CleveMed Blogs

When developing a movement disorder monitor it is especially important to consider the desired end user. Even the most advanced movement disorder device would be worthless if the user was either unsure or unable to operate it. This is something CleveMed focused on when developing Kinesia HomeView (a take-home PD symptom monitor to help clinicians observe patients’ symptom patterns over a period of time). Movement disorders involve symptoms that are challenging to design considerations. By bringing PD patients who experience these symptoms into the office to interact with Kinesia HomeView, important feedback about the system’s mechanical and software design was gained. Design features that could have been burdensome to the end user were addressed and changed as necessary. In this article I would like to mention some of the features that were refined as a result of the user-feedback:

Mouse replaced with Touch-screen:

Using a computer mouse to record diary information wasn’t always feasible for focus group participants who experienced tremor, so the mouse was replaced with a touch-screen computer. This allows the user to hit a large target on the screen as opposed to worrying about the fine-tuned control required to navigate a mouse.

Motion sensor simplified for easier application:

In order for the system to be effective, a motion sensor needs to be placed on the hand by the PD patient. In its preliminary design, the sensor unit for HomeView was rather bulky, and some participants who were experiencing tremor found it cumbersome to strap it on both wrist and hand as required. After feedback the sensor was condensed into a single compact housing attached to the index finger. This new design can be slid directly over the finger.

Patient-friendly docking station for charger:

Finally, charging of the finger sensor battery was changed from a USB cable to a docking station. The docking station allows the end user to connect the sensor using a much larger target than a USB cable provides.

If CleveMed had not consulted with Parkinson’s disease patients about the design of Kinesia HomeView, the end product would have been far from ideal for home use. Getting user feedback is important throughout the development process of new medical devices like Kinesia HomeView. Engineers who don’t have the same life experience as the desired end user, will be unable to consider every aspect that could challenge the proper use of a device. The more a company incorporates the end user in the product development process, the more successful their end product will be.

Parkinson’s disease (PD) is a degenerative disorder of the central nervous system. The signs of Parkinson’s disease can be classified into three main categories: primary motor symptoms, secondary motor symptoms, and non-motor symptoms. Since Parkinson’s disease symptoms can range from motor to cognitive, coping with Parkinson’s disease can be very challenging.

Primary Motor Symptoms:

The primary Parkinson’s disease motor symptoms include resting tremor, bradykinesia (slowed movements), rigidity, and postural instability.

• Resting Tremor, the most common primary motor symptom of PD affects approximately 70% of people with Parkinson’s disease.¹ Tremor can affect the hand, foot, one side of the body, the jaw, and even the face. Since PD’s tremor is characterized mostly by resting tremor, the tremor occurs when the affected body part is not doing work and it usually subsides when the individual begins an action. Severe tremor can impair a person’s ability to perform everyday tasks, such as eating and getting dressed. (View video)
• Bradykinesia is characterized by slowed movements and incomplete movements. Furthermore, individuals who experience bradykinesia may have difficulty initiating movements, as well as sudden stopping of an ongoing movement, often called “freezing”.¹ Bradykinesia can significantly affect tasks such as walking.
• Rigidity is characterized by stiffness and inflexibility of the muscles.
• Postural Instability is characterized by impaired balance and coordination.

It is clear that the presence of one or more of the primary PD motor symptoms can be extremely detrimental to an individual’s quality of life.

Secondary Motor Symptoms:

The secondary Parkinson’s disease motor symptoms include symptoms such as stooped posture, fatigue, speech problems, and loss of facial expressions. Some individuals affected by PD may also experience drooling, difficulty swallowing, and sexual dysfunction.

Non-motor Symptoms:

Furthermore, there are non-motor symptoms of PD, which include confusion, sleep disturbances, constipation, skin problems, depression, anxiety, slowed thinking, urinary problems, fatigue, loss of energy, and compulsive behavior.

As I mentioned before, because Parkinson’s disease symptoms can range from motor to cognitive, coping with Parkinson’s disease can be very challenging.Currently, relatively little is known about the disease, and many research groups are attempting to determine both the cause and source of PD. Studying the symptoms with appropriate tools (like wireless accelerometers) can give clinicians and researchers clues into the underlying mechanisms that cause them.

CleveMed continues to design and build medical devices to monitor and measure Parkinson’s disease symptoms.

One of the most difficult aspects of monitoring Parkinson’s disease (PD) motor symptoms, is that the severity of tremor and bradykinesia (slowed movements) greatly fluctuates throughout the day.

When medication is at its peak effectiveness, the patient is said to be “On.” Similarly, when medication has completely worn off, the subject is said to be “Off.” Symptoms are often worst first thing in morning, but improve after the first dose of medication. However, as the medication wears off, symptoms return mid-day. These cycles of waxing and waning motor symptoms continue throughout the day. Controlling these “On” and “Off” cycles can be difficult, as patients with PD are typically evaluated in the neurologists’ office, which only allows the physician to capture a snapshot of motor symptoms. Furthermore, patients typically are instructed to refrain from taking medication the night prior to the office visit. A state of anxiety in this condition may amplify PD symptoms during motor evaluation. Monitoring motor symptoms at home would provide clinicians with improved tracking of these complex motor fluctuations and in-turn optimize medication dose to improve patient quality of life.

Kinesia is a compact wireless system developed by CleveMed to quantify movement disorder symptoms. In clinical trials, Kinesia objectively quantified tremor and bradykinesia in PD patients in the clinic. Objective symptom ratings output by the Kinesia system were highly correlated to clinician ratings. CleveMed has recently begun a clinical study in which the Kinesia system is being used throughout the day, at home, by patients with PD. Preliminary results demonstrate that Kinesia can capture the “On” and “Off” motor symptom fluctuations in a subject’s home. Monitoring PD symptoms on a more continuous basis at a patient’s home should improve clinical outcomes and decrease costs especially for disparate patient populations in areas not in close proximity to movement disorder specialists.

While most people know what tremor is when they see it, they may not realize that many different types of tremor exist and why it is important to recognize them. The current gold standard of visual assessment may be blind to subtle characteristics unique to different tremor types. Tremor is a common motor symptom associated with a number of neurological disorders. Defined as rhythmic, involuntary, to-and-fro movements of a body part, tremor is most common in the hands, but can occur in the arms, legs and head. Tremor can be an especially debilitating movement disorder symptom and make activities of daily living, such as dressing, eating and writing, difficult or sometimes impossible without the help of a family member of caretaker.

Several movement disorders produce tremor as a motor symptom. The two most common are essential tremor (ET) and Parkinson’s disease (PD). ET is a common disorder characterized by uncontrolled trembling of the hands and often involuntary nodding of the head. It is the most prevalent movement disorder, affecting nearly 10 million people in the United States alone. PD is a progressive disease associated with the destruction of brain cells that produce dopamine and characterized by muscular tremor, slowing of movement, partial facial paralysis and peculiarity of gait and posture. There are currently about 1 million people in the United States living with PD.

In addition to different disorders producing tremor, different tremor types may exist within a particular disorder, each with unique physical characteristics. Two of these important characteristics are amplitude and frequency. Amplitude refers to how big the movement is while frequency refers to the speed or rate at which the oscillation is happening. Rest tremor is one type that occurs when the affected limb is completely at rest. Resting tremors occur at a specific frequency, usually 4 – 7 Hz, and are most commonly associated with PD, but in some cases found in other movement disorders. Postural tremor occurs when a specific body part is held motionless against gravity, such as extending the arms out, pointing with the hands or sitting upright without back support. Postural tremor typically occurs at a frequency of 9 – 11 Hz and can be associated with PD or ET. Other types of tremor include kinetic tremor, which occurs during a voluntary movement such as writing, drinking or eating and intention tremor, which is unique in that is occurs during a visually guided movement toward a target destination.

Distinguishing tremor types and quantitative features is very important for research, clinical judgments and intervention efficacy. CleveMed has developed a device called Kinesia™ that can be used to detect and monitor subtle differences in tremor characteristics. Kinesia is a small wireless device worn on the patient’s finger and wrist to monitor three dimensional motion. Currently being evaluated in several clinical studies around the United States, this device is intended to help standardize tremor evaluations and provide clinicians with a tool to better quantify tremor features when the signs are too subtle for clinical differentiation alone. Improving and standardizing the clinical evaluation of tremor may ultimately improve the understanding of tremor subtypes, increase efficacy of interventions and maximize patient quality of life.