Diabetes is a metabolic disease that also involves the peripheral nervous system. Living with high blood sugar over a period of years puts the body at risk for permanent organ damage. One of the risks associated with diabetes is arteriosclerosis of the blood vessels, which also carries with it an increased risk for cardiovascular disease. High blood sugar levels may affect the blood vessels in the eye, thus increasing the risk of haemorrhage and blood clots damaging the eye. In the past, diabetes used to be a common cause for blindness, but thanks to modern treatments this is rarely seen nowadays.
The loss of sensibility in the hands in combination with retinopathy is especially debilitating since this may significantly decrease the patient’s ability to read Braille with their fingers.
The kidneys contain a vast number of tiny blood vessels which may be afflicted by arteriosclerosis, hence impairing the kidney’s ability to filter blood. Currently, approximately one-fifth of Swedish kidney transplant and dialysis patients have diabetes.
Impaired sensation in the foot increases the risk of skin ulceration since the patient loses protective sensation and can easily injure the skin. Diabetes may also cause damage to the feet due to restricted blood circulation in both large and small blood vessels, as well as blood circulation being impaired in both large and small blood vessels, as well as due to the impairing of the nerve function, which affects the sense of touch. With a reduced sense of touch one may easily step on sharp objects or walk with sand in the shoes without even noticing. This may lead to diabetic ulcers which, due to the impaired blood circulation, may take a long time to heal.
There is also a tisk that the muscles in the feet become weakened, which may cause the feet to be deformed. Over time, the foot load will also change, increasing the risk of abrasions. According to Stig Attvall, senior lecturer at the Diabetes Center, Sahlgrenska University hospital, damage to foot nerves, so-called peripheral sensory neuropathy, is seen in approximately 70-100% of diabetes patients with diabetic ulcers.
In cases of excessive diabetic ulcers, it is common for the foot to be completely or partially amputated. Diabetics today make up a vast portion of foot amputees worldwide. The risk of a diabetic developing diabetic ulcers during his/her lifetime amounts to approximately 25%. In the United States, an estimated 1.5 million diabetes-related ulcers are treated each year7, in addition to the 65,700 foot amputations carried out each year.
In Europe, an estimated 1–1.4 million diabetics are afflicted by diabetic ulcers9. The vast number of diabetic ulcers and the related amputations (where applicable) could be substantially reduced if treatment efforts were implemented earlier. It should also be emphasized that the nerves in the arms and hands nerves may be affected by diabetes, which increases the risk of nerve entrapment (so-called carpal tunnel syndrome). Carpal Tunnel Syndrome (CTS) is more common on diabetes patients compared with the healthy population. Early detection is important since surgical treatment carries a good prognosis, and often leads to considerably improved sensibility in the hand. For the foot, assessment of the protective sensation is essential for evaluation of the risk for skin ulceration. Being able to detect diminished protective sensation at an early stage reduces the risk for time-consuming medical foot ulcer care and amputations.
Today's methods for routine assessment of sensation in the hand and foot are primitive and not sufficiently standardised. For investigation of foot sensibility, tuning forks or a biothesiometer, working within one frequency band, are usually used. Both precision and accuracy are very low for that type of device. In fact, methods which only assess vibration sense within one frequency have proven quite insufficient for reliable results. http://care.diabetesjournals.org/content/36/4/1033.full
Peripheral sensory neuropathy in one’s feet leads to loss of the protective sensibility and an increased risk of diabetic ulcers. Thus, regular examinations are crucially important. This means annual checkups conducted by a doctor or diabetes nurse. For the examination, it’s recommended to check the ability to sense vibrations, pressure, pain and pulse.
Should diabetic ulcers arise, it is important for the wound(s) to be assessed at a diabetes clinic as soon as possible. Depending on the wound type, a number of resources are applied, so-called multidisciplinary teams, to mitigate and suppress the wound development. A multidisciplinary team consists of various professional groups, involved with (amongst other things) the improvement of the foot health status.
If the circulation is impaired, vascular surgery may be necessary. If the wound is infected, antibiotics are prescribed. The foot may need to be relieved in order to allow for a proper healing process, which is facilitated by the use of custom shoes and various soles. As the diabetic ulcer may take a very long time to heal, it is definitely preferable for it to never form in the first place. Using improved sensory diagnostics,
it is possible to detect patients carrying a higher risk of developing permanent damages may be found. By screening patients with sensory impairment in their feet at an early stage, risk categories can be found before the patients develop diabetic ulcers.
A major problem is caused by the fact that today’s methods for sensory measurement are crude, subjective and time consuming. Different doctors or nurses often will get different results for the same patient.
Also, to effectively examine a population currently amounting to some 387 million people globally with current methods would take up enormous amounts of resources.
The VibroSense Meter is a system intended for early detection and diagnosis of impaired vibration sensibility in the hand and fingers. The system is specially designed to be a useful tool for the assessment and health surveillance required by EU directive 2002/44/EC.
The device is a powerful tool to find early sign of sensibility impairment before it has become a permanent vibration injury. It can also be used for preventive measures at the workplace, particularly to control the medical effects due to modifications of the workplace.
The VibroSense Meter consists of a measurement unit and PC software. The measurement unit contains advanced mechanics and electronics for the measurement of vibration perception thresholds in the fingers based on Multi-Frequency Tactilometry. A patented “Applied Skin Force Control” scheme secures the measurement accuracy according the ISO 13091-1 standard, i.e. limits for skin indentation.
Multi Frequency Tactilometry (also called vibrometry) is an objective medical quantitative sensory test method used in diagnostics of sensibility by measuring the ability to perceive vibration on fingers and feet. The basic method is described in the ISO 13091-1/2 standard. Vibrometry performed at several frequencies, i.e. Multi-frequency Tactilometry, provides an early indication of sensory impairments due to incipient neuropathy or nerve entrapments such as Carpal tunnel syndrome.
Multi Frequency Tactilometry (also called vibrometry) is an objective medical quantitative sensory test used to evaluate how well fingers and feet are able to perceive vibrations. The basic method is described in the ISO 13091-1/2 standard.
Vibrometry performed at several frequencies (Multi-frequency Tactilometry) provides an early indication of sensory impairment due to incipient neuropathy or nerve entrapment, such as Carpal tunnel syndrome. Multi Frequency Vibrometry was developed by Professor Göran Lundborg et. al, at the Skåne University Hospital in Sweden. The method is similar to the common hearing test. One finger is exposed to controlled mechanical vibrations of varying intensity and frequency. The patient indicates by pushing a button when s/he feels a vibration on the exposed finger. The VibroSense Meter is a superior example of a medical device for Multi-frequency Vibrometry examinations.
- The PC software contains:
- Automatic comparison against comprehensive normative age-matched population data.
- Questionnaires adopted for hand-arm vibration screening, including the Stockholm Workshops Scale grading.
- Inbuilt measuring of finger skin temperature, prior to each vibrogram recording.
- Support for long-time follow up of groups or individuals.
- Support for statistics regarding preventive measures in the workplace environment.
- VibroSense Meter Target use:
- Screening of large groups, including pre- and post- employment screening
- Medical control of people in risk groups such as diabetics, patients treated with chemotherapy
- Preventive measures at the workplace.
- Accessories included: Measurement Unit, Trigger Switch, Power Supply, Carrying Case, PC software (VSM).
- The integrated questionnaire for HAVS is included as standard.
Hand-Arm Vibration Syndrome (HAVS) is the medical term for symptoms caused by vibration damages that may occur in the fingers, hands and arms when working with vibrating tools or machinery. Vibration injuries are divided into three subgroups: neurological disorders, vascular and musculoskeletal.
Early symptoms are usually tingling and/or numbness in the hands and fingers. After a while, this turns to impaired sensibility and limited dexterity. Fully developed neurological vibration damage is irreversible, causing a high level of disability and work impairment. At this stage, hand function is severely reduced; the patient might drop things easily or have problems with tasks such as pouring water into a glass or inserting a key into a lock. Carpal Tunnel Syndrome is another common neurological vibration injury. If detected in time, most patients are expected to make a full recovery.
These injuries affect the capillaries (small blood vessels) in the hand and fingers, causing these to constrict (vasospasm). This causes blanching (episodes of whiteness), usually triggered by exposure to cold. Other terms are "Vibration induced White Fingers" (VWF) or "secondary Raynaud's disease". During the episodes of blanching, caused by a temporary ristriction of blood circulation to parts of the fingers or the hand, the person experiences numbness in the areas that have turned white. When the blood then returns, i.e. during the release of the vasospasm, the person is often experiencing a major discomfort such as tingling and pain.
Musculoskeletal injuries may take the form of arthritis, tendonitis and changes in muscle fibres, and can result in impaired grip force, reduced mobility and pain in the hand and arm. It is not clear why this is associated with reduced grip strength, but it might be due to damage to nerves and muscle structures. Many of those suffering from musculoskeletal vibration injuries are not diagnosed since many routine clinical tests often show normal results. It is noteworthy that the muscle mass is often intact, but microscope studies of muscle biopsies have shown that there may be significant changes in the fibres.
It is well known that exposure to prolonged (i.e. for several years) exposure to vibration is harmful, and can cause various types of hand dysfunctions. Most common are loss of sensibility, blanching, and decreased grip force in the hands—that is, Hand-Arm Vibration Syndrome (HAVS). The tendency to develop vibration injuries in the hands varies significantly between individuals; some get these symptoms after a few years of vibration exposure, while others can work for decades without problems. When a vibration injury is fully developed, it is irreversible. The affected person will, in other words, not recover even if the vibration exposure ceases. At this point it cannot be cured by medical or surgical means. Therefore, it is extremely important to detect incipient vibration damage while prophylactic measures are still effective.
It might, for example, be possible to change tools or methods in order to prevent irreversible vibration injury. Vibration injuries are common in many industries with vibration exposure, such as construction, cutting and sheet metal work, auto repair, welding and electrical work. The problems are also common occupations where the hands are exposed to very high-frequency vibrations, such as dental technicians and dentists. The injuries often impact the working-age population (young or middle-aged men) and the consequences can be very serious. Damage to the nerves of the hand leads to reduced dexterity and impaired fine-motor skills (“clumsiness”), and, in some cases, severe pain and cramps. Finger blanching is usually triggered by exposure to a humid or cold environment and can be extremely painful.