Implement holder for use by motor disabled patients

A holder for a wiring implement, such as a ball-point cartridge, eating implements, such as a fork, a knife or like implement. The holder is arranged for holding the implement (12) and comprises means (5, 6, 8, 9) for vibrating the housing (1) with a frequency in the order of 50 to 100 Hz and an amplitude of the force causing the vibration in the order of 0.3 to 2.5 Newton. Preferably, the frequency and amplitude are adjustable. The vibrating holder enables greatly improved motor control of the implement in question for many patients.

FIELD OF THE INVENTION
 This invention relates to an aid for mitigating certain discomforts
 resulting from diseases, in particular muscular diseases such as
 Parkinson's disease, but also rheumatism. Although the aid according to
 the invention can be employed in several fields, the following description
 will be focused on a writing implement for Parkinson patients.
 BACKGROUND OF THE INVENTION
 Characteristic symptoms of Parkinson's disease, which, for that matter,
 need not occur all at the same time, include: shaking, muscular rigidity
 and paucity of movement. This does not involve palsy but a (temporary)
 disturbance of muscle controls and of muscle coordination. The cause is
 degeneration of areas in the brain, specifically the "black nuclei" and
 the "basal brain", as a result of which insufficient neurotransmitter
 (dopamine) is produced. These areas of the brain are of vital importance
 for a smooth performance of movements, i.e. for an effortless initiation
 of a movement, proper control during the movement, and the termination of
 the movement. These areas further ensure that when the flexors of a limb
 are to contract, the extensors relax at the same time. This interaction is
 of importance for a smooth performance of to-and-fro movements, as during
 eating, writing, handiwork, getting dressed and undressed. These are the
 first movements to present problems in Parkinson's disease. When the
 performance of the movements no longer proceeds automatically, it will be
 attempted to perform them more deliberately, which requires an effort.
 This most conspicuous symptom of Parkinson's disease, i.e. shaking
 (tremor), involves an involuntary rhythmic movement of a number of
 muscles, mostly of one or both hands. This movement is most clearly
 visible if the hand is at rest. The frequency of this so-called rest
 tremor is 4-7 Hz. During sleep the tremor does not occur and emotions may
 aggravate the tremor distinctly.
 Another symptom is muscular rigidity. Such rigidity, also referred to as
 hypertonia, arises in that the muscles are continuously in a state of
 slight contraction and this rigidity must be overcome before a movement
 can be initiated.
 The third symptom mentioned, paucity of movement (hypokinesia), is a result
 of the muscular rigidity. Fine to-and-fro movements, as in tying
 shoe-laces, are more difficult to perform.
 There are not as yet any medicines to cure the disease. Treatment is
 primarily focused on removing complaints. Thus, the deficiency of
 neurotranamitter (such as dopamine) is supplemented by medicines. Further,
 the symptoms of the disease can be suppressed by surgical intervention in
 the brain, which is obviously a hazardous enterprise.
 As already observed in the foregoing, writing can present problems. Indeed,
 writing is a complex process that proceeds automatically under normal
 circumstances. It refires the hand muscles to be supple and a proper
 coordination of the fine movements. In Parkinson's disease this
 coordination is disturbed, and patients experience this as a major
 drawback.
 Accordingly, a need exists for writing implements whereby this drawback is
 eliminated as far as possible. A known proposal towards facilitating
 writing for patients suffering from muscular diseases, including Parkinson
 patients, concerns the ergonomics of the writing pen. A slender pen is
 more difficult to hold and aggravates tremor. Using a pen with a spherical
 grip which can be embraced by the hand with a good fit enables writing
 from the wrist. Another known proposal involves a so-called soft grip,
 i.e. a flexible sleeve which can be fitted over a pen and has a lobed
 configuration, viewed in cross section, which urges the writing fingers in
 the correct position and provides a proper hold without effort.
 German patent application 1611549 (Brown et al) and European patent
 application 0569638 (Hart Enterprises) disclose marker or decoration pens
 in the toy domain, which are provided with means for setting the pen into
 vibration.
 They have in common that the eccentric weight is provided at the rear end
 of the pen and that an eccentric oscillating movement is thereby generated
 also at the rear end of the drawing implement, such that when the pen is
 moved along a straight line over the paper, the entire pen oscillates,
 with the part held by the fingers being the fulcrum, and the writing end
 makes an opposite oscillating movement. If the pen, as is commonly done,
 in held obliquely to the paper and a pulling movement over the paper is
 performed, the result will be a decorative, repetitive loop pattern.
 The known pens are neither designed nor suitable for producing normal
 handwriting. Writing with them is even virtually impossible.
 SUMMARY OF THE INVENTION
 The object of the invention is to provide an aid for reducing the
 inconveniences described in the foregoing, which result from tremor,
 muscular rigidity and hypokinesia, which inconveniences occur in writing,
 eating, handling certain tools, such as a screwdriver, etc. In the
 embodiment as a writing implement, the aid must enable a normal writing
 result as far as possible, it must be a proper fit in the hand, and it is
 desired for the external configuration to correspond as much as possible
 to that of normal writing implements. Further, especially with regard to
 holders for writing implements, it should be possible to make use of
 standard parts as much as possible, and the use of the writing implement
 should not require the user to perform any complex operations.
 This is accomplished according to the present invention by providing a
 holder for an implement, such as a writing implement, such as a ball-point
 cartridge, an eating implement, such as a fork, a knife or the like,
 arranged for holding the implement, comprising means for causing the
 holder to vibrate with a frequency in the order of 50 to 100 Hz and an
 amplitude of the force causing the vibration in the order of 0.3 to 2.5
 Newton.
 Surprisingly, by causing the implement holder to vibrate, the
 controllability of the implement is highly improved for many patients.
 The invention is based on the insight that, among other things, the tremor
 of parts of the body as is inherent to Parkinson's disease decreases
 considerably when such parts come into contact with a mechanical
 vibration, in particular if this vibration emanates from the object to be
 controlled.
 More particularly, tremor in Parkinson patients has a frequency of 4-7 Hz.
 while objects by which a decrease of the tremor can be effected have a
 much higher frequency. Accordingly, no damping by vibration in opposite
 phase can be involved. Possible explanation are that vibrations have a
 relaxing effect on stiffened muscles, and that the tremor is drowned out,
 and hence smoothed, by vibrations with a higher frequency than the tremor.
 Further, it is known in general in massaging that stiffened muscles can be
 stimulated by electrical pulses and also by rhythmic massage. Good results
 are achieved with a massaging frequency of 80 Hz. The rhythmic ticking of
 a metronome at a frequency of 60-70 Hz also has a favorable effect on the
 movements of Parkinson patients. Such rhythmic stimuli, however, are not
 administered by an object to be controlled.
 Preferably, the frequency and amplitude mentioned are settable.
 For instance when the holder is applied in combination with a writing
 implement, such as a ball-point refill or cartridge, and a Parkinson
 patient takes the thus designed, vibrated pen in his hand, what happens is
 that, instead of the tremor becoming worse as the patient makes a forced
 effort to assume the writing posture, the vibrating holder has a calming
 influence on the hand, so that gripping the pen and writing with it leads
 to considerably better writing results. The same applies if the holder is
 used in combination with other implements, for instance a fork. The
 patient's efforts to hold the fork properly usually lead to a stronger
 tremor and hence to spilling and the like. By the use of the vibrating
 holder according to the invention, the tremor is at the least reduced and
 this will lead to a more relaxed eating behavior.
 Preferably, the means for setting the housing into vibration comprise a
 source of oscillation and a mass movable relative to the housing by that
 source, while the area in which the mass can oscillate in the housing is
 adjustable.
 In further elaboration of the invention, the holder can be provided with a
 hollow sleeve accommodated coaxially within the holder housing, which
 sleeve is bearing-mounted at the front and at the rear of the housing and
 is coupled to the rotary shaft of a driving motor which is accommodated
 with a source of energy in a motor housing connected with the holder
 housing, the sleeve being provided with at least one eccentric weight
 which, being adjustable over the length and in circumferential direction
 of the sleeve, is fixable thereon.
 By making the holder at least partly detachable, it is easy, in the
 ball-point embodiment, to replace an empty ball-point cartridge. In the
 embodiment as a fork holder a fork with an adapted handle can easily be
 mounted in the holder from the front.
 Further, by displacing the eccentric weight and varying the frequency, it
 is possible for the vibration produced to be adjusted to the user's
 personal need in order to arrive, for instance in the case of the
 ball-point embodiment, at an optimum writing result. The required force of
 vibration and the point where it is generated differs from one patient to
 another, for instance adjacent the fingertips, or some centimeters removed
 therefrom, adjacent the ball of the hand. This must be determined
 experimentally. It is observed that small variations in the frequency have
 little influence on the writing result.

DETAILED DESCRIPTION OF THE INVENTION
 To clarify the invention, a preferred exemplary embodiment of the holder
 for an implement, in particular writing implements, will be described with
 reference to the drawing.
 The drawing shows an axial cross-sectional view of a holder for a
 ball-point refill or cartridge of a commercially available type.
 According to the drawing, the holder comprises a housing 1 with an axial
 receiving space 2 for the implement and with a front end or tip 3. Located
 at the rear end of housing 1 is a motor housing 4, in which a motor 5 and
 a battery 6 or other source of energy are diagrammatically indicated.
 Rotary motors of small dimensions which are supplied by standard batteries
 are also commercially available in various designs. By means of a slide
 bearing 7 at the front and the motor shaft 8 at the rear, a hollow sleeve
 9 is rotatably bearing-mounted in the housing 1. By the motor shaft 8 the
 rear end of the sleeve 9 is centered in the holder housing 1.
 The sleeve 9 is provided with an axial bore 13 of longitudinal grooves 10
 distributed in circumferential direction of the sleeve. Two eccentric
 weights 11 are fixed in such longitudinal grooves 10 by clamping. If the
 sleeve 9 is driven by the motor, the housing 1 is caused to vibrate.
 A ball-point cartridge 12 of a conventional model is received in the bore
 13 of the sleeve 9. The cartridge reaches by the writing end thereof
 through a corresponding passage in the tip 3 of the holder hoing 1 and is
 held pressed against a ball 15 at the rear end by a helical spring 14,
 which ball 15 rests against a conical seat formed in the bottom of the
 sleeve. This prevents the cartridge 12 from revolving along with the motor
 shaft 8.
 It has been determined experimentally that in an aid 5according to the
 invention designed as a ball-point pen, the frequency of oscillation
 should preferably be adjustable at least between 50 and 100 Hz and that in
 general optimum results are achieved with about 60-80 Hz.
 With two eccentric weights, each of about 3 grams, each separately
 displaceable in radial and axial direction in the front half of the pen,
 both the form of the oscillation and the amplitude of the force causing
 the oscillation can be set. The amplitude of the force causing the
 vibration is adjustable between about 0.3 N and 2.5 N, given immovable
 fixation of the holder. In the case of free movability of the holder, this
 amplitude leads to an oscillating movement of the holder corresponding to
 the amplitude mentioned and the mass of the holder.
 The diameter of the housing should preferably be between 16 and 18 mm and
 the tip should preferably be narrow (slender).