Cranial Plagiometer

Abstract

This present invention is a tool used to measure cross-sectional diameter of infant heads. It has a pivoting center point which allows for a simultaneous dual-axis measurement. Each leg is able to move independently and contains a small potentiometer, able to measure degree of extension of each independent leg. Legs work in pairs utilizing basic trigonometry of measuring an angle between two known set lengths to give a distance between the two points on that one leg pair. A small computational accessory we'll allow real time measurement of each leg pair distance, as well as calculating the difference between those two distances. An elastic band will be attached to each of the legs for secure attachment, ease of use, and consistency between measurements. 20 25 20 14 12 27 F eb 2 02 5 A B S T R A C T 2 0 2 5 2 0 1 4 1 2 2 7 F e b 2 0 2 5 T h i s p r e s e n t i n v e n t i o n i s a t o o l u s e d t o m e a s u r e c r o s s - s e c t i o n a l d i a m e t e r o f i n f a n t h e a d s . I t h a s a p i v o t i n g c e n t e r p o i n t w h i c h a l l o w s f o r a s i m u l t a n e o u s d u a l - a x i s m e a s u r e m e n t . E a c h l e g i s a b l e t o m o v e i n d e p e n d e n t l y a n d c o n t a i n s a s m a l l p o t e n t i o m e t e r , a b l e t o m e a s u r e d e g r e e o f e x t e n s i o n o f e a c h i n d e p e n d e n t l e g . L e g s w o r k i n p a i r s u t i l i z i n g b a s i c t r i g o n o m e t r y o f m e a s u r i n g a n a n g l e b e t w e e n t w o k n o w n s e t l e n g t h s t o g i v e a d i s t a n c e b e t w e e n t h e t w o p o i n t s o n t h a t o n e l e g p a i r . A s m a l l c o m p u t a t i o n a l a c c e s s o r y w e ' l l a l l o w r e a l t i m e m e a s u r e m e n t o f e a c h l e g p a i r d i s t a n c e , a s w e l l a s c a l c u l a t i n g t h e d i f f e r e n c e b e t w e e n t h o s e t w o d i s t a n c e s . A n e l a s t i c b a n d w i l l b e a t t a c h e d t o e a c h o f t h e l e g s f o r s e c u r e a t t a c h m e n t , e a s e o f u s e , a n d c o n s i s t e n c y b e t w e e n m e a s u r e m e n t s . A B S T R A C T 2 0 2 5 2 0 1 4 1 2 2 7 F e b 2 0 2 5 Figure 1 Figure 1 20 25 20 14 12 27 F eb 2 02 5 2 0 2 5 2 0 1 4 1 2 2 7 F e b 2 0 2 5 F i g u r e 1 2 0 2 5 2 0 1 4 1 2 2 7 F e b 2 0 2 5

Description

TECHNICAL FIELD This device is aimed at health care and medical professionals to improve accuracy and measurement compliance when assessing cranial shape in infants and neonates. BACKGROUND OF THE INVENTION Currently, there are few tools involved in the measurement of infant and neonate head shape as a part of the diagnosis and management of plagiocephaly. The current options available involve one of three pathways; imaging the infants head, taking a photo or 3D scan and then interpreting data either locally or remotely, or by utilizing a set of calipers which can measure one axis at a time. Each of these options has its own limitations. Firstly, imaging requires exposing the infant to ionizing radiation by X-ray or CT scan. The amount of radiation that that infant would be exposed involves risk not in proportion to the benefit of calculating a distance on the infants skull. Secondly, taking images and sending off may involve risk of bias or user error based on angles of the images that were taken. Lastly, using calipers involves utilizing standardized locations to measure the distances of the skull. In instances of poor patient compliance - which is not unusual in neonates and infants - this measurement may not be accurate. SUMMARY OF THE INVENTION This device aims to improve on the shortcomings of noted in the background section. It does not involve any ionising radiation, nor does it require interpretation of an image which may be inaccurate. It aims to build upon the limitations of the calipers however deducing patient compliance issues and improving accuracy of measurement. This device aims to improve patient compliance and speed of measurement by incorporating a dual axis measurement and utilizing and elastic band to ensure proper position and secure 2025201412   27 Feb 2025 attachment at this point to allow for a quick and accurate measurement. A digital measurement of each axis simultaneously provides practitioners with information they require immediately, while also providing the value of diagonal difference - a measurement listed as a gold standard when it comes to measuring infants with head shape asymmetry. This device allows for axial rotation to be able to measure axes individually, or a pivot and measure dual axis. This would allow the device to be rotated and measure diagonal difference or transcranial measurements. To use this device it would be unfolded from its stored or single axis measurement state into its transdiagonal difference measurement state. An elastic band which attaches to the device would go over the child’s head into prepositioned locations based on aligning markings on the elastic to anatomical landmarks on the front and back of the skull. The attachment points of this device on the dedicated elastic band will ensure that each of the measurement points are positioned accurately. Potentiometers within each of the legs would be able to use basic geometry determine distances between two external points. Upon holding a steady reading, the electronic measurement device will hold that reading when the practitioner removes the device from the infant's head. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the device in a position to measure across 2 axes with each of the legs in that closed in position. This viewpoint is taken from the front, above and to the side. Figure 2 shows the device when viewed from front on. This shows the rotational capacity of this device across its central axis, and the attachment of the legs to the body section. Figure 3 is a view of the device from its apex in its 2-axis measurement state. Figure 4 is a view similar to Figure 1 but showing the device in a single-axis or its storage state. 2025201412   27 Feb 2025 Figure 5 is a top-down view of the device in its single axis or storage state similar to that of Figure 4. Figure 6 is the side-on view of the device in single axis or storage state. Figure 7 demonstrates the device in its 2-axis measurement state at full extension. Figure 8 shows a band that attaches to the end of the legs to allow for repeatability of assessment and secure attachment. DETAILED DESCRIPTION OF EMBODIMENTS This device is a four-legged tool that allows the measurement across an infant's head in either single- or two-axis plane. The central section houses attachment points for the four legs, and a central pivot which allows rotation around the Z-axis for one leg pair. A small computational device shall be housed on the central section (Figures 1 & 2), which can instantaneously measure angles generated by small potentiometers of the legs at their insertion point to the main body section. By understanding the set length of each leg pair, and the angle generated at the leg attachment point to the body a distance between the feet of each leg can be determined. This is known as a transcranial measurement. In the single axis measurement state, by placing the device across the coronal plane of the skull, a cranial lateral measurement can be made, or conversely if placed in the sagittal plane of the skull, an anteroposterior measurement can be made. Both of these measurements are required for accurate assessment of brachycephaly, a form of plagiocephaly. In this position, the screen of the device will show the measurement recorded on one line, which will remain on the display until measurement is reset. This will allow for ease and repeatability of measurement. When the legs are rotated around the Z-axis to activate the two axis measurement, as illustrated from the single-axis position in Figure 5 to the dual-axis position in Figure 3, an elastic band with alignment markers (Figure 8) can magnetically be attached to the feet of the legs, allowing the practitioner to slide the band over the infant head ensuring the alignment markers are placed over appropriate landmarks on the infant skull to allow transdiagonal 2025201412   27 Feb 2025 measurements. The band itself will have two markers and four ferromagnetic mounted attachments for the legs to attach to. An instructional pamphlet or video will educate practitioners on the landmarks the tape will need to cover. The device will then securely attach via magnetic points housed within the feet of the device to simultaneously measure both transdiagonal axes. These measurements will be displayed on one line each, with the third line generating a number representing the difference between those two measurements. This measurement is known as the transdiagonal difference, and is an important measurement for plagiocephaly progress and management. The dual hinge design for each leg pair would allow a broad range of measurement to occur; a minimum distance of 40mm (Figure 1) to a maximum of 200mm between each foot (Figure 7), with an angle measurement of 0° (closed position) to 48° (extended position) at each attachment point. By linking the known length of the leg and the angle generated by its movement, a distance from the foot to the point at 0° can be determined utlising the Law of Cosines. When combined with the leg pair opposite and the known distance between each foot pair at rest, the simple computational device can quickly determine distance between each foot pair and subsequently the diagonal difference if in dual-axis measurement position.

Claims

1. A cranial measurement tool comprising:|a central housing;|four legs connected to the central housing, the legs arranged in two opposing pairs;|a pivot mechanism within the central housing permitting rotation of at least one pair of legs about a central axis relative to the other pair;each leg incorporating a potentiometer configured to detect angular displacement of the leg relative to the central housing;|a computational unit disposed within the central housing and operatively connected to the potentiometers, the computational unit being configured to calculate inter-leg distances based on the angular displacement of the legs using trigonometric relationships^an elastic alignment band configured to engage the ends of the legs, the band including anatomical alignment markers and ferromagnetic or magnetic attachment points to enable repeatable placement on an infant’s skull; anda digital display configured to output measurement values;wherein the computational unit is further configured to simultaneously calculate and display a transdiagonal difference between two diagonal cranial measurements.

2. The cranial measurement tool of claim 1, wherein the tool is configurable between a single-axis mode, in which one opposing pair of legs measures a coronal or sagittal cranial axis, and a dual-axis mode, in which both opposing pairs of legs measure diagonal cranial axes simultaneously^3. The cranial measurement tool of claim 1 or 2, wherein the elastic alignment band is sized and marked to correspond to anatomical landmarks of a neonate or infant skull, thereby improving compliance and repeatability of measurements.|4. The cranial measurement tool of any one of claims 1 to 3, wherein the digital display is configured to hold and retain a measured value after removal of the tool from the infant’s head to enable stable and repeatable readings.

Images