WO2008051168A1

WO2008051168A1 - Wrist stabiliser

Info

Publication number: WO2008051168A1
Application number: PCT/SG2007/000360
Authority: WO
Inventors: Choon Meng Ting
Original assignee: Healthstats International Pte Ltd
Priority date: 2006-10-26
Filing date: 2007-10-22
Publication date: 2008-05-02
Also published as: SG142189A1

Abstract

The invention is an apparatus for stabilising a forearm, wrist, hand and fingers in a Z- positive intrinsic position including a support means for supporting the forearm, wrist, hand and fingers and a securing means. The support means includes a forearm segment for supporting the forearm, a hand segment for supporting a back of a palm and a fingers segment for supporting the fingers. The securing means secure said fingers to the support means to maintain a constant wrist tension.

Description

WRIST STABILISER

FIELD OF INVENTION

The present invention relates to an apparatus for stabilising a hand, wrist and fingers for the positioning of an arterial pulse-pressure sensor over a radial artery.

BACKGROUND OF THE INVENTION

During an operation, there is a need to monitor the blood pressure of a patient throughout the operation. Currently, there are two common methods of monitoring the blood pressure (BP) invasive method using intra arterial (IA) lines, or the non-invasive method. For both methods, the blood pressure reading requires a consistent and stable condition.

For the invasive method, an IA line is inserted into a radial artery at the wrist of a user. A transducer platform has to be levelled with the heart of a user by manual judgement using the eye. If the IA line comes off accidentally, the IA line cannot be re-inserted back into the same artery. The IA line will have to be inserted into a radial artery on the other wrist. Hence, the arm of the user is set to a fixed position by using a splint to minimise the IA line from coming off due to movement of the arm.

In a non-invasive applanation tonometry method, an arterial pulse-pressure sensor senses the pressure of the applanated radial artery at the wrist of the patient. Normally, the tonometric sensor is first calibrated using the result of an oscillometric method BP reading of the brachial artery at the level of the heart and the calibrated waveform, and the reading is used as a reference for monitoring the radial artery blood pressure. A slight movement in the arm or muscle contraction is likely to cause a change in the sensor's applanation pressure and result in an inaccurate blood pressure reading.

Hence, for both methods, it is critical to maintain the arm in a fixed and relaxed position for the duration of monitoring the blood pressure. In the prior art, a wrist stabiliser provides a means for strapping the hand to an apparatus in a fixed supine position for blood pressure reading. However, for blood pressure reading, besides maintaining the wrist in a fixed position, changes in the positioning of the fingers will affect the consistency of the reference waveform or reading. When using the wrist stabiliser in the prior art, a conscious effort is required to keep the fingers in a constant position throughout a duration for monitoring the blood pressure reading. There must be constant tension and strength exerted by the arm and fingers to maintain a constant pressure. Further, when the arm is in a supine position for long duration, it is likely to cause discomfort in the shoulder and elbow and may even result in aching.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, there is provided an apparatus for stabilising a forearm, wrist, hand and fingers which includes a support means for supporting the forearm, wrist, hand and fingers and a securing means for securing the hand and forearm to the support means. The support means includes a forearm segment for supporting the forearm, a hand segment for supporting a back of a hand, a fingers segment for supporting the fingers.

In an embodiment of the invention, the support means further includes a retaining means, which includes a first wing on one side of the support means retaining one side of the wrist and forearm. The retaining means and securing means maintain the hand and forearm in a fixed position when the orientation of the fixed position may be varied.

In another embodiment, the retaining means includes a first wing and a second wing on opposite sides of the support means retaining both sides of the wrist and forearm.

In yet another embodiment, the retaining means includes a first hand wing on one side of the support means for retaining one side of the hand and a first forearm wing on the same side of the support for retaining the forearm.

In the preferred embodiment of the invention, the retaining means includes two hand wings each on opposite sides of the support means for retaining the hand and two forearm wings each on opposite sides of the support means for retaining the forearm. In an embodiment, the securing means is a strap threaded in the forearm segment and the fingers segment.

In an embodiment of the invention, the securing means includes an arm strap for strapping the forearm to the forearm segment, a fingers strap for strapping the fingers to the fingers segment, wherein the forearm, wrist and fingers are maintained in the fixed position.

In the preferred embodiment, the securing means includes an arm strap for strapping the forearm to the forearm segment, a fingers strap for strapping the fingers to the fingers segment, a thumb strap for strapping the thumb to the portion of the retaining means next to the thumb wherein the forearm, wrist and fingers are maintained in the fixed position.

Preferably, the support means includes an aperture in between the forearm segment and the hand segment to allow access for other accessories.

In an embodiment of the invention, the fingers segment, the forearm wings and hand wings are hingedly connected to the support structure.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1A illustrates the invention with a support means and a securing means for securing the fingers to the support means.

Figure 1B illustrates a perspective view of the support means.

Figure 2A illustrates a preferred embodiment of the invention.

Figure 2B illustrates a top view of the support means.

Figure 2C illustrates a side view of the support means.

Figure 2D illustrates a perspective view of the support means.

Figure 3A illustrates a semi-prone position of the arm in the preferred embodiment. Figure 3B illustrates a supine position of the arm in the preferred embodiment.

Figure 4A illustrates a Z-positive intrinsic position of a hand.

Figure 4B illustrates a X-negative intrinsic position of a hand.

Figure 5 illustrates an embodiment of the invention.

Figure 6 illustrates an embodiment of the invention.

Figure 7 illustrates an embodiment of the invention.

Figure 8 illustrates an embodiment of the invention.

Figure 9A illustrates two sides of a fingers strap.

Figure 9B illustrates two sides of a thumb strap.

Figure 9C illustrates two sides of an arm strap.

Figure 1OA illustrates the padding or cushion for fingers segment.

Figure 10B illustrate the padding or cushion for the hand segment.

Figure 10C illustrate the padding or cushion for the forearm segment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A user refers to the patient or any such person who uses the apparatus for stabilising his wrist or keeping his wrist in a fixed position for a prolonged duration. In the description, some features of the apparatus are used for supporting one side of the hand and/ or forearm. We will refer to the right side of the hand as a first side, and the left side as the second side. The orientation such that when a left arm is in a supine position and viewed from the user's point of view, the right side is the side proximal to the body and the left side is the side distal to the body. The references made to the hand are for the purposes of the ease of description. The following description will only refer to the left hand of a user, as the effects of the invention are the same when used on a user's left or right hand.

The present invention provides an apparatus 100, as shown in Figure 1A for stabilising a forearm, wrist, hand and fingers including a support means for supporting said forearm, wrist, hand, fingers and a securing means. The support means includes a forearm segment 10 for supporting the forearm, a hand segment 12 for supporting the back of the palm, and a fingers segment 14 for supporting the fingers. The apparatus further includes a securing means 20 for securing the fingers to the support means to maintain a constant wrist tension.

Preferably, the apparatus 100 as shown in Figure 2A has a support means as shown in a top view in Figure 2B, a side view in Figure 2C and a perspective view in Figure 2D. The support means further includes retaining means 16A, 16B, 17A, 17B. The retaining means 16A, 16B, 17A, 17B and the securing means 20 maintain the hand and forearm in a fixed position when the orientation of the fixed position is varied from a semi-prone position as shown in Figure 3A to a supine position as shown in Figure 3B.

In Figure 2C, the hand segment 12 of the support means is arched so as to project the wrist at a maximum angle such that the radial artery is most protruded to enable a good reading when reading a blood pressure of the user by either the invasive or non-invasive methods.

The support means further includes a base 13 so that the apparatus is stable when set on a flat surface.

For the purposes of reading a blood pressure, the ideal fixed position of the hand is a Z- positive intrinsic position, which is illustrated in Figure 4A. In this position, all the fingers are in extension. To advantageously obtain a tension to the wrist to assist in the locating of a user's artery, the fingers segment 14 is secured to the support means by a securing means 20. This position allows the wrist, hand and fingers to be relaxed and yet provides a constant tension to the wrist. The user does not have to exert any effort to stay in the position, thus allowing the user to be relaxed and comfortable during prolonged use. As the wrist experiences a constant tension by virtue of the securing means 20, the blood pressure reading obtained will therefore be more reliable. When a blood pressure sensor is attached to a user in this relaxed and effortless position, the reading error is minimised. Figure 4B shows the Z-negative position when using the wrist stabiliser in the prior art wherein the securing means is only applied to the forearm and hand. As discussed previously, this position requires the user to actively maintain tension and strength in order to get a constant sensor pressure for blood pressure monitoring as the prior art does not facilitate a way to achieve this passively. As can be appreciated, it is almost impossible for a user to actively maintain a constant tension and therefore readings obtained using the teachings of the prior art are likely to be fraught with errors.

In one embodiment of the invention as shown in Figure 5, the retaining means includes a first wing 16 on a left side of the supporting means to retain the wrist and the forearm of a user's right arm when the right arm is in a semi-prone position. The semi-prone position is a preferred position for prolonged usage as it prevents discomfort on the musculoskeletal system of the shoulder and elbow, providing a more relaxed position to the user than the supine position. However, this embodiment can only be used for either the left or the right hand. If the wing is located on the right of the support means, the apparatus can best be used for the left arm and if the wing is located on the left, the apparatus can best be used for the right arm .

In another embodiment of the invention as shown in Figure 6, the retaining means further includes a second wing 17 positioned opposite to the first wing 16, which is the right side of the support means. This embodiment allows the apparatus to be used on either arm.

In yet another embodiment, an apparatus 100 for stabilising a hand, wrist and forearm including a support means for supporting the forearm, wrist and hand and a securing means 20 for securing the fingers and forearm to the support means. The support means as shown in Figure 7 includes a forearm segment 10 for supporting the forearm, a hand segment 12 for supporting a back of a palm, a fingers segment 14 for supporting the fingers and a retaining means. The retaining means includes a left hand wing 16A on one side of the support means for retaining the left side of the right hand and a left forearm wing 16B for retaining said left side of the right forearm. This provides allowance for any straps or devices to be fixed at the wrist.

In the preferred embodiment, the retaining means as shown in Figure 8 further includes a right hand wing 17A for retaining the right side of the left hand and a right forearm wing 17B for retaining the right side of the left forearm. This embodiment allows the apparatus to be used on either hand and yet provides allowance for any straps or devices to be fixed at the wrist.

In the above embodiments, the securing means 20 is a strap which is threaded into the forearm segment 10 to secure the forearm to the forearm segment, and threaded into the fingers segment 14 to secure the fingers to the fingers segment, thus maintaining the arm and wrist in an ideal fixed Z-positive intrinsic position.

In another embodiment, the securing means 20 includes an arm strap 2OA for strapping the forearm to the forearm segment 10, a fingers strap 2OB for strapping the fingers to the fingers segment 14, wherein the forearm, wrist and fingers are maintained in an ideal fixed Z-positive intrinsic position when the orientation of the position is changed from a supine position in Figure 3B to a comfortable semi-prone position in Figure 3A.

Preferably, the securing means 20 includes an arm strap 2OA for strapping the forearm to the forearm segment 10, a fingers strap 2OB for strapping the fingers to the fingers segment 14 and a thumb strap 2OC for strapping the thumb to the portion of the retaining means next to the thumb. This will maintain the forearm, wrist, thumb and fingers in an ideal fixed Z-intrinsic position when the orientation of the position is changed from a supine position in Figure 3B to a comfortable semi-prone position in Figure 3A.

Figures 9A₁ 9B and 9C illustrate the fingers strap, thumb strap and arm strap respectively. The straps are preferably made of an elastic band having Velcro™ loops on one side 32 and Velcro™ hooks on one end of the other side 34 such that each strap is secured when the hooks are secured to the loops. The securing means may also be in the form of a belt and buckle arrangement.

Preferably, the support means further includes an aperture 22 in between said forearm segment 10 and said hand segment 12 to allow access to other accessories. For example, the accessories may be wires connecting the arterial pulse-pressure sensor to a monitor.

In another embodiment, the fingers segment 14 is hingedly connected to the support structure such that the angle of said fingers segment from the horizontal or vertical axes is adjustable. This will allow the fingers to be resting at a comfortable angle which is adjustable for each user.

In the above embodiments the retaining means includes wings, the wings are hingedly connected to the support structure such that the angle of the wings from the horizontal or vertical axes is adjustable to suit different users wishing to secure the arm and hand in a fixed position. Figure 8 illustrates an example of an embodiment having hinges 24 for the wings 16A, 16B, 17A, 17B to be hingedly connected to the support structure. This feature is useful since it is not cost effective to manufacture the apparatus in different sizes. Providing different sizes of the apparatus will require moulds of different sizes which will increase the costs of production and there is a hassle of having to keep inventory.

In an alternative embodiment the retaining means includes wings which are not adjustable, wedges are provided to be inserted between the hand and the wings such that the arm is secured in a fixed position.

Still further, paddings or cushions as illustrated Figures 10A, 1OB and 10C are provided on each of the segments for the comfort of the user. Figure 10A shows the padding or cushion having a shape for the fingers segment 14, Figure 10B for the hand segment 12 and Figure 10C for the forearm segment 10.

A further application of the apparatus is for stabilising the hand after a surgery on the hand, wrist or forearm where there is a need to maintain the arm, wrist and hand in a fixed position effortlessly and comfortably.

Claims

We claim :

1. An apparatus for stabilising a forearm , wrist, hand and fingers in a Z-positive intrinsic position including a. a support means for supporting said forearm, wrist, hand and fingers including i. a forearm segment for supporting said forearm; ii. a hand segment for supporting a back of a palm; iii. a fingers segment for supporting the fingers; and b. a securing means for securing said fingers to said support means to maintain a constant wrist tension.

2. An apparatus as claimed in any of the preceding claims wherein said securing means further includes an arm strap for securing said forearm to said support means.

3. An apparatus as claimed in any of the preceding claims wherein said securing means is a strap threaded in said forearm segment and said fingers segment.

4. An apparatus as claimed in any of the preceding claims wherein said securing means includes an arm strap for strapping said forearm to said forearm segment, a fingers strap for strapping said fingers to said fingers segment, to maintain said forearm, wrist and fingers in said fixed position.

5. An apparatus as claimed in claim 4 wherein said securing means further includes a thumb strap for strapping the thumb to the portion of the retaining means next to the thumb.

6. An apparatus as claimed in any of the preceding claims wherein said support further includes iv. a retaining means including a first wing supporting a first side of said wrist and said forearm, wherein said retaining means and said securing means maintain said hand and forearm in a fixed Z-positive intrinsic position when the orientation of said fixed position is varied.

7. An apparatus as claimed in claim 6 wherein said retaining means further includes a second wing, positioned on a side opposite to said first wing.

8. An apparatus as claimed in claim any of the preceding claims 1 to 5 wherein said retaining means includes a first hand wing for supporting a first side of said hand and a first forearm wing for supporting said first side of said forearm.

9. An apparatus as claimed in claim 8 wherein said retaining means further includes a second hand wing for supporting the side of said hand opposite to said first hand wing and a second forearm wing for supporting the side of said forearm opposite to said first forearm wing.

10. An apparatus as claimed in any of the preceding claims wherein said support means further includes an aperture in between said forearm segment and said hand segment to allow access for other accessories.

11. An apparatus as claimed in any of the preceding claims wherein said fingers segment is hingedly connected to said support structure such that the angle of said fingers segment from the horizontal or vertical axes is adjustable.

12. An apparatus as claimed in any of the preceding claims 6 or 7, further includes hingedly connecting one of said first wing or second wing to said support structure such that the angle of said wings from the horizontal or vertical axes is adjustable.

13. An apparatus as claimed in any of the preceding claims 8 or 9, further includes hingedly connecting one of the first forearm wing, second forearm wing, first hand wing or second hand wing to said support structure such that the angle of said wings from the horizontal or vertical axes is adjustable.