**2. Smartphone: wireless accelerometer platform for quantifying human movement**

Following this requirement definition LeMoyne and Mastroianni successfully acquired of an appropriate software application to record the accelerometer signal data and convey the data package as an email attachment. This capability transformed the smartphone from a telecommunication utility to a wearable and wireless accelerometer sensor system capable of measuring human motion within the context of an assortment of scenarios. Given the compact nature of the smartphone, it can be easily mounted about an assortment of readily identifiable anatomical mounting positions. Preliminary research, development, testing, and evaluation of the smartphone emphasized the role of quantifying gait and Parkinson's disease [1–3, 23, 24].

During 2010 LeMoyne and Mastroianni applied the smartphone as a wearable and wireless gait analysis device. The smartphone was equipped with an application that enabled it to function as a wireless accelerometer platform. The recorded data package of the acceleration waveform was conveyed by wireless transmission to the Internet as an email attachment [23].

of these applications derives from preliminary research, development, testing, and evaluation

Inertial sensors such as accelerometers were originally proposed for the quantification of human movement, however at the time of this perspective they were not sufficiently evolved. The technology evolution of accelerometer systems proceeded in tandem with disparate industries relative to the biomedical, rehabilitation, and health industry [4, 5]. Quantification of rehabilitation status can facilitate the modification of a therapy intervention, especially with the expert clinical acuity of a trained expert, however traditional quantification apparatus, such as gait analysis quantification equipment, is generally restricted to a clinical environment [6, 7]. The role of the accelerometer system steadily progressed with the biomedical, rehabilitation, and health community [8]. Eventually with the development of wireless technology supporting inertial sensors, such as accelerometers and gyroscopes, other techniques,

The wireless accelerometer has been successfully demonstrated as a wearable system for the quantification of human movement [4]. Tandem operated wireless accelerometer systems have been successfully applied to the quantified evaluation of hemiplegic gait [10–12]. Other associated endeavors have demonstrated the role of wireless accelerometers for quantifying reflex response and even reflex latency [13–19]. Further testing and evaluation has revealed the utility of wireless accelerometers for quantifying movement disorder tremor, such as for Parkinson's disease [20, 21]. Further evolution of the capability of wearable and wireless applications is featured through the research, development, testing, and evaluation of smartphones and portable media devices as wireless accelerometer and gyroscope platforms [1–3, 22].

Ever since the origins of the smartphone, one of its well known features is the observation that the screen will shift orientation based on movement and position. This capability is due to its inertial sensor, originally consisting of an accelerometer and now also a gyroscope. With this feature noted LeMoyne and Mastroianni sought to utilize this inertial sensor package to characterize human movement, much like their previous application of wireless accelerometers

**2. Smartphone: wireless accelerometer platform for quantifying human** 

Following this requirement definition LeMoyne and Mastroianni successfully acquired of an appropriate software application to record the accelerometer signal data and convey the data package as an email attachment. This capability transformed the smartphone from a telecommunication utility to a wearable and wireless accelerometer sensor system capable of measuring human motion within the context of an assortment of scenarios. Given the compact nature of the smartphone, it can be easily mounted about an assortment of readily identifiable anatomical mounting positions. Preliminary research, development, testing, and evaluation of the smartphone emphasized the role of quantifying gait and Parkinson's disease [1–3, 23, 24].

of wireless accelerometer nodes that are essentially wearable for similar scenarios [4].

such as tethering, became effectively outmoded [9].

2 Smartphones from an Applied Research Perspective

for similar endeavors [1–3, 22].

**movement**

Another major observation of the capabilities of this application was based on the remote nature between the experimental site and post-processing resources. The gait experiment was conducted in the region of Pittsburgh, Pennsylvania. However, the post-processing resources were situated in the greater Los Angeles area. The implications of the research endeavor are that with a suitable software application the smartphone operating as a wireless accelerometer can quantifying human movement characteristics, such as gait, with post-processing resources situated anywhere in the world. Essentially the email resource symbolizes a functional semblance of a cloud computing resource [23].

For the scope of gait analysis the smartphone was secured about the lateral malleolus near the ankle joint by an elastic band. Each gait experiment recorded on the order of 10 s of steady state walking. Temporal and kinematic parameters, such as the stance to stance temporal disparity and stance to stance time averaged acceleration, were acquired in an accurate and consistent manner [23]. Further testing and evaluation of the smartphone as a wireless accelerometer platform for gait analysis were successfully demonstrated using alternative mounting positions, such as the lateral epicondyle of the femur and the lumbar-sacral aspect of the spine [25, 26].

During 2010 LeMoyne and Mastroianni also applied the smartphone as a wearable and wireless accelerometer for the quantified acquisition of Parkinson's disease tremor. Measuring Parkinson's disease at the convenience of a patient's homebound setting is of paramount significance, in order to provide optimal acuity for expert clinical medical therapy intervention. A smartphone could measure Parkinson's disease hand tremor through mounting to the dorsum of the hand. With the experiment conducted in Pittsburgh, Pennsylvania and postprocessing resources situated trans-continentally in greater Los Angeles, the application again demonstrates the ability to remotely situate experimental and post-processing resources. Tremor characteristics were successfully quantified for a person with Parkinson's disease and contrasted to a non-Parkinson's subject [24].

The implications of the research, development, test, and evaluation demonstrated by LeMoyne and Mastroianni elucidate the broad power of wearable and wireless systems, such as the smartphone as a wireless accelerometer platform. The smartphone can be easily mounted to effectively any portion of the body that best defined the characteristics of the human movement feature under consideration, such as the near the ankle joint for gait or dorsum of the hand for Parkinson's disease tremor. From the experimental site, the recorded accelerometer signal data can be conveyed through wireless Internet connectivity to a post-processing resource anywhere in the world. In essence a subject can access the best clinical resources in the world from the convenience of a familiar homebound and autonomous setting. Further testing and evaluation of the smartphone as a wireless accelerometer pertained to the quantification of reflex response.

The reflexes of the lower limb are synergistically interrelated with the function of gait [19]. Therefore with the success of the smartphone as a wireless accelerometer platform for quantifying gait, the patellar tendon reflex response logically should also be a readily quantifiable aspect of human movement. Preliminary testing and evaluation the smartphone as a wireless accelerometer for quantifying reflex response pertained to manual stimulation of the patellar tendon reflex [27]. The accurate and consistent quantification of the patellar tendon reflex can be further facilitated through the application of a potential energy impact pendulum for evoking the tendon reflex response with a prescribed amount of energy that is also targeted to a specified aspect of the patellar tendon [14–19].

Using a remote and effectively rural area as an experimental site, LeMoyne and Mastroianni applied a smartphone as a wireless accelerometer platform in conjunction with a potential energy impact pendulum. The integration of these devices readily acquired a recording of the reflex response acceleration waveform for the patellar tendon. The trial data was conveyed by wireless transmission to the Internet as an email attachment. Remotely situated post-processing resources applied software automation to quickly determine the efficacy of the experimental trial data. The findings advocate that the patellar tendon reflex response can be readily acquired through the integral application of the potential energy impact pendulum with the smartphone as a wireless accelerometer platform in an accurate and consistent manner [28]. Further establishment of the smartphone for quantifying the reflex response was demonstrated though the application of an artificial reflex system [29].

Further investigation of the opportunities for gait quantification emphasized the evaluation of gait for people with transtibial amputation. In consideration of people with transtibial amputation, they require a different mounting technique as opposed to merely applying an elastic band to secure the smartphone. In order to resolve this matter, a 3D printed mounting adapter was applied to secure the smartphone to the transtibial prosthesis. The smartphone conveniently measured the acceleration waveform of the subject's gait respective of the transtibial prosthesis. Automated software facilitated the post-processing endeavor with gait characteristics acquired in an accurate and reliable manner [30].
