaches for analyzing and combining subjective and objective measures, and handling data from longitudinal studies.

Intervertebral discs allow the spine to transfer loads and motion in the upper body. They redistribute compressive loads, resist rotational and shear forces, and at the same time impart various motions in each of the spinal vertebral segments. Pain and disability result from degenerative disc disease, herniated discs, and injuries from trauma. Reduced movement and pain are associated with these conditions and may result in collapse, spontaneous or post-traumatic tears, and additional transferred pressure on surrounding nerves. A shift in the mechanical axis of the load may also occur, causing irritation and pain as well as abnormal bone growth. When non-surgical methods are ineffective at treating these disorders, surgical alternatives include fusion, considered to be gold standard, and disc replacement. Disc replacement is proposed in the literature to provide higher joint mobility, shorter surgery time, shorter recovery time and potentially, a decreased occurrence of adjacent level degeneration, though long term outcomes are not available at this time. Many disc replacement devices are patented and available for the cervical and lumbar spine as well as of the replacement of the nucleus. This paper classifies the devices into the following: a) cervical devices (23 devices), b) lumbar devices (29 devices), and c) nucleus replacement (20 devices) and summarizes the device characteristics, materials used, their design features, and regulatory status. A limited amount of biomechanics and outcome results are also reported for select few cases.